ROLE OF IgG4 IN THE DEVELOPMENT OF CERTAIN AUTOIMMUNE DISEASES

This article analyzes the role of immunoglobulin G4 (IgG4) in the development of certain autoimmune diseases. The authors present IgG4 as a unique subclass of immunoglobulins characterized by anti-inflammatory and immunomodulatory properties. It has been demonstrated that an imbalance between IgG4 and other classes or subclasses of immunoglobulins can lead to various consequences, tilting the clinical picture towards suppression of inflammation or its activation. IgG4-related diseases form an ever-growing group of fibroinflammatory diseases with specific clinical features: pseudotumours, storiform fibrosis, and obliterative phlebitis. The article provides a detailed description of the pathogenesis of IgG4-associated diseases, including autoimmune pancreatitis, Sjögren's syndrome, systemic lupus erythematosus, and rheumatoid arthritis. IgG4-related diseases represent a group of fibroinflammatory conditions characterized by plasma cell infiltration and storiform fibrosis. Particular attention is given to the mechanisms of B-cell activation, which produce profibrotic molecules, and the role of IgG4 in promoting fibrosis and inflammation. The authors note that elevated serum IgG4 levels do not always correlate with clinical disease activity. The article discusses modern diagnostic criteria for IgG4-related diseases, including histopathological and radiological signs, as well as exclusion criteria. Recent research findings are presented, highlighting new biomarkers for diagnosing and monitoring these diseases. The role of IgG4 in rheumatological practice, particularly in rheumatoid arthritis, is also examined. The authors emphasize that IgG4 may serve as a promising biomarker for disease activity and treatment efficacy. The article underscores the need for further research to deepen the understanding of IgG4 mechanisms and its role in the development of autoimmune and rheumatic diseases.