Prolonged and Severe Gestational Thyrotoxicosis Due to Enhanced hCG Sensitivity of a Mutant Thyrotropin Receptor.

CONTEXT: Gestational thyrotoxicosis, whether associated with hyperemesis gravidarum or not, is thought to be due to excessive human chorionic gonadotropin (hCG) secretion. CASE DESCRIPTION: We report here the second case of gestational thyrotoxicosis associated with hyperemesis gravidarum due to a mutation of the TSH receptor, providing thyroid hypersensitivity to hCG. CONCLUSION: Severe and lasting gestational thyrotoxicosis with normal hCG concentration should lead to sequencing of the TSH receptor gene.

Postoperative follow-up of Cushing's disease using cortisol, desmopressin and coupled dexamethasone-desmopressin tests: a head-to-head comparison.

OBJECTIVE: Predicting the outcome of patients operated on for Cushing's disease (CD) is a challenging task. Our objective was to assess the accuracy of immediate postsurgical plasma cortisol, desmopressin test and the coupled dexamethasone-desmopressin test (CDDT) as predictors of outcome. DESIGN AND PATIENTS: Sixty-seven patients with initial remission and a minimal postsurgical follow-up greater than 18 months were included in this retrospective bicentre study. MEASUREMENTS: Follow-up included 3-6 months followed by yearly 24-h urinary-free cortisol, ACTH and cortisol plasmatic levels, a 1-mg overnight dexamethasone suppression test (1-mg DST), desmopressin test and the CDDT. ROC curves were performed to define the optimal threshold of immediate postsurgical cortisol level and 3- to 6-month desmopressin test and CDDT, as predictors of final outcome in comparison with classical biological markers of recurrence. RESULTS: Eleven patients presented recurrence. The patient's median follow-up was 52 months (range, 18-180). As early predictors of outcome, immediate postsurgical plasma cortisol level <35 nmol/l predicted the lack of recurrence with 93% negative predictive value (NPV), whereas predictive positive value (PPV) was 25%. During the follow-up, the CDDT was more precise than the desmopressin test in predicting the lack of recurrence (100% NPV) when performed in the first 3 years after surgery. Positivity of the CDDT was defined based on ROC curves by ACTH and cortisol increments >50%. The CDDT was highly reproducible, as the same response was observed every year in 91% of the patients. CONCLUSIONS: Adding the CDDT the first 3 years after surgery to immediate postsurgical cortisol evaluation should allow obtaining an optimal follow-up management of patients operated for Cushing's disease.