Quantification of the expression level of the gene encoding the catalytic subunit of telomerase in testicular tissue specimens predicts successful sperm recovery

BACKGROUND: The objective of the present study was to evaluate the quantitative detection of human telomerase reverse transcriptase (hTERT) mRNA as a new molecular diagnostic parameter in the work-up of testicular tissue specimens from patients presenting with non-obstructive azoospermia. M ETHODS: hTERT mRNA expression was quantified in 49 cryopreserved testicular tissue specimens by fluorescence real-time RT-PCR in a LightCycler(R). This was paralleled by conventional histological work-up in all tissue specimens and additional semithin sectioning preparation in cases with maturation arrest (n = 20) and Sertoli cell-only syndrome (SCOS; n = 12). RESULTS: The average normalized hTERT expression (N(hTERT)) was 136.1 +/- 41.7 copies (mean +/- standard deviation) in tissue specimens with presence of haploid germs cells, N(hTERT) = 48.2 +/- 21.0 copies in those with maturation arrest and N(hTERT) = 2.7 +/- 2.8 copies in those with SCOS. The discriminant analysis showed that detection of N(hTERT) was able correctly to classify 89.0% of the investigated tissue specimens. CONCLUSIONS: Our results demonstrate that quantitative detection of hTERT mRNA expression in testicular tissue enables a molecular-diagnostic subclassification of spermatogenesis disorders. Quantitative detection of hTERT in testicular biopsies is thus well suited for predicting successful sperm recovery in patients with azoospermia and is a useful molecular diagnostic parameter for supplementing the histopathological evaluation.