Immunogenetic and hormonal study of cryptorchidism.

Ninety-four cryptorchids, 50 monolateral and 44 bilateral, aged from 2-9.4 yr (mean, 5.1 +/- 0.5 yr), were studied for the hormonal and immunogenetic profile. Pituitary-gonadal function was studied by evaluation of basal and peak GnRH-stimulated serum FSH and LH. In 83 cases, the serum testosterone (T) level was measured before and after CG treatment. No significant differences, between patients and age-matched controls, were found in either FSH or LH levels, whether under basal conditions or after GHRH stimulation. The mean basal serum T level was similar in mono and bilateral cryptorchids and in controls but, on the 15th day after treatment, it was significantly lower in the bilateral cryptorchids (P less than 0.05). CG administration led to testicular descent in 42 patients (23 with monolateral and 19 with bilateral cryptorchidism) and failed in 41 (21 with monolateral and 20 with bilateral cryptorchidism), independently of T increase. Immunogenetic investigation demonstrated that HLA-A11 and A23 were significantly overrepresented in the whole group of cryptorchids in comparison with the controls (P = 0.004 and P = 0.0123, respectively). HLA-A11 was more common in the bilateral form (P less than 0.05), whereas HLA-A29 was more frequent in the monolateral one (P less than 0.05). Forty percent of the bilateral cryptorchids with unsuccessful treatment had the HLA-A11 allele (P less than 0.01) and 70% the HLA-DR5.