INTERPLAY BETWEEN ENDOMETRIAL MICROBIOTA AND ANTIMICROBIAL PEPTIDES IN WOMEN WITH DIFFERENT INFERTILITY FORMS

Abstract Introduction Antimicrobial peptides able to induce immune disorders and inflammation in the uterine cavity are tightly bound to microbial composition of the upper and lower reproductive tract. An interplay between uterine microbiota and innate and adaptive immune system is crucial for maintaining a balanced environment for embryo implantation processes. Objective: to evaluate an interplay between endometrial microbiota and antimicrobial peptides in women with different infertility forms. Materials and methods A total of 181 reproductive age women were examined. Group I included 165 women with infertility of various origins, Group II included 16 oocyte donors. Group I was divided into three subgroups (IA - adhesions in the uterine cavity, IB - endometrial polyps, IB - other infertility forms). The endometrial microbiota was studied using quantitative real-time PCR (Femoflor 16, DNA-technology, Moscow). Defensin (DEFa1), fibroblast growth factor 2 (FGF2), transforming growth factor Beta1 (TGF-β1) in the endometrium were determined using ELISA (Cloud-Clone Corporation, Wuhan, China). Results Lactobacilli were most frequently detected in the endometrium. Atopobium vaginae, Enterobacteriaceae, Lachnobacterium spp., Mobiluncus spp., Peptostreptococcus, Mycoplasma hominis, Ureaplasma spp. were also found in main group, but not in comparison group. All patients in group I, regardless of the infertility form, had significantly increased DEFa1 (p0.01) level compared to group II. High concentrations of DEFa1 were also found when Atopobium vaginae was detected in the uterine cavity of women with any infertility form (p0.001). Conclusion The endometrial microbiota and related immune changes are closely interconnected. Infertility increases the concentration of defensins (DEFa1) in the uterine cavity, leading to disturbed processes of embryo implantation, whereas the presence of microorganisms primarily Atopobium vaginae, aggravates such alterations.