IL36G genetic variant is independently associated with susceptibility, severity and joint involvement in psoriasis

Abstract Objective/Design: A case-control study aims to evaluate the frequency of the IL36G C>T (rs13392494) and the IL36G A>G (rs7584409) variants and their association with susceptibility, joint involvement and severity of psoriasis (PsO). Subjects and Methods: The study included 154 patients with PsO and 154 controls from Brazilian population. The IL36G (rs13392494 and rs7584409) variants were genotyped by allelic discrimination assay using the real-time polymerase chain reaction. The severity of PsO was assessed using the Psoriasis Area and Severity Index (PASI). Results: Plaque PsO, PsA, and PASI > 10 were observed among 95.8%, 16.1%, and 27.9% of patients, respectively. The IL36G rs7584409 variant showed a protective effect in PsO whereas the IL36G rs13392494 variant was not associated with susceptibility to PsO. The G allele of the IL36G rs7584409 in heterozygosis and homozygosis (dominant model) was positively associated with PASI >10 and the GG genotype of this variant was associated with the presence of PsA. Conclusion: The presence of the G allele of the IL36G rs7584409 variant was associated with protection to PsO, higher PASI and the presence of PsA than the A allele suggesting that this variant may be used as a potential genetic biomarker to predict severity and joint involvement of the PsO.