The New Molecular Landscape of Cushing’s Disease

Silviu Sbiera#Timo Deutschbein#Isabel Weigand, Martin Reincke, Martin FassnachtcorrespondenceBruno Allolio
#These authors contributed equally to this work.
A few days after acceptance of this manuscript, Bruno Allolio passed away.

Cushing’s disease (CD) is caused by corticotropin-secreting pituitary adenomas and results in substantial morbidity and mortality. Its molecular basis has remained poorly understood until the past few years, when several proteins and genes [such as testicular orphan nuclear receptor 4 (TR4) and heat shock protein 90 (HSP90)] were found to play key roles in the disease. Most recently, mutations in the gene of ubiquitin-specific peptidase 8 (USP8) increasing its deubiquination activity were discovered in a high percentage of corticotroph adenomas. Here, we will discuss emerging insights in the molecular alterations that finally result in CD. The therapeutic potential of these findings needs to be carefully evaluated in the near future, hopefully resulting in new treatment options for this devastating disorder.

Trends

Transsphenoidal surgery and radiotherapy are the treatment of choice in CD. However, despite high initial remission rates, a significant percentage of patients relapse.

Owing to the poor understanding of the pathophysiology of CD, drug therapy is still limited and often only ameliorates the clinical manifestations through blocking of ACTH release or adrenal cortisol synthesis.

Recent research has identified several important proteins (e.g., EGFR, HSP90, TR4, and AVPR1b) whose deregulation is associated with CD and may therefore represent potential therapeutic targets.

Frequent, novel mutations in the USP8 gene that are associated with corticotroph pituitary adenomas were recently discovered that result in reduced EGFR degradation and increased POMC activation in vitro.

Keywords:

Cushing’s disease, pituitary, gene expression, epidermal growth factor receptor, ubiquitin-specific peptidase 8, 14-3-3 proteins

The entire article is available by subscription only.  More information here.

Does a Normal Urine Free Cortisol Result Rule out Cushing’s Syndrome?

Endocrine Society’s 97th Annual Meeting and Expo, March 5–8, 2015 – San Diego
SAT-384:
Does a Normal Urine Free Cortisol Result Rule out Cushing’s Syndrome?
1 and 2

  • 1Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
  • 2National Institutes of Health, Bethesda, MD
Presentation Number: SAT-384
Date of Presentation: March 7, 2015
Abstract:Background: Urine free cortisol (UFC) has been traditionally used as one of the first steps in the diagnostic evaluation of Cushing’s syndrome (CS) (1). False positive results, especially values less than twice the upper limit of normal (ULN), can be seen in uncontrolled diabetes, obesity, depression, alcoholism, increased fluid intake, overcollection and stress. False negative results have also been reported with incomplete collection, in mild or cyclic CS and in patients with renal insufficiency (2-3). We evaluated the diagnostic accuracy of UFC and 24-hour urine 17-hydroxycorticosteroids (17OHCS) in patients with CS.Methods: Retrospective study of all CS patients evaluated at the National Institutes of Health (NIH) from 2009 to 2014. Screening tests used for CS included UFC, 17OHCS, late night salivary cortisol (LNSC), midnight serum cortisol and low dose (1mg overnight or 2-day 2mg/day) dexamethasone suppression test (DST). Values above reference range for UFC, 17OHCS and LNSC, a midnight serum cortisol ≥ 7.5 mcg/dL, and post-dexamethasone cortisol values ≥ 1.8 mcg/dL were considered abnormal. Hourly 24-hour sampling for cortisol was performed in a few cases with a mild clinical phenotype and equivocal test results. UFC was measured using liquid chromatography/tandem mass spectrometry (LC-MS/MS). 17OHCS was measured using colorimetric methodology with Porter-Silber reaction (reported as mg/g of creatinine). Mean of the first two UFC and 17OHCS values (appropriate collection by urine volume and creatinine) obtained within 30 days of initial NIH presentation were used for the purpose of this study.

Results: Seventy-two patients were diagnosed with CS (aged 18-77 years, 51 females). Of these, 51 had Cushing’s disease (CD), 10 had ectopic CS while 2 had an adrenal source of Cushing’s based on pathology. Biochemical tests including inferior petrosal sinus sampling (IPSS) suggested ectopic CS but no tumor was found (occult) in 6 patients. IPSS was indicative of a pituitary source in 2 patients with failed transsphenoidal surgery while one patient did not complete evaluation for ACTH-dependent CS. UFC results were available in all, 17OHCS in 70, LNSC in 21, midnight serum cortisol in 68 and DST results in 37 patients. UFC was falsely normal in six and only minimally elevated (< 2 x ULN) in 13 patients (normal renal function, no history of cyclicity, all had CD). Of these 19 patients, 24h 17OHCS was abnormal in all, LNSC was abnormal in 12, midnight serum cortisol was abnormal in 18 and DST was abnormal in 12 patients. Hourly 24-hour sampling for cortisol performed in 3 of these patients revealed abnormal nadir (> 7.5 mcg/dL) and mean daily serum cortisol (> 9 mcg/dL) levels.

