Interleukin-6 and tumor necrosis factor-alpha gene polymorphisms in chronic idiopathic urticaria

<b>Background</b>\ud \ud - This study was performed to evaluate association of gene polymorphisms among proinflammatory cytokines and susceptibility to chronic idiopathic urticaria (CIU).\ud Methods\ud \ud - Ninety patients with prolonged urticaria more than 6 weeks were included as case group. Single nucleotide polymorphisms (SNPs) of IL-6 (G/C −174, G/A nt565) and TNF-α (G/A −308, G/A −238) were evaluated, using polymerase chain reaction (PCR); and the results were compared to the control group.\ud \ud <b>Results</b>\ud \ud - G allele was significantly higher in the patients at locus of −238 of promoter of TNF-α gene (p<0.001). Frequency of following genotypes were significantly lower in patients with CIU, compared to controls: AG at −308 and GA at −238 of TNF-α gene (p<0.05 and p<0.001, respectively), CG at −174 and GG at +565 of IL-6 gene (p<0.05). Additionally, following genotypes were more common among patients with CIU: GG at −308 and −238 of TNF-α gene (p<0.05 and p<0.001, respectively), GG at −174 and GA at +565 of IL-6 gene (p<0.05).\ud \ud <b>Conclusions</b>\ud \ud - Pro-inflammatory cytokine gene polymorphisms can affect susceptibility to CIU. TNF-α promoter polymorphisms as well as IL-6 gene polymorphisms are associated with CIU