Neither IL-1β, IL-1 receptor antagonist, nor TNF-α polymorphisms are associated with susceptibility to COPD

Abstract

The cytokines that contribute to airway inflammation, including interleukin-1β (IL-1β)and tumour necrosis factor α (TNFα), might have key roles in the development of chronic obstructive pulmonary disease (COPD). Interleukin-1 receptor antagonist (IL-1RN), the physiological antagonist of IL-1β, is also known to play a crucial role in several chronic inflammatory diseases. In this study, we investigated the association of the polymorphisms of IL-1β, IL-1RN and TNFα with susceptibility to COPD. To elucidate the genotype of the IL-1β polymorphisms at position - 511 base and at the amino acid residue 105, the IL-1RN polymorphism in intron 2, and TNFα polymorphism at position - 308, polymerase chain reaction (PCR) and restriction enzyme fragment length polymorphism (RFLP) were performed on blood samples from both patients with COPD (n = 53) and control subjects (n = 65). There were no differences on the allele and genotype frequency of IL-1β, IL-1RN, and TNFα between the two groups. We could not find a significant link between the polymorphism of TNFα, which was previously reported to be associated with chronic bronchitis, and COPD. Furthermore, no association between genetic polymorphisms of IL1-β and IL-1RN and individual susceptibility to COPD was found.