Evaluation of the usefulness of antymüllerian hormone and inhibin B as markers of ovarian activity in patients with Turner syndrome – preliminary results

Introduction
Spontaneous puberty occurs in 30% of patients with Turner Syndrome. Its absence is an indication for hormone replacement therapy (HRT). No reliable markers of spontaneous puberty have been defined to date.

Aim of the study
To evaluate the usefulness of antymüllerian hormone (AMH) and inhibin B assessment in predicting ovarian function and spontaneous puberty in girls with TS.

Material and methods
The study included 35 TS patients treated with human recombinant growth hormone (rhGH). Gonadal axis function parameters (LH, FSH and estradiol) were evaluated at the age of physiological puberty (10–12 years, mean 10.5 years), before introduction of HRT. Ad-ditionally AMH and inhibin B levels were assessed. In follow up patients were divided into 2 groups: with (SP) and without (WP) spontaneous puberty. Spontaneous puberty was defined as Tanner stage 2 or higher breast development.

Results
WP patients were observed until the mean age of 16y. SP occurred in 16 patients (mean age 10 years). Patients with SP presented with significantly lower mean FSH level (1.14–91.1 mIU/ml, mean mIU/ml 24.5 vs. 7.7–196.4 mIU/ml, mean 66.5 mIU/ml, p = 0.002), higher mean estradiol (10.5–68.8 pg/ml, mean 28.4 pg/ml vs. 6.1–26.0 pg/ml, mean 14.9 pg/ml, p = 0.005), AMH (0.0–3.11 ng/ml, mean 0.8 ng/ml vs. 0.0–0.002 ng/ml, mean 0.003 ng/ml, p = 0.001) and inhibin B (0.0–110.0 pg/ml, mean 29.1 pg/ml vs. 0.0–11.0 pg/ml, mean 1.06 pg/ml, p = 0.026) levels. In three SP patients without elevated FSH level (FSH < 35 mIU/ml) we found zero concen-tration levels of AMH and inhibin B. SP patients had mosaic (non 45,X) karyotype in 87.5% and WP patients only in 47%.

Conclusions
AMH and inhibin B assessment may be a valuable complement to the diagnosis of ovarian function in patients with TS. Low levels of these parameters may indicate a risk of ovarian failure even in patients with spontaneous puberty and without hypergonadotropic hy-pogonadism.