Expression of IL-12, IL-10, PGE2, sIL-2R and sIL-6R in seminal plasma of fertile and infertile men

The involvement of cytokines and other immunoregulatory factors in male infertility is still unclear. In the present study we compared the levels of IL-12, IL-10, PGE2, sIL-2R and sIL-6R in the seminal plasma (SP) of fertile and infertile men. Four groups were included: fertile donors (FERT), infertile men with azoospermia (AZOO), and infertile men with either oligoterato-asthenoazoospermia (OTA), or OTA with genital infection (OTA-INF). Cytokines and cytokine-soluble receptors in semen were evaluated by specific ELISA commercial kits. The levels of IL-12, sIL-2R and sIL-6R were similar in SP of fertile and infertile men. The mean levels of IL-10 in the SP of FERT, OTA and AZOO were 5.6 +/- 0.9, 4 +/- 2.8 and 8 +/- 3.5 pg ml(-1), respectively, and did not differ significantly. The mean level of IL-10 in SP from OTA-INF (0.9 +/- 0.5 pg ml(-1)) was significantly lower than that for FERT (5.6 +/- 1.9 pg ml(-1); P = 0.02) and AZOO (8.2 +/- 3.4 pg ml(-1); P = 0.05), but not significanitly different from that for OTA (3.7 +/- 2.1 pg ml(-1) ). The mean SP level of PGE2 was significantly lower in SP of OTA-INF than FERT (7.67 +/- 2.26 and 19.67 +/- 3.69 mu g ml(-1), respectively; P<0.02). In conclusion, the seminal plasma from fertile and infertile men contained similar levels of IL-12, sIL-2R and sIL-6R. However, the levels of IL-10 were significantly lower in SP from OTA-INF compared to FERT and AZOO. Our results indicate that specific cytokines and their soluble receptors are involved in the male reproductive system.