Conclusion
The novel immunoprecipitation assay is suitable to detect and monitor the levels of anti-EJ autoantibody. The serum levels of anti-EJ, IP-10, IL-6, MCP-1, and VEGF may be related to disease activity in myositis patients with anti-EJ antibodies.
Methods
Sera of 236 Chinese patients with myositis were screened for anti-EJ by a novel immunoprecipitation assay of flag-tagged GlyRS. Anti-EJ positive patients are evaluated for the clinical features and cytokine profile.
Objective
This study aimed to clarify the clinical features, the serum level of autoantibodies, and cytokine of myositis patients with anti-EJ antibody, which targets glycyl tRNA-synthetase (GlyRS).
Results
The sera from 4 of 236 adult myositis patients were found to carry the anti-EJ using established novel immunoprecipitation assay and immunoblotting. The prevalence of anti-EJ in our cohorts is about 1.7%. The decline of anti-EJ level was detected in two patients during disease remission. Interstitial lung disease and muscle weakness, but not skin involvement, are common clinical features of anti-EJ positive patients. Moreover, using a cytokine profile analyses, we found that the serum levels of IP-10, IL-6, MCP-1, and VEGF were significantly elevated in patients with anti-EJ and gradually decreased during disease remission of two patients, whereas IL-8 level was obviously reduced in these patients.