Immunopathology and Laboratory Diagnosis of Rheumatoid Arthritis: A Review of Literature

This review explores rheumatoid arthritis, an autoimmune disorder whose immunopathology involves a convergence of genetic susceptibility (notably HLA-DRB1 shared epitope alleles) and environmental exposures (smoking, infections) leading to an aberrant immune response. RA is a prevalent autoimmune disease globally, and though historically considered uncommon in Africa, emerging data show it is an important and likely under-recognized health issue in regions like Nigeria. Epidemiologically, ~0.5% of the world’s population is affected with millions suffering chronic pain and disability. In Africa and Southeastern Nigeria, true prevalence is uncertain due to diagnostic gaps, but RA cases are increasingly reported as awareness grows. Autoimmune processes – generation of RF and ACPA autoantibodies, activation of T cells and macrophages, and a cytokine-driven inflammation – result in synovial damage and systemic effects. Understanding these mechanisms explains why specific biomarkers (RF, ACPA) are useful in diagnosis and why therapies targeting cytokines (like TNF or IL-6 inhibitors) are effective. In laboratory diagnosis, we identified the core tools: RF and ACPA testing for confirming autoantibodies, ESR and CRP for gauging inflammation, and newer panels for disease activity. In resource-constrained settings, basic assays can be performed with relatively low-cost methods (e.g. ESR by Westergren, RF by latex agglutination), but introducing more specific tests like anti-CCP is vital for improving diagnostic specificity. We provided practical outlines for these assays, emphasizing adherence to SOPs and quality control to ensure accuracy of results.