RT Journal Article SR Electronic T1 Association of IRF5 Polymorphisms with Susceptibility to Macrophage Activation Syndrome in Patients with Juvenile Idiopathic Arthritis JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 769 OP 774 DO 10.3899/jrheum.100655 VO 38 IS 4 A1 MASAKATSU YANAGIMACHI A1 TAKUYA NARUTO A1 TAKAKO MIYAMAE A1 TAKUMA HARA A1 MASAKO KIKUCHI A1 RYOKI HARA A1 TOMOYUKI IMAGAWA A1 MASAAKI MORI A1 HIDENORI SATO A1 HIROAKI GOTO A1 SHUMPEI YOKOTA YR 2011 UL http://www.jrheum.org/content/38/4/769.abstract AB Objective. Systemic-onset juvenile idiopathic arthritis (systemic JIA) and macrophage activation syndrome (MAS), the most devastating complication of systemic JIA, are characterized by abnormal levels of proinflammatory cytokines. Interferon regulatory factor 5 (IRF5) is a member of the IRF family of transcription factors, and acts as a master transcription factor in the activation of genes encoding proinflammatory cytokines. Polymorphisms in the IRF5 gene have been associated with susceptibility to autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Our aim was to assess associations of IRF5 gene polymorphisms with susceptibility to systemic JIA and MAS. Methods. Three IRF5 single-nucleotide polymorphisms (rs729302, rs2004640, and rs2280714) were genotyped using TaqMan assays in 81 patients with systemic JIA (33 with MAS, 48 without) and 190 controls. Results. There were no associations of the IRF5 gene polymorphisms or haplotypes under study with susceptibility to systemic JIA. There was a significant association of the rs2004640 T allele with MAS susceptibility (OR 4.11; 95% CI 1.84, 9.16; p = 0.001). The IRF5 haplotype (rs729302 A, rs2004640 T, and rs2280714 T), which was reported as conferring an increased risk of SLE, was significantly associated with MAS susceptibility in patients with systemic JIA (OR 4.61; 95% CI 1.73, 12.3; p < 0.001). Conclusion. IRF5 gene polymorphism is a genetic factor influencing susceptibility to MAS in patients with systemic JIA, and IRF5 contributes to the pathogenesis of MAS in these patients.