We have previously shown that high level of seminal interleukin (IL)-18 is positively associated with a greater risk of pregnancy failure in women exposed to their partners' seminal plasma (SP) during the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycle. Since IL-18 and IL-1β considered to be the key immune markers of stress, here we ask whether their increase in SP may be due to the stress experienced by men engaged in the IVF programs. Therefore, we correlated seminal IL-18 with IL-1β and both cytokines with the seminal steroids, whose increase indicates the activation of neuroendocrine stress response systems. Retrospective analysis of stored seminal samples was performed. Based on previously identified cutoff level for content of IL-18 per ejaculate, samples with high IL-18 content from IVF failure group (n = 9), as well as samples with low IL-18 content from IVF success group (n = 7), were included in the study. Seminal cytokines were evaluated using FlowCytomix™ technology. A set of 16 biologically active steroids in SP was quantified by liquid chromatography coupled with mass spectrometry. Concentrations and total amounts per ejaculate of cytokines and steroids were determined. A positive significant correlation was found between the levels of IL-18 and IL-1β. There was also a positive correlation between IL-18 or IL-1β and 17-α-hydroxypregnenolone, 17-α-hydroxyprogesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, progesterone, corticosterone, 11-deoxycorticosterone, and the ratio of DHEAS/cortisol. We suggested that stress-related overexpression of immune and hormonal factors in SP may be the key link between male stress and embryo implantation failure.
Keywords: IVF/ICSI outcome; Interleukin-18; Interleukin-1β; Seminal plasma; Steroid hormones; Stress.