Objectives To analyze the effects of cyclophosphamide (CYC) pulse therapy on parameters of lung function in patients (pts) with systemic sclerosis (SSc).
Methods Thirty pts with SSc (25 women and 5 men, aged 30-70 years, mean disease duration <2 years) were included in this study. The main reason for the beginning of CYC was the decrease of forced vital capacity (FVC) under 80% or single-breath diffusing capacity of carbon monoxide (DLco) under 70% of predictive value. Based on the relationships of FVC%/DLco% pts were divided into two groups: 13 pts with FVC%/DLco%<1,6 (group I) and 17 pts with FVC%/DLco%>1,6 (group II). Monthly CYC pulses in a dose of 500 mg/m2 body surface were given for the period of 6 months, followed by 3-monthly frequency maintenance pulses treatment for the next 18 months. The efficacy was evaluated by comparing FVC% and DLco% at the baseline, 1 month after the sixth pulse, and after 24 months from the start of therapy.
Results At baseline, there were no significant group differences for the age of onset of SSc, digital ulcers or scars, arthritis, dyspnea and fatigue, presens of basilar Velcro-like crackles on lung auscultation, presens of fibrosis on chest radiography, gastroesophagel reflux, renal involvement and assessed value of the right ventricular systolic pressure. Pts from group II had an earlier onset of Raynaud's phenomenon (RP), longstanding RP, diffuse cutaneous SSc, systemic inflamation defined by increase in CRP, anticentromere antibody positivity, higher values of FVC% and lower values of DLco% than those with group I (46.15±17.82 years; 5.82±5.99 years; 13 pts; 12.25±26.02; 7 pts; 105.05±15.37%; 58.21±7.94% versus 51.96±9.6 years; 2.96±3.25 years; 6 pts; 10.70±8.53;2 pts; 85±12.79% and 69.28±9.91% respectively; p<0.05). In group I mean FVC values improved for 2.91% and DLco values declined for 4.69% over the 6-months period (p=0.321 v.s. 0.109, respectively), while in group II mean FVC values improved for 6.34% and DLco values improved for 6.90% (p=0.104 v.s. 0.169, respectively). Eight pts from group I and twelve pts from group II completed the maintenance phase. In group I mean FVC values improved for 2.3% and DLco values declined for 4.96% over the 24-months period, while in group II mean FVC values improved for 0.8% and DLco values declined for 0.31% over the 24-months period.
Conclusions Our results suggest that CYC was able to prevent deterioration of FVC after 6 and 24 months in all pts with SSc and lung involvement. Surprisingly enought, the fact is that only in patients with FVC%/DLco%>1.6, having a risk factor for future development of SSc associated pulmonary arterial hypertension, CYC was able to prevent deterioration of DLco after 6 months of therapy, but not such results were observed after 24 months of therapy. The maintenance of treatment with CYC may be necessary only for patients with FVC%/DLco%<1.6
Disclosure of Interest None declared