Characterization of Adrenal miRNA-Based Dysregulations in Cushing’s Syndrome

Abstract

MiRNAs are important epigenetic players with tissue- and disease-specific effects. In this study, our aim was to investigate the putative differential expression of miRNAs in adrenal tissues from different forms of Cushing’s syndrome (CS). For this, miRNA-based next-generation sequencing was performed in adrenal tissues taken from patients with ACTH-independent cortisol-producing adrenocortical adenomas (CPA), from patients with ACTH-dependent pituitary Cushing’s disease (CD) after bilateral adrenalectomy, and from control subjects. A confirmatory QPCR was also performed in adrenals from patients with other CS subtypes, such as primary bilateral macronodular hyperplasia and ectopic CS. Sequencing revealed significant differences in the miRNA profiles of CD and CPA. QPCR revealed the upregulated expression of miR-1247-5p in CPA and PBMAH (log2 fold change > 2.5, p < 0.05). MiR-379-5p was found to be upregulated in PBMAH and CD (log2 fold change > 1.8, p < 0.05). Analyses of miR-1247-5p and miR-379-5p expression in the adrenals of mice which had been exposed to short-term ACTH stimulation showed no influence on the adrenal miRNA expression profiles. For miRNA-specific target prediction, RNA-seq data from the adrenals of CPA, PBMAH, and control samples were analyzed with different bioinformatic platforms. The analyses revealed that both miR-1247-5p and miR-379-5p target specific genes in the WNT signaling pathway. In conclusion, this study identified distinct adrenal miRNAs as being associated with CS subtypes.

1. Introduction

Cushing’s syndrome (CS) results from the excessive secretion of cortisol, leading to visceral obesity, resistance to insulin, osteoporosis, and altered lipid and glucose metabolism [1,2]. Excessive production of cortisol by the adrenal glands can be either ACTH-dependent or -independent. In the majority of patients, hypercortisolism is due to ACTH secretion by corticotroph adenomas of the pituitary gland (Cushing’s disease, CD) or by ectopic tumors [3]. Approximately 20% of cases are ACTH-independent, where cortisol is secreted autonomously by the adrenal cortex. The pathology of ACTH-independent cases is diverse; they are most often caused by unilateral cortisol-producing adrenocortical adenomas (CPA). Rare causes are cortisol-secreting adrenocortical carcinomas (ACC), primary bilateral macronodular adrenocortical hyperplasia (PBMAH), bilateral CPAs, and primary pigmented nodular adrenal disease (PPNAD) [4,5]. Irrespective of the subtype, prolonged exposure to cortisol in CS is associated with increased mortality and cardiovascular morbidity in its patients [6]. Treatment is based on the underlying cause of hypercortisolism, with pituitary surgery or adrenalectomy being the preferred choice. Medical therapy options in CS are few and consist of pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists [7]. For the timely diagnosis and targeted management of CS and its subtypes, a comprehensive understanding of cortisol secretion, in terms of canonical signaling pathways as well as upstream epigenetic factors, is needed.
MiRNA molecules have emerged as key epigenetic players in the transcriptional regulation of cortisol production. Briefly, the deletion of Dicer in adrenals, a key miRNA processing enzyme, revealed diverse expression changes in miRNAs along with related changes in steroidogenic enzymes such as Cyp11b1 [8]. Furthermore, key enzymes in the cortisol biosynthesis pathway, namely Cyp11a1, Cyp21a1, Cyp17a1, Cyp11b1, and Cyp11b2, were also found to be regulated by various miRNAs (miRNA-24, miRNA-125a-5p, miRNA-125b-5p, and miRNA-320a-3p) in in vitro studies [9]. Consequently, various studies have also characterized miRNA expression profiles in CS subtypes. Importantly, miRNA expression in the corticotropinomas of CD patients was found to vary according to USP8 mutation status [10]. Other studies have also identified specific miRNA candidates and associated target genes in the adrenals of patients with PPNAD [11], PBMAH [12,13], and massive macronodular adrenocortical disease [14]. Interestingly, no common miRNA candidates were found among these studies, indicating the specificity of miRNAs to the different underlying pathologies in CS.
There are limited studies directly comparing miRNA expression profiles of ACTH-dependent and ACTH-independent CS patients. Consequently, in our previous study, we found differences in expression profiles when comparing circulating miRNAs in CD and CPA patients [15]. We hypothesized that the presence of ACTH possibly influences the miRNA profile in serum due to the upstream differential expression in the origin tissues. In this study, we aim to further explore this hypothesis by comparing the miRNA expression profile of adrenal tissues in ACTH-dependent and ACTH-independent CS. In brief, miRNA specific sequencing was performed in two prevalent subtypes of CS: in CD, the most prevalent ACTH-dependent form; and in CPA, the most prevalent ACTH-independent form. Specific miRNA candidates related to each subtype were further validated in other forms of CS. To further investigate our hypothesis, the response of miRNA candidates following ACTH stimulation was assessed in mice, and the expression of miRNAs in murine adrenals was subsequently investigated. Finally, an extensive targeted gene analysis was performed based on in silico predictions, RNA-seq data, and luciferase assays.

2. Results

2.1. Differentially Expressed miRNAs

NGS revealed differentially expressed miRNAs between the different groups analyzed (Figure 1). CD and CPA taken together as CS showed a differentially expressed profile (42 significant miRNAs) in comparison to controls. Moreover, individually, CPA and CD were found to show a significantly different expression profile in comparison to controls (n = 38 and n = 17 miRNAs, respectively). Interestingly, there were no significantly upregulated genes in the adrenals of patients with CD in comparison to the control adrenals. A comparative analysis of the top significant miRNAs (log2 fold change (log2 FC) > 1.25 & p < 0.005) between the two groups was performed and the representative Venn diagrams are given in Figure 2. Briefly, miR-1247-5p, miR-139-3p, and miR-503-5p were significantly upregulated in CPA, in comparison to both CD and controls. Furthermore, miR-150-5p was specifically upregulated in CPA as compared to CD. Several miRNAs (miR-486-5p, miR-551b-3p, miR-144-5p, miR-144-3p, and miR-363-3p) were found to be significantly downregulated in the groups of CPA and CD in comparison to controls. MiR-19a-3p and miR-873-5p were found to be commonly downregulated in CPA in comparison to both CD and controls. Principal component analyses based on miRNA sequencing did not identify any major clusters among the samples. Furthermore, the miRNA profile was not different among the CPA samples based on the mutation status of PRKACA (Supplementary Materials Figure S1).
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Figure 1. Differentially expressed miRNAs from sequencing. Volcano plot showing the relationship between fold change (log2 fold change) and statistical significance (−log10 p value). The red points in the plot represent significantly upregulated miRNAs, while blue points represent significantly downregulated miRNAs. CPA, cortisol producing adenoma; CD, Cushing’s disease; Cushing’s syndrome represents CPA and CD, taken together.
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Figure 2. Venn analyses of the common significant miRNAs from each group. The significantly expressed miRNAs from each sequencing analysis were shortlisted and compared between the groups. CPA, cortisol producing adenoma; CD, Cushing’s disease.

2.2. Validation and Selection of Candidate miRNAs

For validation by QPCR, the most significant differentially expressed miRNAs (log2 FC > 1.25 & p < 0.005) among the groups were chosen (Table S1). According to the current knowledge, upregulated miRNAs are known to contribute more to pathology than downregulated miRNAs [16]. Since the total number of significantly upregulated miRNAs was six, all these miRNAs were chosen for validation. Contrarily, 25 miRNAs were significantly downregulated among the groups. In particular, miR-486-5p, miR-551b-3p, miR-144-5p, miR-144-3p, and miR-363-3p were found to be commonly downregulated in the CS group in comparison to controls; therefore, these miRNAs were chosen for validation.
Among the upregulated miRNA candidates, miR-1247-5p QPCR expression confirmed the NGS data (Figure 3A, Table S1). Moreover, miR-150-5p and miR-139-3p were upregulated in CPA specifically in comparison to CD, and miR-379-5p was upregulated in CD in comparison to controls by QPCR. In the case of downregulated genes, none of the selected miRNAs could be confirmed by QPCR (Figure 3B). Thus, analysis of the six upregulated and five downregulated miRNAs from NGS yielded two significantly upregulated miRNA candidates, miR-1247-5p in CPA and miR-379-5p in CD, when compared to controls. These miRNA candidates were taken up for further QPCR validation in an independent cohort of other subtypes of CS (Figure 4), namely ACTH-dependent ectopic CS (n = 3) and ACTH-independent PBMAH (n = 10). The QPCR analysis in the other subtypes revealed miR-1247-5p to be consistently upregulated in ACTH-independent CS (PBMAH and CPA) in comparison to ACTH-dependent CS (CD and ectopic CS) and controls. On the other hand, miR-379-5p was upregulated in CD and PBMAH in comparison to controls.
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Figure 3. QPCR analyses of significant miRNAs from sequencing analyses. Data are represented as mean ± standard deviation (SD) of −dCT values: (A) Expression analysis of significantly upregulated miRNAs; (B) Expression analysis of common significantly downregulated miRNAs. Housekeeping gene: miR-16-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).
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Figure 4. QPCR analyses of significantly upregulated miRNAs from validation QPCR. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: miR-16-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

2.3. In Vivo Assessment of ACTH-Independent miR-1247-5p

To analyze the influence of ACTH on miRNA expression, the expression of miR-1247-5p and miR-379-5p were assessed in the adrenal tissues of ACTH stimulated mice at different time points. For this analysis, miR-96-5p was taken as a positive control, as it has previously been reported to be differentially expressed in ACTH stimulated mice [17]. The analyses revealed that the expression of miR-1247-5p and miR-379-5p did not change at different timepoints of the ACTH stimulation (Figure 5). Meanwhile, the positive control of mir-96-5p showed a dynamic expression pattern with upregulation after 10 min, followed by downregulation at the subsequent 30 and 60 min time points, in concordance with previously reported findings [18].
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Figure 5. Analysis of miRNA expression in ACTH stimulated mice tissue. QPCR analyses of positive controls, miR-96-5p, and candidates miR-379-5p and miR-1247-5p. Mice were injected with ACTH, and adrenals were collected at different timepoints to assess the impact of ACTH on miRNA expression. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: miR-26a-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

2.4. In Silico Analyses of miRNA Targets

Two diverse approaches were employed for a comprehensive in silico analysis of the miRNA targets. First, the predicted targets of miR-1247-5p and miR-379-5p were taken from the TargetScan database, which identified miRNA–mRNA target pairs based on sequence analyses [19]. The expression status of these targets was then checked in the RNA sequencing data from CPA vs. controls (miR-1247-5p) and PBMAH vs. controls (miR-379-5p). Targets that showed significant expression changes in the sequencing data were shortlisted (Figure 6A). Among the 1061 predicted miR-1247-5p targets, 28 genes were found to show significant expression changes in CPA (20 upregulated, 8 downregulated). On the other hand, for 124 predicted miR-379-5p targets, 23 genes were found to show significant expression changes in PBMAH (20 upregulated, 3 downregulated). Interestingly, the selected targets were found to be unique for each miRNA, except for FICD (FIC domain protein adenylyltransferase) (Figure 6B).
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Figure 6. (A) Differentially expressed target genes of miRNAs from sequencing. Data are represented as log2 fold change in comparison to the controls. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05. (B) Venn analyses of common significant miRNA target genes and related pathways. The significantly expressed targets from each sequencing analysis were shortlisted and compared between the groups. Predicted pathways of the targets from the Panther database were shortlisted and compared between the groups.

