Desmopressin is Promising Alternative in Diagnosing Cushing’s Disease

Posted on November 15, 2017 by MaryO

Bilateral inferior petrosal sinus sampling (IPSS) — a procedure that uses desmopressin to determine levels of ACTH hormone from veins that drain from the pituitary gland, is a sensitive way to diagnose patients with Cushing’s disease and find tumors, a Chinese study shows.

The study, “Tumour Lateralization in Cushing’s disease by Inferior Petrosal Sinus Sampling with desmopressin,” appeared in the journal Clinical Endocrinology.

Cushing’s disease is characterized by excessive production of the adrenocorticotropin hormone (ACTH) caused by a tumor in the pituitary gland. ACTH is the hormone that causes the adrenal glands to produce cortisol.

Currently, pituitary imaging is insufficient to confirm a Cushing’s diagnosis. This is because 70 percent of pituitary adenomas in Cushing’s are microadenomas, which are physically very small. As a result, 40 percent of Cushing’s patients are reported as being healthy.

This means that a Cushing’s diagnosis requires a combination of techniques including clinical symptoms, imaging methods and endocrinological assays that include measures of serum cortisol and ACTH levels.

IPSS determines ACTH levels from veins that drain from the pituitary gland. ACTH levels are then compared to ACTH levels in blood. Higher levels in the pituitary gland indicate a pituitary tumor.

IPSS can also be used to determine tumor lateralization, which refers to which side of the pituitary gland the tumor is located on. The test is 69 percent accurate.

Doctors administer IPSS along with corticotropin-releasing hormone (CRH) stimulation. IPSS with CRH is considered the gold standard for preoperative diagnosis of Cushing’s, with a diagnostic sensitivity (or true positive rate) of 95 percent and specificity (or true negative rate) of 90 to 95 percent. Unfortunately, the high cost and limited availability of CRH make it impractical for many patients.

Desmopressin has been used to replace CRH to stimulate ACTH secretion for IPSS, and prior studies have shown that desmopressin’s sensitivity is comparable to that of CRH.

Researchers at Peking Union Medical College in Beijing conducted a retrospective analysis of their experience using desmopressin-stimulated IPSS to determine its diagnostic value for Cushing’s and its predictive value for tumor lateralization.

Researchers analyzed 91 Cushing’s patients who either had negative findings on the MRI imaging of the pituitary or negative high-dose dexamethasone suppression tests, which is another method of evaluation. All patients underwent IPSS with desmopressin, followed by pituitary surgery to extract the tumor.

Of the 91 patients tested, 90 patients had confirmed Cushing’s. And of these, 89 had positive IPSS findings, which led to a sensitivity of 98.9 percent for this test. One patient out of 91 who did not have Cushing’s also underwent this test, which led to a negative IPSS result and a specificity of 100 percent.

Researchers also determined tumor lateralization in patients who were ultimately diagnosed with Cushing’s and underwent surgery. Results of the IPSS showed a 72.5 percent concordance between the results from the IPSS and the surgery.

Therefore, IPSS with desmopressin is a comparable approach to IPSS with CRH for the diagnosis of Cushing’s. It also demonstrates moderate accuracy in determining the location of tumors.

“Like many medical centers in China, we currently have no supply of CRH, while desmopressin is readily available,” researchers concluded. “Moreover, desmopressin is cheaper than CRH. As our data and other studies indicate, IPSS with desmopressin yielded comparable outcomes to IPSS with CRH. Therefore, desmopressin-stimulated IPSS might serve as a possible alternative to CRH-stimulated IPSS.”

From https://cushingsdiseasenews.com/2017/11/14/ipss-desmopressin-alternative-method-diagnosis-cushings-disease/

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Study Highlights Importance of Clinical Follow-Up in Cushing’s Patients After Adenoma Removal

Posted on October 27, 2017 by MaryO

A rare case of Cushing’s syndrome (CS) in a 17-year-old patient with multiple pituitary adenomas highlights the importance of clinical follow-up in order to determine the best treatment options for patients.

The study, “A rare case of multiple pituitary adenomas in an adolescent Cushing disease presenting as a vertebral compression fracture,” was published in the journal Annals of Pediatric Endocrinology and Metabolism. 

