2017 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Adult and Juvenile Idiopathic Inflammatory Myopathies and Their Major Subgroups

Publication date

2017-12

Authors

Lundberg, Ingrid E
Tjärnlund, Anna
Bottai, Matteo
Werth, Victoria P
Pilkington, Clarissa
de Visser, Marianne
Alfredsson, Lars
Amato, Anthony A
Barohn, Richard J
Liang, Matthew H.

Editors

Advisors

Supervisors

Document Type

Article

Collections

Open Access logo

License

taverne

Abstract

Objective: To develop and validate new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIM) and their major subgroups. Methods: Candidate variables were assembled from published criteria and expert opinion using consensus methodology. Data were collected from 47 rheumatology, dermatology, neurology, and pediatric clinics worldwide. Several statistical methods were utilized to derive the classification criteria. Results: Based on data from 976 IIM patients (74% adults; 26% children) and 624 non-IIM patients with mimicking conditions (82% adults; 18% children), new criteria were derived. Each item is assigned a weighted score. The total score corresponds to a probability of having IIM. Subclassification is performed using a classification tree. A probability cutoff of 55%, corresponding to a score of 5.5 (6.7 with muscle biopsy) “probable IIM,” had best sensitivity/specificity (87%/82% without biopsies, 93%/88% with biopsies) and is recommended as a minimum to classify a patient as having IIM. A probability of ≥90%, corresponding to a score of ≥7.5 (≥8.7 with muscle biopsy), corresponds to “definite IIM.” A probability of <50%, corresponding to a score of <5.3 (<6.5 with muscle biopsy), rules out IIM, leaving a probability of ≥50–<55% as “possible IIM.”. Conclusion: The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for IIM have been endorsed by international rheumatology, dermatology, neurology, and pediatric groups. They employ easily accessible and operationally defined elements, and have been partially validated. They allow classification of “definite,” “probable,” and “possible” IIM, in addition to the major subgroups of IIM, including juvenile IIM. They generally perform better than existing criteria.

Keywords

Adolescent, Adult, Biopsy, Child, Consensus, Europe, Female, Humans, Male, Middle Aged, Muscle, Skeletal, Myositis, Practice Guidelines as Topic, Rheumatology, Sensitivity and Specificity, Societies, Medical, Symptom Assessment, United States, Young Adult, Taverne, Immunology and Allergy, Rheumatology, Immunology

Citation

Lundberg, I E, Tjärnlund, A, Bottai, M, Werth, V P, Pilkington, C, de Visser, M, Alfredsson, L, Amato, A A, Barohn, R J, Liang, M H, Singh, J A, Aggarwal, R, Arnardottir, S, Chinoy, H, Cooper, R G, Dankó, K, Dimachkie, M, Feldman, B M, Garcia-De La Torre, I, Gordon, P, Hayashi, T, Katz, J D, Kohsaka, H, Lachenbruch, P A, Lang, B A, Li, Y, Oddis, C V, Olesinska, M, Reed, A M, Rutkowska-Sak, L, Sanner, H, Selva-O'Callaghan, A, Song, Y-W, Vencovsky, J, Ytterberg, S R, Miller, F W, Rider, L G, International Myositis Classification Criteria Project Consortium, the Euromyositis Register, and the Juvenile Dermatomyositis Cohort Biomarker Study and Repository (UK and Ireland) & van Royen, A 2017, '2017 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Adult and Juvenile Idiopathic Inflammatory Myopathies and Their Major Subgroups', Arthritis & Rheumatology, vol. 69, no. 12, pp. 2271-2282. https://doi.org/10.1002/art.40320