2.5. In Vitro Analyses of miR-1247-5p Targets

For in vitro analyses, we focused on downregulated targets, as we expect our upregulated miRNA candidates to cause a downregulation of the target mRNAs. For our downregulated mRNAs, only targets of miR-1247-5p were found to have published links to CS, namely Cyb5a, Gabbr2, and Gnaq (Table 1). Therefore, these three targets were then verified by QPCR in the groups of CPA, CD, PBMAH, ectopic CS, and controls (Figure 6). Only Cyb5A was found to be significantly downregulated in ACTH-dependent forms (ectopic CS and CD) as well as in ACTH-independent CS (PBMAH and CPA) in comparison to controls. Consequently, to assess whether Cyb5a is indeed regulated by miR-1247-5p, a dual luciferase assay was performed. To prove our hypothesis, treatment of Cyb5a-WT cells with miR-1247-5p mimic was expected to lead to a reduced luminescence, whereas no effects were expected in cells treated with the miR-1247-5p inhibitor or the Cyb5a-mutant (with a mutation in the miR-1247-5p binding site). As shown in Figure 7, transfection of miR-1247-5p significantly reduced luminescence from Cyb5a-WT in comparison to cells transfected with Cyb5a-WT and miR-1247-5p inhibitors. However, these predicted binding results were not found to be specific, as there were no significant differences when compared to wells transfected with Cyb5a-WT alone (Figure 8). Consecutively, when the mutated Cyb5a-Mut were transfected along with the mimics and inhibitors, no significant differences in luminescence were observed in the transfected population. Thus, direct interaction between miR-1247-5p and its predicted target gene Cyb5A could not be conclusively proven using this luciferase assay.
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Figure 7. QPCR analyses of the top predicted targets of miR-1247-5p. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: PPIA. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).
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Figure 8. Results of dual luminescence assay on cells transfected with miR-1247-5p mimics and related controls. Cells were transfected with plasmids containing either the WT or Mut miRNA binding sequence in Cyb5a. Either miR-1247-5p mimics or miR-1247-5p inhibitors were transfected together with the respective plasmids. Data are represented as mean ± standard error of mean (SEM) of relative luminescence unit values. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p value < 0.05 (*).
Table 1. Analysis of the predicted targets of miR-1247-5p and their expression levels in comparison to controls (log2 fold change). Published literature on target genes in reference to CS is highlighted in bold.
Table

2.6. Pathway Analyses of miRNA Targets

For the pathway analysis (Reactome) we used the 28 predicted miRNA-1247-5p targets and the 23 predicted miRNA-379-5p targets from TargetScan, which were significantly differently expressed in the RNA-seq (Figure 6). Concurrently, the pathways commonly enriched by both miRNAs included the WNT signaling pathway and N-acetyl-glucosamine synthesis (Figure 9A). As a complementary approach, in silico analyses were also performed based on the targets from miRTarBase. In this database, targets are shortlisted based on published experimental results. In this analysis, miR-1247-5p (n = 21) and miR-379-5p targets (n = 85) were unique. While the validated targets of miR-379-5p were found to show significant changes in expression in the RNA-seq data from PBMAH (n = 12), none of the validated miR-1247-5p targets were found to show significant expression changes in the RNA-seq data from CPA. Therefore, all the validated targets of the miRNAs were subjected to pathway analyses (Panther). Interestingly, the WNT signaling pathway was also found to be commonly regulated by both miRNAs using this approach (Figure 9B). Finally, the expression status of target genes related to WNT signaling pathways were checked in our RNA-seq data (Figure S2). Given the upregulated status of the miRNAs, a downregulated expression of its target genes was expected. However, a significantly upregulated expression was observed for DVL1 in CPA in comparison to controls and for ROR1 in PBMAH in comparison to controls.
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Figure 9. Pathway analyses of miRNA target genes. (A) The predicted targets were matched with the RNA-seq expression data. For miR-1247-5p, CPA vs. controls expression data; and for miR-379-5p, PBMAH vs. controls expression data. The significantly expressed target genes were then subjected to pathway analyses by Reactome. The significantly enriched pathway networks (p < 0.05) and their related genes are given. (B) The experimentally validated target genes from miRTarBase were analyzed for their role in pathways by the Panther database. The target genes and their related pathways are given. The commonly represented pathways are marked in bold.

3. Discussion

MiRNAs are fine regulators of both physiology and pathology and have diverse roles as diagnostic biomarkers as well as therapeutic targets. While circulating miRNAs have been investigated as potential biomarkers for hypercortisolism in CS subtypes (36), comprehensive analyses of their pathological role in CS subtypes have not yet been performed. This study hoped to uncover the pathological role of miRNAs in different CS subtypes as well as identify unique epigenetic targets contributing to hypercortisolism in these subtypes. As such, miRNA sequencing was performed in the ACTH-independent CPA and ACTH-dependent CD, with additional QPCR validation in PBMAH and ectopic CS. As expected, miRNA expression profiles in CD and CPA were very different.

3.1. ACTH-Independent Upregulated miRNAs in CS

Among the analyzed miRNAs, only miR-1247-5p and miR-379-5p showed the most prominent changes in expression levels. Briefly, miR-1247-5p was significantly upregulated in ACTH-independent forms of CS, CPA, and PBMAH (Figure 1 and Figure 3) while miR-379-5p was found to be upregulated in CD and PBMAH, in comparison to controls. Even though CD and PBMAH represent CS subtypes with different ACTH dependence, albeit both with hyperplastic tissue, it is interesting to find a shared miRNA expression status. Concurrently, miRNAs have been identified as dynamic players in regulating the acute effect of ACTH on adrenal steroidogenesis in in vivo murine studies [20,21]. Further diverse miRNAs have been characterized to regulate steroidogenesis in ACTH and dexamethasone treated rats [22] (suppressed ACTH) as well as in in vitro studies [20]. It is possible that miR-379-5p contributes to the adrenal hyperplasia present in both PBMAH and CD by targeting specific genes related to hyperplasia, and miR-1247-5p by contributing to cortisol production independent of ACTH regulation in CPA and PBMAH.
Interestingly, the miRNA candidates (mir-1247-5p and miR-379-5p) in our study have not been previously characterized in any of these studies. Furthermore, the expression of mir-1247-5p and miR-379-5p were found to be independent of ACTH stimulation, underlying their role in CS independently of the HPA axis control and postulating specific regulatory processes.

3.2. Target Genes of miRNAs in CS

Initially, we focused on the selection of known CS specific target genes that could be directly repressed by miRNAs, thereby contributing to pathology. The predicted target genes of miR-1247-5p and miR-379-5p were assessed for their downregulated expression status in the RNA-seq data. Among the selected target genes, only Cyb5a was found to be significantly downregulated in all forms of CS (Figure 6). Cytochrome b5 (CYB5A) is a marker of the zona reticularis and is an important regulator of androstenedione production [23,24]. Based on its role in adrenal steroidogenesis, it is possible that Cyb5a is downregulated by miR1247-5p. To prove our hypothesis, a dual luciferase assay was performed in HELA cell line to identify a direct interaction between Cyb5a and miR-1247-5p (Figure 7). Unfortunately, a direct interaction could not be proven, indicating that miR-1247-5p perhaps regulates its target genes in different ways.

3.3. Pathway Analyses of miRNA Targets

To identify miRNA specific regulatory processes, comprehensive target and pathway analyses were performed. Independent pathway analyses of the respective targets with two different databases of Reactome and Panther showed the WNT signaling pathway as a common targeted pathway of both mir-1247-5p and miR-379-5p (Figure 8). The WNT signaling pathway represents a crucial regulator in diverse developmental as well as pathological processes with tissue-specific effects [25,26]. Consequently, the WNT pathway has been largely characterized as one of the dysregulated pathophysiological mechanisms in CPA. Mutations in PRKACA, one of the WNT signaling proteins, are present in approximately 40% of CPA [27]. In the case of CD, dysregulated WNT signaling has been characterized as promoting proliferation in ACTH-secreting pituitary adenomas [28]. Moreover, activating mutations in beta catenin, one of the WNT signaling pathways, has been characterized as driving adrenal hyperplasia through both proliferation-dependent and -independent mechanisms [29]. Thus, it could be hypothesized that by targeting specific genes in the pathway, miRNAs drive specific pathophysiological processes in diverse CS subtypes.

3.4. MiRNA Target Genes in WNT Signaling

DVL1 (TargetScan) and DVL3 (miRTar) are the shortlisted target genes of miR-1247-5p in the WNT signaling pathway. These genes are members of canonical WNT pathways and, importantly, activation of the cytoplasmic effector Dishevelled (Dvl) is a critical step in WNT/β-catenin signaling initiation [30,31]. Interestingly, no difference in DVL1 and DVL3 gene expression was found in the analyses of ACTH-secreting pituitary adenomas [32]. Therefore, it could be possible that DVL1 and DVL3 are only targeted by miR-1247-5p specifically in the adrenal of CPA and PBMAH patients, leading to its characterized tumor progression. EDN1, TGFBR1 (TargetScan), and ROR1 (miRTar) were the target genes of miR-379-5p related to the WNT pathway. In epithelial ovarian cancer, Endothelin-1 (EDN-1) was found to regulate the epithelial–mesenchymal transition (EMT) and a chemoresistant phenotype [33]. In the case of receptor tyrosine kinase-like orphan receptor 1 (ROR1), higher expression of the gene was associated with a poor prognosis in ovarian cancer [34]. Concurrently, suppression of TGFBR1-mediated signaling by conditional knockout in mice was found to drive the pathogenesis of endometrial hyperplasia, independent of the influence of ovarian hormones [35]. Therefore, it could be hypothesized that the dysregulated expression of these factors in adrenals could trigger similar hyperplastic effects mediated by these factors, as in ovarian tissues.

3.5. Bottlenecks and Future Outlook

Interestingly, among these genes, only DVL1 and ROR1 were found to be significantly upregulated in the RNA-seq data (Figure S2). The major regulatory role of miRNAs in gene expression come from their ability to repress gene expression at the level of transcription and translation. There are also reports of miRNA-mediated gene upregulation; however, the physiological evidence of the role is still unresolved [36]. Therefore, it is interesting to see the selected targets of miR-1247-5p and miR-379-5p upregulated. Moreover, it should be noted that most of the experimentally validated miRNA targets were identified by CLIP methods [37]. Crosslinking immunoprecipitation (CLIP) are binding assays that provide genome-wide maps of potential miRNA-target gene interactions based on sequencing. Moreover, these assays do not make functional predictions on the outcome of miRNA binding, and neither do upregulation or downregulation [38,39]. Therefore, in our current experimental setting, we could only identify potential miRNA target genes and speculate on their pathological role based on the published literature and in silico analyses. Furthermore, extensive mechanistic analyses based on these potential targets could help in elaborating the specific epigenetic pathways that fine-tune CS pathology in different subtypes.

4. Materials and Methods

4.1. Sample Collection and Ethics Approval

All patients were registered in the German Cushing’s Registry, the ENS@T or/and NeoExNET databases (project number protocol code 379-10 and 152-10). The study was approved by the Ethics Committee of the University of Munich. All experiments were performed according to relevant guidelines and protocols, and written informed consent was obtained from all patients involved. The adrenal samples used in the sequencing (miRNA and RNA) belong to the same patient.
For miRNA-specific next-generation sequencing (NGS), a total of 19 adrenocortical tissue samples were used. The cohort consisted of the following patient groups: ACTH-independent CPA, n = 7; ACTH-dependent hypertrophic adrenals of CD patients after bilateral adrenalectomy, n = 8; normal adjacent adrenal tissue from patients with pheochromocytoma as controls, n = 8. For QPCR validation, the patient groups included adrenal tissue from ACTH-independent PBMAH, n = 10, and ACTH-dependent ectopic CS, n = 3.
In the case of mRNA sequencing, a total of 23 adrenocortical tissue samples were used. This includes the following patient groups: CPA, n = 7; PBMAH, n = 8; normal adjacent adrenal tissue from patients with pheochromocytoma as controls, n = 8.
The clinical characteristics of the patients are given in Table 2. Furthermore, of the eight CPA samples in the study, three of them carried known somatic driver mutations in the PRKACA gene and in the ten PBMAH samples, two carried germline mutations in the ARMC5 gene.
Table 2. Clinical characteristics of the patient groups. Data are given as median with 25th and 75th percentiles in brackets. CPA, cortisol producing adenoma; CD, Cushing’s disease.
Table
The adrenal tissues were stored at −80 °C. Total RNA isolation was carried out from all adrenal cortex samples by an RNeasy Tissue Kit (Qiagen, Hilden, Germany). The isolated RNA was kept frozen at −80 °C until further use.

4.2. MiRNA and RNA Sequencing

RNA integrity and the absence of contaminating DNA were confirmed by Bioanalyzer RNA Nano (Agilent Technologies, Santa Clara, CA, USA) and by Qubit DNA High sensitivity kits, respectively. Sequencing libraries were prepared using the Illumina TruSeq Small RNA Library Preparation Kit. NGS was performed on 2 lanes of an Illumina HiSeq2500 (Illumina, CA, USA) multiplexing all samples (paired end read, 50 bp). The quality of sequencing reads was verified using FastQC0.11.5 (http://www.bioinformatics.babraham.ac.uk/projects/fastqc, date last accessed: 13 March 2020) before and after trimming. Adapters were trimmed using cutadapt [40]. Reads with <15 bp and >40 bp insert sequences were discarded. An alignment of reads was performed using miRBase V21 [41,42] with sRNAbench [43]. EdgeR and DeSeq in R were used for further analyses [44,45]. MiRNAs with at least 5 raw counts per library were included. RNA-seq was performed by Qiagen, Hilden, Germany. For mRNA, sequencing was performed on Illumina NextSeq (single end read, 75 bp). Adapter and quality trimming were performed by the “Trim Reads” tool from CLC Genomics Workbench. Furthermore, reads were trimmed based on quality scores. The QC reports were generated by the “QC for Sequencing Reads” tool from CLC Genomics Workbench. Read mapping and gene quantification were performed by the “RNA-seq Analysis” tool from CLC Genomics Workbench [46]. The miRNA-seq data generated in this study have been submitted to the NCBI (PRJNA847385).

