Drs. Hall and Casciola-Rosen contributed equally to this work.
Anti–Melanoma Differentiation–Associated Protein 5–Associated Dermatomyositis: Expanding the Clinical Spectrum
Article first published online: 26 JUL 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis Care & Research
Volume 65, Issue 8, pages 1307–1315, August 2013
How to Cite
Hall, J. C., Casciola-Rosen, L., Samedy, L.-A., Werner, J., Owoyemi, K., Danoff, S. K. and Christopher-Stine, L. (2013), Anti–Melanoma Differentiation–Associated Protein 5–Associated Dermatomyositis: Expanding the Clinical Spectrum. Arthritis Care Res, 65: 1307–1315. doi: 10.1002/acr.21992
- Issue published online: 26 JUL 2013
- Article first published online: 26 JUL 2013
- Accepted manuscript online: 22 FEB 2013 10:51AM EST
- Manuscript Accepted: 12 FEB 2013
- Manuscript Received: 12 SEP 2012
- Huayi and Siuling Zhang Discovery Fund
- NIH. Grant Numbers: R37-DE12354-12S1, R01-AR-44684, P30-AR-053503
- Rheumatology Research Foundation Within Our Reach Grant
- The Johns Hopkins Rheumatic Diseases Research Core Center
Autoantibodies against melanoma differentiation–associated protein 5 (MDA-5) have been described in several Asian dermatomyositis (DM) cohorts, often associated with amyopathic DM and rapidly progressive interstitial lung disease (ILD). A recent study of a DM cohort seen at a US dermatology clinic reports that MDA-5 autoantibodies are associated with a unique cutaneous phenotype. Given the widening spectrum of clinical findings, we evaluated the clinical features of anti–MDA-5–positive patients seen at a US myositis referral center.
One hundred sixty DM patients were screened for MDA-5 autoantibodies by immunoprecipitation and antibody titers were analyzed in longitudinal serum samples. Anti–MDA-5–positive patients were evaluated for the presence of additional myositis autoantibodies. Patient clinical characteristics were compared by retrospective chart review.
MDA-5 was targeted in 11 (6.9%) of 160 patients with DM. Of these, 9 presented with a symmetric polyarthropathy, 6 demonstrated overt clinical myopathy, and 8 had ILD. Eight anti–MDA-5–positive patients exhibited the clinical attributes of the antisynthetase syndrome in the absence of Jo-1 or other antisynthetase autoantibodies. MDA-5 autoantibody titers did not correlate with clinical course.
MDA-5 autoantibodies are found in DM patients presenting with a symmetric polyarthritis, clinically similar to rheumatoid arthritis. These patients often have features of the antisynthetase syndrome, but in the absence of antisynthetase autoantibodies. Most anti–MDA-5–positive patients had overt clinical myopathy and ILD. The latter, while occasionally severe, typically resolved with immunosuppressive therapy. In this cohort, the MDA-5 phenotype is frequently a clinical mimic of the antisynthetase syndrome and is not associated with rapidly progressive ILD.