Background The primary cause of death in patients with systemic sclerosis (SSc) is interstitial lung disease (ILD). Several retrospective studies have shown some effect of cyclophosphamide (CYC) on ILD. In one randomized controlled trial a small but significant effect on pulmonary function was shown after oral CYC (Taskin,2006). Hoyles (2006) showed a trend towards improvement of forced vital capacity after monthly CYC infusions. In our centre, intravenous CYC pulses are the first choice of therapy in SSc-ILD.
Objectives To analyze 1) the effects of iv CYC pulses (750mg/m2) on pulmonary function in SSc-ILD in our cohort, and 2) whether this effect is dependent on the extent of ILD.
Methods Patients with SSc-ILD receiving CYC pulses between 2003 to 2015 were classified by the Goh criteria (2008) in either limited or extensive ILD, using HRCT at baseline judged by two raters. Pulmonary function tests were performed at 0, 6 and 12 months. Missing outcome data due to drop-out, but not death, were replaced by last observation carried forward.
Results 79 patients were included, 42 with limited ILD, 37 with extensive ILD. There were no differences in age, gender, SSc subtype classification, disease duration or autoantibody status between the two groups. Baseline FVC (median 80% vs. 91%) and DLCO (39% vs. 50%) were lower in extensive ILD (p<0.05).
After 12 months, FVC (p=0.08)), and DLCO (p=0.62) did not worsen compared to baseline values. There were no differences in the degree of change in FVC and DLCO between limited and extensive ILD. Forty-eight patients completed 12 cycles of CYC. Per protocol analyses showed not significant differences between limited and extended ILD.
Conclusions 1. CYC pulse therapy does not worsen pulmonary function in SSc-related ILD after 1 year. 2. The extent of ILD does not influence the effect of CYC.
Disclosure of Interest None declared