Failure of gonadotropin therapy secondary to chorionic gonadotropin-induced antibodies.

Seventeen years after first receiving treatment with hCG (at age 8 yr), a man with hypogonadotropic hypogonadism no longer responded to gonadotropin therapy. He had received hCG for 6 months when he was 8 yr old, from age 18-21 yr and from age 21-25 yr, when the resistance developed. Anti-hCG antibodies were found in his serum. Three sequential treatment regimens were tried to obviate the effect of these antibodies. 1) hCG treatment (2000 IU, three times per week) concomitant with weekly plasmapheresis (since the patient's response to an hCG challenge test was improved after a reduction of antibody titer by plasmapheresis) resulted in only a temporary increase in testosterone production. 2) Treatment with human (h) LH (400 IU/week) and hFSH (25 IU/week) was used because of the low cross-reaction of the antibodies with hLH and a response to a hLH-challenge test. This treatment maintained serum testosterone levels within the normal range for long periods, but had to be discontinued when the supply of hLH was exhausted. 3) Pulsatile LHRH administration (25 ng/kg, sc, every 2 h) for 2 months did not induce the release of pituitary gonadotropins. These results indicated that 1) conventional hCG treatment was impaired by antibody-induced changes in the kinetics of hCG after its im administration; 2) hLH was an effective substitute for hCG, and the combined hLH-hFSH administration initiated a moderate amount of spermatogenesis; and 3) the patient differs from most individuals with hypogonadotropin hypogonadism in that he did not have normal responses to repetitive LHRH administration.