How do rheumatoid factor and IgG contribute to inflammation in rheumatoid arthritis?

In the pathology of rheumatoid arthritis, rheumatoid factor acts as an autoantibody that specifically targets the tail region of IgG molecules.12

When these two components bind, they form immune complexes that deposit within the synovial membranes of the joints. This deposition triggers a type III hypersensitivity reaction, which contributes to inflammation through the following mechanisms:2

• Complement Activation: The immune complexes activate the complement system, a cascade of proteins that promotes an inflammatory response.23
• Cell Recruitment: The process attracts granulocytes and other immune cells to the joint.2
• Tissue Damage: These recruited cells release enzymes that break down cartilage and collagen, leading to the destruction of the joint surface and causing the pain and swelling characteristic of the disease.12

This autoimmune process is a fundamental driver of the chronic inflammation and joint destruction seen in affected individuals.142