Desmopressin found to aid diagnosis of Cushing’s disease in 4 children
Using lab-made hormone in BIPSS test could be cost-effective, small study says
A test that uses the hormone-release stimulant desmopressin to trace the source of excess adrenocorticotropic hormone (ACTH) helped correctly diagnose Cushing’s disease in four children, but was less reliable in precisely locating the disease-causing tumor, according to a report from Iran.
Desmopressin could be a “cost-effective alternative” to corticotropin-releasing hormone (CRH), the standard stimulant used in a type of diagnostic test, bilateral inferior petrosal sinus sampling (BIPSS), the researchers wrote. However, “further research is needed to optimize diagnostic strategies for pediatric [Cushing’s syndrome] management.”
The report, “A case series of bilateral inferior petrosal sinus sampling using desmopressin for evaluation of ACTH-dependent cushing’s syndrome in pediatric patients: insights from Iran,” was published in the Journal of Diabetes & Metabolic Disorders.
Endogenous Cushing’s syndrome in children is uncommon but, as in adults, it occurs when the body produces too much cortisol. It can be caused by tumors forming in different parts of the body, most commonly in the brain’s pituitary gland — in which case, it is called Cushing’s disease.
These pituitary tumors release ACTH, which signals the adrenal glands to produce cortisol. In addition to most of the symptoms seen in adults, Cushing’s in children can cause stunted growth. However, diagnosing Cushing’s in children remains challenging.
The gold standard for detecting an ACTH-producing pituitary tumor is a test called BIPSS, which measures ACTH in the blood draining from the pituitary gland. To make it more effective, doctors usually use CRH to stimulate the release of ACTH, but it isn’t widely available in many countries.Â
Desmopressin, a lab-made version of a naturally occurring hormone called vasopressin, may work just as well as CRH, at least in adults.
The study and its findings
This study looked at how well desmopressin worked during BIPSS in four children suspected of having Cushing’s disease in Iran. It aimed to see if the disease could be diagnosed and show exactly where the tumor was located in the brain.
Among the four children — three of them girls — the median age was 14.5 years, with symptoms lasting a median of 12 months. All had elevated ACTH and cortisol levels, but findings from pituitary MRI scans were inconclusive.
BIPSS showed clear signs of a pituitary source for ACTH in every case, both before and after desmopressin was given. No side effects occurred during or after the test, which correctly diagnosed all four children. Sensitivity was of 100%, meaning the test correctly identified everyone who had the disease.
However, when it came to finding the exact side of the pituitary gland the tumor was located on, BIPSS was only right in two of the four cases. Tumor location was confirmed later during transsphenoidal adenomectomy, a surgery to remove the pituitary tumor. All four children underwent this surgery and remained in remission — defined based on low cortisol — throughout follow-up.
“Despite its high sensitivity, BIPSS exhibited limitations in accurately localizing pituitary adenomas,” the researchers wrote. “Clinicians should thus employ caution when interpreting BIPSS results and consider additional imaging and clinical judgment.”
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