CS is a very rare disease with an incidence of 0.7-2.4 cases per million, per year. It is caused by exposure to very high levels of the hormone cortisol. In children, the most common symptom is weight gain without height gain. In some rare cases, tumors known as multiple pituitary adenomas (MPAs) appear, and patients have elevated levels of adrenocorticotropic hormone (ACTH). Surgical removal through transsphenoidal surgery (TSS) is considered the best treatment, and the first TSS has a success rate of more than 90%.

However, since 15% of patients have a recurrence, ongoing monitoring and follow-up after TSS are important. The importance of this follow-up care is highlighted in a recent case report.

The study described the case of a 17-year-old male adolescent who was 149.5 cm tall (4’9″) and weighed 63.6 kg (140 lbs). The patient was referred to a hospital for the evaluation of a vertebral compression fracture and obesity. Over four years, the patient gained 23 kg (51 lbs) without an increase in height. Despite showing many of the features of CS, this patient had not been previously diagnosed with CS.

He had high levels of ACTH and cortisol, and an MRI suggested the presence of an 8-mm (0.8 cm) micro-adenoma. After TSS, the patient’s morning ACTH and cortisol levels were reduced, and a persistent headache had improved. But there was no reduction in weight.

Three months after the TSS, the patient’s body mass index did not show improvement, and both cortisol and ACTH levels were elevated again. MRI revealed a new 9 mm (0.9 cm) micro-adenoma, which was removed with a second TSS. However, cortisol and ACHT remained elevated after the second surgery, with no evidence of a pituitary tumor in MRI scans.

Researchers recommended additional options, such as total removal of the pituitary gland, radiotherapy, or removal of both adrenal glands, options that the patient and his family declined. He continued to receive treatment for osteoporosis, hypertension, and increased lipid levels.

“In conclusion, we reported the clinical course of Cushing disease with 2 distinct pituitary adenomas. Since there is no consensus as to the best treatment for relapsing or persistent Cushing disease and since only a few cases of MPA among pediatric Cushing disease have been reported, a close followup of tumor status, severity of hypercortisolism, and patients’ perspectives are the major parameters used to determine the best treatment option for each patient. In addition, early recognition and diagnosis of pediatric Cushing disease would lead to earlier recovery, improved growth, and better quality of life,” the researchers wrote.

From https://cushingsdiseasenews.com/2017/10/27/cushings-disease-rare-case-report-highlights-importance-early-diagnosis-follow-up-care/

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New ACTH Detection Method Improves Cure Rates in Cushing’s Disease Patients

Posted on October 20, 2017 by MaryO

Researchers have identified a new, quick method for detecting ACTH-producing tumors – called Elecsys – that can improve the cure rates of Cushing’s disease patients undergoing surgery.

The study, “Long-term outcomes of tissue-based ACTH-antibody assay–guided transsphenoidal resection of pituitary adenomas in Cushing disease,” was published in the Journal of Neurosurgery.

Transsphenoidal resection (TSR) – a surgical procedure performed through the nose and sphenoid sinus to remove a pituitary tumor – has been the method of choice for treatment for Cushing’s disease.

However, it often fails to localize the tumor with precision, leading to an incomplete resection (removal). This is likely a result of the preoperative methods used to guide surgeons before surgery, which include both magnetic resonance imaging (MRI) and a minimally invasive procedure called bilateral inferior petrosal sinus sampling (BIPSS) that measures ACTH in the veins that drain the pituitary gland.

However, both “suffer from suboptimal sensitivity and thus allow for incomplete resections, specially if pathological frozen sections fail to identify tumor,” researchers wrote.

MRI, for example, detects only 50 percent of Cushing’s adenomas, limiting surgeons’ ability to conduct curative TSR surgeries. Therefore, better diagnostic and tumor localization techniques are needed to increase the likelihood that initial surgeries can remove the entire tumor and cure patients.

A team of researchers at Yale School of Medicine evaluated a new method for guiding tumor localization during TSR. The method – a double-antibody sandwich assay for ACTH – is performed in the operating room in resected pituitary samples from patients. ACTH (adrenocorticotropic hormone) is a hormone produced in the pituitary gland in the brain, that simulated cortisol production in the adrenal glands. In patients with Cushing disease the pituitary gland releases too much ACTH.

