Gonadotropin responses to luteinizing releasing factor in boys treated with cyclophosphamide for nephrotic syndrome.

Cyclophosphamide therapy of the nephrotic syndrome has been associated with oligo- and azoospermia and with abnormalities of testicular histology in adults and pubertal boys. In 15 prepubertal boys, no abnormalities of basal serum levels of LH, FSH, or T were found when they were studied 8 months to 7 years after cyclophosphamide therapy. Five boys were pubertal during therapy were found to have elevated mean basal values of gonadotropins with normal testosterone levels and elevated LH responses to LRF; the FSH responses to LRF were elevated in four patients. One of four boys who were prepubertal during therapy but pubertal at the time of testing had an elevated basal LH and LH response to LRF. Three boys who were prepubertal at the times of therapy and testing had normal LH responses to LRF. The LRF test may provide a means of identifying the patient who has sustained testicular injury and who may require testicular biopsy.