The Expression Of Soluble Human Leukocyte Antigen G In Severe Preeclampsia

Preeclampsia is a kind of pregnancy induced hypertension, and a multisystem disorder of human pregnancy. It is characterized by hypertension, proteinuria, edema and lead to impairments to many organs. More serious syndromes include convulsion, coma, heart failure, cerebral hemorrhage, placental abruption and DIC. It is one of the leading causes of maternal and fetal mortality. The pathogenesis of this disease has remained unknown. It is mainly relevant to the shallow infiltrate of trophoblast and the injury of endotheliocyte. The symptoms will vanish quickly after birth indicates that fetus and placenta play important effects. Fetus can growth successfully in the maternal uterus and avoid the rejection effect, mainly because trophoblast express a human nonclassic major histocompatibility compex (MHC) molecul: human leukocyte antigen G (HLA-G). HLA-G encods seven kinds of protins, including four membrane-bound (mHLA-G) and three soluble forms (sHLA-G). HLA-G is constitutively expressed on trophoblasts, fetal endothelial and epithelial cells during pregnancy. HLA-G is also expressed in some malignancies and on macrophages and dendritic cells (DC) in tumoral and inflammatory diseases. It has been detected in human peripheral blood, cord blood, amniotic fluid, lymph fluid, etc. Its distribution still need to be clarified.sHLA-G can spread all over the body through the circulation system, so to play the systematically immunoregulation role. The abonormal expression may lead to pathological pregnancy. This study compare the level of sHLA-G in plasma, in placenta and in placenta tissue culture supernatant of patients with preeclampsia and normal pregnancy, to explore the origin of sHLA-G and its significance in preeclampsia.Objective: we sought to evaluate the levels of sHLA-G protein in plasma, in placenta tissue culture supernatant of patients with severe preeclampsia during the third trimester, and to detect its isoforms mRNA in the same samples to explore the origin of sHLA-G and its significance in preeclampsia.Methods:â‘ Enzyme linked immunosorbent assay (ELISA) was used to detect the level of sHLA-G in plasma in preeclampsia group (n = 20) and in normal pregnancy group (n = 20) from October of 2008 to April 2009 in Tangdu hospital. Then detect its expression in the same person's placenta tissue culture supernatant.â‘¡Real-time fluorescence quantitative PCR was used to compare the expression of different isoforms mRNA of sHLA-G(HLA-G5, G6, G7)in preeclampsia and normal pregnancy.Results:â‘ The plasma level of sHLA-G in preeclampsia group was lower than that in normal pregnancy group (P < 0.05).â‘¡The level of sHLA-G in placenta tissue culture supernatant in preeclampsia group was lower than in normal pregnancy group (P < 0.05).â‘¢The expression of HLA-G5, G6 mRNA in preeclampsia group was lower than in control group, and the expression of HLA-G7 mRNA has no significant difference between the two groups. Conclusion:A reduced level of sHLA-G protein in plasma and in placenta tissue culture supernatant and the lower expression of placenta tissue HLA-G5, G6 mRNA during the third trimester may associate with the pathogenesis of preeclampsia, and placenta maybe one of the origin of sHLA-G in plasma.