In the new method – called Elecsys – samples are squeezed between sandwich-like system composed of two antibodies that recognize two sections of the ACTH protein. The three-step procedure is quick, allowing doctors to analyze samples in the operating room and determine if they have removed the entire tumors.

The performance and outcomes associated with the Elecsys were assessed by reviewing data of tissue samples from 14 patients with ACTH-secreting adenomas, who underwent TSR surgeries between 2009 and 2014.

“The intraoperative TSR protocol was modified with the introduction of the ACTH assay such that if either the assay or the frozen-section pathology returned results positive for tumor, that area of the gland was resected,” the researchers explained.

The new ACTH method detected tumor tissue and was capable of distinguishing it from normal tissue with a 95% sensitivity and 71.3% specificity. These values are comparable to those using the standard method for tumor localization, which requires frozen sections of the tumor. This suggests that the test can be used either in conjunction with or in place of frozen sections.

Also, 85.7% of the patients achieved long-term disease remission, with the remission rate exceeding the rate with previous methods (71.9%).

Overall, “these preliminary findings reflect the promising potential of tissue-based ACTH-antibody-guided assay for improving the cure rates of Cushing’s disease patients undergoing TSR. Further studies with larger sample sizes, further refinements of assay interpretation, and longer-term follow-ups are needed,” the study concluded.

From https://cushingsdiseasenews.com/2017/10/19/acth-detection-method-improved-cure-rates-cushings-disease-study-shows/

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Increase in Glucose Uptake by Cushing’s Disease-associated Tumors Could Improve Early Detection

Posted on October 13, 2017 by MaryO

An increase in glucose uptake by Cushing’s disease-associated pituitary tumors could improve their detection, new research shows.

The study, “Corticotropin releasing hormone can selectively stimulate glucose uptake in corticotropinoma via glucose transporter 1,” appeared in the journal Molecular and Cellular Endocrinology.

The study’s senior author was Dr. Prashant Chittiboina, MD, from the Department of Neurosurgery, Wexner Medical Center, The Ohio State University, in Columbus, Ohio.

Microadenomas – tumors in the pituitary gland measuring less than 10 mm in diameter – that release corticotropin, or corticotropinomas, can lead to Cushing’s disease. The presurgical detection of these microadenomas could improve surgical outcomes in patients with Cushing’s.

But current tumor visualization methodologies – magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) – failed to detect a significant percentage of pituitary microadenomas.

Stimulation with corticotropin-releasing hormone (CRH), which increases glucose uptake, has been suggested as a method of increasing the detection of adenomas with 18F-FDG PET, by augmenting the uptake of 18F-FDG – a glucose analog.

However, previous studies aiming to validate this idea have failed, leading the research team to hypothesize that it may be due to a delayed elevation in glucose uptake in corticotropinomas.

The scientists used clinical data to determine the effectiveness of CRH in improving the detection of corticotropinomas with 18F-FDG PET in Cushing’s disease.

They found that CRH increased glucose uptake in human and mouse tumor cells, but not in healthy mouse or human pituitary cells that produce the adrenocorticotropic hormone (ACTH). Exposure to CRH increased glucose uptake in mouse tumor cells, with a maximal effect at four hours after stimulation.

Similarly, the glucose transporter GLUT1, which is located at the cell membrane, was increased two hours after stimulation, as was GLUT1-mediated glucose transport.

These findings indicate a potential mechanism linking CRH exposure to augmented glucose uptake through GLUT1. Expectedly, the inhibition of glucose transport with fasentin suppressed glucose uptake.

The researchers consistently observed exaggerated evidence of GLUT1 in human corticotropinomas. In addition, human corticotroph tumor cells showed an increased breakdown of glucose, which indicates that, unlike healthy cells, pituitary adenomas use glucose as their primary source of energy.

Overall, the study shows that corticotropin-releasing hormone (CRH) leads to a specific and delayed increase in glucose uptake in tumor corticotrophs.

“Taken together, these novel findings support the potential use of delayed 18F-FDG PET imaging following CRH stimulation to improve microadenoma detection in [Cushing’s disease],” researchers wrote. The scientists are now conducting a clinical trial to further explore this promising finding.

