Improvement of lung function in patients with systemic sclerosis after 6 months cyclophosphamide pulse therapy

This study aims to analyze the effects of cyclophosphamide pulse therapy on parameters of lung function in patients with systemic sclerosis. Nineteen patients with systemic sclerosis (15 women and four men, aged 25–67 years, mean disease duration 5 years and 9 months) were included in this study. The main reason for the beginning of cyclophosphamide therapy was the decrease of transfer-factor (DLCO) or diffusing coefficient for carbon monoxide (DLCO/VA) under 70% of predictive value. Intravenous cyclophosphamide was administered monthly in a dose of 500 mg/m² body surface. The efficacy was evaluated by comparison of forced vital capacity (FVC), DLCO, and DLCO/VA at the baseline and 1 month after the sixth pulse. Statistical analyses were performed using Student’s T test and Wilcoxon’s test. The difference between FVC at the baseline (86.6%) and at the end of the follow-up period (89.2%) was not statistically significant (t=−1.25, p>0.05). However, a significant increase of DLCO (from 61.2% to 70.5%, z=−2.04, p=0.04) and DLCO/VA (from 57.8% to 72.5%, z=−2.67, p=0.008) was observed. Minor side effects were noticed in some patients. Two patients had nausea after cyclophosphamide infusion, two patients had insignificant decrease of creatinine clearance, and two patients had temporary and mild leukopenia. In patients with systemic sclerosis and lung involvement, an improvement of lung-diffusing capacity was noticed 6 months after the beginning of cyclophosphamide pulse therapy, with only minor side effects.