RESUMO
We studied the distribution of deletion polymorphisms of GSTT1 and GSTM1 glutathione transferase genes by PCR in patients with stage I and II chronic obstructive pulmonary disease (COPD) and in smokers without COPD. The significance of the differences in allele and genotype distribution between the groups was estimated by the X2 test and BIOSTAT software package. The study revealed a significant rise in the frequency of deletion polymorphisms of GSTT1 transferase genes in patients with stage I COPD compared with controls. The odd ratio between the groups was 0.6 which suggests a two-fold decrease in the risk of COPD. Simultaneous increase in the frequency of "zero" GSTT1 genotype in patients with stage 2 COPD is indicative of rapid progress of the disease in the presence of homozygous deletion of GSTT1. The difference between the frequency of homozygous deletion of GSTM1 was insignificant. The "zero" GSTT1 genotype in heavy smokers was associated with a decreased risk of COPD and may be regarded as a marker of the diminished impact of smoking on the pulmonary function. The homozygous deletion of GSTT1 in patients at the early stages of COPD suggests the risk of its rapid progress. Deletion polymorphism of GSTT1 glutathione transferase gene is recommended to use as a marker for predictive diagnostics of development and progress of COPD.
