Abstract
Background
The fact that only 10-20% of chronic cigarette smokers develop chronic obstructive pulmonary disease (COPD) reflects the presence of genetic factors associated with the susceptibility to COPD. Recently, it was reported that the surfactant protein A increases the secretion of matrix metalloprotease 9, which degrades extracellular matrices of the lung, through a Toll-like receptor 2 (TLR2). In this context, possible role of TLR2 in the pathogenesis of COPD was postulated, and a functional dinucleotide repeat polymorphism in intron II of TLR2 was evaluated for any association with COPD.
Method
Male patients with COPD and male smokers with a normal pulmonary function were enrolled in this study. The number of Guanine-Thymine repeats in intron II of the TLR2 gene were counted. Because the distributions of the repeats were trimodal, the alleles were classified into three subclasses, 12-16 repeats: short (S) alleles; 17-22 repeats: medium length (M) alleles; and 23-27 repeats: long (L) alleles.
Result
125 male patients with COPD and 144 age- and gender-matched blood donors with a normal lung function were enrolled. There were no differences in the distribution of each allele subclass (S, M and L) between the COPD and control group (p=0.75). The frequencies of the genotypes with and without each allele subclass in the COPD and control group were similar.