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

Abstract Objective and design: A case-control study evaluated the association of the IL36G C>T (rs13392494) and the IL36G A>G (rs7584409) variants with susceptibility, joint involvement and severity of psoriasis (PsO). Material: 154 PsO patients and 154 controls were included. The Classification Criteria for Psoriatic Arthritis and the Psoriasis Area and Severity Index (PASI) were determined. The variants were genotyped using the real-time polymerase chain reaction. Results: PsO patients were older and had higher body mass index than controls (p 10. The IL36G rs1339294 variant showed no association with PsO while the IL36G rs7584409 variant showed a protective effect in PsO. The G allele of the IL36G rs7584409 was positively associated with PASI >10 (p=0.031) and the GG genotype of this variant was associated with the presence of PsA (p=0.014). The C/A haplotype in a recessive model (CACA versus C/G and T/A carriers) was associated with PsO (p=0.035) while the C/G haplotype in a dominant model (C/A carriers versus C/G and T/A carriers) showed a protective effect for PsO (p=0.041). Conclusion: The G allele of the IL36G rs7584409 variant was associated with protection to PsO, higher PASI and PsA than the A allele suggesting that this variant may be a potential genetic biomarker to predict severity and joint involvement of the PsO.