Clinical Features and Cytokine Profile in Myositis Patients with Anti-EJ Autoantibodies Detected by a Novel Immunoprecipitation Assay.

Yang Yang,Yisha Li,Ke Liu,Li Wang,Yangtengyu Liu,Li Huang,Huali Zhang,Meidong Liu,Xiaoxia Zuo,Hui Luo

doi:10.1155/2019/1856180

Abstract

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). 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. 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. 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.

Highlights

Antisynthetase syndrome (ASS) has been characterized as the clinical combination of myositis, interstitial lung disease (ILD), fever, arthritis, Raynaud’s phenomenon (RP), and Mechanic’s hands with the presence of anti-aminoacyl-tRNAsynthetase antibodies [1]
Our report retrospectively screened anti-EJ antibody in sera from 236 Chinese patients with idiopathic inflammatory myopathies (IIM) by established immunoprecipitation assay and four patients were positive for anti-EJ, A
The immunoprecipitation assay of flag-tagged glycyl tRNA-synthetase (GlyRS) overexpressed in HEK293 cells was suitable to detect the decline of anti-EJ autoantibody level in longitudinal sera from two patients during disease remission, which is consistent with the improved muscle weakness and normal muscle enzymes level

Summary

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). 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. The sera from 4 of 236 adult myositis patients were found to carry the anti-EJ using established novel immunoprecipitation assay and immunoblotting. The decline of anti-EJ level was detected in two patients during disease remission. 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. 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

Introduction

Materials and Methods

Result

Findings

Discussion