4.3. Validation of Individual miRNAs

MiRNAs and genes significantly differentially expressed by NGS were validated by QPCR. Reverse transcription of miRNA-specific cDNA was performed by using the TaqMan MicroRNA Reverse Transcription Kit (Thermo Fisher Scientific, Munich, Germany), and the reverse transcription of RNA genes was done by using the Superscript VILO cDNA synthesis Kit (Thermo Fisher Scientific, Munich, Germany). 50 ng of RNA was used for each of the reverse transcription reactions. Quantitative real-time PCR was performed using the TaqMan Fast Universal PCR Master Mix (2×) (Thermo Fisher Scientific, Munich, Germany) on a Quantstudio 7 Flex Real-Time PCR System (Thermo Fisher Scientific, Munich, Germany) in accordance with the manufacturer’s protocol. All QPCR reactions were performed in a final reaction volume of 20 μL and with 1 μL of 1:5 diluted cDNA. Negative control reactions contained no cDNA templates. Gene expression was quantified using the relative quantification method by normalization with reference gene [47]. Statistical analysis using the bestkeeper tool was used to compare and select the best reference gene with stable expression across the human adrenal samples [48]. Reference genes with significantly different Ct values (p-value < 0.01) between the samples were excluded. Furthermore, primer efficiency and the associated correlation coefficient R2 of the selected reference gene were determined by the standard curve method in serially diluted cDNA samples [49]. In the case of miRNA reference genes, miR-16-5p [48,50,51] and RNU6B [52] previously used in similar studies were compared. MiR-16-5p was found to show the most stable expression levels across the samples with a p-value of 0.452 in comparison to RNU6B which had a p-value of 0.001. In the case of RNA reference genes, PPIA [53] and GAPDH [54] were compared. Here, PPIA was found to show the most stable expression levels across the samples with a p-value of 0.019 in comparison to GAPDH which had a p-value of 0.003. Therefore, these genes were used for the normalization of miRNA and RNA expression in human adrenal samples.

4.4. Target Screening

In silico prediction of the possible miRNA targets was performed using the miRNA target database, TargetScan, and miRTarBase [19,37]. The top predicted targets were further screened based on their expression status in the RNA-seq data from the adrenocortical tissues of CPA, PBMAH, and controls (unpublished data). Pathway analyses of the targets were performed using Reactome [55] and Panther [56] online platforms. The selected downregulated targets were analyzed by QPCR in the adrenocortical samples to confirm their expression status. The successfully validated candidates were then analyzed for regulation by the miRNA using a dual luciferase assay [57].

4.5. Dual Luciferase Assay

The interaction between the predicted 3′-UTR region of Cyb5a and miR-1247-5p was detected using a luciferase activity assay. The 3′UTR sequences of Cyb5a (129 bp) containing the predicted miR-1247-5p binding sites (psiCHECK-2 Cyb5a 3′UTR WT) were cloned into the psiCHECK-2 vector (Promega, Fitchburg, WI, USA). A QuikChange Site-Directed Mutagenesis kit (Agilent Technologies, CA, USA) was used to mutate the miR-1247-5p binding site (psiCHECK-2 Cyb5a 3′UTR mutant) according to the manufacturer’s protocol. All the sequences were verified by Sanger sequencing. Then, 200 ng of the plasmid was used for each transfection. Synthetic miR-1247-5p mimics and specific oligonucleotides that inhibit endogenous miR-1247-5p (miR-1247-5p inhibitors) were purchased from Promega and 100 nmol of the molecules were used for each transfection according to the manufacturer’s protocol. For the assay, HeLa cells were seeded in 96-well plates and incubated for 24 h. The following day, cells were transfected using the following different conditions: (1) psiCHECK-2 Cyb5a 3′UTR WT + miR-1247-5p mimic; (2) psiCHECK-2 Cyb5a 3′UTR WT + miR-1247-5p inhibitor; (3) psiCHECK-2 Cyb5a 3′UTR WT + water; (4) psiCHECK-2 Cyb5a 3′UTR mutant + miR-1247-5p mimic; (5) psiCHECK-2 Cyb5a 3′UTR mutant + miR-1247-5p inhibitor; (6) psiCHECK-2 Cyb5a 3′UTR mutant + water. Forty-eight hours later, luciferase activity in the cells was measured using the dual luciferase assay system (Promega, Fitchburg, WI, USA) in accordance with the manufacturer’s instructions. Renilla luciferase activity was normalized to firefly luciferase activity. Each treatment was performed in triplicate. Any interaction between the cloned gene, Cyb5a (WT and mutant), and miR-1247-5p mimic is accompanied by a decrease in luminescence. This decrease in luminescence would not be observed when the plasmids are transfected with the miR-1247-5p inhibitor, indicating that observed luminescence differences are caused by specific interactions between the plasmid and the miR-1247-5p mimic. Transfection of the plasmid with water corrects any background interactions between the cloned gene and endogenous miRNAs in the culture.

4.6. In Vivo ACTH Stimulation

Experiments were performed on 13-week-old C57BL/6 J female mice (Janvier, Le Genest-Saint-Isle, France). Mice were intraperitoneally injected with 1 mg/kg of ACTH (Sigma Aldrich, Munich, Germany) and adrenals were collected after 10, 30, and 60 min of injections. In addition, control adrenals were collected from mice at baseline conditions (0 min). Mice were killed by cervical dislocation and adrenals were isolated, snap-frozen in liquid nitrogen, and stored at −80 °C for later RNA extraction. MiR-26a was taken as a housekeeping gene in the QPCR [58]. All mice were maintained in accordance with facility guidelines on animal welfare and approved by Landesdirektion Sachsen, Chemnitz, Germany.

4.7. Statistical Analysis and Software

R version 3.6.1 was used for the statistical analyses. To identify RNAs differentially expressed, a generalized linear model (GLM, a flexible generalization of ordinary linear regression that allows for variables that have distribution patterns other than a normal distribution) in the software package edgeR (Empirical Analysis of DGE in R) was employed to calculate p-values [45,59]. p-values were adjusted using the Benjamin–Hochberg false discovery rate (FDR) procedure [60]. Disease groups were compared using the unpaired Mann–Whitney test, and to decrease the false discovery rate a corrected p-value was calculated using the Benjamin–Hochberg method. p adjusted < 0.05 and log2 fold change >1.25 was applied as the cut-off for significance for NGS data. GraphPad Prism Version 8 was used for the statistical analysis of QPCR. To calculate differential gene expression, the dCt method (delta Ct (cycle threshold) value equals target miRNA’s Ct minus housekeeping miRNA’s Ct) was used (Microsoft Excel 2016, Microsoft, Redmond, WA, USA). For QPCR, an ANOVA test with Bonferroni correction was used [61] to assess significance; p-values < 0.05 were considered significant.

5. Conclusions

In conclusion, while comprehensive information regarding the role of miRNAs in acute and chronic phases of steroidogenesis is available, there is little known about the pathological independent role of miRNAs in the pathology of CS. In our study, we have described ACTH-independent miR-1247-5p and miR-379-5p expression in CS for the first time. Thus, by regulating different genes in the WNT signaling pathway, the miRNAs may individually contribute to the Cushing’s pathology in specific subtypes.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ijms23147676/s1.

Author Contributions

Conceptualization, S.V., A.C. and A.R.; methodology, S.V., R.Z. and M.E.; software, S.V. and M.E.; validation, R.Z., A.O., D.W. and B.W.; formal analysis, S.V.; investigation, S.V., R.Z., M.E., A.O. and D.W.; resources, A.C., B.W., M.R. and A.R.; data curation, S.V. and R.Z.; writing—original draft preparation, S.V., R.Z. and A.R.; writing—review and editing, S.S., M.R. and A.R.; visualization, S.V.; supervision, A.R.; project administration, A.R.; funding acquisition, A.C., S.S., M.R. and A.R. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) (within the CRC/Transregio 205/1 “The Adrenal: Central Relay in Health and Disease”) to A.C., B.W., S.S., M.R. and A.R., and individual grant SB 52/1-1 to S.S. This work is part of the German Cushing’s Registry CUSTODES and has been supported by a grant from the Else Kröner-Fresenius Stiftung to MR (2012_A103 and 2015_A228). A.R. was supported by the FöFoLe Program of the Ludwig Maximilian University, Munich. We thank I. Shapiro, A. Parl, C. Kühne, and S. Zopp for their technical support.

Institutional Review Board Statement

The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of the Ludwig Maximilian University, Munich (protocol code 379-10, 152-10 and 20 July2021).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The miRNA-seq data generated in this study have been submitted to the NCBI (PRJNA847385).

Conflicts of Interest

The authors declare no conflict of interest.

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Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma

Introduction: Pasireotide (PAS) is a novel somatostatin receptor ligands (SRL), used in controlling hormonal hypersecretion in both acromegaly and Cushing’s Disease (CD). In previous studies and meta-analysis, first-generation SRLs were reported to be able to induce significant tumor shrinkage only in somatotroph adenomas. This systematic review and meta-analysis aim to summarize the effect of PAS on the shrinkage of the pituitary adenomas in patients with acromegaly or CD.

Materials and methods: We searched the Medline database for original studies in patients with acromegaly or CD receiving PAS as monotherapy, that assessed the proportion of significant tumor shrinkage in their series. After data extraction and analysis, a random-effect model was used to estimate pooled effects. Quality assessment was performed with a modified Joanna Briggs’s Institute tool and the risk of publication bias was addressed through Egger’s regression and the three-parameter selection model.

Results: The electronic search identified 179 and 122 articles respectively for acromegaly and CD. After study selection, six studies considering patients with acromegaly and three with CD fulfilled the eligibility criteria. Overall, 37.7% (95%CI: [18.7%; 61.5%]) of acromegalic patients and 41.2% (95%CI: [22.9%; 62.3%]) of CD patients achieved significant tumor shrinkage. We identified high heterogeneity, especially in acromegaly (I2 of 90% for acromegaly and 47% for CD), according to the low number of studies included.

Discussion: PAS treatment is effective in reducing tumor size, especially in acromegalic patients. This result strengthens the role of PAS treatment in pituitary adenomas, particularly in those with an invasive behavior, with progressive growth and/or extrasellar extension, with a low likelihood of surgical gross-total removal, or with large postoperative residual tissue.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022328152, identifier CRD42022328152

Introduction

Pasireotide (PAS) is a novel somatostatin receptor ligand (SRL) with a high affinity for the somatostatin receptor (SSR) type 5 (12). Somatotroph adenomas are usually responsive to first-generation SRLs (octreotide and lanreotide), as they are able to reduce growth hormone (GH) secretion through SSR type 2 (3). In the flow-chart of acromegaly treatment, PAS is suggested in case of resistance to first-generation SRLs, as SSR type 5 is also abundantly expressed in GH-secreting adenomas (3). A phase III study with PAS long-acting release (LAR) proved its efficacy in first-generation SRLs-resistant acromegalic patients after 6 months (4). In the extension study (Colao A et al.), 37% of patients achieved normalization of insulin-like growth factor 1 (IGF-1) and/or GH levels <1 µg/L, considering both those performing the extension treatment and those crossing over from the first-generation SRL-control group to the PAS LAR group. Nearly two-thirds of responses were achieved after at least 6 months of treatment. Up-titration of the dose from 40 to 60 mg monthly enriched the number of responders, suggesting that the PAS LAR effect may be both time- and dose-dependent (5). Concomitant improvement in signs and symptoms has also been confirmed in other series (69).

