ESPE Abstracts

Introduction and objective: Gonadectomy was carried out for a long time after the diagnosis of complete androgen insensitivity syndrome (CAIS). It is now recommended to leave the gonads in situ in order to guarantee endogenous hormone production. It is unclear how best to clinically monitor testicular function. The aim of the study was to investigate whether inhibin B can be used as a future follow-up parameter to screen for gonadal function in CAIS patients.

Material and Methods: A total of 57 adolescent and adult CAIS patients who presented to two DSD centers (Lübeck and Pisa) were included. Hormonal parameters were retrospectively evaluated. Ideally, we included different time points: during puberty (12-16 years), in early adulthood (17-21 years) and later adulthood (22-50 years). We evaluated the testosterone/LH ratio as a measure of Leydig cell function and the inhibin B/FSH quotient which is normally used as a marker for Sertoli cell function.

Results: Testosterone levels were elevated and within the typical male reference range (6.20 ng/ml +/- 3.08). FSH values increased with age. Inhibin B levels were high and even above the typical male reference range (383.8 pg/ml+/- 206.5 SD). Throughout adulthood, inhibin B levels decreased by 52.53% (P=0.0030) and the inhibin B/FSH ratio by 75.56% (P=0.0103).

Conclusion: Our data show that inhibin B and the inhibin B/FSH ratio are suitable functional markers for gonadal function in CAIS patients. From adolescence onward, these parameters and testosterone levels may be useful to examine gonadal function and to possibly detect a loss of function that may necessitate hormone replacement in CAIS patients.