Background Systemic sclerosis (SSc) is characterized by systemic excessive fibrosis, and interstitial lung disease (ILD) is an important organ involvement strongly associated with morbidity and mortality1). Recent report showed that extent of ILD could predict prognosis of patients with SSc-ILD, and 70% as %FVC or 20% involvement determined by HRCT were reported as thresholds for the differentiation of patients into limited (LD) or extended (ED) ILD2). On that note, adequate target for the introduction of the treatment is still unclear.
Objectives To elucidate the better target for the treatment of patients with SSc-ILD.
Methods This was a single-center study. Patient with SSc-ILD treated with cyclophosphamide during 2008 to 2015 in our hospital were consecutively involved. SSc patients were fulfilled 1980 American College of Rheumatology (ACR) classification criteria3) or 2013 ACR/EULAR classification criteria4). Patients were stratified into 2 groups, extensive or limited lung disease, based on the disease extent over 20% or less using CT scan2), respectively. Baseline data of pulmonary function tests and other clinical parameters were retrospectively collected from medical records, and response at 6 months after the treatment was evaluated by the change of data of pulmonary function tests before and after the treatment. Each parameter was compared between ED and LD groups.
Results Sixteen patients with SSc-ILD who were treated with cyclophosphamide were involved. Mean age was 57.3±15.1 years and ratio of female patients and diffuse cutaneous SSc were 81%, 50%, respectively. Autoantibody profiles were 2 with anticentromere antibodies (13%), 8 with anti-topoisomerase I antibodies (50%), 1 with anti-U1 ribonucleoprotein antibody (6%) and 5 with antinuclear antibody positive without SSc-specific antibodies (31%). Disease duration at diagnosis of ILD was 26.4±31.9 months. Based on the criteria, 9 (56%) were stratified as ED and 7 (44%) as LD. At baseline, %FVC was higher (86.1±14.2 vs 67.2±16.8%, p<0.05) and disease duration was shorter in LD (12.6±24.8 vs 37.2±33.8 months, p<0.05) but other clinical parameters including age, sex, smoking, autoantibody profiles, mean cumulative dose of prednisolone or cyclophosphamide and serum KL-6 levels were comparable between 2 groups. Response to treatment was better in patients with LD compared to ED; improvement of %FVC (6.80±5.59 vs 0.04±3.92%, p<0.05), favorable outcome of %DLCO but not significant (3.37±12.77 vs 0.70±6.18%).
Conclusions SSc patients with LD, who had earlier and milder disease, showed better short-term response to treatment compared to those with ED. These results suggest that earlier intervention could lead to better prognosis in patients with SSc.
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Disclosure of Interest None declared