Abstract:

Objective To investigate the clinical significance of anti-Sj?gren's syndrome type A antibody (SSA) and anti-Sj?gren's syndrome type B antibody (SSB) in idiopathic inflammatory myopathies (IIM) and IIM associated interstitial disease (ILD). Methods A total of 102 patients with IIM were selected. The general information, clinical manifestations and auxiliary examinations were collected. Their positive rates of anti-SSA and anti-SSB antibodies in IIM patients were analyzed. IIM patients were divided into the SS antibody negative group (73 patients) and the SS antibody positive group (29 patients) according to the results of anti SSA and SSB antibody tests. The clinical significance of anti-SSA and anti-SSB antibodies in IIM and IIM related ILD was analyzed. Results Compared with patients in the SS antibody positive group, patients in the SS antibody negative group were more likely to experience dry mouth, increased erythrocyte sedimentation rate (ESR) and increased immunoglobulin A (IgA) levels (P<0.05). The general situation score of the MDAAT (myositis disease activity assessment tool) was significantly higher in the SS antibody positive group than that in the SS antibody negative group (P<0.05), and there were no significant differences in scores of other MDAAT items between the two groups (P>0.05). There were no significant differences in the positive rate of myositis autoantibodies, recurrence rate, hormone therapy and immunosuppressive therapy between the two groups (P>0.05). The proportion of patients treated with intravenous human immunoglobulin was higher in the SS antibody positive group than that of the SS antibody negative group (P<0.05). Non-specific interstitial pneumonia (NSIP) was the most type of ILD in both the SS antibody negative group and the positive group, followed by usual interstitial pneumonia (UIP). Patients with IIM who were positive for anti-SSA/SSB antibodies were more likely to progress to the overlapping syndrome of combined SS. Conclusion Positive anti-SSA and anti-SSB antibodies in IIM patients are associated with dry mouth symptoms, and anti-SSA/SSB antibodies may become one of the important laboratory indicators for judging patient conditions and predicting disease outcomes.

Key words: idiopathic inflammatory myopathy, Sj?gren's syndrome, lung diseases, interstitial, autoantibody, anti SSA antibody, anti SSB antibody