A 50-year-old woman presents with a 6-month history of joint pain, stiffness, and swelling affecting both hands and wrists. She describes morning stiffness lasting more than an hour, which improves with activity. She also reports fatigue and occasional low-grade fevers. Physical examination reveals bilateral swelling and tenderness of the MCP and PIP joints. Laboratory tests show elevated rheumatoid factor (RF) and anti-citrullinated peptide antibodies (anti-CCP). X-ray of the hands shows joint space narrowing, periarticular osteopenia, and marginal erosions. Which of the following best describes the underlying mechanism of her condition?
