Association of glutathione S-transferase polymorphisms with the severity of mustard lung

Abstract

<i><b>Introduction:</b></i> Glutathione S-transferase (GST) is one of the major detoxifiers in alveoli. Polymorphism in GST genes can influence the ability of individuals to suppress oxidative stress and inflammation. The present study was aimed to explore the hypothesis that the genetic polymorphisms of GST <i>T1</i>, <i>M1</i> and <i>P1</i> are associated with the severity of the mustard lung in the sulfur mustard-exposed individuals. <i><b>Methods:</b></i> Blood samples were taken from 185 sulfur mustard-exposed and 57 unexposed subjects. According to the stage of the mustard lung, sulfur mustard-exposed patients were categorized in the mild/moderate and severe/very severe groups. A multiplex PCR method was conducted to identify <i>GSTM1</i> and <i>GSTT1</i> null genotypes. To determine the polymorphisms of GSTP1 in exon 5 (Ile105Val) and exon 6 (Ala114Val), RFLP-PCR method was performed. <i><b>Results:</b></i> The frequency of <i>GSTM1</i> homozygous deletion was significantly higher in the severe/very severe patients compared with the mild/moderate subjects (66.3% vs. 48%, <i>P</i> = 0.013). The <i>GSTM1</i> null genotype was associated with the severity of mustard lung (adjusted odds ratio [OR], 2.257; 95% CI, 1.219-4.180). There was no significant association between <i>GSTT1</i> and <i>GSTP1</i> polymorphisms with the severity of the mustard lung. <i><b>Conclusion:</b></i> The different distribution of <i>GSTM1</i> null genotype in severe/very severe and mild/moderate groups indicated that the severity of the mustard lung might be associated with the genetic polymorphism(s).