OBJECTIVE: The Endocrine Society Clinical Guidelines recommend measuring 24-h urinary free cortisol (UFF) levels using a highly accurate method as one of the first-line screening tests for the diagnosis of Cushing's Syndrome (CS). We evaluated the performance of UFF, urinary free cortisone (UFE), and the UFF:UFE ratio, measured using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. SUBJECTS AND METHODS: The LC-MS/MS was used to analyze UFF and UFE levels in 43 surgically confirmed CS patients: 26 with Cushing's disease (CD, 16 de novo and ten recurrences), 11 with adrenal CS and six with ectopic CS; 22 CD patients in remission; 14 eu-cortisolemic CD patients receiving medical therapy; 60 non-CS patients; and 70 healthy controls. Sensitivity and specificity were determined in the combined groups of non-CS patients, healthy controls, and CD in remission. RESULTS: UFF>170 nmol/24 h showed 98.7% specificity and 100% sensitivity for de novo CS, while sensitivity was 80% for recurrent CD patients, who were characterized by lower UFF levels. The UFF:UFE and UFF+UFE showed lower sensitivity and specificity than UFF. Ectopic CS patients had the highest UFF and UFF:UFE levels, which were normal in the CD remission patients and in those receiving medical therapy. CONCLUSIONS: Our data suggest high diagnostic performance of UFF excretion measured using LC-MS/MS, in detecting de novo CS. UFF:UFE and UFF+UFE assessments are not useful in the first step of CS diagnosis, although high levels were found to be indicative of ectopic CS.
The diagnostic performance of urinary free cortisol is better than the cortisol:cortisone ratio in detecting de novo Cushing's syndrome: the use of a LC-MS/MS method in routine clinical practice
CECCATO, FILIPPO;ANTONELLI, GIORGIA;Barbot M.;BOSCARO, MARCO;PLEBANI, MARIO;SCARONI, CARLA
2014
Abstract
OBJECTIVE: The Endocrine Society Clinical Guidelines recommend measuring 24-h urinary free cortisol (UFF) levels using a highly accurate method as one of the first-line screening tests for the diagnosis of Cushing's Syndrome (CS). We evaluated the performance of UFF, urinary free cortisone (UFE), and the UFF:UFE ratio, measured using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. SUBJECTS AND METHODS: The LC-MS/MS was used to analyze UFF and UFE levels in 43 surgically confirmed CS patients: 26 with Cushing's disease (CD, 16 de novo and ten recurrences), 11 with adrenal CS and six with ectopic CS; 22 CD patients in remission; 14 eu-cortisolemic CD patients receiving medical therapy; 60 non-CS patients; and 70 healthy controls. Sensitivity and specificity were determined in the combined groups of non-CS patients, healthy controls, and CD in remission. RESULTS: UFF>170 nmol/24 h showed 98.7% specificity and 100% sensitivity for de novo CS, while sensitivity was 80% for recurrent CD patients, who were characterized by lower UFF levels. The UFF:UFE and UFF+UFE showed lower sensitivity and specificity than UFF. Ectopic CS patients had the highest UFF and UFF:UFE levels, which were normal in the CD remission patients and in those receiving medical therapy. CONCLUSIONS: Our data suggest high diagnostic performance of UFF excretion measured using LC-MS/MS, in detecting de novo CS. UFF:UFE and UFF+UFE assessments are not useful in the first step of CS diagnosis, although high levels were found to be indicative of ectopic CS.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
