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

Objective

To clarify the association of clinical and prognostic features with dermatomyositis (DM)-specific autoantibodies (Abs) in adult Japanese patients with DM.

Design

Retrospective study.

Setting

Kanazawa University Graduate School of Medical Science Department of Dermatology and collaborating medical centers.

Patients

A total of 376 consecutive adult Japanese patients with DM who visited our hospital or collaborating medical centers between 2003 and 2008.

Main Outcome Measures

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.

Results

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 (P < .01 for both comparisons). Nearly all deaths occurred within 1 year after diagnosis in patients with anti–CADM-140.

Conclusion

Dermatomyositis-specific Abs define clinically distinct subsets and are useful for predicting clinical outcomes in patients with DM.