Association between single nucleotide polymorphisms IL17RA rs4819554 and IL17E rs79877597 and Psoriasis in a Spanish cohort.

Background: The IL17 pathway plays an important role in the pathogenesis of psoriasis (PsO). Objectives: To determine whether the variation at the IL17 pathway genes was linked to the risk for PsO or had an effect on disease severity and the risk for Psoriatic arthritis (PsA). Methods: Cross-sectional observational study of 580 psoriasis patients and 567 healthy controls who were genotyped for six single nucleotide polymorphisms (SNPs) in the IL17RA (rs4819554, rs879577), IL17A (rs7747909), IL17F (rs763780, rs2397084), and IL17E (rs79877597) genes. Results: We found significant higher frequencies of IL17RA rs4819554 G carriers among the patients (OR = 1.33, 95%CI = 1.05-1.69; p = 0.017). The IL17RA rs4819554 G allele and IL17F rs2397084 TT genotype were significantly more frequent among Cw6 positive patients (p = 0.037 and p = 0.010, respectively). The IL17E rs79877597C allele was significantly more common among patients with severe forms of PsO (p = 0.010; OR = 2.42, 95%CI = 1.23-4.76), and the CC genotype with the presence of arthritis (p = 0.032; OR = 1.50, 95%CI = 1.04-2.18). Conclusions: We identified the IL17RA rs4819554 SNP as a risk factor for PsO. The IL17E rs79877597 SNP was a modifier of the risk for PsO disease severity and PsA. (C) 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.