Conclusion: UFC can be falsely normal or only minimally elevated in mild CS. Multiple collections and use of complimentary screening tests including 24-hour urine 17OHCS and LNSC can help make a diagnosis and prevent delay in treatment.

(1) Newell-Price J, et al. Cushing’s syndrome. Lancet. 2006;367(9522):1605-17.  (2) Alexandraki KI, et al. Is urinary free cortisol of value in the diagnosis of Cushing’s syndrome. Curr Opin Endocrinol Diabetes Obes. 2011;18:259–63.  (3) Kidambi S, et al. Limitations of nocturnal salivary cortisol and urine free cortisol in the diagnosis of mild Cushing’s syndrome. Eur J Endocrinol. 2007;157(6):725-31

Nothing to Disclose: STS, LKN

Sources of Research Support: This research was in part supported by the intramural research program of NICHD/NIH

Read the entire article at http://press.endocrine.org/doi/abs/10.1210/endo-meetings.2015.ahpaa.9.sat-384

Lowest cortisol levels found in women with overweight, mild obesity

Women with overweight and class I obesity appear to have the lowest cortisol levels, while more significant obesity appears to be associated with higher cortisol levels, according to recent findings.

In the cross-sectional study, Karen K. Miller, MD, of Massachusetts General Hospital, and colleagues evaluated 60 premenopausal women aged 18 to 45 years: 28 with overweight or obesity, 18 with anorexia nervosa and 21 healthy controls at normal weight. Overweight was defined as BMI 25 to 29.9 kg/m2, and obesity was classified as class I (30-34.9 kg/m2) and class II (35-39 kg/m2).

Anorexia nervosa was classified based on DSM-IV criteria, which includes extreme fear of weight gain, body image dysmorphia, weight that is 85% of ideal body weight and cessation of menstruation for 3 consecutive months. Participants were asked to collect 24-hour urine samples, in addition to 11 p.m. and 7 a.m. salivary samples within 1 week of an inpatient hospital visit. For each sample, researchers assessed creatinine clearance, and urinary free cortisol/creatinine clearance was calculated for each specimen to account for the decreased creatinine and filtered cortisol linked to anorexia nervosa.

During the inpatient visit, participants underwent placement of an IV catheter and fasting blood was sampled every 20 minutes from 8 p.m. to 8 a.m. Fasting cortisol and cortisol binding globulin concentrations were measured at 8 a.m. Participants were asked to take 5 g of oral dexamethasone every 6 hours for 48 hours to decrease endogenous disparities in cortisol levels.

The researchers found that with the exception of dexamethasone-suppression-CRH testing, all cortisol measures exhibited a U-shaped association with BMI, most notably urinary free cortisol/creatinine clearance (P = .0004) and mean overnight serum cortisol (P < .0001).

The lowest cortisol levels were seen in the overweight-class I obesity range, and these were also associated with visceral fat tissue and total fat mass. Participants with anorexia nervosa had higher mean cortisol levels than participants with overweight or obesity. Attenuated inverse relationships were seen between lean mass and some measures of cortisol, and most measures of cortisol were inversely related to posterior-anterior spine and total hip bone mineral density.

According to the researchers, these findings have not determined the precise nature of the relationship between cortisolemia, hypothalamic-pituitary-adrenal activation and adiposity.

“The [hypothalamic-pituitary-adrenal] axis activation associated with obesity and excess adiposity raises the question of whether hypercortisolemia contributes to increased adiposity in the setting of caloric excess, whether increased adiposity drives [hypothalamic-pituitary adrenal] activation, or whether the relationship between hypercortisolemia and adiposity is bidirectional,” the researchers wrote. – by Jennifer Byrne

Disclosure: The researchers report no relevant financial disclosures.

