Lack of Association Between the TGF-β1 Gene and Development of COPD in Asians: A Case–Control Study and Meta-analysis
BACKGROUND The main risk factor for chronic obstructive pulmonary disease (COPD) is cigarette smoking. However, only 10% - 20% of chronic heavy smokers develop systematic COPD. We hypothesized that the inheritance of gene polymorphisms could influence the development of COPD, which was investigated by studying two single nucleotide polymorphisms (SNP) in exon 1 of the transforming growth factor-beta1 (TGF-beta1) gene. METHODS We enrolled 219 patients with COPD as the research group and 148 healthy people as the control group, all of whom were Chinese Han people. The polymorphisms of the TGF-beta1 gene, 869T/C and 915G/C, were analyzed using the method of amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). RESULTS The occurrence of the TGF-beta1 gene 869T/C polymorphism in patients with COPD was significantly different from the control group (P < 0.05), in which the relative risk of this disease increased in cases who had the C allele (OR: 1.131, 95%CI: 1.101 - 1.539). There was no increased frequency of TGF-beta1 915G/C gene in COPD patients compared with control subjects (P > 0.05). CONCLUSIONS The polymorphism 869T/C in TGF-beta1 gene has a significant association with disease occurrence in COPD patients and the C allele might be a risk factor. The homozygous wild-type CC of 869T/C on TGFbeta1 could be a predisposing factor in COPD and those who carry the C allele might have particularly susceptibility to developing COPD.