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

The presence of cytokines such as the tumour necrosis factoralpha (TNF) and interleukin 2 (IL2) in human spermatozoa isstill to be defined. The aim of this study was to measure theconcentration of both soluble factors in seminal fluid. Datafrom normal semen samples (n = 24) confirmed the presence ofIL2 (258 ± 84 fmol/ml corresponding to 953 ± 369fmol/total volume of ejaculate) and TNFa (62.2 ± 16.4fmol/ml corresponding to 231.3 ± 86 fmol/total volumeof ejaculate). A significant positive correlation (r = 0.59;P < 0.01) was observed between the TNFa and the IL2 concentrations.The concentrations of these cytokines were not related to spermparameters. 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 agentswere lower than in the control group, whereas TNF concentrations(68.6 ± 12.3 fmol/ml; 241.3 ± 78.9 fmol/totalvolume of ejaculate) were not significantly different from thecontrols. Further studies are needed to determine the potentialrole of these cytokines in the physiology of semen and theirusefulness as indicators of reproductive pathology.