From http://www.healio.com/endocrinology/obesity/news/online/%7B73cac1c4-af30-4f24-89e3-86f50d05aaa2%7D/lowest-cortisol-levels-found-in-women-with-overweight-mild-obesity

An Open Label Study to Assess the Safety and Efficacy of COR-003 (2S, 4R ketoconazole) in the Treatment of Endogenous Cushing’s Syndrome

RESEARCH STUDY SUMMARY

An Open Label Study to Assess the Safety and Efficacy of COR-003 (2S, 4R ketoconazole) in the Treatment of Endogenous Cushing’s Syndrome

PURPOSE

The primary objectives of this study are to evaluate the efficacy of ascending doses of COR-003 in subjects with elevated levels of cortisol due to endogenous Cushing’s Syndrome by assessment of reduction in Urinary Free Cortisol (UFC) concentrations and to identify the range of safe and effective doses of COR-003 that reduce mean UFC concentrations ≤ULN (upper limit of normal) of the assay at month 6 of the maintenance phase of dosing without a prior dose increase in that phase.

TO LEARN MORE

CW ID: 208654
Date Last Changed: June 25, 2015

Inclusion Criteria:

Subjects eligible for enrollment in the study must meet all the following criteria:

  • Male or female, ≥18 year of age
  • Confirmed diagnosis of persistent or recurrent CS (with or without therapy) or newly diagnosed disease, if they are not candidates for surgery. Subjects in whom surgery will be delayed beyond 5 months will be permitted to participate. CS will be defined according to the criteria in the guidelines for diagnosis of CS (Nieman 2008). Previous medical records will be collected and used to support the diagnosis. The diagnostic criteria for appropriateness of inclusion of each subject into the study will be reviewed by the Medical Monitor. Diagnosis of the disease will be based on the association of clinical features of endogenous CS (see Appendix G in clinical protocol), review of past medication history, excluding exogenous sources of glucocorticoids, and abnormal values from two of the three following tests:
    • Elevated 24-hour UFC levels ≥1.5X ULN of assay based on a minimum of 4 measurements from adequately collected urine. Urine may be collected on sequential days.
    • Abnormal DST: Elevated 8 AM serum cortisol ≥1.8 ug/dL (50 nmol/L) after 1 mg dexamethasone orally at 11 PM the evening prior (if not conducted already in the diagnostic workup of the subject within the previous 6 months; previous test results and details of conduct will need to be available; normal serum cortisol ≤ 1.4 ug/dL)
    • Elevated late night salivary cortisol concentrations (at least 2 measurements) >ULN at screening
    • [NOTE: For subjects with estimated glomerular filtration rate (eGFR as determined by MDRD equation >40 and <60 mL/min) a late night salivary cortisol test (≥2 measurements) MUST be conducted in addition to measuring UFC levels to demonstrate evidence of CS.]
  • Previously irradiated subjects will be allowed as long as the radiation treatment occurred ≥2 years ago and they do have stable UFC levels based on 24-hour urine collections for at least 6 months. The total number of previously irradiated subjects will not exceed 10.
    • In the vast majority of subjects treated with radiation, efficacy is observed in <2 years.
  • Confirmed diagnosis of persistent or recurrent endogenous hypercortisolemia as defined by UFC concentrations on repeated determinations (described in Inclusion #2) caused by either ACTH-dependent or ACTH-independent etiologies.
  • Subjects on treatment for CS for whom treatment has been inadequate or not well tolerated must agree to the following minimum washout periods as determined by the nature of their treatment before baseline assessments are performed for participation in this study:
    • Inhibitors of steroidogenesis: 2weeks; subjects on ketoconazole will be considered inadequately treated if they had failed to normalize UFC with a dose lower than or equal to 600 mg/day (also see Exclusion 7 below).
    • Dopamine agonists: bromocriptine (2 week), cabergoline (8 weeks)
    • Octreotide acetate LAR and lanreotide Autogel®: 12 weeks
    • Lanreotide SR/long-acting pasireotide: 8 weeks
    • Octreotide acetate (immediate release formulation) or short-acting pasireotide: 1 week
    • Mifepristone (RU 486): 4 weeks
  • Subjects on megasterol acetate (medroxyprogesterone acetate) must agree to a wash out of ≥6 weeks prior to receiving the first dose of the study medication.
  • Female subjects should be either post-menopausal, surgically sterile, or women of child-bearing potential (WOCP) with a negative serum beta human chorionic gonadotropin (ßhCG) pregnancy test prior to entering the study and who agree to use an acceptable method of contraception, for the duration of the study. Condoms will be considered an acceptable form of contraceptive.
  • 12-lead ECGs show no acute ischemia or clinically significant abnormality needing medical intervention
  • Ability to comprehend and comply with procedures
  • Agree to commit to participate in the current protocol
  • Subjects provide written informed consent prior to any study procedures being performed (all subjects should be able to understand the informed consent form and any other documents that subjects are required to read)

