Altered secretion of Sertoli cells hormones in 2-year-old prepubertal cryptorchid boys: a cross-sectional study

In cryptorchid boys, failures in germ cell development have been clearly established. Some studies reported some abnormalities in Sertoli cells morphology but the results regarding their endocrine secretion remain controversial. To compare testicular hormone levels in young boys with and without cryptorchidism, we performed a cross-sectional hospital-based study. From surgery appointment records, we identified a case group of boys with unilateral or bilateral cryptorchidism and a control group undergoing dental care, minor osteoarticular or dermal surgery. Blood samples were withdrawn during the surgical procedure to perform testosterone, inhibin B and anti-müllerian hormone (AMH) immunoassays. We included 27 cryptorchid boys and 27 controls aged of 26.6 vs. 24.2 months, respectively (p = 0.172) far from the post-natal mini-puberty and the corresponding hormonal surges. Age-adjusted AMH and inhibin B levels were significantly lower in cryptorchid than in control boys (AMH: 87 ng/mL vs. 135 ng/mL; p = 0.009, inhibin B: 97 pg/mL vs. 133 pg/mL; p = 0.019, respectively). Moreover, AMH and inhibin B levels were significantly lower in the bilateral cryptorchid subgroup, being 50% lower than in the controls (p = 0.011 and 0.019, respectively) and while both hormones levels were independent in controls, they became strongly correlated in bilateral cryptorchid boys (R² = 0.75, p = 0.001). In addition, testosterone levels were still detectable in some boys, with significantly lower levels in cryptorchid group than in controls. Overall, 2-year-old cryptorchid patients presented a simultaneous and significant drop in AMH and inhibin B levels, suggesting a functional defect of Sertoli cells. This deficiency appeared more pronounced in bilateral cryptorchidism and thus, regarding the pivotal role of Sertoli cells in germ cell development, it may explain the compromised fertility found later in men born with such a malformation.