Rheumatoid arthritis pathogenesis primarily involves activation of which immune cells?

• A. B and T cells
• B. Neutrophils
• C. Eosinophils
• D. Platelets

Answer: (A)

Rheumatoid arthritis is driven by the adaptive immune response, with both B and T lymphocytes playing central roles. Autoreactive CD4+ T helper cells become activated and secrete cytokines (like TNF-α, IL-6, IL-1) that activate macrophages and synovial fibroblasts, fueling chronic synovitis and pannus formation. B cells contribute by producing autoantibodies such as rheumatoid factor and anti-CCP, which form immune complexes and amplify inflammation, while also presenting antigen to T cells to sustain the response. Neutrophils, eosinophils, and platelets participate in and modulate inflammation, but they are not the primary initiators of the autoimmune process.