Exclusion Criteria:

Subjects will be excluded from the study if any of the following criteria are met:

  • De novo Cushing´s disease AND a candidate for pituitary surgery
    • If surgery is to be delayed for >5 months, subjects may be allowed to participate in the trial while awaiting surgery, but must agree to complete this study prior to surgery.
  • Subjects treated with radiation within the previous 2 years.
    • In the vast majority of subjects treated with radiation, efficacy is observed in <2 years.
  • Characteristics of pseudo-CS (see Appendix H in clinical protocol)
  • Subjects with adrenal carcinoma
  • Body Mass Index (BMI) exceeding 50 kg/m2
  • Body habitus preventing repeated venipuncture as required by protocol
  • Subject is currently in another study or has received any investigational treatment (drug, biological agent or device) within 30 days or 5 half lives of screening, whichever is longer
  • History of significant abnormalities in liver function tests on ketoconazole; history of therapeutic response failure to ketoconazole as defined by lack of normalization of UFC at a dose greater than 800 mg/day; lack of therapeutic response failure at maximum dose of mitotane
  • Male and female subjects with QTc interval of >470 msec
  • History of Torsades des Pointes or ventricular tachycardia or ventricular fibrillation
  • Subjects with a non-endogenous source of hypercortisolemia such as exogenous source of glucocorticoids or therapeutic use of ACTH
  • History of malignancy, other than thyroid, early stage prostate, squamous cell and basal cell carcinoma, within 3 years prior to the initial dose of the study medication. Subjects with history of carcinoma must have a life expectancy of >1 year and must be on stable doses of their specific therapies. Subjects with early stage prostate cancer undergoing no treatment due to low grade potential may be enrolled.
  • Diagnosis of HIV
  • History of persistent uncontrolled hypertension (>210/110 mmHg) despite medical intervention
  • Subjects with hypercholesterolemia who are on current atorvastatin or simvistatin and not willing or unable to change to alternative therapies as noted (pravastatin, fluvastatin, and rosuvastatin) with 2 weeks of study screening
  • Subjects with T2DM or with a history of hyperglycemic episodes requiring repeated, frequent hospitalizations
  • Subjects with decreased renal function as defined by eGFR ≤40 mL/min, using Modified Diet in Renal Disease (MDRD) equation for estimating renal function (eGFR).
  • Any other clinically significant medical condition, as determined by the Investigator that precludes enrollment and participation in the study through completion (for example, New York Heart Association (NYHA) class III or IV congestive heart failure).
  • Known hepatic disease, other than mild to moderate hepatic steatosis consistent with fatty infiltration (non-alcoholic steatohepatitis [NASH]), with ongoing sustained biochemical activity (subjects with CS would be at risk for NASH)
  • History of recurrent gall stone attacks or pancreatitis
  • Positive for hepatitis B surface antigen (HbsAg) or positive hepatitis C test
  • Liver function tests (LFT) must not be above the following cut-offs at screening: ALT and/or AST >3.0X ULN, alkaline phosphatase (AP) >1.5X ULN and total bilirubin >ULN. If all LFTs are within normal limits (WNL) and total bilirubin is elevated, examination of direct and indirect bilirubin may be conducted. Subjects with indirect total bilirubin up to 3X ULN are presumed to have Gilbert’s syndrome and may be enrolled if all other LFTs are WNL.
  • Presence of any other clinically significant medical condition, as determined by the Investigator that would preclude the subject from being able to follow instructions or to perform the necessary procedures (for example, psychiatric instability or severe disability)
  • Compression of the optic chiasm
  • Abnormal free T4. Subjects with TSH
  • Excessive alcohol intake (>20 g per day for females (1.5 standard alcohol drinks) or >30 g per day for males (2.0 standard alcohol drinks) (a standard drink contains 14 g of alcohol: 12 oz of beer, 5 oz of wine or 1.5 oz of spirits) or drug abuse. (1.0 fluid oz (US) = 29.57 ml)
  • The subject is currently taking any H2 receptor antagonists or proton-pump inhibitors (which inhibit absorption of COR-003). Only over-the- counter liquid and tablet antacids are allowed which should be used in moderation and taken a minimum of 2 hours after dosing of COR-003.
  • The subject is receiving the following concomitant therapies:
    • Weight loss medications (prescription or over the counter)
    • Coadministration of COR-003 and drugs primarily metabolized by the cytochrome P450 3A4 enzyme system may result in increased plasma concentrations of the drugs that could increase or prolong both therapeutic and/or adverse effects. Therefore, appropriate dosage adjustments may be necessary.
    • Medications with metabolism largely mediated by CYP3A4 and a narrow therapeutic margin include: cyclosporine, midazolam, triazolam, alprazolam, digoxin, coumarin-derivatives, phenytoin, rifampin, erythromycin, clarithromycin, loratadine, astemizole, terfenadine, nicotinic acids, resins, orlistat, sibutramine, HIV protease inhibitors, thiazolidinodiones, aliskiren, and spironolactone.
    • A complete list of medications metabolized by or with an effect on cytochrome P450 3A4 is provided in Appendix K. Also see Section 10.2.
    • Coadministration of strong inducers or inhibitors of CYP3A4 enzyme system that may interfere with COR-003 and cannot be discontinued prior to the start of the study (see Appendix K for the list)
    • Statins other than pravastatin, fluvastatin and rosuvastatin
    • Following herbal medicines should be avoided: St John’s Wort, yohimbe and red rice yeast
    • Potent topical steroids, containing urea or salicylic acid, which are applied over 20% of the body
    • Inhaled steroid medications that exceed minimal to moderate use
    • Carbamazipine, fenofibrate, carbenoxolone
    • Excessive ingestion of genuine licorice
  • Pregnant or lactating women
  • Any other condition which would increase the risk of participation in the trial in the opinion of the Investigator

