<h3>Objective</h3> To clarify the association of clinical and prognostic features with dermatomyositis (DM)-specific autoantibodies (Abs) in adult Japanese patients with DM. <h3>Design</h3> Retrospective study. <h3>Setting</h3> Kanazawa University Graduate School of Medical Science Department of Dermatology and collaborating medical centers. <h3>Patients</h3> A total of 376 consecutive adult Japanese patients with DM who visited our hospital or collaborating medical centers between 2003 and 2008. <h3>Main Outcome Measures</h3> Clinical and laboratory characteristics of adult Japanese patients with DM and DM-specific Abs that include Abs against Mi-2, 155/140, and CADM-140. <h3>Results</h3> In patients with DM, anti–Mi-2, anti–155/140, and anti–CADM-140 were detected in 9 (2%), 25 (7%), and 43 (11%), respectively. These DM-specific Abs were mutually exclusive and were detected in none of 34 patients with polymyositis, 326 with systemic sclerosis, and 97 with systemic lupus erythematosus. Anti–Mi-2 was associated with classical DM without interstitial lung disease or malignancy, whereas anti–155/140 was associated with malignancy. Patients with anti–CADM-140 frequently had clinically amyopathic DM and rapidly progressive interstitial lung disease. Cumulative survival rates were more favorable in patients with anti–Mi-2 compared with those with anti–155/140 or anti–CADM-140 (<i>P</i> &lt; .01 for both comparisons). Nearly all deaths occurred within 1 year after diagnosis in patients with anti–CADM-140. <h3>Conclusion</h3> Dermatomyositis-specific Abs define clinically distinct subsets and are useful for predicting clinical outcomes in patients with DM.

Clinical Correlations With Dermatomyositis-Specific Autoantibodies in Adult Japanese Patients With Dermatomyositis