The Relationship Between SHLA-G Expression Of In Vitro Fertilization Cleavage Stage Embryo And Pregnancy

Human leukocyte antigen G(HLA-G) is a nonclassical classⅠantigen that may play an important role in maternal-fetal immune tolerance.In contrast to the classical HLA-I molecules,HLA-G is characterized by a low polymorphism, limited distribution to normal tissues and seven isoforms resulting from its primary mRNA alternative splicing.Four exist as membrane-anchored molecules (HLA-G1,-G2,-G3,and -G4).The remaining three isoforms(HLA-G5,-G6,and -G7) represent soluble molecules.The HLA-G gene expresses in vascular endothelial cells of fetus chorionic villus,amniotic fluid,proliferating cytotroblast cells of chorionic villus and epithelial tissue of thymus.It plays a role in maternal-fetal tolerance maintaining normal pregnancy.The dilemma that commonly confronts assisted reproduction technology (ART) practitioners is whether to sanction the transfer of multiple embryos in an effort to optimize success rates,or to limit the number of embryos transferred in order to minimize the risk of multiple gestations.sHLA-G expression has been detected in the culture media harbouring groups of 3-day-old cleaved embryos were positively correlated both with cleavage rate and with subsequent implantation potential by Fuzzi et al.,in 2002.Identification of a chemical marker in human embryo culture media that relates to embryo quality and implantation potential could be an invaluable tool in conjunction with morphological parameters in embryo selection for transfer.This study examines sHLA-G concentration in the media surrounding individual 3-day in vitro fertili-zation (IVF)-derived embryos,to determine whether such measurement could serve as a "mark" of embryo selection for transfer.Objective:to measure levels of embryonic secretion of soluble leukocyte antigen G(sHLA-G) from in vitro fertilization(IVF),assisted reproduction technology(ART),to investigate the correlation between soluble HLA-G and clinical pregnancy rates.Methods:selection patients of in vitro fertilization and embryo transfer (IVF-ET) between March and June 2008 in reproductive center of TangDu hospital,collection the cultured individually embryo culture supernatants, sHLA-G concentration were measured by ELISA assay kit.Result:in the eighty four embryo culture supernatants from forty one patients,the positive rate of sHLA-G was 52%(44/84).Concentration of sHLA-G in embryo culture media was variable and in the low range 3-16 ng/ml.When at least one transferred embryos were sHLA-G+,pregnancy rate were 69%,and only embryos transferred that were negative for sHLA-G had a pregnancy rate of 18%,there was a significant difference(P＜0.05);in the thirty one patients who transferred only two embryos from in vitro fertilization.When transferred embryos were sHLA-GH+-,pregnancy rate were 78%,and transferred embryos were sHLA-G--,there was a significant difference(P＜0.0125 ).Conclusion:addition of sHLA-G to traditional morphological criteria may be useful as a clinical tool for embryo selection,predict pregnancy rate of IVF.