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 24.48 U/ml, respectively, p < 0.001). However, no significant association was observed between the HLA-G 14 bp 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 14 bp polymorphism and serum sHLA-G level in different ethnic populations of PE should be taken into consideration.

Evaluation of Exhausted Regulatory T Cells in Preeclampsia.

BACKGROUND: The development of a maternal immune response to fetal antigens and deficiency in regulatory T-cells (Tregs) may lead to preeclampsia. A plausible explanation for the reduced Treg cell function in women with preeclampsia is the presence of exhausted Treg cells which express CD279 or programmed cell death receptor-1 (PD-1), a negative regulatory molecule associated with limited proliferative capacity and reduced immune suppression. OBJECTIVE: To assess the number of Treg CD4+ CD25 high and exhausted Treg CD4+ CD25 high CD279+ cells in women with preeclampsia (PE group) and healthy pregnant women (HP group) during the third trimester of pregnancy. METHODS: Three-color flow cytometry was used to determine the proportion of Treg and exhausted Treg cells in 40 women in the PE group and 37 women in the HP group. Participants' blood samples were placed in EDTA blood collection tubes. Peripheral mononuclear cells were separated from the samples and stained with flurochrome-conjugated antibodies against human CD4, CD25 and CD279 markers, and subsequently analyzed by flow cytometry. RESULTS: The PE group had fewer Tregs compared to the HP group (p=0.011). There was a significant increase in the percentage of exhausted PD-1+(CD279) Tregs (p=0.035) in the PE group comparisons with the HP group. CONCLUSION: The increased number of PD-1 (CD279) molecules on the Treg cells may play a role in preeclampsia, hence it recommendation as a therapeutic target for the disease.