Reduced level of sex-specific antigen (H-Y antigen) on lymphocytes in some patients with bilateral cryptorchidism.

Sex-specific (Sxs) antigen on the surface of nucleated cells from normal human males seems to be essential for the formation of testes. The relative quantity of the antigen on lymphocytes was evaluated by absorption experiments in a complement-dependent cytotoxicity test or in an ELISA technique using antisera against Sxs antigen produced by immunization of female rats. Lymphocytes from 13 normal males were Sxs-antigen positive, and cells from 12 normal females were characterized as Sxs-antigen negative. However, in the testing of lymphocytes from nine boys with bilateral cryptorchidism, only six revealed a normal male absorption pattern, whereas the antigen level on cells from three boys, all of them with normal karyotype, was reduced compared with the normal male level. No correlation between Sxs-antigen level and testosterone response after treatment with hCG could be demonstrated.