Testicular function following bone marrow transplantation performed during or after puberty

Testicular function was assessed in eight males who had undergone bone marrow transplantation (BMT) during or shortly after puberty. Their ages ranged between 10 years, 10 months and 17 years, 3 months (median, 13 years, 7 months) at the time of BMT, and they were followed 13 to 77 months (median, 36 months) posttransplantation. Therapy for BMT consisted of high-dose, short-term chemotherapy either alone (Group I) or in combination with single-dose irradiation, total lymphoid (Group II) or total body (Group III). Subjects in Group III had all received combination chemotherapy prior to BMT. Hormonal and clinical evidence of germ-cell dysfunction was common in that 6 patients manifested elevated plasma levels of follicle-stimulating hormone (FSH), and four subjects were found to have a subnormal testicular volume. Of the six patients with abnormal FSH values, four were followed serially, and all showed normalization over time. Leydig cell function was less impaired in that seven of the eight patients produced normal adult male levels of testosterone, including three subjects with elevated luteinizing hormone (LH) levels. All eight developed normal adult male secondary sexual characteristics. It is concluded that the therapy utilized for BMT causes damage primarily to germinal epithelium which appears amenable to recovery. This may be due, in part, to the use of single dose rather than fractionated radiation.