MYOSITIS AND MYOPATHIES: Edited by Andrea Doria, Anna Ghirardello and Mariele GattoMyositis autoantibodies: recent perspectivesRiddell, Victoriaa; Bagby, Stefana; McHugh, NeilbAuthor Information aDepartment of Biology and Biochemistry bDepartment of Pharmacy and Pharmacology, University of Bath, Bath, UK Correspondence to Neil McHugh, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. Tel: +44 0 7748338739; e-mail: [email protected] Current Opinion in Rheumatology: November 2020 - Volume 32 - Issue 6 - p 548-552 doi: 10.1097/BOR.0000000000000742 Buy Metrics Abstract Purpose of review To provide an overview of recent discoveries related to myositis-specific autoantibodies (MSAs) and assays used for their measurement. Recent findings New autoantibody specificities have been reported including a MSA directed against eukaryotic initiation factor 3 and a myositis-associated autoantibody directed against heat shock factor 1. The association of anti-TIF1γ with cancer-associated dermatomyositis dependent on age has been confirmed in several large cohorts. Despite MSAs being almost entirely mutually exclusive, several myositis autoantigens are overexpressed in regenerating muscle and do not correlate with the corresponding MSA in any one patient. Further mechanisms may determine the final MSA specificity and are likely to include the need for autoantigen processing and presentation with adaptive T-cell help. The presence of CD4-positive T cells specific for histidyl tRNA synthetase protein in bronchial lavage fluid from antisynthetase patients lends support to this view. Finally, it is widely held that MSA do play an important role in clinical practice among some evidence and concern about commercial assay reliability. Summary MSAs continue to provide important tools for clinical diagnosis and management as well as insights into disease mechanisms. Further improvement in the standardization and reliability of routine detection of MSAs is a high priority. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.