The role of detection of myositis specific and associated antibodies in Japanese patient with interstitial lung disease

Background: Myositis specific antibodies (MSA) and Myositis associated antibodies (MAA), especially anti aminoacyl tRNA synthetases antibodies (ARS antibody) are associated with interstitial lung disease (ILD). Aim: To clarify the clinical role of detecting these antibodyies. Subject: 56 patients were selected from the data base of Kinki-Chuo Chest Medical center from June 2002 through December 2013 with the selection criteria; (1) The patient were suspected secondary ILD, but without definite diagnosis collagen vascular diseases. (2) The sera were stored with informed consent. All patients were Japanese. Method: We detected MSA (OJ, EJ, PL12, PL7, Jo1;these are ARS antibody, and SRP, Mi2) and MAA (Ro52, PM-Scl75, PM-Scl100, Ku) by Myositis Profile 3 Euroline (Euroimmun, Lübeck, Germany). The patients were classified to 3 groups (Group1: ARS antibody positive, Group 2: Antibody other than ARS antibody positive, Group 3: No detected antibody). Clinical features and survival (90 days, 1 year) were compared between 3 groups. Results: The number of patients, 16 in Group1, 16 in Group 2 and 24 in Group 3. There was no difference of age and gender and serum Krebs von den Lungen-6, surfactant protein (SP)-D, SP-A, %FVC, %DLCO between the groups. However, serum creatine kinase (CK) was the significantly highest in Group 1 (Kruskal-Wallis test, p=0.001). The survival (90 days, 1 year) was similar between groups. Conclusion: The clinical features were similar, except for CK. Farther examination is required to determining the clinical role of detecting these antibodies.