RHEUMATOID ARTHRITIS: ETIOLOGY, CLINICAL PRESENTATION, PATHOGENESIS AND MODERN DIAGNOSTICS

Rheumatoid arthritis is a chronic systemic autoimmune disease in which persistent synovial inflammation leads to cartilage loss, bone erosion, disability and a shortened life expectancy. Its burden is growing worldwide, and outcomes depend largely on how early the disease is recognised and treated. This review summarises current knowledge on the etiology, pathogenesis, clinical presentation and diagnosis of rheumatoid arthritis, with emphasis on what a therapist needs in daily practice. A narrative analysis of classification criteria, systematic reviews, meta-analyses, cohort studies and international recommendations was performed. The analysis showed that the disease develops through successive phases: genetic susceptibility, environmental triggers such as smoking and periodontal infection, a preclinical phase of autoimmunity that may last several years, and finally clinically evident synovitis. Antibodies to citrullinated proteins have a specificity of about 95%, compared with about 85% for rheumatoid factor, and their presence predicts a more erosive course. The 2010 classification criteria of the American College of Rheumatology and the European League Against Rheumatism, together with ultrasound and magnetic resonance imaging, allow the disease to be identified months earlier than with older approaches. Combining clinical examination, serology, acute-phase reactants and imaging gives the best chance of starting treatment within the "window of opportunity".