title: The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome.
abstract: 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.
  
  
  METHODS
  A retrospective case-record study.
  
  
  METHODS
  Fifty-six patients with confirmed ACTH-dependent Cushing's syndrome underwent BIPSS with desmopressin stimulation when presenting negative pituitary tumour imaging.
  
  
  METHODS
  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 >or= 2) and in 47 patients after desmopressin stimulation (CEN:PER >or= 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 >or= 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.
authors.affiliation: Division of Endocrinology and Metabolism, University of Sao Paulo School of Medicine, Sao Paulo, SP, Brazil.
authors.forename: Marcio Carlos
authors.initials: MC
authors.lastname: Machado
authors.forename: Sandra Valeria
authors.initials: SV
authors.lastname: de Sa
authors.forename: Sorahia
authors.initials: S
authors.lastname: Domenice
authors.forename: Maria Candida B Villares
authors.initials: MC
authors.lastname: Fragoso
authors.forename: Paulo
authors.initials: P
authors.lastname: Puglia
authors.forename: Maria Adelaide Albergaria
authors.initials: MA
authors.lastname: Pereira
authors.forename: Berenice Bilharinho
authors.initials: BB
authors.lastname: de Mendonça
authors.forename: Luiz Roberto
authors.initials: LR
authors.lastname: Salgado
mesh_terms: D000182:ACTH Syndrome, Ectopic / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D000236:Adenoma / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D003480:Cushing Syndrome / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D003894:Deamino Arginine Vasopressin; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D017591:Petrosal Sinus Sampling / Q000379:methods*; D010911:Pituitary Neoplasms / Q000097:blood / Q000175:diagnosis / Q000601:surgery; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical
chemical_list: D000324:Adrenocorticotropic Hormone; D003894:Deamino Arginine Vasopressin; D006854:Hydrocortisone