Measures to assess disease activity in juvenile dermatomyositis had been established and validated by the International Myositis Assessment and Clinical Studies Group (IMACS) and the Pediatric Rheumatology INternational Trials Organization (PRINTO). The American College of Rheumatology and the European League Against Rheumatism provisionally endorsed these core measures.
The various societies and work groups used different criteria in their individual guidelines for judging clinical response in juvenile dermatomyositis, and various core measures were combined in an effort to increase sensitivity and decrease the sample sizes needed.
Even though these preliminary responses in juvenile dermatomyositis criteria improved assessment of patients’ responses to treatment, they were limited by their differences, a lack of randomized trial data, and a lack of final consensus.
For these reasons, Lisa Rider and colleagues, in a multinational effort between the IMACS and the PRINTO, published the fully validated response criteria for juvenile dermatomyositis for 2016 in a recent Annals of the Rheumatic Diseases article.
Candidate definitions were evaluated by the working group using consensus profile ratings to assess sensitivity, specificity, and area under the curve to validate the definition’s performance as a tool to measure clinical response. Thresholds for minimal, moderate, and major improvement were developed.
• 312 candidate definitions for response to treatment in juvenile dermatomyositis were examined; 101 displayed excellent performance for minimal improvement (sensitivity and specificity, ≥ 80%, and area under the curve, ≥ 0.90).
• 30 candidate definitions also performed well in 2 clinical trials, showing statistically significant differentiation between treatment arms (P<0.05) and treating physician’s improvement scores at 24 weeks (P<0.001).
This project was supported by the American College of Rheumatology, the European League Against Rheumatism, the NIH, Istituto G. Gaslini, the Paediatric Rheumatology INternational Trials Organization, Cure JM Foundation, Myositis UK, the Myositis Association, and the Ministry of Health, Czech Republic.
Lisa G. Rider, Rohit Aggarwal, Angela Pistorio, et al. “2016 American College of Rheumatology/European League Against Rheumatism Criteria for Minimal, Moderate, and Major Clinical Response in Juvenile Dermatomyositis: An International Myositis Assessment and Clinical Studies Group/Paediatric Rheumatology International Trials Organisation Collaborative Initiative.” Ann Rheum Dis. 2017;76:782-791. doi: 10.1136/annrheumdis-2017-211401.