The 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is not associated with HELLP syndrome

Abstract

Plasminogen activator inhibitor-1 (PAI-1) is a major inhibitor of fibrinolysis, and a single nucleotide insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene has been identified. Subjects homozygous for the 4G allele have the highest PAI-levels due to increased PAI-1 gene transcription. Pre-eclampsia, and one of its most severe forms, the HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, are characterized by increased placental thrombosis based on a procoagulatory state in the mother. Several studies have investigated the role of the PAI-1 4G/5G polymorphism in pre-eclampsia, but no study has focused especially on HELLP syndrome. Therefore we aimed to assess the association between HELLP syndrome and the 4G/5G polymorphism in the PAI-1 gene. Genotyping of the PAI-1 4G/5G promoter polymorphism was performed in 102 Caucasian women with HELLP syndrome and 102 Caucasian women with uncomplicated pregnancies. The 4G/4G genotype was more frequent in women with HELLP syndrome than in controls (35.3% vs. 22.5%, respectively) but this difference was not significantly different (P = 0.129). The frequency of the 4G allele was 0.588 in patients and 0.515 in controls. These data suggest that women carrying a 4G/4G genotype of the PAI-1 gene are not at increased risk for developing HELLP syndrome and are thus in line with the majority of previous studies on the association between the PAI-1 4G/5G polymorphism and pre-eclampsia.