MRI assessment of erosion repair in patients with long-standing rheumatoid arthritis receiving double-filtration plasmapheresis in addition to leflunomide and methotrexate: a randomized controlled trial.

The objective of this study is to investigate whether the addition of double-filtration plasmapheresis (DFPP) to leflunomide and methotrexate repairs MRI bone erosion in patients with long-standing rheumatoid arthritis (RA). Seventy-two patients with highly active RA of > 3 years' duration were randomized to receive DFPP in addition to DMARDs (leflunomide and methotrexate) or DMARDs. Contrast-enhanced MRI of the right wrist was performed at months 0, 6, and 12. MRI bone erosion, synovitis, and bone edema were scored with validated methods. The primary endpoint was the change in MRI bone erosion over 12 months. Patients treated with DFPP in addition to DMARDs demonstrated significantly greater decrease in MRI erosion score compared with those treated with DMARDs, being 11.3 ± 9.6 at month 12, compared with 16.9 ± 8.3 in patients with DMARDs (P < 0.001), and compared with 14.4 ± 9.6 at baseline (P < 0.001). 84.2% of patients treated with DFPP in addition to DMARDs demonstrated a decrease in MRI erosion score. Synovitis and bone edema improved significantly with DFPP in addition to DMARDs compared with DMARDs at months 6 and 12. (1.05 ± 1.7 and 2.0 ± 3.9 compared with 8.0 ± 1.4 and 12.6 ± 7.9 at month 12). Patients without synovitis and bone edema reached in 55.3% among patients with DFPP in addition to DMARDs. This study demonstrated that DFPP combination therapy significantly decreased bone erosion and received the primary goal of repair of erosions through abrogating MRI inflammation (synovitis and bone edema) in long-standing RA patients with high disease activity. The findings suggest that addition of DFPP is associated with repair of erosions and further suppression of inflammation.