The TNF-α-308G/A Gene Polymorphism and Serum TNF-α Levels in Women With Preeclampsia

Objective: Worldwide, preeclampsia (PE) is a multifactorial disorder reported in 2-5% of pregnancies, which increases mortality during pregnancy. In general, 10-15% of maternal deaths are directly related to PE and eclampsia. One of the susceptibility genes for PE is tumor necrosis factor-α (TNF-α) expressed by most immune cells. TNF-α is a protein involved in various biological processes, including proliferation and apoptosis, as well as the expression of inflammatory genes. The goal of this study was to investigate the role of TNF-α single nucleotide polymorphism (SNP) -308G/A (rs1800629) and their relationship with TNF-α in PE patients. Materials and methods: The SNP was genotyped in 90 cases and 90 controls. Whole blood was collected from women with PE and normal pregnancy in EDTA containing tubes, and DNA extraction was performed from their blood lymphocytes according to a standard phenol-chloroform procedure. Then, DNA was genotyped by real-time PCR and the polymorphism was detected by TaqMan assay. Serum levels of TNF-α protein were measured by enzyme-linked immunosorbent (ELISA) assay. Results: TNF-α levels in women with PE were significantly higher than in healthy ones (p<0.001). We did not observe any correlation between allelic outbreak (p=0.3) and TNF-α-308G/A polymorphism (p=0.7) with the incidence of PE. Conclusion: Although TNF-α-308G/A gene polymorphism does not appear to affect susceptibility to PE, an increased level of serum TNF-α can be used as a predictor for PE during pregnancy. We recommend that more research be conducted on possible factors related to the incidence of PE.