Association of xenobiotic metabolizing gene polymorphisms and chronic obstructive pulmonary disease in Indian population

Background and Aim: Genetic susceptibility to the development of chronic obstructive pulmonary disease might depend on variation in the activities of enzymes that detoxify cigarette smoke products. We studied the relationship of GSTP1, GSTM1, and GSTT1 gene polymorphisms with COPD risk in a case- control study of Indian patients and controls. Material and methods: A total of 186 patients with COPD and 160 healthy controls were included in the study. The Frequencies of GSTP1, GSTM1 alleles was determined by using conventional Multiplex PCR and GSTP1 by polymerase chain reaction and restriction fragment length polymorphisms technique. Results: A significant case –control difference was observed for the presence of null GSTM1, (61.8% Vs 55.0 %, P= 0.04). No difference was observed in the frequency of GSTT1 Null genotype and COPD susceptibility. (54.8% vs 50.6% OR: 1.26; CI: 0.87- 1.84; P value = 0.82) For GSTP1 polymorphism we found that Subjects homozygous variants Val/ Val were at increased risk of developing COPD (OR: 2.58; CI: 1.2- 4.8) as compared to heterozygote variants Ile/ Val (OR: 1.28 CI: 0.7-2.14) Also, the mutant allele frequency (Val) was significantly higher in patients as compared to controls and the difference was found to be statistically significant. (OR: 1.8 CI: 1.4- 4.2; P Value =0.001) Conclusion: We propose that subjects with GSTM1 null allele and GST P1 homozygous isoleucine genotypes are at higher risk of COPD and are significant indicators of susceptibility to chronic obstructive pulmonary disease in Indian population. Keywords: Chronic Obstructive Pulmonary Disease, Polymerase chain reaction, Gluthathione S- transferase.