Rheumatoid Arthritis: Types, risk factors and Laboratory Biomarkers

Abstract

Background: Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disorder characterized by persistent synovial inflammation, progressive joint destruction, and extra-articular manifestations. Laboratory biomarkers play a pivotal role in confirming diagnosis, stratifying disease severity, predicting prognosis, and monitoring therapeutic response. Objectives: This review summarizes the diagnostic, prognostic, and monitoring value of established and emerging laboratory biomarkers in RA, highlighting their clinical utility and limitations. Methods: Electronic databases, including PubMed, Scopus, and Web of Science, were systematically searched for studies evaluating biomarkers in RA. Biomarkers were categorized into serological (RF, anti-CCP, anti-MCV, anti-CarP), inflammatory (ESR, CRP, calprotectin), and emerging molecular markers (14-3-3η, MMP-3, cytokine panels, and lipid/metabolic profiles). Data on sensitivity, specificity, predictive value, and clinical correlations were extracted. Results: Rheumatoid arthritis (RA) types are Seropositive RA, Seronegative RA, Early RA, and Established RA. RA risk factors are Genetic Factors, such as the HLA-DRB1 gene, Environmental and Lifestyle Factors, including (1) Cigarette smoking, (2) Infections, ​(3) Dietary factors, (4) Hormonal influences, and ​(5) Obesity/Metabolic syndrome.

Laboratory Biomarkers: Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies remain the most reliable diagnostic markers, with anti-CCP offering superior specificity (~95–98%). Acute-phase reactants such as ESR and CRP correlate with disease activity and therapeutic response but lack diagnostic specificity. Novel biomarkers, including 14-3-3η protein, anti-CarP antibodies, and MMP-3, demonstrate potential for early detection and prognostication, especially in seronegative patients. Multi-biomarker panels integrating serological and molecular data enhance diagnostic accuracy.