The role of microRNA-146a (miR-146a) and its target IL-1R-associated kinase (IRAK1) in psoriatic arthritis susceptibility.

MicroRNAs have shown different expression patterns in immune diseases. The present study explores the association of miRNA-146a variant rs2910164 and of two IRAK1 (target of miR-146a) polymorphisms rs3027898 and rs1059703 with psoriasic arthritis (PsA). Twenty-nine PsA and 66 controls were enrolled in the study. To study if the statistical significant differences between patients with PsA and controls are independent to psoriasis, we expanded the study in 49 patients with ankylosing spondylitis (AS). Strong statistical significant difference was observed in IRAK1 rs3027898 polymorphism distribution between patients with PsA and controls (P = 0.003), as between patients with AS and controls (P < 0.001). Marginally significant difference was observed in distribution of IRAK1 rs1059703 genotypes between patients with PsA and controls (P = 0.058), but no difference was observed in miRNA-146a rs2910164 distribution (P = 0.394). This is the first study that addresses IRAK1 rs3027898 polymorphism association with PsA susceptibility, but further studies could help to understand the extent of the proposed association.