Association of polymorphisms of cytokine genes (IL1B, IL1RN, TNFA, LTA, IL6, IL8, and IL10) with chronic obstructive pulmonary disease

Abstract

To assess the role that polymorphisms of cytokine genes play in genetic predisposition to chronic obstructive pulmonary disease (COPD), the allele and genotype distributions of IL1B, IL1RN, TNFA, LTA, IL6, IL8, and IL10 were studied in COPD patients (N = 319) and healthy individuals (N = 403), residents of Ufa, Bashkortostan. Genotype IL1RN*2/IL1RN*2 of IL1RN was identified as a risk factor for COPD, its frequency being 9.80% in the COPD patients and 4.67% in the healthy subjects (x 2 = 5.45, df = 1, P = 0.02, OR = 2.21). Genotype GG of the LTA polymorphism A252G was significantly more common in the COPD patients than in the controls (7.84% vs. 3.72%; x 2 = 5.00, df = 1, P = 0.026). In patients with COPD stage IV, the frequency of this genotype was twice as high as in those with COPD stages II and III (11.18% vs. 4.79%; x 2 = 3.08, df = 1, P = 0.08). Genotype GG of the TNFA polymorphism G(−308)A in combination with genotype AA of the LTA polymorphism A252G was significantly less frequent in the COPD patients than in the healthy subjects (38.55% vs. 46.93%; x 2 = 8.82, df = 1, P = 0.0039). Genotype GG of the IL6 polymorphism G(−174)C was more frequent in the patients with COPD stage IV (43.75% vs. 31.54% in the patients with COPD stages II and III, x 2 = 4.15, P = 0.042). No significant differences were found between the groups of COPD patients and healthy subjects concerning the genotype frequencies of the polymorphisms T(−511)C and T3953C of IL1B, G(−308)A of TNFA, G(−174)C of IL6, A(−251)C of IL8, and C(−627)A of IL10.