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Clinical manifestations of dermatomyositis and clinically amyopathic dermatomyositis patients with positive expression of anti–melanoma differentiation–associated gene 5 antibody
Author(s) -
Cao Hua,
Pan Meng,
Kang Yanqing,
Xia Qunli,
Li Xia,
Zhao Xiaoqing,
Shi Ruofei,
Lou Jianghua,
Zhou Min,
Kuwana Masataka,
Ding Xiaoyi,
Zheng Jie
Publication year - 2012
Publication title -
arthritis care and research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.032
H-Index - 163
eISSN - 2151-4658
pISSN - 2151-464X
DOI - 10.1002/acr.21728
Subject(s) - medicine , dermatomyositis , antibody , interstitial lung disease , gastroenterology , connective tissue disease , melanoma , autoantibody , pathology , connective tissue , immunohistochemistry , lung , immunology , autoimmune disease , cancer research
Objective To investigate the clinical features of dermatomyositis (DM) and clinically amyopathic DM (CADM) patients with the presence of anti–melanoma differentiation–associated gene 5 (anti–MDA‐5) antibodies. Methods We screened the serum anti–MDA‐5 antibody levels of 140 patients with various connective tissue diseases (CTDs), including 32 with DM and 32 with CADM, or idiopathic pulmonary fibrosis (IPF). The clinical courses of DM/CADM patients with a positive expression of anti–MDA‐5 antibodies were delineated. Results Anti–MDA‐5 antibodies were detected at a significantly higher frequency in CADM patients than in DM patients (12 of 32 versus 3 of 32; P = 0.016), but were not detected in patients with other CTDs or IPF and healthy controls. Patients with a positive expression of anti–MDA‐5 antibodies developed significantly more skin ulcerations (12 of 15 versus 4 of 49; P < 0.001) and interstitial lung disease (ILD; 15 of 15 versus 31 of 49 [ P = 0.003]) than those without anti–MDA‐5 antibodies. High‐resolution computed tomography scores of the MDA‐5–positive subset were increased compared with the MDA‐5–negative group (mean ± SD 117.7 ± 76.3 versus 54.4 ± 50.7; P = 0.004), and the scores correlated well with anti–MDA‐5 antibody levels (r 2 = 0.582, P = 0.029). The respiratory symptoms as well as skin ulcerations were dramatically improved in patients with anti–MDA‐5 antibody levels <500 units/ml after treatment, whereas patients with anti–MDA‐5 antibody levels >500 units/ml were resistant to the treatment and died of respiratory failure in a short period of time. Conclusion Anti–MDA‐5 antibody levels closely correlate with the severity of skin ulcerations, ILD, and the prognosis of the disease. Dynamic observation of serum anti–MDA‐5 antibody levels would be helpful in predicting the course of ILD and facilitating better therapeutic targeting.