SSR type 5 is the predominant isoform in human corticotroph adenomas, since it is not down-regulated by high cortisol levels, as SSR type 2 does. Therefore, PAS is the only SRL available in patients with Cushing’s Disease (CD) (2). In a phase III study, subcutaneous (s.c.) PAS proved to be effective in normalizing urinary free cortisol (respectively in 13% and 25% of patients taking 600 µg or 900 µg bis-in-die for 12 months) (10), achieving significant clinical improvement (11). In the same clinical setting, PAS LAR showed similar efficacy and safety profiles (12). These benefits could be maintained for up to 5 years in an extension study (1314). In a recent meta-analysis, PAS treatment provided disease control in 44% of 522 patients with CD (15). Patients harbouring USP-8 mutations demonstrated an increased SSR type 5 expression in the corticotroph adenoma, increasing the likelihood of a positive response to PAS therapy (16). The safety profile of PAS is similar to that of first-generation SRLs, except for a significant worsening in glucose homeostasis (17).

Despite the normalization of hormonal excess, another goal of the medical treatment in GH-secreting pituitary adenomas is the reduction of the size of the adenoma (18). First-generation SRLs proved to be effective in achieving tumor shrinkage in acromegaly: Endocrine Society clinical practice guidelines suggested their role as primary therapy in poor surgical candidates and in those with extrasellar extension without chiasmal compression (18). Cozzi et al. reported in a large prospective cohort of acromegalic patients a significant Octreotide-induced tumor shrinkage in 82% of those receiving SRL as first-line treatment; most of them exhibited an early shrinkage with a progressive trend in reduction later on (19). A meta-analysis of 41 studies reported a significant tumor shrinkage in 50% of included patients (20). Data from the primary treatment with once-monthly lanreotide in surgical naïve patients demonstrated its efficacy in reducing tumor volume, achieving significant tumor shrinkage in 63% of them (21). Hypo-intensity on T2-weighted sequences at baseline magnetic resonance imaging (MRI) seems to predict tumor volume reduction during first-generation SRLs treatment (22). Regarding patients with CD, most patients presented a microadenoma, usually not aggressive or invasive: only in selected cases tumor shrinkage is an aim to achieve in patients with corticotropinoma.

As available data are scarce (or limited to selected studies), and the issue of pituitary adenoma shrinkage is of primary importance in the management of tumors that cannot be addressed through surgery, the aim of this systematic review and meta-analysis is to summarize available data regarding the effect of PAS on tumor size.

Materials and Methods

We used the Population-Intervention-Comparison-Outcome (PICO) model to formulate the research questions for the systematic review (23), as summarised in Figure 1. The systematic review and meta-analysis were conducted and are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) statement (24). We registered the protocol on the International Prospective Register of Systematic Reviews database (PROSPERO, https://www.crd.york.ac.uk/PROSPERO, number CRD42022328152).

Figure 1
www.frontiersin.orgFIGURE 1 PICO (Population-Intervention-Comparison-Outcome) model design to our study.

Search Strategy

An extensive Medline search was performed for the research question by two of the authors (F.C. and A.M.) independently, discrepancies were resolved by discussion. The literature search was performed up to January 2022, no language restriction was applied. Research included the following keywords: 1) (“acromegalies” [All Fields] OR “acromegaly”[MeSH Terms] OR “acromegaly”[All Fields]) AND (“pasireotide”[Supplementary Concept] OR “pasireotide”[All Fields]); 2) (“pituitary ACTH hypersecretion”[MeSH Terms] OR (“pituitary”[All Fields] AND “ACTH”[All Fields] AND “hypersecretion”[All Fields]) OR “pituitary ACTH hypersecretion”[All Fields]) AND (“pasireotide”[Supplementary Concept] OR “pasireotide”[All Fields]).

Inclusion and exclusion criteria were specified in advance and protocol-defined, in order to avoid methodological bias for post-hoc analysis. The searches were designed to select all types of studies (retrospective, observational, controlled, randomized, and non-randomized) conducted in patients with acromegaly or CD treated with PAS as monotherapy; the assessment of the proportion of significant tumor shrinkage was an inclusion criterion. Search terms were linked to Medical Subject Headings when possible. Keywords and free words were used simultaneously. Additional articles were identified with manual searches and included a thorough review of other meta-analyses, review articles, and relevant references. Consolidation of studies was performed with Mendeley Desktop 1.19.8.

Study Selection

We included all original research studies conducted in adult patients that underwent PAS treatment used as monotherapy (s.c. bis-in-die and intramuscular once/monthly), that provided sufficient information about tumor size reduction during treatment. In case of overlapping cohorts of patients (as clinical trials with core and extension phases), we included only the extension study, in order to select those patients with measurable tumor shrinkage after long-term treatment. Local reports regarding patients involved in multicenter trials were excluded from the analysis, as they had been already considered in the larger series. Reviewers were not blinded to the authors or journals when screening articles.

Data Extraction and Quality Assessment

Two authors (F.C. and A.M.) read the included papers and extracted independently relevant data, any disagreements were resolved by discussion. If data were not clear from the original manuscript, the authors of the primary study were contacted to clarify the doubts.

Contents of data extraction in the selected paper included: name of the first author, year of publication, setting (referral centre, academic hospital, mono- or multi-centric collection), type of treatment, its dose schedule and duration, pituitary imaging method during follow- up, the endpoint type regarding adenoma size analysis (i.e. primary vs exploratory). When data were reported for each patient or for subgroups, a global percentage of significant tumor shrinkage was calculated considering all subjects involved in the study.

To assess the risk of bias in the included studies, the critical appraisal tool from Joanna Briggs’s Institute (JBI) was adapted to evaluate those considered in our metanalysis (25). Among the items proposed, we selected the most appropriate to our setting: 1. Were the inclusion criteria clearly identified? 2. Were diagnostic criteria for acromegaly or CD well defined? 3. Were valid methods applied to evaluate tumor shrinkage? 4. Was the inclusion of participants consecutive and complete? 5. Was the reporting of baseline participants’ features (demographic and clinical) complete? 6. Was the report of the outcomes clear? 7. Was the report of demographics of the involved sites complete? 8. Was statistical analysis appropriate? For each aspect we assigned as possible choices of answer: yes, no or unclear.

Data Synthesis and Analysis

A qualitative synthesis was performed summarizing the study design and population characteristics (age, male to female ratio, macro- to micro-adenoma ratio, prior treatments).

A random-effect model was used to estimate pooled effects. Forest plots for percentages of significant tumor size reduction were generated to visualize heterogeneity among the studies. In order to assess publication bias, despite the low number of articles considered, we performed funnel plot and asymmetry analysis adjusted for the low number of studies (an Egger’s regression test and a three-parameter selection model where two tailed p < 0.05 was considered statistically significant). The I2 test was conducted to analyze the heterogeneity between studies: an I2 >50% indicated a between-study heterogeneity.

Statistical analyses were performed with R: R-4.1.2 for Windows 10 (32/64 bit) released 2021-11-01 and R studio desktop RStudio Desktop 1.4.1717 for Windows 10 64 bit (R Foundation for Statistical Computing, Vienna, Austria, URL https://www.R-project.org/).

Results

Study Selection

The study selection process for acromegaly is depicted in Figure 2. The electronic search revealed 179 articles, with one duplicate (N = 178). After the first screening, 141 articles did not meet the eligibility criteria and were discarded. The full-text examination of the remaining studies excluded additional 31 articles: 27 did not provide adequate data about tumor size, two represented the core phase of an extension study, another one referred to a subset of patients from a larger study, and the last one did not provide sufficient data about the percentage of tumor size reduction. Thus, six studies fulfilling eligibility criteria (reported in Tables 12), were selected for data extraction and analysis.

Figure 2
www.frontiersin.orgFIGURE 2 Search strategy for acromegaly. * Petersenn S, 2010 (PAS sc, phase II) and Colao A, 2014 (PAS LAR). ** Shimon I, 2015 (PAS LAR). *** Tahara S, 2019 (PAS LAR, phase II). PAS, pasireotide, sc, subcutaneous, LAR, long-acting release.

Table 1
www.frontiersin.orgTABLE 1 Studies considered for the metanalysis in acromegaly.

Table 2
www.frontiersin.orgTABLE 2 Studies considered for the metanalysis in acromegaly.

The study selection process for CD is depicted in Figure 3. The electronic search revealed 122 articles; an additional one had been included post-hoc, through reference analysis of selected articles (N = 123). After the first screening, 91 articles did not meet the eligibility criteria and were discarded. The full-text examination of the remaining studies excluded 29 more articles: 23 did not provide sufficient data on tumor shrinkage, two of them represented the core phase of extension studies, two referred to subsets of patients included in a larger study and two did not provide sufficient data regarding the percentage of tumor size reduction. Thus, three studies fulfilling eligibility criteria (reported in Tables 34) were selected for data extraction and analysis.

Figure 3
www.frontiersin.orgFIGURE 3 Search strategy for Cushing’s Disease. * Lacroix A, 2018 (PAS LAR, phase III) and Lacroix A, 2020 (PAS sc, phase III post-hoc analysis). ** Simeoli C, 2014 (PAS sc) and Colao A 2012 (PAS sc, phase III). *** Daniel E, 2018 (PAS sc and LAR) and Trementino L, 2016 (PAS sc). PAS, pasireotide, sc, subcutaneous, LAR, long acting release.

Table 3
www.frontiersin.orgTABLE 3 Studies considered for the metanalysis in Cushing’s Disease.

Table 4
www.frontiersin.orgTABLE 4 Studies considered for the metanalysis in Cushing’s Disease.

Study Characteristics

Four multi- and two mono-centric studies in patients with acromegaly were considered and analyzed, all presenting a prospective design. Tumor size analysis was not one of the primary endpoints in any of the considered studies; from an initial overall recruitment of 358 patients, only 265 were included for tumor size reduction analysis. Most patients had previously undergone different treatments (Table 1). All studies, except one, used PAS LAR, dose titration was allowed in all trials. Median follow-up ranged from 6 to 25 months; MRI was performed to evaluate tumor size reduction and the criteria for considering it significant was mainly based on tumor volume analysis, except for Lasolle H et al. which considered median height reduction (26). Data from the PAOLA study provided separate percentages of significant tumor shrinkage for PAS at 40 mg or 60 mg once monthly; considering that respectively 12 and 7 patients showed a reduction >25%, a significant shrinkage was reported in 19 out of 79 considered cases (24%) (4). Stelmachowska-Banás et al. described one patient with McCune-Albright’s syndrome presenting with pituitary hyperplasia, without a visible adenoma at MRI; as its pituitary volume decreased during treatment, the patient was included in the group with significant tumor shrinkage (27). No study provided information about macro- to micro-adenoma ratio. Data regarding age and male to female ratio are also reported in Table 2.

Three studies including patients with CD met the eligibility criteria (Tables 34); all of them presented a multicentre prospective design, recruiting 139 patients, most of them assuming PAS as a second-line treatment, after a surgical failure. For tumor shrinkage analysis, a subgroup of 34 patients was considered, taking s.c. PAS bis-in-die in two studies and PAS LAR in the third; in all cases titration was admitted. Tumor size analysis was a secondary endpoint in all three studies. Follow-up ranged from 6 to 60 months; tumor size assessment was performed with pituitary MRI. Only Pivonello et al. evaluated maximum diameter, instead of tumor volume changes (28). The population analyzed for tumor shrinkage mainly presented with a microadenoma. Data regarding age and gender are reported in Table 4. In the trial reported by Petersenn S et al., we arbitrarily fixed the criterion to define a significant tumor volume reduction (at least 25% of the baseline size of the pituitary adenoma), and the proportion of responders was calculated from the supplementary materials accordingly (3/6 = 50%) (13). Pivonello et al. separated patients exhibiting mild-moderate from those with severe hypercortisolism; we considered them together for tumor size analysis obtaining an overall proportion of significant size reduction of 21.4% (3 out of 14 subjects) (28).

Risk of Bias

The evaluation of the risk of bias performed with the adapted JBI tool is reported in Table 5. All studies presented clear diagnostic and inclusion criteria, except that of Lasolle H et al. (26). Although all papers reported a valid tool for tumor shrinkage analysis (MRI), two of them did not analyse tumor volume and did not provide a clear definition of significant size reduction (2628). Regarding other items, the majority of the considered studies did not appear to present a clear source of bias.

Table 5
www.frontiersin.orgTABLE 5 Evaluation of the risk of bias performed with the adapted Joanna Briggs’s Institute (JBI) tool.

