Relationship between adult dark spermatogonia and secretory capacity of Leydig cells in cryptorchidism

Abstract

Objective: To examine whether hormonal therapy before orchidopexy affects the histology of the testis and to assess the responsiveness of the Leydig cells, as it has been shown that although basal plasma testosterone levels are within the 'normal' range in cryptorchid boys there is an insufficient increase of testosterone after a human chorionic gonadotrophin (hCG) stimulation in approximately 30% of cryptorchid boys.

Patients and methods: In all, 55 boys (aged 1-7 years) with a unilateral undescended testis were included in the study and divided into two groups. Group I (32 boys) received hormonal therapy before orchidopexy; 17 boys received a long-acting LHRH analogue (buserelin) administered as a nasal spray in doses of 20 microg/day for 28 days, followed by 1500 IU hCG intramuscularly (i.m.) once a week for 3 weeks, and the remaining 15 received 1500 IU hCG i.m. once a week for 3 weeks. Group II (33 boys) had orchidopexy alone. During orchidopexy biopsies were taken from the undescended and contralateral descended testes of the boys in both groups for histological analyses. Variations in the number of adult dark (Ad) spermatogonia per tubule (Ad/T) were assessed and testosterone levels were measured during the course of the hormonal therapy (before treatment, 14 days after initiation of buserelin administration, 24 h after each hCG injection, and 3 months after cessation of therapy).

Results: In group I, 17 boys (53%) had a 'normal' Ad/T after hormonal treatment vs only six (18%) in group II after orchidopexy alone (P = 0.019). In the hormonally treated boys (group I) we compared the testosterone values 24 h after the second injection of hCG (when the response was most pronounced). Those with a normal Ad/T had a mean (sd) testosterone level of 199.5 (97.6) ng/dL vs 99.6 (85) ng/dL in those with an inadequate Ad/T response to hormonal therapy (P < 0.003).

Conclusion: We have confirmed that there are two subgroups of cryptorchid boys. Patients with a sufficient Leydig cell secretory capacity will have normal testicular histology and Ad spermatogonia count after hormonal treatment. While those with a suboptimal Leydig cell capacity will have a low Ad spermatogonia count and consequently poor prognosis for future fertility, despite successful surgery. As to whether different types and durations of the hormonal therapy in patients with impaired Leydig cell response could lead to improved testicular histology and consequently improved prognosis for future fertility, remains to be answered.