Telomerase activity and expression of telomerase subunits in the testicular tissue of infertile patients

Objective: Determination of telomerase activity and the expression of human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT) in the testicular tissue of patients with infertility arising from various causes. Design: Prospective observational study. Setting: A university hospital. Patient(s): Thirty-three patients with azoospermia arising from various causes. There were 12 testicular biopsy specimens from patients with Sertoli cell-only syndrome, 9 from patients with maturation arrest, and 12 from patients with obstructive azoospermia and normal histologic findings. Intervention(s): Thirty-three testicular biopsies. Main Outcome Measure(s): Correlation of histologic findings at testicular biopsy with telomerase activity, hTERT, and hTR. Result(s): All 12 biopsy specimens from patients with obstructive azoospermia were positive for telomerase activity, hTR, and hTERT. Biopsy specimens from the 9 patients with maturation arrest were positive for telomerase activity in 8 cases, hTR in 9 cases, and hTERT in 5 cases. None of the patients with Sertoli cell-only syndrome showed either telomerase activity or hTERT, but all of them showed hTR. Conclusion(s): Telomerase activity and evidence of hTERT in testicular tissue are highly sensitive and highly specific markers of gametogenesis, which could gain in importance as part of the fertility workup before microinjection procedures.