Meta-Analysis

In the six studies considered for acromegaly, 37.7% (95%CI: [18.7%; 61.5%]) of patients demonstrated a significant tumor size reduction (Figure 4). As expected, heterogeneity in tumor reduction between studies was high (I2 = 90%). We attempted to address publication bias despite the low-number of studies (Figure 6A): Egger’s regression test did not indicate the presence of funnel plot asymmetry (intercept = -3.15 with 95%CI: [-10.17; 3.85], t = -0.883, p = 0.427) and the three-parameter selection model performed for p < 0.05 (and p < 0.1 as a sensitivity analysis) suggested absence of publication bias (28).

Figure 4
www.frontiersin.orgFIGURE 4 Pooled effect for the proportion of responders (i.e. presenting significant tumor shrinkage) in acromegaly. CI, confidence interval.

In the three studies considered for CD, 41,2% (95%CI: [22.9%; 62.3%]) of patients overall demonstrated a significant tumor size reduction (Figure 5). The heterogeneity in tumor reduction between the studies represented by I2 amounted to 47%. Publication bias analysis (Figure 6B) was performed using Egger’s regression test (intercept = -1.828 with 95%CI: [-14.53; 10.88], t = -0.282, p = 0.825) without evidence of asymmetry. The three-parameter selection model on the contrary could not be performed due to the small number of studies.

Figure 5
www.frontiersin.orgFIGURE 5 Pooled effect for the proportion of responders (i.e. presenting significant tumor shrinkage) in Cushing’s Disease. CI, confidence interval.

Figure 6
www.frontiersin.orgFIGURE 6 (A) Funnel plot assessing publication bias for Acromegaly. (B) Funnel plot assessing publication bias for Cushing’s Disease.

Discussion

The biochemical efficacy of medical treatment with PAS in GH- or ACTH-secreting pituitary adenomas has been described in previous metanalyses for acromegaly (2930) and CD (15), the latter also exploring the clinical benefit. In addition to these reports, this meta-analysis shows that PAS treatment can induce an additional clinically significant tumor shrinkage in approximately 40% of patients.

Acromegaly

Overall, PAS treatment provided tumor shrinkage in 37.7% of the considered patients. A previous metanalysis on octreotide in acromegaly provided a higher percentage of tumor size reduction (over 50%) (20). Nevertheless, since PAS treatment is usually considered as a second- or third-line treatment in the therapeutic flow-chart of acromegaly, the population recruited is mainly composed of patients with first-generation SRL-resistant somatotroph adenomas. This bias in recruited populations of acromegalic patients may explain this difference in the outcome. In a direct comparison, although PAS LAR seemed more effective in achieving biochemical control, both the SRLs, the first- and the second-generation types, achieved similar percentages of tumor shrinkage (67). Moreover, in the crossover extension, the switch from octreotide to PAS was more effective than the reverse schedule, achieving a slightly higher percentage of further significant tumor shrinkage (8). Lasolle et al. reported that the expression of SSR type 5 and the granulation pattern are of limited value for the prediction of PAS responsiveness: 5 out of 9 somatotropinomas in their series were densely granulated (two did not respond to PAS), and the expression of SSR type 5 was modest in one controlled patient (26).

Other than SRLs, a further therapeutic option targeting the somatotroph adenoma is cabergoline, either as monotherapy in mild cases or as an add-on treatment for resistant adenomas (18). In a previous metanalysis, cabergoline in monotherapy resulted less effective than SRLs, achieving tumor shrinkage in about one third of the enrolled patients (31). It should also be mentioned that some studies reported an escape phenomenon from its treatment efficacy (32).

Data coming from the combination of PAS LAR and pegvisomant in acromegaly were not considered in our metanalysis, due to inclusion criteria and variable combination therapy of the two drugs (33). Since some cases of adenoma growth had been reported during pegvisomant use (3435), this combination therapy represents a rational approach, but tumor volume analysis is less reliable, given the purpose of our study. Despite concerns regarding tumor growth, pegvisomant effectiveness in acromegaly is well documented (1829), although the cost of this combination treatment can limit its applicability in real-life practice. Moreover, it is worth mentioning Coopmans and collaborators’ follow-up analysis, suggesting a PAS mediated anti-tumoral effect in acromegaly. During treatment, patients exhibited a significant increase in T2-weighted sequences signal at MRI; moreover, patients exhibiting this MRI characteristic in their adenomas showed a more evident decrease in IGF-1 levels, but not a similar pattern in reduction of pituitary adenoma size (36). This finding may be related to cell degeneration or tumor cell necrosis, without necessarily determining significant tumor size reduction. Further studies, probably with more data coming from histological reports, may be necessary to better understand these findings.

Cushing’s Disease

Overall, PAS treatment provided significant tumor shrinkage in 41.2% of CD patients. Regarding pituitary-directed drugs, at this moment available for CD treatment, the efficacy of cabergoline has been proven in vitro studies, but its efficacy in clinical trials is still debated (1537). In a previous prospective study, cabergoline induced significant tumor shrinkage (defined as tumor volume reduction >20%) in 4 out of 20 (20%) of the patients recruited after 24 months (38). PAS is the only pituitary-directed treatment for this condition approved by Drug Agencies. Although few studies have been considered in this metanalysis, due to the strict inclusion criteria, PAS appears more effective in tumor size reduction versus cabergoline, resulting in a better choice in CD therapy when aiming to control the pituitary adenoma.

In contrast to acromegaly, the majority of CD patients present a microadenoma, suggesting that tumor size might be a less relevant issue during medical treatment, even if the “cure” of the disease may forecast the resolution of the adenoma. Besides, up to 30% of CD patients, depending also on MRI accuracy and neuro-radiologist’s expertise, may present with negative imaging that prevents any evaluation of tumor shrinkage (39). In spite of that, endocrinologists, not so infrequently, deal with aggressive corticotroph adenomas, characterized by invasive local growth and/or resistance to conventional therapies. This challenging entity often requires multidisciplinary expertise to suggest different approaches, including PAS treatment (40). It should be mentioned that some non-pituitary targeting drugs, as inhibitors of cortisol synthesis, have been associated with tumor growth, due to cortisol-ACTH negative feedback. In particular, during osilodrostat treatment in a phase III study, four recruited patients discontinued osilodrostat after a significant increase in tumor volume (two with micro- and two with macro-adenomas 41), and this growth had also been described during ketoconazole and mitotane treatments (42). Thus, it may be speculated that PAS could provide a rational approach as an combination treatment with steroidogenesis inhibitors. Moreover, after bilateral adrenalectomy, pituitary adenoma tumor size is of the utmost importance, as patients may be at risk of developing a progression of the adenoma, the so-called Nelson’s syndrome. In a prospective study from Daniel E et al., PAS proved to be also effective in this setting, reducing ACTH levels and stabilizing the residual tumor over a treatment period of 7 months (43). Further studies, with longer treatment observation, may reveal whether PAS may achieve significant tumor shrinkage in these patients, as suggested by previous case reports in literature (4445).

Conclusion

The main limitation of our study resides in the scarce literature provided up to now (260 patients with acromegaly and 34 with CD), in the different therapy schedules and different criteria for tumor shrinkage in the selected study (largest tumor diameter vs a selected percentage of reduction). Moreover, in none of the study tumor reduction was one of the primary endpoints, and surgery was performed before PAS in most patients (78-88% of CD and 43-96% of acromegaly).

PAS is a novel compound, with a rising role in the treatment of secreting pituitary adenomas. Thus, this topic might be amplified with more data coming from further clinical studies, as real-life studies, possibly also addressing markers predictive of response to this treatment (e.g., expression of SSR type 2 and type 5 or somatic mutations in USP8 at tissue level of ACTH-secreting adenomas). Nevertheless, we can already state that PAS treatment is effective in reducing tumor size, especially in acromegaly. Our results strengthen the role of PAS treatment in somatotroph and corticotroph adenomas, especially when tumor volume is a relevant issue (i.e. tumor progression, extrasellar invasion) (1839), as a neoadjuvant treatment before surgery or as tailored treatment, alone or in combination, in persistent disease or when surgery is not feasible. Future research aiming to characterize markers predictive of response could help to identify optimal candidates for this treatment.

Data Availability Statement

The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.

Ethics Statement

Informed consent was obtained from all subjects participating in the studies analyzed.

Author Contributions

Authors involved contributed to research as reported: literature search (FC, AM), preparation of original draft (FC, AM, MB, LD), literature review (CS, FC, AM, MF), manuscript editing (CS, FC, AM, MB, LD, MF) and supervision (RM, CS). All authors approved the final version of the paper.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s Note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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Keywords: pasireotide, cushing, acromegaly, tumor volume, tumor size

Citation: Mondin A, Manara R, Voltan G, Tizianel I, Denaro L, Ferrari M, Barbot M, Scaroni C and Ceccato F (2022) Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma: A Systematic Review and Meta-Analysis. Front. Endocrinol. 13:935759. doi: 10.3389/fendo.2022.935759

Received: 04 May 2022; Accepted: 06 June 2022;
Published: 01 July 2022.

Edited by:

Mohammad E. Khamseh, Iran University of Medical Sciences, Iran

Reviewed by:

Rosa Paragliola, Catholic University of the Sacred Heart, Rome, Italy
Marek Bolanowski, Wroclaw Medical University, Poland
Adriana G Ioachimescu, Emory University, United States

Copyright © 2022 Mondin, Manara, Voltan, Tizianel, Denaro, Ferrari, Barbot, Scaroni and Ceccato. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Filippo Ceccato, filippo.ceccato@unipd.it

ORCID: Alessandro Mondin, orcid.org/0000-0002-6046-5198
Renzo Manara, orcid.org/0000-0002-5130-3971
Giacomo Voltan, orcid.org/0000-0002-3628-0492
Irene Tizianel, orcid.org/0000-0003-4092-5107
Luca Denaro, orcid.org/0000-0002-2529-6149
Marco Ferrari, orcid.org/0000-0002-4023-0121
Mattia Barbot, orcid.org/0000-0002-1081-5727
Carla Scaroni, orcid.org/0000-0001-9396-3815
Filippo Ceccato, orcid.org/0000-0003-1456-8716

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

From https://www.frontiersin.org/articles/10.3389/fendo.2022.935759/full

Hypercortisolemic Cushing’s Patients Possess a Distinct Class of Hematopoietic Progenitor Cells Leading to Erythrocytosis

Abstract

Although human cultures stimulated with dexamethasone suggest that the glucocorticoid receptor (GR) activates stress erythropoiesis, the effects of GR activation on erythropoiesis in vivo remains poorly understood.

We characterized the phenotype of a large cohort of patients with Cushing’s Disease, a rare condition associated with elevated cortisol levels. Results from hypercortisolemic patients with active Cushing’s were compared with those obtained from eucortisolemic patients after remission and from non-diseased volunteers. Active Cushing’s patients exhibit erythrocytosis associated with normal hemoglobin F levels. In addition, their blood contained elevated numbers of the GR-induced CD163+ monocytes and a unique class of CD34+ cells expressing CD110, CD36, CD133 and the GR-target gene CXCR4.

When cultured, these CD34+ cells generated similarly large numbers of immature erythroid cells in the presence and absence of dexamethasone, with raised expression of the GR-target gene GILZ. Of interest, blood from Cushing’s patients in remission maintained high numbers of CD163+ monocytes and, although their CD34+ cells had a normal phenotype, these cells were unresponsive to added dexamethasone.

Collectively, these results indicate that chronic exposure to excess glucocorticoids in vivo leads to erythrocytosis by generating erythroid progenitor cells with a constitutively active GR.

Although remission rescues the erythrocytosis and the phenotype of the circulating CD34+ cells, a memory of other prior changes is maintained in remission.

From https://haematologica.org/article/view/haematol.2021.280542

Subclinical Hemorrhage of ACTH-secreting Pituitary Adenomas in Children and Adolescents Changes Their Biochemical Profile

Journal of the Endocrine Society, Volume 6, Issue 7, July 2022, bvac080, https://doi.org/10.1210/jendso/bvac080

Abstract

Context

Subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration (SPH) presents mainly in large tumors and prolactinomas. The characteristics of patients with Cushing disease (CD) and SPH are not known.

Objective

To determine if SPH affects the presentation and biochemical profile of young patients with CD.

Methods

Pediatric and adolescent patients who were diagnosed with CD between 2005 and 2021 and available magnetic resonance imaging images were evaluated for SPH. The clinical and biochemical characteristics of patients with and without SPH were compared.

