Promoter region polymorphisms in the transforming growth factor beta-1 (TGFβ1) gene and serum TGFβ1 concentration in preeclamptic and control Iranian women

Preeclampsia (PE) is a pregnancy associated disorder characterized by hypertension and proteinuria, which causes neonatal and maternal morbidity and mortality. The Th1/Th2 cytokine paradigm of the immune adaptation in pregnancy is now expanded to include Th1/Th2/Th17 and regulatory T (Treg) cells. Among cytokines, TGFβ1 has properties that justify evaluation of its role in PE etiopathology. In this investigation the polymorphisms of the TGFβ1 gene at promoter region, positions −800G→A and −509C→T, were studied in 142 PE and 140 normal pregnant female subjects using PCR-RFLP. Additionally, serum TGFβ1 was determined by ELISA. At position −800G→A genotypes and allele frequencies showed no significant differences between PE patients (GG 73.9%; GA 21.1%; AA 4.93%) and normal control (GG 70%; GA 28.6%; AA 1.4%) women. However the AA genotype at this position was more frequent in PE patients than in the control group. At −509C→T position, genotypes and allele frequencies showed no significant differences between PE patients and control individuals. The CC genotype at −509C→T position was more prevalent in PE patients than in the control group. The mean serum TGFβ1 level was significantly higher (62.14 ng/ml) in PE patients compared with pregnant and non-pregnant control groups (and 47.01 and 40.68 ng/ml, respectively). In conclusion, the promoter region polymorphisms of TGFβ1 may not be associated with PE, but serum levels of this cytokine may contribute to the etiopathology of PE.