Background Lung involvement in the form of interstitial lung disease (ILD) is one of the most serious manifestations of systemic sclerosis (SSc). ILD develops in up to 80% of patients with SSc overall and may be life threatening and require aggressive therapy. Patients with severe SSC-associated ILD have a survival rate of only 58% within 10 years from disease onset. Rituximab (RTX) is monoclonal antibody against human CD20 that targets B cells. We assessed the safety and a possible effect of treatment with RTX in patients with SSc.

Objectives To assess the safety and efficacy of treatment with RTX in patients with SSc.

Methods There were 16 SSc patients (pts) in the study. The female/male ratio was 14/2. The mean (SD) age of the pts was 48,2 (12,4) years. The duration of disease from the first non Raynaud’s phenomenon was 5,2 (4,7) years. A total of 12 (87,5%) pts had diffuse SSc, 4 (12,5%) had limited cutaneous SSc. All patients had SSc-assotiated ILD, more of them were treated previously with immunosuppressive agent (n=14). 16 pts with SSc received 1cycle of RTX and 9 pts went on RTX treatment and had a follow-up of 1,5 year. All pts were treated by prednizolon 10-15 mg per day. One patient had co-treatment with cyclophosphamide during 6 month after RTX. We evaluated the modified Rodnan skin score (mRSS), forced vital capacity (FVC), diffusing capacity of carbon monoxide (DLCO), the Valentini Disease Activity index, levels of B-cells in peripheral blood before, in 6 months, in one year and in 1,5 years after completed RTX.

Results We found a linear improvement of lung function and skin thickening during 1,5 years of 1st course RTX treatment. After six months pts presented a median decrease of the skin score was significantly compared to baseline (mean ± SD: 8,2±5,6 vs 12,9±8,1, respectively, p<0,02). The Valentini Disease Activity index compared to baseline also significantly decreased in 1 year (mean ± SD: 1,2±0,4 vs 2,9±1,7, respectively, p<0,01). The median percentage of improvement of FVC in 1,5 years was 10%, however these results were not significant. The median percentage of DLCO in 1,5 years increased insignificantly only 3%. Complete depletion of peripheral blood B-cells was observed in all pts and persistence during year. During RTX treatment infections occurred in 2 pts, one of them had herpes zoster after 2 weeks, and another one had acute bronchitis after 2 month. These infections were successfully treated and did not have complications. Two pts had ST instability on ECG after 10 days after RTX infusion without consequences.

Conclusions Our results indicate possible beneficial effect of RTX therapy on skin fibrosis and lung involvement in SSc pts. RTX therapy causes stabilization and improvement of SSc. This study reported also the safety of RTX in SSc pts.

Disclosure of Interest None Declared