Effect of long-term treatment with rituximab on pulmonary function and skin fibrosis in patients with diffuse systemic sclerosis.

Objectives: To assess the safety and efficacy of long-term treatment with rituximab (RTX) in patients with systemic sclerosis (SSc).

Methods: Eight patients with SSc-associated interstitial lung disease (ILD) received 4 cycles of RTX and had a follow-up of 2 years. Lung involvement was assessed by pulmonary function tests and chest HRCT. Skin involvement was assessed both clinically and histologically.

Results: We found a linear improvement of lung function and skin thickening over the 2 years of RTX treatment. There was a significant increase of FVC at 2 years compared to baseline (mean ± SEM: 77.13±7.13 vs. 68.13±6.96, respectively, p<0.0001). Similarly, DLco increased significantly at 2 years compared to baseline (mean ± SEM: 63.13±7.65 vs. 52.25±7.32, respectively, p<0.001). Skin thickening, assessed with the MRSS, improved significantly at 2 years compared to baseline (mean ± SEM: 4.87±0.83 vs. 13.5±2.42, respectively, p<0.0001). A reduction in myofibroblast score was seen histologically following RTX treatment.

Conclusions: Our results indicate that long-term treatment with RTX may favourably affect lung function and skin fibrosis in patients with SSc. Larger scale, multicentre, randomised, controlled studies are needed to further explore the efficacy of RTX in SSc.