ABSTRACT
Pregnancy is a successful transplantation. Factors evading rejection of the fetus by the mother's immune system are poorly understood and success rate and maintenance of embryos in assisted reproductive technologies [ART] may also depend on the same factors. The molecules of HLA-G are non-classical major histocompatibility complex class I antigens that have recently attracted attention in regards to pregnancy. The aim of the present study was to determine the concentration of HLA-G and its correlation with success or failure rates of ICSI. Serum samples of 107 women who were undergoing ICSI [the case group] were collected before and 14 days after embryo transfer, as were serum samples of 24 women with normal pregnancy [the control group] in the first trimester of pregnancy. Soluble HLA-G1 and G5 isoforms and the total sHLA-G were assayed by sandwich ELISA. Nonparametric Kolmogorov-Smirnov [K-S], Mann Whitney U and Wilcoxon tests were used for statistical analysis. No significant differences were observed in clinical variables including age, infertility duration and treatment regimen between the control and the case groups. Levels of sHLA-G1 and sHLA-G5 and the total sHLA-G prior and after ICSI in the control group, respectively, were 47.4 +/- 62.8 U/ml, OD: 1.47 +/- 0.58 prior and 59.6 +/- 69.5 U/ml, OD: 1.38 +/- 0.57 after ICSI. In the non-pregnant group, the values respectively were 35.7 +/- 55.2 U/ml, OD: 1.37 +/- 0.45 prior and 39.7 +/- 57.2 U/ml, OD: 1.31 +/- 0.46 after ICSI, corresponding to the control group; 53.16 +/- 47.92 U/ml and OD: 1.29 +/- 0.49. No significant statistical differences were found between the pregnant, nonpregnant and the control groups. No significant changes in the serum levels of sHLAG1 and sHLA-G5 isoforms and the total sHLA-G were observed following embryo transfer. No significant correlation was found between sHLA-G and the success of pregnancy in women undergoing ART. It seems that serum HLA-G has no prognostic value in the prediction of ICSI failure
ABSTRACT
Pregnancy is a successful transplantation. The factors evading rejection of the fetus are poorly understood. Recently an interest has grown, in HLA-G molecules as one of these factors. Since these antigens are mainly expressed on the surface of cytotrophoblasts that are in direct contact with maternal tissues, it has been suggested that these molecules may have a role in induction of immune tolerance in mothers. To find the association of soluble HLA-G [sHLA-G] and the success of pregnancy with intracytoplasmic sperm injection [ICSI] procedure. In this study, the supernatant of 287 individually cultured embryos corresponding to 96 women under ICSI procedure were assayed for soluble HLA-G1 and G5 by a sandwich ELISA. Clinical pregnancy successfully occurred in 30 of candidates. No differences in clinical parameters [age, infertility duration, stimulation regimen] were observed between pregnant and nonpregnant women under ICSI procedure. None of the embryo supernatants in either group showed any detect-able sHLA-G molecules. Our results showed that detectable level of sHLA-G is not produced by day 2 embryos and such a measurement may not provide reliable information for embryo selection and estimation of pregnancy success