Long-term efficacy of B cell depletion therapy on lung and skin involvement in diffuse systemic sclerosis

To assess the long-term efficacy and safety of single and multiple courses of rituximab therapy in systemic sclerosis (SSc) patients with and without lung disease.

A total of 20 SSc patients with a diffuse disease were treated with rituximab. At baseline and during follow-up the lung involvement was evaluated with pulmonary function tests (FVC and DLCO) and with lung high-resolution computed tomography (HRCT).

The skin score, activity, and severity indices improved significantly after 12 months and at final follow-up compared to baseline. After 12 months, there was a significant increase of FVC and TLC compared to baseline (p = 0.024 and p = 0.005, respectively), while the mean DLCO value remained stable. Considering the last available follow-up in six patients with restrictive lung disease at baseline, two patients (33.3%) experienced an increase of more than 10% of FVC, one patient had a decrease of FVC >10%, while in three patients FVC remained stable (50%). After the mean follow-up of 48.5 ± 20.4 months, among the patients with normal lung parameters at baseline, FVC remained stable in 12 (85.7%) and in one patient (14.3%) it increased by more than 10%. At the final follow-up, the alveolar and interstitial HRCT scores remained stable in more than 80% of patients, both in patients with and without restrictive lung disease at baseline.

Anti-CD20 B cell depletion therapy is effective on skin involvement but seems also to preserve the pulmonary function, as supported by a stable or improved FVC and stable interstitial score, suggesting a possible role of rituximab as a modifying therapy overall in early diffuse SSc.