Clinical characteristics of 30 patients with interstitial pneumonia associated with anti-aminoacyl-tRNA-synthetase antibodies

RATIONALE: Anti-aminoacyl transfer RNA synthetases (ARS) antibodies are a group of myositis specific autoantibodies. It also is frequently found in patients with complicating interstitial pneumonia. However, the clinical characteristics in these patients with anti-ARS antibody were not yet fully elucidated. METHODS: We retrospectively investigated clinical symptoms, radiological findings, treatments, and its outcome in 30 patients with anti-ARS antibody-positive interstitial pneumonia (ARS-IP) in our institution. The radiological patterns of interstitial pneumonia were evaluated with thin-sliced HRCT by two specialists. Anti-ARS antibodies were evaluated using RNA immunoprecipitation assey and anti-synthetase ELISA kit (BML, Japan). RESULTS: Mean age was 59.4 years (28-82), 60.0% were female. Nine patients were with anti-Jo-1, 7 with anti-EJ, 4 with anti-PL-12, 3 with anti-PL-7, 2 with anti- OJ, and 5 with unknown or anti-KS. Seven cases were diagnosed as having ARS-IP with dermatomyositis (DM), and 7 with polymyositis. There were no differences in the demographic features, laboratory data, HRCT findings, between ARS-IP with myositis and without. ARS-IP with myositis recurs more often than without myositis (p=0.019). Serum creatinine kinase (CK) levels were elevated in 13 patients. Patient achieved good responses to initial corticosteroid and immunosuppressant. Mean observation time was 64.9 months (4 months- 138 months). CONCLUSIONS: Most of the patients with interstitial pneumonia associated with anti-ARS antibodies showed remarkable responses to the therapy and favorable outcome.