Distinct arthropathies of the hands in patients with anti-aminoacyl tRNA synthetase antibodies: usefulness of autoantibody profiles in classifying patients

OBJECTIVE: The aim of this study was to characterize arthropathies of the hands associated with antiaminoacyl tRNA synthetase (ARS) autoantibodies. METHODS: Fifty-six patients with anti-ARS antibodies were selected from consecutive patients who visited Keio University Hospital between1983 and 2011, based on their joint symptoms and the availability of hand X-rays. Their clinical characteristics, anti-CCP antibodies, RF, and hand X-ray findings were retrospectively examined. RESULTS: Based on characteristic hand X-ray findings, the anti-ARS-positive patients with joint symptoms could largely be categorized into three groups. The predominant group (64%) was patients with no significant X-ray findings. The remaining patients with destructive changes were classified into two distinct groups. One group had mainly erosions in the PIP and MCP joints and/or ankylosis of the wrists with anti-CCP and RF, which is consistent with the features of RA. The other group showed subluxation of the thumbs and periarticular calcification that was independent of anti-CCP or RF, which is exclusively found in anti-Jo-1-positive patients. CONCLUSION: Autoantibody profiles, including anti-CCP, RF and individual anti-ARS specificities, are useful in classifying anti-ARS-associated arthropathies of the hands into RA or anti-Jo-1-related disorders.