Session Information
Date: Tuesday, October 23, 2018
Title: Muscle Biology, Myositis and Myopathies Poster III: Treatment and Classification Criteria
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: The aim of this study is to evaluate sensitivity, limitations and assessment of 2017 ACR/EULAR IIMs classification criteria (ACR/EULAR2017) in 123 patients with idiopathic inflammatory myopathy (IIM).
Methods: Demographic data, clinical and serological features of 123 patients with a clinical diagnosis of IIM fulfilling Bohan/Peter criteria and followed up between1994-2018 in our clinic, were collected according to a pre-defined protocol and ACR/EULAR2017 were applied to patients. Muscle biopsy scoring was performed on 70 patients who had biopsy records. Sensitivities and specificity on subset determination of the criteria of were analysed.
Results: The median age of patients was 46±15 and average follow up was 77 months. In 66% of the patients, the diagnosis was dermatomyositis (DM), in 28% polymyositis (PM), in 6% was immune-mediated necrotizing myopathy (IMNM) and inclusion body myositis (ICM). The frequency of arthritis, dysphagia, respiratory muscle involvement, interstitial lung disease and malignancy were detected 25, 35, 12, 29, 24% respectively, and mortality was 19%. ANA positivity was 38% and anti Jo-1 was present in 12% of the patients. Definite or possible IIM according to ACR/EULAR2017 was found in 95% of the patients regardless of muscle biopsy scoring (Possible IIM:7%; definite IIM:87%). The classification percentage of DM was 99 (all definite), PM 91 (probable and definite PM:21 and 70%), IMNM 100 (probable and definite IMNM:33 and 67), ICM 0 when ACR/EULAR2017 were applied to subsets of IIM without muscle biopsy scoring. On the other hand; in the classification made by including muscle biopsy scoring on the IIM subsets DM was 100% (probable and definite:3 and 97%), PM was 93% (probable and definite PM:30 and 63%), IMNM 83% (all probable), ICM 100% (probable and definite ICM:50 and 50%).
One of the DM patients and a patient with DM without dermatitis were classified as PM, 4 patients with hypomyopathic DM (HDM) were classified as amyopathic DM (100%) and 6 patients with IMNM was classified as PM (100%).
Conclusion: Without muscle biopsy and EMG, 95% of 123 IIM patients fulfilling Bohan/Peter criteria can be classified with the new ACR/EULAR2017. The sensitivity of the criteria is higher in DM (%99) but lower in PM (91%) and increased when muscle biopsy records are included (98%). On the other hand insufficient biopsy results may cause a slight change from definite to probable PM. ADM patients within the subset of DM were defined 100% correctly. Although ACR/EULAR2017 might have drawbacks in the classification of HDM and IMNM, significant improvement in the classification process with the advantage of weighting towards clinical assessment have been observed.
To cite this abstract in AMA style:
Oguz E, Sahin E, Erdugan M, Artim-Esen B, Gül A, Ocal L, Inanc M. Classification of Idiopathic Inflammatory Myopathies: Assessment of 123 Patients According to 2017 Acr/EULAR Criteria Followed up By a Single Center from Turkey [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/classification-of-idiopathic-inflammatory-myopathies-assessment-of-123-patients-according-to-2017-acr-eular-criteria-followed-up-by-a-single-center-from-turkey/. Accessed .« Back to 2018 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/classification-of-idiopathic-inflammatory-myopathies-assessment-of-123-patients-according-to-2017-acr-eular-criteria-followed-up-by-a-single-center-from-turkey/