AB0019 A genetic association between juvenile idiopathic arthritis and the il10 polymorphism
Authors: V. A. Malievsky, T. V. Viktorova, K. V. Danilko, L. Nazarova
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Juvenile idiopathic arthritis (JIA) is a generic term for arthritis that has an onset before the age of 16 and persists for more than 6 weeks. JIA is probably a collection of diseases with complex overlapping etiologies, with each subtype influenced by multiple genetic susceptibility loci and mediated by environmental effects [1]. Such genes as <i>IL10</i>, <i>IL2RA</i> [2], <i>IL2-21</i> [3], show some evidence of association with clinically distinct autoimmune phenotypes in different populations. <h3>Objectives</h3> The goal of the study was to test the hypothesis that variants of <i>IL10, IL2RA, IL2-21</i> genes could underlie susceptibility to different subtypes of JIA in patients from Russia. <h3>Methods</h3> Allele and genotype frequencies of <i>IL10</i> (rs1800872), <i>IL2RA</i> (rs2104286), <i>IL2-21</i> (rs6822844) SNPs were assessed using RCR-RFLP method. A cohort of 135 JRA patients and 97 healthy controls from Bashkortostan, Russia was tested. Patients were diagnosed according to the ILAR criteria [4]. There were 58 persistent oligoarthritis, 40 rheumatoid factor (RF)-negative polyarthritis and 38 other subtypes patients. Chi-square (χ<sup>2</sup>) test and odds ratio (OR) were estimated to evaluate the association. <h3>Results</h3> All SNPs were in Hardy Weinberg Equilibrium. The genotype CC and allele C of <i>IL10</i> conferred risk to the JIA cohort as a whole (p=0,007, OR=2,203 95%CI 1,287-3,769 and p=0,006, OR=1,824 95%CI 1,210-2,749, correspondingly). A dominant model improved the OR (for AA+CA genotypes p=0,0041, OR=0,46 95%CI 0,27-0,79). When analyses were repeated after stratification by subtypes, the data were significant only in the persistent oligoarthritis cohort: the genotype CC and allele C at <i>IL10</i> SNP were associated with disease susceptibility (p=0,003, OR=3,057 95%CI 1,527-6,122 and p=0,003, OR=2,541 95%CI 1,442-4,476, correspondingly). But this patients group was the biggest. For the <i>IL2RA</i> and <i>IL2-21</i> polymorphisms no difference was observed in allele and genotype frequencies between JIA patients and controls. <h3>Conclusions</h3> We have demonstrated associations of <i>IL10</i> variant with persistent oligoarthritis in patients from Bashkortostan, Russia. Our results confirmed partly that clinically distinct autoimmune phenotypes share common genetic susceptibility factors in JIA patients. <h3>References</h3> Glass DN, Giannini EH. Juvenile rheumatoid arthritis as a complex genetic trait. Arthritis Rheum. 1999. Nov;42(11):2261-8. Hinks A, Ke X, Barton A, Eyre S, Bowes J, Worthington J, Thompson SD, Langefeld CD, Glass DN, Thomson W; UK Rheumatoid Arthritis Genetics Consortium;British Society of Paediatric and Adolescent Rheumatology Study Group. Association of the IL2RA/CD25 gene with juvenile idiopathic arthritis. Arthritis Rheum. 2009. Jan;60(1):251-7. Hinks A, Eyre S, Ke X, Barton A, Martin P, Flynn E, Packham J, Worthington J. Childhood Arthritis Prospective Study; UKRAG Consortium; BSPAR Study Group, Thomson W. Association of the AFF3 gene and IL2/IL21 gene region with juvenile idiopathic arthritis. Genes Immun. 2010. Mar;11(2):194-8. Petty RE, Southwood TR, Manners P, Baum J, Glass DN, Goldenberg J, He X, Maldonado-Cocco J, Orozco-Alcala J, Prieur AM, Suarez-Almazor ME, Woo P. International League of Associations for Rheumatology. International League of Associations for Rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001. J Rheumatol. 2004. Feb;31(2):390-2. <h3>Disclosure of Interest</h3> None Declared