Tumor necrosis factor‐α gene promoter polymorphism is not associated with smoking‐related COPD in Thailand

OBJECTIVE: Susceptibility to COPD is, in part, genetically determined. Tumour necrosis factor (TNF)-alpha gene promoter polymorphisms have been investigated in different populations with inconsistent results. This study aimed to determine the genetic predisposition in Thai smoking-related COPD patients. METHODOLOGY: The polymorphism at position -308 of the TNF-alpha gene promoter was examined in 57 patients with smoking-related COPD, 67 smoker control subjects, and 116 control anonymous blood donors. Genomic DNA from peripheral blood lymphocytes was used for genotypic analysis by polymerase chain reaction with sequence specific primers. RESULTS: TNF-alpha-308*2 allele frequency was not significantly different between the population control subjects and the smoking-related COPD patients (4.7% vs. 7.9%, P= 0.14). This allele frequency was also not significantly different between smokers with and without COPD (7.9% vs. 7.5%, P= 0.46). CONCLUSIONS: Although it has been speculated that TNF-alpha might have a causal relationship with COPD, a role for the TNF-alpha gene promoter polymorphism in disease development in Thailand was not demonstrated.