The pituitary-gonadal axis in cryptorchid infants and children.

We have attempted to document in cryptorchid children that there is an LH deficiency and a secondary deficiency of testosterone. We have shown a diminished LH peak after LH-RH in cryptorchid versus normal infants (P less than 0.05). The postnatal surge of testosterone is significantly low (P less than 0.001) in permanent cryptorchids versus infants with secondary testicular descent, whose levels are similar to those in controls. In permanent cryptorchids during the same period (0-4 months), LH and testosterone levels were significantly lower (P less than 0.01 and P less than 0.05 respectively) than in infants with secondary descent, and the levels of testosterone and LH were correlated in both populations. In children, a low basal level of LH was observed at pubertal stage P2, and LH peak after LH-RH was significantly reduced at stages P1 and P2 (P less than 0.01 and P less than 0.05 respectively). The post-stimulatory levels of testosterone after hCG were reduced at the same stages (P less than 0.01, P less than 0,05), and the two levels were correlated (P less than 0.01). No differences are seen for LH and testosterone afterwards. It has been possible to show by immunofluorescence on pituitary cells the occurrence of antigonadotropin cell antibodies (AGCA) in more than 50% of our patients, with no relation to age and no correlations between endocrinological data and the presence or absence of AGCA. The relatively low success rate of hCG treatment, mainly in young children, and of GnRH irrespective of the regimen of treatment, does not exclude the role of primary LH deficiency in cryptorchidism.