THU0397 The prognostic value of autoantibodies in systemic sclerosis and a two-year follow-up of forced vital capacity

Background Systemic sclerosis (SSc) is a connective tissue disease involving the skin and internal organs of the body. Affection of the lungs and the vascular system significantly increases the morbidity and mortality. Controlling disease progression represents a challenge in clinical practice. Objectives We aimed to address prognostic factors of disease activity and study the progress of interstitial lung disease (ILD) under conventional disease modifying anti-rheumatic drugs (DMARDs) therapy. Methods Data of SSc patients (limited or diffuse) followed up in the Rheumatology Department Clinics throughout the past 2 years were collected for a retrospective study. The positivity of Antinuclear (ANA), Anti-centromere (ACA) and Anti-Scl70 antibodies was gathered from patients’ data. Disease activity was assessed by the European Scleroderma Study Group (EScSG) activity index. Forced vital capacity (FVC) was used to mark the progress of ILD. Friedman and Wilcoxon signed rank tests were used for comparison of paired data as appropriated. Mann-Whitney U test, Kruskal-Wallis test and Chi-Square test were used to compare between two or more groups. Results The data of 42 SSc patients (59.5% limited SSc and 40.5% diffuse SSc) with a mean age 40±12 years were enrolled. 83.3% of the patients showed ANA positivity. ACA was positive in 28.6% of the patients and Anti-Scl70 in 23.8% while 47.6% of the patients were negative for both. DMARDs were indicated according to organ involvement, and changes were made according to breakthrough events. Low scores of EScSG were noticed in the ACA +ve group compared to intermediate scores in the Scl70 +ve group and high scores in the negative group at baseline (p=0.082) and 24 month follow-up (p=0.045). The frequency of pitting digital ulcers at baseline was lowest in the ACA +ve group compared to the highest frequency in the negative group (p=0.026), however, there was no difference between the groups at the 24 month follow-up. ANA did not affect the activity throughout the studied period. Follow up of FVC in the two years with different DMARDs is illustrated in figure 1. Patients followed on methotrexate (MTX) after cyclophosphamide (CYC) or mycofenolate (MMF) had raised FVC (p=0.033 and p=0.054 respectively) comparable to azathioprine (AZA) after CYC or MMF (p=0.031 and p=0.27 respectively). Conclusions ACA is proposed to be a marker of low disease activity and good response to therapy. Despite the risk of inducing ILD, MTX maintained a favourable effect on FVC throughout a follow-up period. Disclosure of Interest None declared