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 ca uses. Design: Prospective observational study. Setting: A university hospital. Patient(s): Thirty-three patients with azoospermia arising from various cau ses. There were 12 testicular biopsy specimens from patients with Sertoli c ell-only syndrome, 9 from patients with maturation arrest, and 12 from pati ents with obstructive azoospermia and normal histologic findings. Intervention(s): Thirty-three testicular biopsies. Main Outcome Measure(s): Correlation of histologic findings at testicular b iopsy with telomerase activity, hTERT, and hTR. Result(s): All 12 biopsy specimens from patients with obstructive azoosperm ia were positive for telomerase activity, hTR, and hTERT. Biopsy specimens from the 9 patients with maturation arrest were positive for telomerase act ivity in 8 cases, hTR in 9 cases, and hTERT in 5 cases. None of the patient s with Sertoli cell-only syndrome showed either telomerase activity or hTER T, but all of them showed hTR. Conclusion(s): Telomerase activity and evidence of hTERT in testicular tiss ue are highly sensitive and highly specific markers of gametogenesis, which could gain in importance as part of the fertility workup before microinjec tion procedures.