Classification of idiopathic inflammatory myopathies based on clinical manifestations and myositis-specific antibodies.
- Author:
Songyuan ZHENG
1
;
Shixian CHEN
1
;
Lisheng WU
1
;
Di ZHAO
2
;
Feilong CHEN
1
;
Junqing ZHU
3
;
Juan LI
1
Author Information
1. School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, Chin.
2. School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
3. Department of rheumatic & TCM medical center, Nanfang Hospital, Guangzhou 510515, Chin.
- Publication Type:Journal Article
- MeSH:
Antibodies;
metabolism;
Humans;
Myositis;
classification;
physiopathology;
Retrospective Studies
- From:
Journal of Zhejiang University. Medical sciences
2020;40(7):1029-1035
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate the classification of idiopathic inflammatory myopathies (IIM) based on clinical manifestations and myositis- specific antibodies using cluster analysis.
METHODS:We retrospectively analyzed the data of patients with IIM admitted in Nanfang Hospital in 2015-2019. The clinical data of the patients including serum creatine kinase (CK), interstitial lung disease (ILD), cancer, and myositis-specific antibodies were collected for two-step cluster analysis to identify the distinct clusters of patients, whose clinical characteristics were subsequently analysed.
RESULTS:A total of 71 patients with IIM were included in this study, including 30 (42.3%) with polymyositis (PM), 20 (28.2%) with classic dermatomyositis (DM), 16 (22.5%) with amyopathic dermatomyositis (CADM), and 5 (7.0%) with immune-mediated necrotizing myopathy (IMNM). Two-step cluster analysis identified 3 distinctive subgroups: Cluster 1 of 15 (51.7%) patients characterized by rash, positive anti-MDA5 antibody and hypoproteinemia ( < 0.05) with normal or slightly elevated CK level, mainly corresponding to CADM; Cluster 2 of 4 (57.1%) patients with significantly elevated CK and positive anti-SRP antibody ( < 0.001) corresponding to IMNM; and Cluster 3 of 17 (48.6%) patients consisting primarily of patients with PM, characterized by positivity for anti- aminoacyl transfer RNA synthetases antibodies (=0.022) corresponding to antisynthetase syndrome (ASS).
CONCLUSIONS:Patients with IIM can be divided into 3 subgroups based on their clinical and serological characteristics (especially myositis-specific antibodies), and among them ASS may represent an independent IIM subgroup with unique clinical characteristics.
