Laboratory diagnostics and pathogenesis of rheumatoid arthritis — the past and the present

Rheumatoid arthritis (RA) is one of the most common systemic connective tissue diseases of autoimmune origin and is characterised by chronic inflammation of joints. The aetiology of this disease has not been fully understood yet. A crucial role in the development of RA is played by multiple genetic (shared epi-tope, HLA-DR genes, family predisposition) and environmental factors (smoking, female-specific factors, bacteria, viruses and mucosal inflammation, periodontal and lung diseases). The purpose of this article is to review the latest data on the pathogenesis of this disease and biomarkers used in the diagnostics of RA. RA is associated with the production of autoantibodies, among which rheumatoid factor (RF) and anti-citrullinated protein (anti-CCP) antibodies are included in the new classification criteria of RA. So far, anti-CCP is the best marker of RA; its high sensitivity and specificity have been helpful in diagnostics and monitoring disease activity and the development of more aggressive disease, as well as the pharmacological treatment used. Recently, anti-carbamylated (anti-carP) antibodies and calprotectin have been described in RA, which also appears to be promising in the diagnostics of this disease.