Association between HLA-G 14bp Gene Polymorphism and Serum sHLA-G Protein Concentrations in Preeclamptic Patients and Normal Pregnant Women

Background: Preeclampsia (PE) is a multisystem syndrome that is a primary source of fetal-maternal morbidity and mortality. Human leukocyte antigen-G (HLA-G) is a nonclassical Major histocompatibility complex (MHC) class-Ib molecule expressed on the extravillous trophoblast and seems to have immunomodulatory functions during pregnancy. The purpose of our study was to investigate whether HLA-G may be a vital marker in the modulation of the pregnancy.Methods: In this case-control study, a number of 150 healthy pregnant women and 150 patients with PE had been genotyped for the 14 base-pair (bp) insertion/deletion polymorphism in exon 8 of the HLA-G gene, and the serum level of soluble HLA-G (sHLA-G) protein was measured using the enzyme-linked immunosorbent assay.Results: Data showed that the PE syndrome was not related to the HLA-G 14 bp genotype. But, the serum level of sHLA-G in PE patients was significantly lower than that in healthy pregnant women in the third trimester (11.74 and 24.48U/ml, respectively, p<0.001). However, no significant association was observed between the HLA-G 14bp genotype and serum sHLA-G level.Conclusion: Our results demonstrate that measurement of sHLA-G protein level may be helpful as a primary diagnosis for the pathogenesis of PE. Overall, this study suggests that the association between HLA-G 14bp polymorphism and serum sHLA-G level in different ethnic populations of PE should be taken into consideration.