Results

Evidence of possible SPH was present in 12 out of 170 imaging studies (7.1%). Patients with and without SPH had similar age at diagnosis and sex distribution but differed in disease duration (median duration: 1.0 year [1.0-2.0] in the SPH group vs 2.5 years [1.5-3.0] in the non-SPH group, P = .014). When comparing their biochemical evaluation, patients with SPH had higher levels of morning adrenocorticotropin (ACTH) (60.8 pg/mL [43.5-80.3]) compared to patients without SPH (39.4 pg/mL [28.2-53.2], P = .016) and the degree of cortisol reduction after overnight high dose (8 mg or weight-based equivalent) dexamethasone was lower (–58.0% [–85.4 to –49.7]) compared to patients without SPH (85.8 [–90.5 to –76.8], P = .035). The presence of SPH did not affect the odds of remission after surgery or the risk of recurrence after initial remission.

Conclusion

SPH in ACTH-secreting pituitary adenomas may affect their biochemical response during endocrine evaluations. They may, for example, fail to suppress to dexamethasone which can complicate diagnosis. Thus, SPH should be mentioned on imaging and taken into consideration in the work up of pediatric patients with CD.

Acute hemorrhage or necrosis of pituitary adenomas (PAs), defined as pituitary apoplexy, is a rare life-threatening condition that requires emergent neurosurgical evaluation [1]. However, subclinical hemorrhage, necrosis, intratumor cystic degeneration, and/or infarct of PAs, herein all events included in the term subclinical pituitary hemorrhage (SPH) for brevity, may occur in up to 7% to 22% of all pituitary tumors [2-9]. SPH is not associated with significant clinical symptoms and is often discovered at the time of routine diagnostic evaluation [2-9].

Previous studies suggested that SPH is more common in large tumors, prolactin-secreting or nonfunctioning PAs, while other factors, such as initiation or withdrawal of treatment with dopamine agonists, use of anticoagulants and others, have also been hypothesized to be involved in this process [56]. Overall, adrenocorticotropin (ACTH)-secreting PAs represent small percentage of SPH (0%-3.2% of cases reported) [3568]. Although pituitary apoplexy is associated with pituitary hormone deficiencies, SPH has a lower if any effect on the function of the remaining pituitary gland when it occurs in nonfunctioning adenomas [34].

The diagnosis of Cushing syndrome (CS) involves elaborate and time-dependent tests that are based on cortisol secretion and its regulation by ACTH [10]. Furthermore, the differential diagnosis of ACTH-dependent causes between ACTH-secreting PAs (Cushing disease, CD) and ectopic ACTH secretion is based on several dynamic tests, such as corticotropin-releasing hormone (CRH) stimulation and dexamethasone suppression [11]. The biochemical profile of corticotropinomas with SPH to both baseline and dynamic endocrine tests is not known.

Materials and Methods

Participants

Individuals enrolled under the protocol 97-CH-0076 (ClinicalTrials.gov identifier NCT00001595) at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), from 2005 to 2020 with confirmed diagnosis of CD, were screened for eligibility in the study. Pediatric and adolescent patients (diagnosis age < 21 years) with imaging studies available before any surgical intervention were included in the analysis. Patients with previous surgery of the pituitary gland or who were evaluated during recurrence were excluded from the study since postoperative changes make imaging findings difficult to distinguish from true SPH, and biochemical presentation at recurrence often differs in severity from initial diagnosis. CS diagnosis was based on criteria defined by the Endocrine Society guidelines and adjusted for the pediatric and adolescent population as needed (abnormal measurements in at least 2 of the following criteria: elevated 24 hour urinary free cortisol [UFC], elevated midnight serum cortisol [> 4.4 mcg/dL in children or > 7.5 mcg/dL for patients age > 18 years], and/or failure to suppress cortisol to 1 mg [or weight-based equivalent dose] overnight dexamethasone suppression test [postdexamethasone cortisol > 1.8 mcg/dL]). CD diagnosis was based on postoperative histologic confirmation of ACTH-secreting PA in most cases, or remission after pituitary surgery even if histologic report failed to identify a PA in the studied material. Remission was defined as postoperative cortisol nadir of less than 2 mcg/dL and/or clinical/biochemical remission during follow-up.

Informed consent was obtained from parents and assent from patients if developmentally appropriate. Study procedures were approved by the NICHD and/or central National Institutes of Health Institutional Review Board.

Magnetic Resonance Imaging Scans

SPH was defined as minimal or no clinical symptoms reported by the patients (apart from those commonly associated with hypercortisolemia) and magnetic resonance imaging (MRI) findings consistent with hemorrhage, intratumor infarction, and/or intratumor cyst formation (suggesting old infarcts) based on the radiologist and the principal investigator’s (C.A.S.) assessment [1213]. MRI scans were performed based on standard clinical protocols as previously described [14]. Briefly, MRIs at the National Institutes of Health were performed before and after intravenous administration of gadolinium contrast material, with a gradient echo sequence and thin slices (≤ 1.5 mm). MRIs were performed in either a 1.5 Tesla or 3 Tesla MR machine from various manufacturers over time.

Clinical and Biochemical Data

Clinical and biochemical data were extracted from electronic medical records. Tumor size was recorded as the maximum dimension retrieved from the histology report. In cases where histologic report was not available, failed to identify a PA in the studied material, or if the histology report recorded only dimensions on fragments of the tumor, the maximum dimension was retrieved from the MRI images. If the MRI was negative and the histology was negative (but the patient achieved remission after surgery), the tumor size was recorded as missing.

Serum cortisol and plasma ACTH levels were calculated as the average value of the corresponding levels performed at 23:30 h and 00:00 h (reported as midnight values) and 07:30 h and 08:00 h (reported as morning values). Twenty-four–hour UFC was calculated as the average of the first 2 or 3 samples reported in the electronic medical records. Given the possible differences in the assays and reported reference range for UFC, we calculated the increase of UFC based on the upper limit of normal according to the following formula: UFC fold change = UFC/upper limit of the reference range. Serum cortisol was measured with solid-phase, competitive chemiluminescent enzyme immunoassay on a Siemens Immulite 2500 analyzer. Plasma ACTH was measured with a chemiluminescence immunoassay on a Siemens Immulite 200 XPi analyzer. UFC was measured with a chemiluminescent enzyme immunoassay until 2011 and with high-performance liquid chromatography–tandem mass spectrometry since 2011. High-dose dexamethasone suppression test was performed as previously described. Briefly, oral dexamethasone (120 mcg/kg, max 8 mg) was administered at 23:00 and cortisol was measured before (8 AM the day of administration) and after (9 AM the day after dexamethasone administration). The change of cortisol was calculated as: 100* [(postdexamethasone cortisol – predexamethasone cortisol)/predexamethasone cortisol]. Levels of cortisol lower than the lower limit of detection of the assay (< 1 mcg/dL) were substituted with the intermediate value (0.5) for all analyses. CRH stimulation test was performed as previously described. Briefly, an intravenous catheter was placed in the forearm the night before testing; the patient was fasting and lying in bed, and ovine CRH (oCRH) was administered (1 mcg/kg, max 100 mcg). Samples for cortisol and ACTH were taken at –5, 0, 15, 30, and 45 minutes after the administration of oCRH. The response to the last was expressed as the percentage change from baseline by subtracting the pretest cortisol and ACTH values from the posttest values and dividing by the former. The mean cortisol increase was estimated at 30 and 45 minutes from baseline. For ACTH the mean increase was estimated at 15 and 30 minutes after the administration of oCRH. CRH stimulation test was not performed after the discontinuation of oCRH by the company in November 2020.

Statistical Analysis

Categorical data are described as counts (proportions) and were compared between groups using the Fisher exact test. Fisher odds ratio (OR) was used to assess the odds of remission based on the presence of SPH and is presented as OR and 95% CI.

Continuous data were checked for normality and not normally distributed data are presented as median (first quartile to third quartile) and were compared between 2 groups using Wilcoxon rank-sum test. The Cox proportional hazards test was used to assess the risk of recurrence based on the presence of SPH and is presented as hazard ratio (HR) and 95% CI. Statistical analyses were performed in R.

Results

Clinical Data

Out of 170 patients with available MRI before first surgery, 12 patients had evidence of possible SPH (7.1%) (Table 1). Various MRI findings were noted (Fig. 1), most commonly hyperintense lesions in T1 and T2 precontrast images (Fig. 1A and 1B), while some patients had intratumor heterogeneity suggestive of cystic formation (Fig. 1C-1F). As expected, the tumor size of patients with SPH as noted in histology reports or MRI images was higher than that in patients without SPH (median size: 8.5 mm [7.0-11.25] in the SPH group vs 5.4 mm [4-8] in the non-SPH group; P < .001).

 

Table 1.

Characteristics of patients with and without subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration

No SPH (N = 158) SPH (N = 12) P
Age at diagnosis, y 13.0 (10.6 to 15.4) 12.5 (10.6 to 15.6) .95
Sex
 Female 89 (56.3%) 5 (41.7%) .49
 Male 69 (43.7%) 7 (58.3%)
Disease duration, y 2.50 (1.5 to 3.0)
n = 138
1.00 (1.0 to 2.0)
n = 10
.014
Morning cortisol, mcg/dL 16.2 (12.6 to 20.4)
n = 139
18.4 (13.7 to 27.5)
n = 10
.28
Midnight cortisol, mcg/dL 14.0 (10.7 to 19.7)
n = 133
16.3 (11.0 to 23.0)
n = 9
.52
UFC fold change 4.89 (2.51 to 8.50)
n = 131
8.81 (6.86 to 9.42)
n = 9
.18
Morning ACTH, pg/mL 39.4 (28.2 to 53.2)
n = 143
60.8 (43.5 to 80.3)
n = 10
.016
Cortisol change during CRH stimulation test, % 68.7 (33.3 to 111)
n = 128
46.0 (–7.46 to 90.7)
n = 8
.22
ACTH change during CRH stimulation test, % 145 (59.6 to 260)
n = 127
103 (–5.75 to 278)
n = 8
.55
Cortisol change during high-dose dexamethasone suppression test, % –85.8 (–90.5 to –76.8)
n = 120
–58.0 (–85.4 to –49.7)
n = 9
.035
Remission
 Yes 127 (80.4%) 10 (83.3%) .99
 No 25 (15.8%) 2 (16.7%)

Number in each cell reports the number of patients with available results.

Abbreviations: ACTH, adrenocorticotropin; CRH, corticotropin-releasing hormone; SPH, subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration; UFC, urinary free cortisol.

 

Figure 1.

Imaging findings in patients with subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration. A, T1, and B, T2 magnetic resonance imaging (MRI) scans of the same patient showing area of high intensity inside the tumor suggesting acute/subacute episode. C, T2, and D, T1 MRI scans of the same patient showing heterogeneity in a large tumor with high-intensity areas suggesting blood-filled cavities and/or necrosis. E, T1, and F, T2 MRI scans of the same patient showing fluid inside the tumor.

Imaging findings in patients with subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration. A, T1, and B, T2 magnetic resonance imaging (MRI) scans of the same patient showing area of high intensity inside the tumor suggesting acute/subacute episode. C, T2, and D, T1 MRI scans of the same patient showing heterogeneity in a large tumor with high-intensity areas suggesting blood-filled cavities and/or necrosis. E, T1, and F, T2 MRI scans of the same patient showing fluid inside the tumor.

Patients with and without SPH were similar in age (median age: 12.5 years [10.6-15.6] in the SPH group vs 13.0 years [10.6-15.4] in the non-SPH group; P = .95) and sex distribution (n of female = 5 (41.7%) in the SPH group vs 89 (56.3%) in the non-SPH group; P = .49). Patients with SPH had a shorter duration of disease as noted by changes in their growth chart parameters (median duration: 1.0 [1.0-2.0] year in the SPH group vs 2.5 [1.5-3.0] years in the non-SPH group; P = .014).

Patients in the 2 groups did not differ on their anthropometric characteristics, including height and body mass index z scores(P > .05). They also had similar blood pressure parameters and did not differ in terms of the frequency of hypertension diagnosis. No patient was on anticoagulation treatment nor had received radiation at the time of the MRI. One patient in the SPH group had a history of lower leg deep vein thrombosis and was previously on low-heparin therapy, but he had stopped treatment at least 6 months before the MRI.

Biochemical Evaluation of Hypercortisolemia

Morning and midnight serum cortisol and 24-hour UFC levels were similar in both groups, but patients with SPH had higher levels of morning ACTH (60.8 pg/mL [43.5-80.3]) compared to patients without SPH (39.4 pg/mL [28.2-53.2]; P = .016). Changes in cortisol and ACTH levels during the CRH stimulation test were similar between the 2 groups, but patients with SPH who underwent the overnight high-dose dexamethasone suppression test (n = 8) had lower suppression of cortisol after dexamethasone (–58.0% [–85.4 to –49.7]) compared to patients without SPH (n = 120) (–86.0% [–90.5 to –76.7]; P = .035) (Fig. 2). When the cutoff of suppression of more than 69% was considered, patients with SPH had a lower chance of suppressing more than 69% compared to patients without SPH (OR: 0.18; 95% CI, 0.03-0.95).

