Comparison of the effectiveness of cyclophosphamide and rituximab treatment in patients with systemic sclerosis-related interstitial lung diseases: a retrospective, observational cohort study

Objectives To compare the effectiveness of cyclophosphamide and rituximab in the treatment of patients with systemic sclerosis with pulmonary involvement (SSc-ILD). Methods Symptoms and the respiratory function parameters of 34 patients receiving cyclophosphamide and 27 patients receiving rituximab for at least 24 months between 1996 and 2018 were compared. Results It was observed that symptoms including cough, Raynaud's phenomenon, digital ulceration, diarrhea, and dysphagia, but not dyspnea, recovered statistically significantly more in the rituximab group (p = 0.004, p = 0.001, p = 0.006, p = 0.005, and p < 0.001, respectively; for dyspnea p = 0.11). When differences in FVC and FVC% values were compared with baseline, it was found that there was a statistically significant increase in FVC (mL) (p = 0.02) and FVC% (p = 0.002) values after 12 months of treatment in patients receiving cyclophosphamide compared with those receiving rituximab. When differences in DLCO and DLCO% values from baseline were compared, a statistically significant increase was seen in DLCO values after 15 and 24 months (p = 0.003 and p = 0.048, respectively) of treatment, also in DLCO% values after 15 and 18 months (p = 0.008 and p = 0.01, respectively) of treatment in patients receiving rituximab compared with those receiving cyclophosphamide. Conclusion It was observed that both cyclophosphamide and rituximab treatments were effective in controlling dyspnea and worsened pulmonary function in SSc-ILD. The effect of cyclophosphamide is more prominent on FVC and rituximab is more effective on DLCO.