Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia.

Abstract

Investigation of the origin of sexual ambiguity is complex. Although testicular function has traditionally been assessed only by examining the steroidogenic capacity of Leydig cells and spermatogenesis, it has recently been shown that the measurement of serum anti-Müllerian hormone (AMH) as a marker of Sertoli cell function may also help clinicians. The aim of this study was to evaluate both Leydig and Sertoli cell functions in 46,XY patients with intersex states in order to establish biochemical patterns that would help to reach an etiologic diagnosis. We measured serum androgens, AMH and gonadotropins in 24 patients with sexual ambiguity and XY karyotype: 8 with gonadal dysgenesis (GD), 3 with 3beta-hydroxysteroid dehydrogenase deficiency (3betaHSD), 5 with androgen insensitivity syndrome (AIS), 4 with 5alpha-reductase 2 (SRD5A2) deficiency, and 4 were of unknown origin or idiopathic. Our results showed that while testosterone was low and gonadotropins elevated in patients with either GD or 3betaHSD, AMH was low in the former and high in the latter. Serum AMH and gonadotropins were normal or high in patients with 3betaHSD or AIS, but these could be distinguished by testosterone levels. Serum testosterone and gonadotropins were normal or high in AIS and SRD5A2 deficiency patients; however, while AMH was elevated in AIS, it was not the case in SRD5A2 deficiency patients, indicating that testosterone is sufficient to inhibit AMH within the testis. In idiopathic cases gonadotropins and testosterone were normal, and AMH was normal or low. We conclude that the combined measurement of androgens, AMH and gonadotropins helps to establish the diagnosis in intersex patients.