An update on autoantibodies in the idiopathic inflammatory myopathies.

Myositis-specific autoantibodies (MSAs) have become pivotal biomarkers for idiopathic inflammatory myopathies and have revolutionized understanding of the heterogeneous disease spectrum that affects both adults and children. The discovery and characterization of MSAs have substantially enhanced patient stratification based on clinical phenotype, thereby facilitating more precise diagnosis and ultimately improving management strategies. Advances in immunoassay technologies in the past 20 years have further propelled the field forward, enabling the detection of a growing repertoire of autoantibodies with high specificity and sensitivity; however, evolving research over the past decade has revealed that even within antibody-defined subsets, considerable clinical diversity exists, suggesting a broader spectrum of disease manifestations than previously acknowledged.