Single-nucleotide polymorphisms of TNFA and IL1 in allergic rhinitis.

BACKGROUND Allergic rhinitis is a complex polygenic disorder of the upper respiratory tract. Given that proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin (IL) 1 seem to play a role in the development of allergic rhinitis, we evaluated the associations between various single-nucleotide polymorphisms (SNPs) of the TNF and IL1 genes in a case-control study. METHODS The study population comprised 98 patients with allergic rhinitis. Genotyping was performed using polymerase chain reaction with sequence-specific primers for 2 TNFA promoter variants (rs1800629 and rs361525), 1 variant in the promoter region of IL1A (rs1800587), 2 SNPs in the IL1B gene (rs16944 and rs1 143634), 1 variant in the IL1 receptor (rs2234650), and 1 in IL1RA (rs315952). RESULTS Patients who were homozygous for the T allele of rs16944 in IL1B had an 8.1-fold greater risk of allergic rhinitis than those with the C allele. In TNFA, a significant relationship was also detected between rs1800629 and rs361525 and allergic rhinitis. Except for rs1800587 in IL1A and rs315952 in IL1RA, significant differences were found between the patient and control groups for all other SNPs. CONCLUSIONS We found that allelic variants in the TNFA and IL1 genes were not only associated with the risk of developing allergic rhinitis, but also affected disease course and severity.