Circulating NK and NKT cells in the diagnosis and treatment of immunological causes of female infertility - retrospective data analysis from the tertiary clinical center.

Immune dysregulation can cause embryo implantation failure, possibly due to mechanisms of innate non-adaptive immunity, including natural killer (NK) and natural killer T (NKT) cells. Retrospective analysis of relative counts and functional properties of NK and NKT peripheral blood cells in women with cellular immunopathology before and after immunomodulatory treatment was realized to evaluate these values in a proportion of clinical post-treatment pregnancies. For retrospective analysis, data were collected from 184 infertile women treated for abnormal functional properties and/or numbers of NK and NKT cells after stimulation with sperm and trophoblast antigens. Flow cytometric analyses of peripheral blood both before and during/after immunomodulatory treatment were performed to determine whether clinical pregnancy was achieved. Of 184 cases, immunomodulatory treatment contributed to clinical pregnancy in 109 women (59 %), all but 25 of whom required assisted reproduction techniques to become pregnant. Clinical pregnancy was associated with significantly lower numbers of circulating NK cells (p = 0.03) and significantly less activation of NK cells by trophoblasts (p < 0.001). Increased numbers of peripheral blood NK cells and their pathological activation by trophoblast antigens are immunological factors of infertility in women. However, when appropriately chosen, immunomodulatory treatment can make clinical pregnancy more likely.