Effect of Rituximab in Patients with Cyclophosphamide-non-responsive Connective Tissue Disease-Related Interstitial Lung Disease: A Case Series Study

Objective: To report our experience of intravenous cyclophosphamide pulse therapy and the effect of rituximab (RTX) therapy in patients with cyclophosphamide-non-responsive connective tissue disease associated interstitial lung disease (CTD-ILD).Methods: We retrospectively evaluated the medical records of patients with CTD-ILD. All patients received intravenous cyclophosphamide pulse (IVCYC) therapy. The patients who received IVCYC+RTX were non-responsive to IVCYC treatment. At 0 to 6 months prior to the treatment, these patients underwent a pulmonary function test (PFT). High resolution computed tomography was performed before the initiation of treatment.Results: Ten patients were enrolled in this study. A significant percentage of patients showed stabilization or improvement of pulmonary function after treatment. The response rates of the IVCYC and IVCYC+RTX groups were 50% (5/10) and 60% (3/5), respectively.Conclusions: Patients with CTD-ILD who received IVCYC with or without RTX therapy showed a significant improvement in lung function. RTX therapy could be employed as a salvage therapy and combined with IVCYC early for refractory CTD-ILD.