From https://cushingsdiseasenews.com/2017/10/12/glucose-uptake-in-cushings-disease-could-improve-presurgical-tumor-detection/

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Crinetics Pharmaceuticals Awarded Two SBIR Grants to Develop New Therapeutics for Congenital Hyperinsulinism and Cushing’s Disease

Posted on September 7, 2017 by MaryO

SAN DIEGO, Sept. 06, 2017 (GLOBE NEWSWIRE) — Crinetics Pharmaceuticals, Inc., a rare disease therapeutics company focused on endocrine disorders and endocrine-related cancers, announced today that it was awarded two new grants from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH) that could total $2.4 million. Both are Small Business Innovation Research (SBIR) grants and include a Fast Track grant for up to $2.1 million and a Phase I grant of $0.3 million, which will be used for the development of Crinetics’ nonpeptide, oral somatostatin agonists for congenital hyperinsulinemia, and the discovery of novel small molecule drugs for Cushing’s disease, respectively.

“We are delighted with the NIH’s continuing support of our programs to develop new drugs for patients with rare endocrine disorders,” said Stephen Betz, Ph. D., Founder and Vice President of Biology of Crinetics. “These awards will enable us to advance our efforts in both hyperinsulinemia and Cushing’s disease, expanding our pipeline to include these diseases with significant unmet medical needs, and bring these treatments to the patients who need them.”

Presently, there are no medical therapies that were specifically developed to treat the life-threatening chronic hypoglycemia precipitated by congenital hyperinsulinism (CHI). The current options for patients are limited to drugs developed for other purposes in the hope that they might help. Despite their poor profiles, these drugs are prescribed because the next line of treatment is typically a partial or full pancreatectomy. Even when successful, patients who undergo the surgery often become diabetic and must actively manage glucose with multiple daily insulin injections for the rest of their lives.

Similarly, first line treatments for Cushing’s disease are surgical and involve removal of either the ACTH-secreting tumor in the pituitary or the adrenal glands themselves. As this is often unsuccessful, contraindicated or delayed, medical therapy for these patients becomes necessary. Current treatment options include inhibitors of steroid synthesis enzymes that can prevent the production of cortisol and improve symptoms, but these treatments also induce a host of unwanted side effects due to the accumulation of other steroid products.

About Congenital Hyperinsulinism (CHI)

Hyperinsulinemic hypoglycemia (HH) is one of the most frequent causes of persistent hypoglycemia in infants and can result in seizures, developmental delays, learning disabilities, and even death. The most severe form of HH is inherited and referred to as CHI. CHI largely results from mutations in key genes in the insulin secretion pathway in the islets of Langerhans in the pancreas.

About Cushing’s Disease

Clinical signs of Cushing’s syndrome include growth of fat pads (collarbone, back of neck, face and trunk), excessive sweating, dilation of capillaries, thinning of the skin, muscle weakness, hirsutism, depression/anxiety, hypertension, osteoporosis, insulin resistance, hyperglycemia, heart disease, and a range of other metabolic disturbances resulting in high morbidity. If inadequately controlled in its severe forms, Cushing’s syndrome is associated with high mortality. The most common form of Cushing’s syndrome is Cushing’s disease which is caused by microadenomas of pituitary corticotropic cells that secrete excess adrenocorticotropic hormone (ACTH).

About the NIDDK

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts and supports research on diabetes and other endocrine and metabolic diseases; digestive diseases, nutrition, and obesity; and kidney, urologic, and hematologic diseases. Spanning the full spectrum of medicine and afflicting people of all ages and ethnic groups, these diseases encompass some of the most common, severe, and disabling conditions affecting Americans. For more information about the NIDDK and its programs, visit www.niddk.nih.gov.

About Crinetics Pharmaceuticals

Crinetics Pharmaceuticals discovers and develops novel therapeutics targeting peptide hormone receptors for the treatment of rare endocrine disorders and endocrine-related cancers. Crinetics was founded by a team of scientists with a proven track record of endocrine drug discovery and development to create important new therapeutic options for endocrinologists and their patients. The company is backed by top life sciences investors, 5AM Ventures, Versant Ventures, and Vivo Capital and is headquartered in San Diego. For more information, please visit www.crinetics.com.

More: http://www.pharmiweb.com/pressreleases/pressrel.asp?ROW_ID=241628#.WbFJGNN97-Y

Filed under: adrenal, Cushing's, pituitary, Rare Diseases, Treatments | Tagged: , , , , , , , , , , , | Leave a comment »

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