Analysis of MHC region genetics in Finnish patients with juvenile idiopathic arthritis: evidence for different locus-specific effects in polyarticular vs pauciarticular subsets and a shared DRB1 epitope.
This study used Finnish juvenile idiopathic arthritis (JIA) probands with pauciarticular and rheumatoid factor (RF) negative polyarticular subtypes of JIA to further define the genetic susceptibility to JIA. We examined 16 markers spanning an 18 cM region of chromosome 6 encompassing the MHC and surrounding genomic region in a set of 235 Finnish JIA nuclear families and 639 Finnish control individuals. Analysis by case/control association and transmission disequilibrium test (TDT) methods each demonstrated strong evidence for a susceptibility locus near the D6S2447 microsatellite (P
This study further defines genetic susceptibility to JIA in the region centromeric to HLA-DRB1. DNA from 234 Finnish JIA nuclear families and 639 elderly Finnish control individuals was genotyped for five functional SNPs within the TAP2 and TAP1 loci ( approximately 200 kb centromeric of HLA-DRB1). Subsets of the controls (186) and patients (145) that had been previously typed for HLA-DRB1 were also genotyped by sequence for the HLA-DPB1 locus. Case/control and transmission disequilibrium test (TDT) methods revealed an association with the DPB1(*)030101 allele for JIA (OR 2.3, 95% CI 1.5-3.5). Notably, a detailed haplotypic analysis of the TAP2/TAP1 loci and their interaction with the HLA-DPB1(*)030101 and DRB1(*)08 and (*)11 alleles showed a variety of over-represented and under-represented TAP2/TAP1 haplotypes not evident in the single marker analysis. The strongest effect was observed in the polyarticular RF negative JIA subgroup for the 2-2-1-2-1 TAP2/TAP1 haplotype (TAP2B and TAP1A alleles) which showed an independent effect from both DRB1(*)08 and (*)11 (P
Objective: Pain is a common and distressing feature of juvenile idiopathic arthritis (JIA). Pain interference (PI) is underexplored in long-term conditions such as JIA. The aim of this study was to explore the factors associated with PI in young adults with JIA. Methods: All consecutive JIA patients aged 18-30 years in three tertiary rheumatology and rehabilitation centres in Finland between September 2015 and April 2016 were included. The patients completed questionnaires addressing demographics, disability, depressive symptoms, pain anxiety, pain intensity, and PI. PI was measured with a single item from the RAND-36 questionnaire. Five response categories were coded into three groups: patients reporting 'extremely', 'quite a bit' or 'moderate' were classified as having significant PI; 'a little bit' as having minor PI; and 'not at all' as having no PI. A leisure-time physical activity metabolic equivalent of task (LTPA MET) was calculated. Statistical comparisons between PI and categorical variables were made using chi-squared or Fisher-Freeman-Halton tests. Results: Of the total 195 patients, 97 (50%) patients reported PI. PI was associated with a wide spectrum of sociodemographic and disease-related variables. Pain intensity scores were higher in patients expressing greater PI (p