Evaluation of glycan expression in endometrial epithelial structures as a predictive factor for endometrial receptivity

Abstract

Aim. To evaluate the endometrial glyotype in the implantation window in patients with infertility in assisted reproductive technologies (ART) programs and to develop criteria for assessing endometrial receptivity based on the analysis of complex changes in the functional groups of glycans in the main endometrial epithelial to use in clinical practice. Materials and methods. The study included 32 infertile patients who took part in ART programs. Pipelle endometrial biopsy was performed during the implantation window in the cycle preceding the cycle of ovarian stimulation and embryo transfer. Using lectin histochemistry and immunohistochemistry, glycans levels in the glycocalyx of endometrial surface epithelium (SE) and glandular epithelium (GE) was studied. Results. Differences in the expression of mannose-rich glycans in SE and N-acetylgalactosamine--terminated glycans in the GE of the endometrium were revealed, as well as the link between the expression of lectin staining glycans: ConA, VVL, UEA-I, SNA, MAL-II, ECL and monoclonal antibodies: anti-MECA -79 mAb and anti-LeY mAb in SE and GE of the endometrium was assessed in patients with infertility, depending on the outcome of the ART program. The estimated threshold levels in glycan expression and the odds ratio for pregnancy occurrence allow to characterize the diagnostic value for the studied glycomarkers and to develop criteria for assessing endometrial receptivity. Conclusion. Based on a comprehensive evaluation of glycans in the main endometrial epithelial structures in the cycle preceding the ART cycle, criteria for assessment of the likelihood of pregnancy have been developed, which can increase the effectiveness of ART programs in patients with infertility.