Decreased levels of interleukin-12 are not correlated with leukocyte concentration and superoxide dismutase activity in semen of infertile men.

The interleukin (IL)-12 levels and the superoxide dismutase (SOD) activity were determined in the seminal plasma of fertile and infertile men with or without leukocytospermia by ELISA. The IL-12 levels differed significantly among the fertile and infertile groups, with the infertile groups showing lower levels that were not modulated by leukocytospermia. The SOD activity did not differ significantly among the fertile and infertile groups and was not correlated with the IL-12 levels. The positive correlation with sperm concentration suggests that IL-12 may have a direct or indirect role in male fertility/infertility and that its levels are not modulated by the presence of leukocytes in the semen.