Tumour necrosis factor alpha and interleukin 2 in normal and infected human seminal fluid

The presence of cytokines such as the tumour necrosis factor alpha (TNF alpha) and interleukin 2 (IL2) in human spermatozoa is still to be defined. The aim of this study was to measure the concentration of both soluble factors in seminal fluid. Data from normal semen samples (n = 24) confirmed the presence of IL2 (258 +/- 84 fmol/ml corresponding to 953 +/- 369 fmol/total volume of ejaculate) and TNF alpha (62.2 +/- 16.4 fmol/ml corresponding to 231.3 +/- 86 fmol/total volume of ejaculate). A significant positive correlation (r = 0.59; P < 0.01) was observed between the TNF alpha and the IL2 concentrations. The concentrations of these cytokines were not related to sperm parameters. In contrast, IL2 concentrations (196.9 +/- 60.4 fmol/ml; 686.2 +/- 236.7 fmol/total volume of ejaculate) evaluated in 16 seminal fluids with identified bacterial agents were lower than in the control group, whereas TNF alpha concentrations (68.6 +/- 12.3 fmol/ml; 241.3 +/- 78.9 fmol/total volume of ejaculate) were not significantly different from the controls. Further studies are needed to determine the potential role of these cytokines in the physiology of semen and their usefulness as indicators of reproductive pathology.