エタネルセプト使用中に膝関節滑膜切除を行った関節リウマチの１例

抄録

    Etanercept, which blocks the action of tumor necrosis factor (TNF), reduces disease activity in patients with rheumatoid arthritis (RA). However, not all patients having synovitis with RA respond to etanercept. We report the case of a RA patient whose knee synovitis was treated by arthroscopic synovectomy, even though etanercept had been used. The patient, a 65-year-old female, had been receiving etanercept 25 mg twice/week, 4 mg MTX/week and 10 mg of glucocorticoid hormone/day. Over a period of 2 months the number of swollen and painful joints gradually decreased, but not the left knee. The knee was swollen and tender, demonstrating active synovitis. Hyaluronic acid or corticosteroid was injected in the knee joint, but the pain and swelling did not decrease. X-ray findings of the knee showed no erosion or joint space narrowing; however, MRI showed a high intensity area in the suprapatellar pouch of the knee consistent with active synovitis in the knee. As the condition persisted, arthroscopic synovectomy was performed. The arthroscopic findings showed villonodular synovitis. After the operation, the symptom in the knee steadily decreased. Etanercept with methotrexate is usually an effective treatment for RA, however, in this case despite receiving such treatment, synovitis of the knee persisted. Our experience demonstrates that arthroscopic synovectomy is a safe and effective treatment for RA cases not responding to etanercept with MTX.