Effects of valganciclovir on spermatogenesis in renal transplant patients - results of a multicenter prospective nonrandomized study

Ganciclovir (GCV) inhibits spermatogenesis in preclinical studies but long-term effects on fertility in renal transplant patients are unknown. In a prospective, multicenter, open-label, nonrandomized study, male patients were assigned to Cohort A [valganciclovir (VGCV), a prodrug of GCV] (n = 38) or B (no VGCV) (n = 21) by cytomegalovirus prophylaxis requirement. Changes in semen parameters and DNA fragmentation were assessed via a mixed-effects linear regression model accounting for baseline differences. Sperm concentration increased post-transplant, but between baseline and treatment end (mean 164 days Cohort A, 211 days Cohort B), the model-based change was lower in Cohort A (difference: 43.82 x 10(6)/ml; P = 0.0038). Post-treatment, sperm concentration increased in Cohort A so that by end of follow-up (6 months post-treatment) changes were comparable between cohorts (difference: 2.09 x 10(6)/ml; P = 0.92). Most patients' sperm concentration improved by end of follow-up; none with normal baseline concentrations (>= 20 x 10(6)/ml) were abnormal at end of follow-up. Changes in seminal volume, sperm motility/morphology, DNA fragmentation, and hormone levels were comparable between cohorts at end of follow-up. Improvement in semen parameters after renal transplant was delayed in men receiving VCGV, but 6 months post-treatment parameters were comparable between cohorts.