Genetic Polymorphism Of Glutathione-S-Transferase And Susceptibility To And Severity Of Chronic Obstructive Pulmonary Disease

Abstract

Chronic tobacoo smoking is a major risk factor in the development of
COPD. However, it is estimated that only 10-20% of chronic heavy
smokers will develop symptomatic COPD. This indicates the possible
contribution of environmental or genetic cofactors to the development
of COPD in smokers. The present work aimed to study the
relationship between GST polymorphism and susceptibility to and
severity of COPD in smokers. A case control study was done on 140
patients with COPD and 140 matched controls. All subjects were
smokers or exsmokers. The GSTM1 and GSTT1 genotypes were
identified by polymerase chain reaction in peripheral blood DNA
samples. Analysis of data was done by IBM computer using SPSS
program. Results shown that the proportion of GSTM1-null genotypes
was significantly higher in patients with COPD than in control
subjects (62.2% versus 32.2%). The odds ratio was 3.5 (95%
confidence interval (CI) =2.1-5.7). Moreover the patients with
GSTM1 null genotype were at high risk of developing the severe type
of COPD. The odds ratio was 3.2 and (95% CI= 1.5-6.7). However the
genotype frequencies of GSTT1-null genotype did not show
significant difference between groups. Our data provide evidence that
smokers with null genotype of GSTM1 were more susceptible to
develop the severe type of COPD.

Key words: COPD ,Genetic polymorphism, GSTT1, GSTM1.