Objectives: The aim of this study was to investigate changes in disease activity, cytokine profiles, and proliferation of peripheral blood mononuclear cells (PBMCs) in active rheumatoid arthritis (RA) patients treated with simvastatin.
Methods: Thirty-three patients with active RA were prescribed simvastatin (40 mg/day) for 3 months. Most of the patients received background traditional disease-modifying anti-rheumatic drugs (DMARDs) in stable doses. At the end of treatment there was a reduction in the 28-joint Disease Activity Score (DAS28) and in the Health Assessment Questionnaire (HAQ) score.
Results: Eleven patients (33%) achieved a moderate European League Against Rheumatism (EULAR) response. There was a decrease in circulating interleukin (IL)-17 concentrations and spontaneous PBMC proliferation. Anti-CD3-stimulated IL-10 and tumour necrosis factor (TNF)alpha production by PBMCs was upregulated after simvastatin therapy. A reduction in serum IL-6 was detected only in the responder group. Baseline circulating IL-10 concentrations were higher in responders than in non-responders.
Conclusion: Simvastatin treatment is associated with moderate clinical improvement in patients with active RA. Immunological changes produced by simvastatin in peripheral blood are complex and may reflect both its anti- and pro-inflammatory properties.