Introduction. Pro-inflammatory cytokine – tumor necrosis factor-alpha (TNFα) is one of the components of the seminal plasma proteome; its meaning has not been definitively revealed. A comparative analysis of the concentration of this protein in the blood serum and in the ejaculate and changes in its level in the semen of men with infertility is оf scientific interest.
The purpose of the study: determination of TNF-α level in the blood serum and seminal plasma of healthy men and patients with reduced fertility.
Materials and methods. 70 men of reproductive age with azoospermia (main group, n=18), with oligoastenozoospermia (comparison group, n=18) and with normal spermogram parameters (control group, n=34) were examined. The ejaculate was examined using an SQA–V semen analyzer (MES, Israel). In seminal plasma samples, the concentration of TNFα was determined using the alpha-TNF-ELISA-BEST test system (A-8756, Vector-Best LLС, Russia).
Results. The concentration of TNF-α in blood serum had a significant variation (CV=85.31%) and amounted to 2.75±2.18 pg/ml, which is 2.55 times lower than the same indicator in seminal plasma (7.01±5.98 pg/ml, CV=126.15%, p<0.00001). When comparing the content of TNF-α in seminal plasma, significant differences were found in the examined patients (Kruskal-Wallis test H=24.75991; p<0.00001). Pairwise comparison revealed a statistically significant difference in the level of TNF-α in seminal plasma between the comparison and control groups (p2-3=0.000023), as well as between the main group and the comparison group
(p1-2=0.000043); there were no significant differences between the main and control groups (p>0.05). When determining the content of TNF-α in the blood serum, there was no statistically significant difference between the groups (p>0.05). There were no correlations between the concentration of TNF-α in blood serum and in seminal plasma (R=0.295374), and the total number of spermatozoa in the ejaculate (R=-0.027945); and the concentration of spermatozoa in the ejaculate (R=-0.042902).
Discussion. It is unlikely that TNFα crosses into seminal plasma from serum against a concentration gradient. It is most likely that TNFα is produced locally in the organs of the reproductive system by resident immune cells or cells involved in spermatogenesis. An increased content of TNF-α in seminal plasma in patients of the comparison group may indicate the presence of an inflammatory process in the reproductive system and a reduced fertility of the ejaculate.
Conclusion. The physiological role of TNFα in sperm, its sources in the organs of the male reproductive system, and the pathogenetic mechanisms of the participation of the TNFα in pathological processes in male reproductive system still remain unclear. All this justifies the need for further study of the TNFα level in seminal plasma in normal conditions and in diseases of the urogenital tract in men.

Keywords: oligoastenozoospermia, seminal plasma, TNFα, azoospermia, ejaculate, tumor necrosis factor-alpha, male infertility