Abstract
Background
Men with non-obstructive azoospermia constitute a challenging subgroup of male infertility patients in whom a genetic cause of defective spermatogenesis may be a contributing factor. The aim of this prospective observational cohort study was to determine whether assessment of meiotic nuclear division 1 (MND1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression (MND1/GAPDH) in testicular tissue could be a prognostic indicator for sperm retrieval and ICSI outcome in patients with non-obstructive azoospermia. The study participants underwent clinical evaluation, conventional semen analysis, serum follicular stimulating hormone (FSH), testosterone assay, scrotal ultrasound examination, microsurgical testicular sperm extraction (mTESE), and assessment of MND1/GAPDH gene expression levels in testicular tissue via quantitative polymerase chain reaction (qPCR) techniques.
Results
The MND1/GAPDH level was associated with the likelihood of identifying sperm in testicular biopsies (odds ratio (OR) 1.25, 95% confidence intervals (CI) 1.14 to 1.34,
p
< 0.0001), which was confirmed by the pairwise comparison of high vs. low levels of MND1/GAPDH (OR 5.34, 95% CI 1.97 to 13.16,
p
= 0.0006). The level of FSH was inversely associated with a lower chance of finding sperm (OR 0.37, 95% CI 0.20 to 0.65,
p
= 0.001). Compared with small testicular volume, normal volume was inversely associated with the chance of sperm presence (OR 0.16, 95% CI 0.06 to 0.47,
p
= 0.0002). However, there was no correlation between MND1/GAPDH levels and ICSI outcome.
Conclusion
Gene expression analysis to predict the likelihood of sperm retrieval following mTESE in patients with non-obstructive azoospermia provides a new avenue for future research, diagnosis and treatment of male factor infertility. Before its wider clinical application, however, this proof-of-concept should be tested in a large multinational, multicenter observational study.