Contact

Adrine Gdakian
UCLA School of Medicine
700 Tiverton Avenue, Factor Building Rm 9-240
Los Angeles, CA 90095
Phone: 310-825-5874
Fax: 310-206-5553

Jessica Rios-Santiago
Coastal Metabolic Research Center University Medical Center, Dept. of Endocrinology
3454 Loma Vista Rd.
Ventura, CA 93003
Phone: 805-658-8460
Fax: 805-658-8462

Betsy Parrott, RN, CCRC
Rhode Island Hospital, Hallett Center for Diabetes and Endocrinology
900 Warren Avenue, Suite 300
East Providence, RI 02914
Phone: 401-444-2091
Fax: 401-444-4921

Becky Wood, CCRP
Swedish Neuroscience Research
500 17th Ave
Professional Bldg 303
Seattle, WA 98122
Phone: 206-320-7115

Moderately impaired renal function increases morning cortisol and cortisol levels at dexamethasone suppression test in patients with incidentally detected adrenal adenomas

Clin Endocrinol (Oxf). 2015 May 23. doi: 10.1111/cen.12823. [Epub ahead of print]

Abstract

OBJECTIVE:

Patients with incidentally detected adrenal adenomas may have subclinical hypercortisolism. We hypothesized that impaired renal function could lead to increased cortisol levels in these patients.

DESIGN:

Descriptive retrospective study of consecutive patients.

PATIENTS:

A total of 166 patients with incidentally detected unilateral adrenal adenomas were examined during 2008-2013.

MEASUREMENTS:

Levels of cortisol, ACTH and cortisol at 1 mg overnight dexamethasone suppression test (DST) were measured. The estimated glomerular filtration rate (eGFR) was calculated using the MDRD equation.

RESULTS:

Renal function was normal, mildly impaired, moderately impaired or severely impaired (eGFR >90, 60-90, 30-60 and 15-30 ml/min/1·73 m2 ) in 34, 54, 10 and 1% of the patients, respectively. Patients with normal and mildly impaired renal function had similar cortisol levels. Patients with moderately impaired renal function, compared to all the patients with eGFR >60 ml/min/1·73 m2 , exhibited increased cortisol (541 vs 456 nmol/l, P = 0·02), increased cortisol at DST (62 vs 37 nmol/l, P = 0·001), but similar ACTH levels (4·1 vs 2·9 pmol/l, P = 0·21). Patients with moderately impaired renal function thus exhibited cortisol at DST ≥50 nmol/l, more often than patients with eGFR >60 ml/min/1·73 m2 (76% vs 30%, P = 0·000), while the prevalence of ACTH below 2 pmol/l was similar (24% vs 31%, P = 0·51).

CONCLUSIONS:

Moderately impaired renal function increases cortisol and cortisol at DST in patients with adrenal adenomas, while mildly impaired renal function has no such effect. Cortisol level at DST ≥50 nmol/l therefore seems to have low specificity in diagnosing subclinical adrenal hypercortisolism, and an additional criterion, for example low ACTH, is required.

© 2015 John Wiley & Sons Ltd.

PMID:
26010731
[PubMed – as supplied by publisher]

From http://www.ncbi.nlm.nih.gov/pubmed/26010731