 

Figure 2.

Cortisol levels before and after high-dose dexamethasone suppression test in patients with and without subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration (SPH).

 Cortisol levels before and after high-dose dexamethasone suppression test in patients with and without subclinical pituitary hemorrhage, necrosis, and/or cystic degeneration (SPH).

Remission After Surgical Treatment and Risk for Recurrence

The chance of immediate postoperative remission after surgery was similar in patients with and without SPH. For patients with initial remission and follow-up of at least 3 months, analysis of the risk of recurrence did not show a difference in recurrence rate between the 2 groups (HR: 1.12; 95% CI, 0.13-9.4, in the SPH group compared to the non-SPH group, adjusting for the neurosurgeon).

Discussion

SPH is often an incidental finding in the imaging evaluation of patients with PAs. The frequency of SPH in patients with CD is low (7.1% in our study) but these patients may differ in terms of their history of shorter duration of symptoms and the biochemical evaluation. More specifically, patients with CD and SPH showed higher ACTH levels and lower suppression of cortisol to high-dose dexamethasone. This, however, did not affect their prognosis in terms of immediate postoperative remission and long-term risk of recurrence.

SPH has been mainly studied in cohorts of patients with various types of PAs. From these studies important conclusions have been made suggesting that the risk of SPH is higher in patients with large nonfunctioning PAs or prolactinomas. Other risk factors for pituitary apoplexy are thought to be size of the adenoma, change in size, initiation, and withdrawal of dopamine agonists, type of dopamine agonist, use of anticoagulants, diabetes mellitus, hypertension, head trauma, radiotherapy, and preceding dynamic endocrine testing.

Patients with CD often represent a small portion of these cohorts, and to our knowledge there is no study to investigate how these patients respond to stimulation/suppression tests. For that reason, we evaluated these findings in our cohort of only patients with ACTH-secreting adenomas. As most of our referrals involve pediatric patients, we limited our cohort only to patients diagnosed at younger than 21 years to have a more homogeneous group.

The pathogenesis of pituitary apoplexy has been hypothesized to lie in more friable vessels in PAs, which, while the tumor increases in size, are more susceptible to rupture or cause surrounding feeding vessels to extend and bleed [715]. CS, because of the coexisting hypercortisolemia, leads independently to endothelial dysfunction and coagulation defects, which are often apparent as easy bruising, thrombotic events, and other signs. However, review of the literature and the estimated frequency of SPH in our cohort suggest that patients with CD are not at increased risk for SPH, potentially related to the relatively small adenomas present in these patients [1617].

The main difference of patients with CD and SPH compared to those without lies in their biochemical testing, more characteristically in lower suppression to dexamethasone. The overnight high-dose dexamethasone suppression test was originally designed to differentiate various types of CS [18]. Although originally described as a highly accurate test, in clinical practice, cutoffs of 50% to 80% have shown variable sensitivity and specificity and certain centers opt not to use this test unless all other diagnostic evaluations yield confounding results [19-21]. In previous studies a threshold of suppression of more than 69% showed the highest accuracy (sensitivity: 71%, specificity: 100%), and we have incorporated this in our diagnostic algorithm (acknowledging the limitations of the test) [2223]. In our analysis, patients with SPH had lower suppression of cortisol under the effect of high-dose dexamethasone and a higher chance of not passing the aforementioned threshold. The mechanism for the lower suppression to dexamethasone of these tumors may be due to lower vascular circulation of dexamethasone at the level of the tumor, and/or the lower sensitivity of necrotic cells to the negative feedback by circulating glucocorticoids.

A limitation of this study was that the diagnosis of SPH was based on MRI findings. However, MRI sequences and machines differed between patients and over time. Thus, although large hemorrhagic/necrotic lesions are probably accurately identified, it is possible that smaller lesions are misclassified as negative; the effect of smaller hemorrhagic areas to the biochemical testing may however be smaller as well. Further, the MRIs were not read by a central radiologist, but rather from the radiologist on call at each time point, and this could lead to discrepancies in readings. In addition, our cohort’s data may not be generalized to the pediatric or adult CD population, as often our referrals consist of patients with difficult to treat, small, or otherwise unusual tumors.

In conclusion, SPH may be incidentally identified in up to 7% of patients with CD. Patients with CD and SPH may differ in terms of their response to endocrine tests, and this finding should be incorporated in their evaluation.

Abbreviations

 

  • ACTH

    adrenocorticotropin

  • CD

    Cushing disease

  • CRH

    corticotropin-releasing hormone

  • CS

    Cushing syndrome

  • HR

    hazard ratio

  • MRI

    magnetic resonance imaging

  • NICHD

    Eunice Kennedy Shriver National Institute of Child Health and Human Development

  • OR

    odds ratio

  • PA

    pituitary adenoma

  • SPH

    subclinical pituitary hemorrhage

  • UFC

    urinary free cortisol

Financial Support

This work was supported by the intramural research program of the Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD 20892, USA.

Disclosures

Dr Stratakis holds patents on the function of the PRKAR1APDE11A, and GPR101 genes and related issues; his laboratory has also received research funding on the GPR101 gene, and on abnormal growth hormone secretion and its treatment by Pfizer, Inc. He is currently employed by ELPEN, SA and has been consulting for Lundbeck Pharmaceuticals and Sync, SA. The other authors have nothing to disclose.

Data Availability

Some or all datasets generated during and/or analyzed during the current study are not publicly available but may be available from the corresponding author on reasonable request.

Published by Oxford University Press on behalf of the Endocrine Society 2022.
This work is written by (a) US Government employee(s) and is in the public domain in the US.
Published by Oxford University Press on behalf of the Endocrine Society 2022.

Successful Immunomodulatory Treatment of COVID-19 in a Patient With Severe ACTH-Dependent Cushing’s Syndrome

Introduction: Patients with Cushing’s syndrome (CS) represent a highly sensitive group during corona virus disease 2019 (COVID-19) pandemic. The effect of multiple comorbidities and immune system supression make the clinical picture complicated and treatment challenging.

Case report: A 70-year-old female was admitted to a covid hospital with a severe form of COVID-19 pneumonia that required oxygen supplementation. Prior to her admission to the hospital she was diagnosed with adrenocorticotropic hormone (ACTH)-dependent CS, and the treatment of hypercortisolism had not been started yet. Since the patient’s condition was quickly deteriorating, and with presumend immmune system supression due to CS, we decided on treatement with intraveonus immunoglobulins (IVIg) that enabled quick onset of immunomodulatory effect. All comorbidities were treated with standard of care. The patient’s condition quickly stabilized with no direct side effects of a given treatment.

Conclusion: Treatment of COVID-19 in patients with CS faces many challenges due to the complexity of comorbidity effects, immunosupression and potential interactions of available medications both for treatment of COVID-19 and CS. So far, there are no guidelines for treatment of COVID-19 in patients with active CS. It is our opinion that immunomodulating therapies like IVIg might be an effective and safe treatment modality in this particularly fragile group of patients.

Introduction

Dealing with corona virus disease 2019 (COVID-19) focused medical attention on several sensitive population groups. While the knowledge is still improving, some of the recognized risk factors for severe form of the disease are male sex, older age, obesity, hypertension, diabetes mellitus, and cardio-vascular disease (1). This constellation of morbidities is particularly intriguing from endocrine point of view, since they are all features of patients with Cushing’s syndrome (CS). Another relevant feature of CS is a propensity for infections due to profound immune suppression, with prevalence of 21-51%; even more so, infections are the second cause of death (31%) in CS after disease progression, and are the main cause of death (37%) in patients who died within 90 days of diagnosis (2).

Immune system alterations in CS lead to depression of both innate and adaptive immune responses, favoring not only commonly acquired but also opportunistic bacterial infections, fungal infections, and severe, disseminated viral infections (3). Susceptibility to infections directly positively correlates with cortisol level, and is more frequent in ectopic ACTH secretion (EAS). Hypercortisolism hampers the first-line response to external agents and consequent activation of the adaptive response (3). Consequently, there is a decrease in total number of T-cells and B-cells, as well as a reduction in T-helper cell activation, which might favor opportunistic and intracellular infections. On the other hand, an increase in pro-inflammatory cytokine secretion, including interleukine-6 (IL-6) and tumor necrosis factor-α (TNF-α) leads to persistent, low-grade inflammation. It is important to note that immune system changes are confirmed both during the active phase and while in remission of CS (3).

In view of the aforementioned data, a few topics emerge regarding patients with CS and COVID-19. Initial clinical presentation may be altered – low-grade chronic inflammation and poor immune reaction might limit febrile response in the early phase of infection, aggravating timely diagnosis (4). Increased cytokine levels may put patients with CS at increased risk of severe course and progression to acute respiratory distress syndrome (ARDS). On the other hand, the rise in cytokine levels associated with exposure to external agents is significantly hampered, probably because of persistently elevated pro-inflammatory cytokine secretion (45). Patients with CS have a possibility for prolonged duration of viral infections and risk for superinfections leading to sepsis and increased mortality risk; this is especially relevant for hospitalized patients and mandates empirical prophylaxis with broad-spectrum antibiotics (6). Both COVID-19 and CS individually represent disease states of increased thromboembolic (TE) risk, requiring additional care (6).

Due to very limited data, it is still not possible to address these topics with certainty and make recommendations for optimal management of these patients. Current clinical practice guidance for management of CS during COVID-19 commissioned by the European Society of Endocrinology (ESE) emphasizes prompt and optimal control of hypercortisolism and adequate treatment of all comorbidities (7). Although individual circumstances must always be considered, we need more direct clinical experience, especially regarding the actual treatment of COVID-19 in this sensitive group. So far, there are only five published case studies of patients with CS and COVID-19, with eight patients in total (812). In this study, we present a patient with newly diagnosed ACTH-dependent CS who was diagnosed with COVID-19 before the initiation of specific medical treatment.

Case Report

A 70-year-old female was admitted to our Covid hospital due to bilateral interstitial pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Six days before she was discharged from endocrinology department of another hospital where she was hospitalized due to newly diagnosed diabetes mellitus. Her personal history was unremarkable, and she was vaccinated with two doses of inactivated COVID-19 vaccine Sinopharm BBIBP. During this hospitalization Cushingoid features were noted (moon face, centripetal obesity, thin extremities with multiple hematomas, bilateral peripheral edema), as well as diabetes mellitus (HbA1c 8.7%), arterial hypertension (BP 180/100 mmHg), hypokalemia (2.0 mmol/L), mild leukocytosis (WBC 12.9x10e9/L) with neutrophilia, and mildly elevated CRP (12.3 mg/L). Hormonal functional testing confirmed ACTH-dependent Cushing’s syndrome: morning ACTH 92.6 pg/mL (reference range 10-60 pg/mL), morning serum cortisol 1239 nmol/L (reference range 131-642 nmol/L), midnight serum cortisol 1241 nmol/L, lack of cortisol suppression in overnight dexamethasone suppression test (978 nmol/L). Pituitary MRI was unremarkable other than empty sella, and CT scan of thorax normal other than left adrenal hyperplasia. Diabetes mellitus was successfully controlled with metformin, hypertension with ACE-inhibitor, Ca-channel blocker and beta-blocker, and hypokalemia with potassium supplementation along with spironolactone. Steroidogenesis inhibitors were not available in this institution, but before referral to a tertiary care hospital she was tested for SARS-CoV-2, and the test came back positive (sample was obtained by nasopharyngeal swab). Since she was asymptomatic, with normal thoracic CT scan and stabile CRP level (9.1 mg/L), she was discharged with detailed recommendations for conduct in case of progression of COVID symptoms.

Next day she started feeling malaise with episodes of fever (up to 38.2°C). Symptomatic therapy was advised in an outpatient clinic (no antiviral therapy was recommended), but 5 days later respiratory symptoms ensued. During examination, the patient was weak, with dyspnea and tachypnea (RR 22/min), afebrile (36.9°C) and with oxygen saturation (SO2) of 85% measured by pulse oximeter. Chest X-ray confirmed bilateral interstitial pneumonia with parenchymal consolidation in the right lower lung lobe, so she was referred to the COVID hospital.

