Objective: To examine the clinical benefit and impact on cytokine production by methotrexate in rheumatoid arthritis.
Methods: Thirty patients with RA were treated with oral methotrexate (mean, 15 mg per week) as monotherapy for 24 weeks. Clinical assessment using the American College of Rheumatology (ACR) criteria for improvement was performed at baseline and at the end of 2, 4, 8, 12 and 24 weeks. The pro-inflammation cytokine TNF-alpha, INF-gamma,IL-1beta, IL-6 and anti-inflammation cytokine IL-10 were measured in RA sera at baseline and after 24 weeks of therapy.
Results: There was remarkable improvement in disease activity following the MTX treatment. At the end of 24 weeks, the percent age of ACR20 was 70% (21/30), ACR50 30% (9/30) and ACR70 10% (3/30). The levels of IL-6 (46.83+/-35.81 vs. 20.92+/-17.98, P=0.001), TNF-alpha (162.52+/-107.63 vs. 18.32+/-14.36, P=0.026) and INF-gamma (67.79+/-43.76 vs. 35.78+/-27.51, P=0.004) were significantly higher than those of the health control at baseline, respectively. The levels of TNF-alpha (123.36+/-89.61,P=0.018), INF-gamma (41.53+/-13.49, P=0.015), IL-1beta (7.47+/-7.33, P=0.026), IL-6 (26.01+/-25.64, P=0.025) were significantly decreased after treatment with methotrexate. In contrast, IL-10 was remarkably increased (71.76+/-41.01, P=0.02).
Conclusion: Methotrexate is effective in patients with rheumatoid arthritis. It can suppress the symptoms and joint damage. In addition, methotrexate treatment decreases the levels of pro-inflammatory cytokine, and increases the level of anti-inflammatory cytokine.