The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome

• Published in: Clinical endocrinology (Oxford) 2007-01, Vol.66 (1), p.136-142
• Main Authors: Machado, Marcio Carlos, De Sa, Sandra Valeria, Domenice, Sorahia, Fragoso, Maria Candida B. Villares, Puglia Jr, Paulo, Pereira, Maria Adelaide Albergaria, De Mendonça, Berenice Bilharinho, Salgado, Luiz Roberto
• Format: Article
• Language: English
• Subjects: ACTH Syndrome, Ectopic - blood; ACTH Syndrome, Ectopic - diagnosis; ACTH Syndrome, Ectopic - surgery; Adenoma - blood; Adenoma - diagnosis; Adenoma - surgery; Adolescent; Adrenals. Adrenal axis. Renin-angiotensin system (diseases); Adrenocorticotropic Hormone - blood; Adult; Biological and medical sciences; Cushing Syndrome - blood; Cushing Syndrome - diagnosis; Cushing Syndrome - surgery; Deamino Arginine Vasopressin; Diagnosis, Differential; Endocrinopathies; Female; Fundamental and applied biological sciences. Psychology; Humans; Hydrocortisone - blood; Male; Medical sciences; Middle Aged; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Petrosal Sinus Sampling - methods; Pituitary Neoplasms - blood; Pituitary Neoplasms - diagnosis; Pituitary Neoplasms - surgery; Retrospective Studies; Statistics, Nonparametric; Stimulation, Chemical; Vertebrates: endocrinology
• ISSN: 0300-0664; 1365-2265
• DOI: 10.1111/j.1365-2265.2006.02700.x

Summary Objective   Bilateral inferior petrosal sinus sampling (BIPSS) with corticotrophin‐releasing hormone (CRH) stimulation is currently the gold standard test for the differential diagnosis of ACTH‐dependent Cushing's syndrome. Reports on the use of desmopressin in this approach are limited. The aim of this study was to evaluate the use of desmopressin during BIPSS in a cohort of patients with ACTH‐dependent Cushing's syndrome. Design   A retrospective case‐record study. Patients   Fifty‐six patients with confirmed ACTH‐dependent Cushing's syndrome underwent BIPSS with desmopressin stimulation when presenting negative pituitary tumour imaging. Measurements   Central to peripheral (CEN:PER) ACTH gradient, lateralization of the ACTH source and surgical tumour confirmation were evaluated. Results   A CEN:PER ACTH gradient was found in 40 patients under basal conditions (CEN:PER ≥ 2) and in 47 patients after desmopressin stimulation (CEN:PER ≥ 3). Ectopic ACTH‐producing tumours (three lung carcinoid tumour, one thymus carcinoid tumour and one thymus hyperplasia) were confirmed in five out of nine patients without the CEN:PER ACTH gradient, and four cases were false negative for Cushing's disease. Lateralization (IPS:IPS ≥ 1·4) was observed in 80·8% of patients under basal conditions (38/47) and in 97·8% after desmopressin (46/47), and it was surgically confirmed in 78·7%. There were no false‐positive cases. Sensitivity and specificity were 92·1% and 100%, respectively. Conclusions   Desmopressin improves the differential diagnosis of ACTH‐dependent Cushing's syndrome by amplifying the CEN:PER and IPS:IPS ACTH gradients, and is therefore a useful ACTH secretagogue in BIPSS.