Contrasting genetic association of IL2RAwith SLE and ANCA – associated vasculitis

AbstractBackgroundAutoimmune diseases are complex and have genetic and environmental susceptibility factors. The objective was to test the genetic association of systemic lupus erythematosus (SLE) and anti-neutrophil cytoplasmic antibody (ANCA) – associated systemic vasculitis (AAV) with SNPs in theIL2RAregion and to correlate genotype with serum levels of IL-2RA.MethodsUsing a cohort of over 700 AAV patients, two SLE case-control studies and an SLE trio collection (totalling over 1000 SLE patients), and a TaqMan genotyping approach, we tested 3 SNPs in the IL2RA locus, rs11594656, rs2104286 & rs41295061, each with a prior association with autoimmune disease; rs11594656 and rs41295061 with type 1 diabetes (T1D) and rs2104286 with multiple sclerosis (MS) and T1D.ResultsWe show that SLE is associated with rs11594656 (P= 3.87 × 10-7) and there is some evidence of association of rs41295061 with AAV (P= 0.0122), which both have prior association with T1D. rs2104286, an MS and T1D – associated SNP in theIL2RAlocus, is not associated with either SLE or AAV.ConclusionWe have confirmed a previous suggestion that theIL2RAlocus is associated with SLE and showed some evidence of association with AAV. Soluble IL-2RA concentrations correlate with rs11594656 genotype in quiescent disease in both AAV and SLE. Differential association of autoimmune diseases and SNPs within theIL2RAlocus suggests that theIL2RApathway may prove to play differing, as yet undefined, roles in each disease.