Destructive Arthropathy Associated with Dermatomyositis Sine Myositis Positive for Anti-Jo-1 and Anti-Cyclic Citrullinated Peptide Antibodies

Abstract

To the Editor: Polymyositis (PM) associated with anti-synthetase antibodies is often accompanied by arthritis, but it is usually mild and self-limiting1. Subluxing arthropathy associated with anti-Jo-1 antibody (anti-Jo-1)-positive PM or dermatomyositis (DM) has been described as a distinct subset of PM/DM2,3. It is characteristically a deforming, predominantly nonerosive arthropathy associated with subluxation of the interphalangeal (IP) joints, especially those of the thumbs. We encountered 2 patients who had severe, deforming, destructive arthropathy associated with DM sine myositis and who were positive for anti-Jo-1 and anti-cyclic citrullinated peptide (anti-CCP) antibodies. Both patients fulfilled the American College of Rheumatology (ACR) criteria for rheumatoid arthritis (RA). ### Patient 1 In 1996, a 57-year-old Japanese woman was referred to our hospital with dyspnea on exertion. She had Gottron’s sign in her hands, elbows, and knees, but there was no weakness, arthralgia, or Raynaud’s phenomenon. Interstitial lung disease (ILD) was detected by chest radiography. Serum creatine kinase (CK) was normal, anti-Jo-1 was positive at 1:2, and rheumatoid factor (RF) and anti-SSA antibody were negative. She was … Address correspondence to Dr. Nagashima; E-mail: naga4ma{at}jichi.ac.jp