Efficacy of low-dose tacrolimus in patients with rheumatoid arthritis who had an inadequate response to disease-modifying antirheumatic drugs

Abstract

Objectives: The aim of this study is to investigate an efficacy of low-dose tacrolimus for patients with rheumatoid arthritis (RA) who showed an inadequate response to disease-modifying antirheumatic drugs (DMARDs) including methotrexate (MTX).
Methods: Forty-seven patients with RA who showed an inadequate response to DMARDs were introduced low-dose tacrolimus between August 2006 and November 2013. Forty patients (34 women and 6 men; mean age, 68 years) continued the tacrolimus administration more than two years and were investigated retrospectively. Starting dosage was 1 to 1.5 mg/day and the dose was increased or reduced depending on their clinical response. Disease activity and clinical response were evaluated by Disease Activity Score including C-reactive protein (DAS28-CRP) and European League Against Rheumatism (EULAR) response criteria. Serum MMP-3 and modified Total Sharp Score (mTSS) by yearly change were evaluated to estimate progression of joint destruction.
Results: The mean tacrolimus dosage was 1.2 mg/day at the baseline and maintained in low-dose. DAS28-CRP was significantly improved at 6 months after administration. At 24 months, 21 (52.5%) showed low disease activity and remission, while 11 cases (27.5%) showed no response by EULAR improvement criteria. The serum MMP-3 was significantly improved at 6 months. Structural remission achievement rate in ΔmTSS≦0.5 was 37.5% and 52.5% in the first and second year, respectively.
Conclusions: Low-dose tacrolimus caused significant improvement in both clinical and structural remission. Tacrolimus is easy to use because of its safety and the effect of even a low-dose can be expected for patients with RA who had an inadequate response to DMARDs including MTX.