[Progress of Autoantibody Examinations for Connective Tissue Diseases]

Connective tissue diseases are chronic inflammatory diseases that can affect multiple organs and, thus, have a broad spectrum of clinical presentations. Various autoantibodies are detected in patients with connective tissue diseases, represented by anti-nuclear antibody for systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM), Sjögren's syndrome, and mixed connective tissue disease. Assessment of the autoantibody profile is fundamental for the clinical management of patients with connective tissue diseases, providing important data for the diagnosis, clinical characterization, and disease activity evaluation. Anti-ribosomal P antibody and anti-NMDA receptor antibody are associated with neuropsychiatric SLE. Anti-synthetase syndrome comprises the association of myositis (PM/DM), interstitial lung disease, fever, Raynaud's phenomenon, mechanic's hands, and anti-aminoacyl tRNA synthetase antibodies. Anti-MDA5 antibody is detected in patients with clinically amyopathic DM, often complicated by rapidly progressive interstitial lung disease. Between 50 and 75% of malignancy-associated DM patients are positive for anti-TIF1-γ antibody. Anti-RNA polymerase III antibody is associated with diffuse cutaneous SSc and renal crisis. This review focuses on the importance and usefulness of these autoantibodies for the diagnosis and management of patients with connective tissue diseases in clinical practice.