Tumor Necrosis Factor-Alpha Polymorphism at Position -238 in Preeclampsia

BACKGROUND Preeclampsia is the most common serious disorder during pregnancy and studies show several immune-related processes in its pathophysiology. The role of cytokines and their expression remains controversial in this field. One of the cytokines of interest in recent studies has been TNF-α, which has been shown to have a higher level in maternal plasma of preeclamptic women. OBJECTIVES This study was designed to evaluate the role of TNF-α polymorphism at position -238 in the risk of developing preeclampsia during pregnancy. PATIENTS AND METHODS One hundred fifty three preeclamptic cases and 140 healthy pregnant women were retrieved from two major hospitals of Mashhad, Iran. Methods a case-control study were designed. Anyone with a history of inflammatory disease, hypertension, or chronic kidney disease was excluded. DNA was extracted from peripheral blood leukocytes. Both groups were genotyped for the polymorphism of the TNF-α gene at position -238 by the RFLP method with Ava II enzyme. Allele and genotype frequencies were compared using one-way ANOVA and the Fisher's exact test. RESULTS There were significant differences between the two groups in TNF-α genotype at position -238 (P < 0.001). In the preeclamptic group, the frequency of the AA genotype was higher (P < 0.001) and the frequency of the GG genotype was lower (P < 0.001). The overall prevalence of the A allele at position -238 was higher in preeclamptic cases (P < 0.001). CONCLUSION In this study group, TNF-α -238 polymorphism was shown to be different in preeclamptic and non-preeclamptic pregnant women. The AA genotype and the A allele may carry an increased risk for developing of preeclampsia.