Laboratory analyses upon admission are presented in the Supplementary Table 1. In addition to her previous testing, elevated chromogranin A (CgA) level was verified (538.8 ng/mL, reference range 11-98.1). The patient was treated with supplemental oxygen with maximal flow of 13 l/min. For the reason of previously confirmed severe endogenous hypercortisolism, glucocorticoids were not administered. Due to limited therapeutic options and presumed further clinical deterioration, we decided to treat the patient with intravenous immunoglobulins (IVIg) 30 g iv for 5 days, starting from the 2nd day of hospitalization. We did not observe any side effects of a given treatment. In parallel, the patient received broad-spectrum antibiotics (ceftazidime and levofloxacin), proton pump inhibitor, LMWH in prophylactic dose, oral and parenteral potassium supplementation along with spironolactone. She continued with her previous antihypertensive therapy with good control of blood pressure. While the patient was on oxygen supplementation, glycaemia was controlled with short acting insulin before meals. Following given treatment, we observed clinical, biochemical (Supplementary Table 1.) and radiological improvement (Supplementary Figure 1). Oxygen supplementation was gradually discontinued. With regard to D-dimer levels and risk factors for TE events due to COVID-19 and CS, we performed color Doppler scan of lower extremities veins, and CT pulmonary angiography, but there were no signs of thrombosis. During hospital stay, there were no signs of secondary infection and cotrimoxazole was not added to the current treatment. The patient was discharged with advice to continue her prior medical therapy along with increased dose of spironolactone and initiation of rivaroxaban. She was referred to the tertiary institution for the initiation of steroidogenesis inhibitor and further diagnostics.

Discussion

Endogenous Cushing’s syndrome is a rare disease with an incidence of 0.7-2.4 million person-years in European population-based studies (13). Significant morbidity yields a standard mortality ratio of 3.7 (95%CI 2.3–5.3), with the highest mortality during the first year after initial presentation. COVID-19 pandemic imposes additional challenge to this fragile group of patients. Due to lack of solid experience, it is still difficult to define potential clinical course and outcome of patients with CS and COVID-19. In addition, currently there are no guidelines for management of SARS-CoV-2 infection in patients with active CS.

So far, only two small case series followed patients with Cushing’s disease (CD) in various disease stages (not all were active) during COVID-19 pandemic (912). Small number of SARS-CoV-2 positive cases (3/22 and 2/61) is clearly biased by shortness of analyzed period (one and a half, and three and a half months). Additionally, a small number of patients was actually tested by nasopharyngeal swab for SARS-CoV-2 even in the presence of indicative symptoms, albeit mild. Nevertheless, all these limitations included, it seems that the prevalence of COVID-19 might be greater in patients with CD than in general population (12). This is accordant with studies on patients on exogenous glucocorticoid (GC) treatment. Overall, there is a growing body of evidence that patients on chronic GC therapy are at higher risk for SARS-CoV-2 infection and a severe course of disese, regardless of age and comorbidities (14). In many studies patients on high-dose GC therapy were at particularly high risk for a severe course of disease, so it is reasonable to assume that there is a dose-dependent effect (14).

All patients except one with endogenous CS and COVID-19 presented in literature were hospitalized, with majority of them requiring oxygen supplementation, which classified them as serious cases of disease (812). Parameters of inflammation (namely CRP) were highly variable (from normal to elevated) and did not seem to reflect severity of COVID-19 consistently. Two patients had fatal outcome; one with postoperative hypocortisolism that required stress doses of hydrocortisone, and with terminal kidney failure as significant comorbidity; the other with suspected EAS who developed ARDS in contrast to normal CRP and absence of fever (912). Based on reported cortisol levels in these patients, it seems that the severity of COVID-19 pneumonia depended on severity of hypercortisolism (812). A patient with probable EAS even developed ARDS, which adds to ongoing controversy regarding the risk of ARDS due to SARS-CoV-2 in patients with CS (315). We ourselves have treated a severely obese female patient with active CD on pasireotide, who developed ARDS despite addition of high doses of methylprednisolone (unpublished data). Additional risk imposed by comorbidities cannot be underestimated (1516). This is particularly relevant for obesity, that not only hampers immune system (leading to increased levels of IL-1, IL-6, and TNF-α), but adipocytes represent a reservoir of SARS-CoV-2 thanks to ACE2 receptor, crucial for virus attachment (15).

Majority of depicted patients with active CS were already medically treated for hypercortisolism but with various compliance (sometimes very poor), and two young patients have just started steroidogenesis inhibitors (metyrapone/ketoconazole). Infection with SARS-CoV-2 was treated by national protocols that were mostly based on supportive care. These protocols changed over time, so a few patients received antiviral therapy (favipiravir), and one young patient with suspected EAS was treated with methylprednisolone along with high doses of ketoconazole (10). Treatment was complicated with adrenal insufficiency (AI) in three patients (81112).

We have presented a patient with CS and rapid development of serious case of COVID-19 pneumonia that required hospital admission and oxygen support. She was febrile and had positive laboratory parameters of inflammation. Her CS was active, with very high cortisol levels, no prior medical treatment and with clinical suspicion of EAS (ACTH-dependent disease of short duration, severe hypercortisolism, hypokalemia, very high CgA, no visible pituitary tumor). With this in mind, and with regard to rapid progression of COVID-19 pneumonia, it was our opinion that the patient required treatment with quick onset and presumable immune system modulation.

A logical approach to treatment of CS during COVID-19 pandemic includes meticulous therapy for comorbidities (namely antihypertensives, anti-diabetic drugs, low molecular weight heparin, etc.), and steroidogenesis inhibitors for treatment for hypercortisolemia (7). While some of these drugs demonstrate quick onset of action regarding normalization of cortisol level (and hence improve clinical comorbidities), rapid effects on immune system responses are not likely, which might be of great relevance in case of acute infection. Secondly, adrenolytic therapy increases a risk of AI, which can be even more perilous than CS in case of infection or other stress situations (8121516). A modified “block and replace” approach may be considered, where addition of hydrocortisone could diminish the risk of AI (7). Still, there are a few potential pitfalls with this regimen as well. Some people fail to respond to high doses of adrenal-blocking agents due to genetic differences in the steroidogenic enzymes, since therapeutic responses to metyrapone and ketoconazole in patients with CS are associated with the polymorphism in the CYP17A1 gene (17). Additionally, there are not enough data about possible interactions between adrenolytic drugs (majority of them being metabolized through the CYP450/CYP3A4 pathway) and medications used to treat COVID-19, most of which are only just emerging (18). Special concerns, amplified with similar potential effects of SARS-CoV-2 itself as well as specific therapies are liver dysfunction (metyrapone, ketoconazole), hypokalemia (metyrapone, ketoconazole), QT-interval prolongation (ketoconazole, osilodrostat), gastrointestinal distress (mitotane, osilodrostat, etomidate) (18). Metyrapone may cause accumulation of androgenic precursors secondary to the blockade of cortisol synthesis, that can virtually enhance expression of transmembrane protease serine 2 (TMPRSS2), found to be essential to activate the viral spikes, induce viral spread, and pathogenesis in the infected hosts (19). Another important issue concerns biochemical estimation of disease control (and hence risk for AI), since most commercially available assays can overestimate cortisol level in patients treated with metyrapone due to cross-reactivity with the precursor 11-deoxicortisol (715). Mass spectrometry is a method of choice to overcome this problem, but it is not available in many centers. Some centers advocate titration and/or temporary halting medical therapies in the treatment of patients with CS in the context of COVID-19 infection (20). Treatement was stopped in a few patients with severe COVID-19 symptoms who were then given high dose GC for a few days with no long-term complications, and with full recovery (20).

There are no data about the effect of anti-viral drugs in patients with CS and COVID-19. A special concern refers to adipose tissuse, as adipose tissue is difficult for antiviral drugs to reach. It cannot be excluded that the constant release of viral replicas from the adipose tissue reservoir may interfere with COVID-19 infection treatment, delaying its resolution and favoring a worse prognosis (15). If antiviral drugs are started, it is suggested that immunocompromised patients may require prolonged therapy (18). However, the timing is difficult in practice and candidates for antivirals are limited.

Since the clinical course of COVID-19 only initially depends on viral replication, immunomodulatory therapy emerged as a valuable treatment option to control the host immune response. This became apparent ever since RECOVERY trial proved efficacy of glucocortiods (21). But this therapeutic option is fairly inapplicable in patients with active CS, since glucocorticoid treatment in chronic hypercortisolism seems to enhance immune system alterations (22). In parallel with the development of new agents, it is prudent to study the efficacy of existing therapeutic options with acceptable safety profile (20). Beside glucocorticoids, inflammation blockers, intravenous immunoglobulin and convalescent plasma were used in various settings (23).

Intravenous immunoglobulin (IVIg) is a blood product prepared from the serum pooled from thousands of healthy donors, containing a mixture of polyclonal IgG antibodies, mostly IgG1 and IgG2 subclasses (2425). Initial rationale for its use was immunodefficiency due to hypoglobulinemia. Since then it has been shown that IVIg exerts pleiotropic immunomodulating action involving both innate and adaptive immunity and it has been used in a variety of diseases (26). In previous studies on MERS (Middle East Respiratory Syndrome) and SARS (Severe Acute Respiratory Syndrome) using IVIg showed beneficial clinical effects (25). Although pathogenesis of COVID-19 has not be fully elucidated, there is a consensus that immune-mediated inflammation plays an important role in the progression of this disease, just as it did in prior coronavirus infections (27). In this context, the actual role of IVIg in COVID-19 patients might be not to boost the immune system, but through its immunomodulatory effect to suppress a hyperactive immune response that is seen in some patients (28). So far, a limited number of studies, case series and meta-analyses demonstrate a promising potential of IVIg in patients with COVID-19. The effect was demonstrated in terms of mortality, improvement of clinical symptoms, laboratory examinations, imaging and length of hospital stay, especially in patients with moderate/severe form of the disease, and with emphasis on early administration (within 3 days of admission) (24252731). A recent double blind, placebo-controlled, phase 3, randomized trial tested hyperimmune intravenous immunoglobulin (hIVIg) to SARS-CoV-2 derived from recovered donors with no demonstrated effect compared with standard of care, but therapy was administered in patients symptomatic up to 12 days (32). Additional clinical trials are underway, hopefully with more guidance for proper selection of patients that might benefit from this type of treatment.

Conclusion

To our knowledge, this is the first case of IVIg treatment in a COVID-19 patient with CS. It is our opinion that immune-modulating properties of IVIg might present an attractive treatment option, especially in those CS patients that show rapid clinical progression and positive laboratory parameters of inflammation. While we await for new therapeutic modalities for COVID-19 and while some of the modalities remain not widely available, IVIg is more accessible, safe method, which could be rescuing in carefully selected patients. Of note, we consider our patient’s vaccinal status as an unquestionable positive contributor to the favorable outcome

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics Statement

Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.

Author Contributions

BP, AS, JV, TG, MJ-L, JV, VS, ZG and TA-V analyzed and interpreted the patient data. BP, AP, DI, and DJ were major contributors in writing the manuscript. All authors contributed to the article and approved the submitted version.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s Note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary Material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fendo.2022.889928/full#supplementary-material

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Keywords: Cushing’s syndrome, COVID-19, IVIg, hypercortisolism, immunomodulation, immunosuppression

Citation: Popovic B, Radovanovic Spurnic A, Velickovic J, Plavsic A, Jecmenica-Lukic M, Glisic T, Ilic D, Jeremic D, Vratonjic J, Samardzic V, Gluvic Z and Adzic-Vukicevic T (2022) Successful Immunomodulatory Treatment of COVID-19 in a Patient With Severe ACTH-Dependent Cushing’s Syndrome: A Case Report and Review of Literature. Front. Endocrinol. 13:889928. doi: 10.3389/fendo.2022.889928

Received: 04 March 2022; Accepted: 17 May 2022;
Published: 22 June 2022.

Edited by:

Giuseppe Reimondo, University of Turin, Italy

Reviewed by:

Nora Maria Elvira Albiger, Veneto Institute of Oncology (IRCCS), Italy
Miguel Debono, Royal Hallamshire Hospital, United Kingdom

Copyright © 2022 Popovic, Radovanovic Spurnic, Velickovic, Plavsic, Jecmenica-Lukic, Glisic, Ilic, Jeremic, Vratonjic, Samardzic, Gluvic and Adzic-Vukicevic. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Bojana Popovic, popbojana@gmail.com

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From https://www.frontiersin.org/articles/10.3389/fendo.2022.889928/full

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