Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by polyarthritis, synovial tissue hypertrophy, infiltration of leukocytes, destruction of cartilage, formation of pannus, and tenosynovitis. It affects approximately 0.5% to 1.0% of the global population, leading to prolonged inflammation that impacts all body organs. This condition can lead to associated complications, including rheumatoid lung disease, carditis, vasculitis, cachexia, anemia, accelerated atherosclerosis, myocardial and cerebrovascular diseases, lymphoma, osteoporosis, depression, physical disabilities, and increased cardiovascular mortality linked to RA symptoms. Early diagnosis and symptom management are essential to prevent severe outcomes. Severity is evaluated using the DAS28 scale and ACR/EULAR classification, as this long-lasting inflammatory disorder is often instigated by a mix of genetic factors and environmental triggers. The presence of anti-citrullinated protein antibodies heightens the risk of recurrence from 13% to 32% within a year. The disease's pathogenesis involves autoreactive immune CD4+ T cells, B cells, macrophages, as well as inflammatory mediators, including cytokines, chemokines, and autoantibodies, with hormonal changes playing a role. Approximately 40% of severe RA patients are HLA-DR4 positive, commonly exhibiting complications like vasculitis, neuropathy (usually associated with vasculitis), serositis, interstitial lung disease, pulmonary nodules, scleritis, glomerulonephritis, and Felty syndrome. Treatment typically involves conventional DMARDs like methotrexate, hydroxychloroquine, and sulfasalazine, as well as synthetic disease-modifying antirheumatic drugs (sDMARDs), including pan-JAK and JAK1/2 inhibitors, along with biological DMARDs (bDMARDs). The microbiome plays a role in the local and systemic inflammatory immune responses, and adjuvant therapy with probiotic bacteria such as Lactobacillus casei or Lactobacillus acidophilus can alleviate symptoms and provide anti-inflammatory benefits. Genetic predispositions significantly influence RA, with heritable traits linked to specific genetic factors like HLA-DR and the "conserved shared epitope" (SE) in the third hypervariable region of the DRB1 chain being associated with a heightened risk of the disease. This review emphasizes interlink between RA, in-relation with inflammation, microbiota and the genetic factors/contributors associated, for in-depth understanding and management of RA.
Rajashekar et al. (Thu,) studied this question.