Follicular fluid concentration of soluble Human-G Leukocytic Antigen (sHLA-G) in in vitro fertilization cycles of women with and without peritoneal endometriosis

Objective: The objective of this research is to investigate the association between the concentrations of soluble human leukocyte G antigen (sHLA-G) in the follicular fluid (FF) in infertile patients with peritoneal endometriosis submitted to in vitro fertilization. Methods: We performed a cross-sectional study, including ninety-six women undergoing in vitro fertilization (IVF) ageing <= 40 years. Infertile patients were classified into two groups: with endometriosis diagnosed by laparoscopy and without endometriosis due to tubal factor. ELISA measured soluble HLA-G in the FF of a pool of punctured (more than 17mm) follicles from women with endometriosis and without endometriosis who were subjected to ovulation induction for IVF. Embryos obtained after fertilization were classified according to the graduated embryo score (GES). Results: Groups were comparables in terms of age, the number of follicles, AMH, FSH and all included reproductive outcomes. There was no association between sHLA-G concentrations and the average score of the generated embryos (p>0.05). Measurement of sHLA-G in the follicle fluid in women with endometriosis and without endometriosis (tubal factor) showed no significant difference (p>0.05). We also compared sHLA-G per follicle and per embryo, which were not different between both groups (p>0.05). Conclusions: Patients with peritoneal endometriosis submitted to IVF did not demonstrate an altered sHLA-G in the follicular fluid compared to the follicular fluid sHLA-G concentration in tubal factor patients. Also, this molecule was not linked to any other reproductive outcome.