ESPE Abstracts

Objective: AMH causes fetal paramesonephric duct regression and is involved in testicular development and function. Sertoli cell AMH remains high during childhood until puberty. The appendix testis (AT), a remnant of the paramesonephric duct, contains both androgen and estrogen receptors. AT androgen receptors have been reported to play a role in embryonic testicular descent. The AT is commonly resected during orchiopexy and abdominal surgery as possible torsion in the future may cause an acute scrotum. Our study aimed to assess AMH concentrations together with the expression of AT androgen and estrogen receptors in cryptorchidism.

Methods: The study included 52 boys, 31 patients with cryptorchidism (PC) and 21 healthy control boys with orthotopic testes who underwent surgery for hydrocele. Plasma AMH was measured using a chemiluminescent enzyme immunoassay. The appendix testis was surgically resected from all the boys studied. AT androgen and estrogen receptor expression was assessed with immunohistochemistry using the monoclonal antibody R441 for the androgen receptors and monoclonal antibody MAB463 for the estrogen receptors. For the estimation of the receptors’ expression the Allred Score method was used. Statistical analysis was performed with Mann-Whitney και Spearman’s rs tests.

Results: AMH concentrations showed statistically significant differences between patients with high (HC) and those with low cryptorchidism (LC) (P=0.019){median=4.7ng/ml, interquartile range (IR) =14.0 ng/ml for HC and median=19.8 ng/ml, IR=19.4 ng/ml for LC}. Estrogen receptor expression was lower in cryptorchid patients’ AT compared to controls (P=0.036). The expression of the AT androgen receptors, though lower in PC, did not present statistically significant differences compared to the controls (P=0.248). In the PC there was a highly positive correlation (rs=0.80) between the expression of the estrogen and androgen receptors (P<0.0001).

Conclusions: Our study suggests that there is an inverse correlation between plasma AMH concentrations and cryptorchidism severity. It is also of interest that the expression of the androgen receptors of the appendix testis was not significantly different between the patients with cryptorchidism and controls, while the expression of the estrogen receptors in the children with cryptorchidism was significantly lower. Our results suggest that the expression of the AT estrogen receptors, and not only the AT androgen receptors as previously reported, may possibly play an important role in the descent of the testes to the scrotum.