Detection of all isoforms of human leukocyte antigen G in maternal serum could be clinically applied for prediction of preeclampsa

Abstract

Previously, a number of previous studies on human leukocyte antigen G (HLA-G) and preeclampsia (PE) have demonstrated that expression of HLA-G is significantly reduced in women with PE. However, no study has confirmed whether maternal serum HLA-G could be used as a clinical test when HLA-G1/-G5 isoforms were measured. Therefore, the present study is to develop a novel HLA-G ELISA which is able to detect all isoforms of HLA-G and then to perform a retrospective case-control study to investigate clinical significance of maternal serum HLA-G for predicting PE. A recombinant HLA-G fragment which containing partial sequences of HLA-G α1 and α2 domains was constructed to develop two novel monoclonal antibodies against HLA-G. A novel HLA-G sandwich ELISA which could detect all isoforms of HLA-G was developed. By using the ELISA, predictive effectiveness of maternal serum HLA-G in a retrospective case control study was evaluated. At the first trimester and early second trimester, detection of maternal serum HLA-G had the sensitivity of 54.3% and 48.5% and the specificity of 97.8% and 96.3% in the prediction of PE. These were significantly higher than those at the third trimester (P<0.05). HLA-G isoforms other than HLA-G1/-G5 are expressed in some pregnant women who have low level or lack HLA-G1/-G5. Measurement of all HLA-G isoforms in maternal serum could be used as a clinical test for early prediction of PE.