Rouster‐Stevens, Kelly

ObjectiveTo develop response criteria for adult dermatomyositis (DM) and polymyositis (PM).MethodsExpert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures. Myositis experts rated greater improvement among multiple pairwise scenarios in conjoint analysis surveys, where different levels of improvement in 2 core set measures were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined the relative weights of core set measures and conjoint analysis definitions. The performance characteristics of the definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using data from a clinical trial. The nominal group technique was used to reach consensus.ResultsConsensus was reached for a conjoint analysis–based continuous model using absolute percent change in core set measures (physician, patient, and extramuscular global activity, muscle strength, Health Assessment Questionnaire, and muscle enzyme levels). A total improvement score (range 0–100), determined by summing scores for each core set measure, was based on improvement in and relative weight of each core set measure. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the total improvement score. The same criteria were chosen for juvenile DM, with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 92% and 98% for minimal, moderate, and major improvement, respectively. Definitions were validated in the clinical trial analysis for differentiating the physician rating of improvement (P < 0.001).ConclusionThe response criteria for adult DM/PM consisted of the conjoint analysis model based on absolute percent change in 6 core set measures, with thresholds for minimal, moderate, and major improvement.

ObjectiveFew data are available regarding the rates of serious adverse events (SAEs) and important medical events (IMEs) outside of product‐based registries and clinical trials for juvenile idiopathic arthritis (JIA). The Enhanced Drug Safety Surveillance Project (EDSSP) was developed to pilot a novel system to collect SAEs/IMEs in children with JIA. This analysis reports the results from this 4‐year (2008–2012) EDSSP.MethodsParticipating physicians were surveyed monthly to ascertain whether their JIA patients experienced an SAE or IME. Sites were surveyed every 6 months to determine the number of unique JIA patients seen at each site during that 6‐month period. Reporting rates were calculated per 100 person‐years and 95% confidence intervals (95% CIs) were calculated based on a Poisson distribution.ResultsThirty‐seven Childhood Arthritis and Rheumatology Research Alliance sites with 115 physicians participated. The mean response rate to the monthly surveys was 65%. There were 147 total SAEs and 145 total IMEs. The largest proportion of SAEs and IMEs occurred in children with polyarticular JIA (39% and 37%, respectively). The majority of SAEs and IMEs were reported for patients receiving therapy with biologic agents (76% and 69%, respectively). The total event rate for SAEs and IMEs combined was 1.07 events per 100 person‐years (95% CI 0.95–1.19). The rates for SAEs and IMEs were 0.54 per 100 person‐years (95% CI 0.45–0.63) and 0.53 per 100 person‐years (95% CI 0.49–0.62), respectively.ConclusionThe EDSSP provided a simple tool for SAE/IME reporting within an established research network and resulted in a similar range of reported events as captured by a traditional product‐based registry.

ObjectiveChildren with childhood‐onset rheumatoid arthritis (RA) include those with rheumatoid factor or anti–citrullinated protein antibody–positive juvenile idiopathic arthritis. To test the hypothesis that adult‐onset RA–associated variants are also associated with childhood‐onset RA, we investigated RA‐associated variants at 5 loci in a cohort of patients with childhood‐onset RA. We also assessed the cumulative association of these variants in susceptibility to childhood‐onset RA using a weighted genetic risk score (wGRS).MethodsA total of 155 children with childhood‐onset RA and 684 healthy controls were genotyped for 5 variants in the PTPN22, TRAF1/C5, STAT4, and TNFAIP3 loci. High‐resolution HLA–DRB1 genotypes were available for 149 cases and 373 controls. We tested each locus for association with childhood‐onset RA via logistic regression. We also computed a wGRS for each subject, with weights based on the natural log of the published odds ratios (ORs) for the alleles investigated, and used logistic regression to test the wGRS for association with childhood‐onset RA.ResultsChildhood‐onset RA was associated with TNFAIP3 rs10499194 (OR 0.60 [95% confidence interval 0.44–0.83]), PTPN22 rs2476601 (OR 1.61 [95% confidence interval 1.11–2.31]), and STAT4 rs7574865 (OR 1.41 [95% confidence interval 1.06–1.87]) variants. The wGRS was significantly different between cases and controls (P < 2 × 10−16). Individuals in the third to fifth quintiles of wGRS had a significantly increased disease risk compared to baseline (individuals in the first quintile). Higher wGRS was associated with increased risk of childhood‐onset RA, especially among males.ConclusionThe magnitude and direction of the association between TNFAIP3, STAT4, and PTPN22 variants and childhood‐onset RA are similar to those observed in RA, suggesting that adult‐onset RA and childhood‐onset RA share common genetic risk factors. Using a wGRS, we have demonstrated the cumulative association of RA‐associated variants with susceptibility to childhood‐onset RA.