Association of tumor necrosis factor alpha gene promoter polymorphism with the presence of chronic obstructive pulmonary disease.

Tumor necrosis factor alpha (TNF-alpha), a potent proinflammatory cytokine, may be involved in the development of chronic obstructive pulmonary disease (COPD). The production of TNF-alpha is elevated in the airways of these patients. A polymorphism at position -308 of the TNF-alpha gene promoter (TNF-alpha-308*1/2) is known to be associated with alteration of TNF-alpha secretion in vitro. In this study we examined the differences in TNF-alpha-308*1/2 allele frequency to investigate the association of this polymorphism with the presence of smoking-related COPD. TNF-alpha-308*1/2 allele frequency in 106 patients (73 men and 33 women) was compared with 110 asymptomatic smoker/ex-smoker control subjects matched for sex and age and population control subjects consisting of 129 blood donors. Genotype was analyzed by the polymerase chain reaction-restriction fragment length polymorphism technique on genomic DNA isolated from peripheral blood lymphocytes. TNF-alpha-308*1/2 allele frequencies were significantly different among the groups: 0.835/0.165 in patients with COPD, 0.918/0.082 in smoker/ex-smoker control subjects, and 0.922/0.078 in population control subjects. These results indicate that TNF-alpha-308*1/2 alleles are significantly associated with the presence of smoking-related COPD.