Effect of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on human sperm motility,...

Male genital tract infections and non-specific inflammatory conditions may be associated with unexplained infertility. Previous studies have shown the presence of cytokines such as tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in the semen of infertile men. However, the mechanism of effect of these cytokines on human sperm function is still controversial. The present study was undertaken to investigate the in-vitro effects of TNF-alpha and IFN-gamma on human sperm motion, viability and the hypoosmotic swelling test (HOST). Washed spermatozoa from normal volunteers (n = 9) were incubated in the presence/absence of TNF-alpha (1 microgram/mL) plus IFN-gamma (0.1 microgram/mL). Sperm motility, viability, HOST, and video sequences were recorded at different time intervals (0, 30, 60 and 180 min). Sperm motion parameters were analysed using computer-assisted semen analysis. There was a time-dependent negative effect of TNF-alpha plus IFN-gamma on sperm motility, viability, HOST, and lateral-head displacement (ALH). The maximum decrease was observed between 60 and 180 min for sperm motility (50.8 +/- 5.6%), viability (52.8 +/- 4.0%), HOST (38 +/- 2%) and ALH (4.7 +/- 0.1 microns) compared to control samples (62.2 +/- 2.8, 62.4 +/- 2.9, 58 +/- 4, and 5.3 +/- 0.4, respectively; All p < 0.05). There was no significant effect on sperm straight-line velocity and mean linearity when compared to control. These data suggest that the common inflammatory cytokines TNF-alpha plus IFN-gamma have only partial detrimental effects on sperm motility, viability, membrane integrity and lateral head displacement, which may contribute to the poor fertilizing potential of human spermatozoa during inflammatory conditions.