OP0273 THE SCLERODERMA CLINICAL TRIALS CONSORTIUM DAMAGE INDEX (SCTC-DI) IN A SYSTEMIC SCLEROSIS COHORT WITH 10-YEARS FOLLOW-UP

Abstract

Background:Systemic Sclerosis (SSc) is characterized by increased mortality and organ damage accrual. A composite SSc Damage Index was recently developed by the Scleroderma Clinical Trials Consortium (SCTC-DI) and was demonstrated as a predictor of mortality both in the Australian derivation cohort and in the Canadian validation cohort.Objectives:To evaluate in a single centre cohort of SSc patients with 10-years follow-up: (1) the evolution of organ damage over time; (2) factors associated with the development and accrual of organ damage.Methods:A retrospective analysis was performed on patients prospectively followed in our centre from 1989 to 2019. Organ damage was evaluated with SCTC-DI (0-55 scale; moderate damage >5, severe damage>12) and comorbidities with Charlson Comorbidity Index (CCI, which includes the age of the patient). Patients were included when a follow-up of at least 10 years was available together with SCTC-DI at the diagnosis (baseline, T0), 1 year (T1), 5 years (T5) and 10 years (T10) after the diagnosis. Univariable and multivariable analysis (logistic regression) were performed when appropriated.Results:253 SSc patients were included (female 93%; Caucasians: 99%; median age at diagnosis: 52 years (IQR: 43-60); diffuse cutaneous subset: 15%; anti-centromere (ACA)+ 55%; anti-Topoisomerase 1 + 20%; anti-RNA polymerase III+: 4%; ever smokers: 28%). Median interval between the first SSc symptom other than Raynaud’s phenomenon and the diagnosis was 1 year. SCTC-DI progressively increased from diagnosis to T10 (p<0.0001; Kruskal-Wallis test).Moderate damage (score:6-12) was observed in 22 patients at T0 (8.7%), in 30 at T1 (11.9%), in 45 at T5 (17.7%) and in 73 at T10 (28.9%). None of the patients had severe damage (score:13-55) at T0 and T1, while it was present in 6 at T5 (2.4%) and in 13 at T10 (5.1%).At T0 no difference in SCTC-DI scores was observed when comparing different subgroups according to gender (female vs. male), disease subsets (diffuse vs. limited) and autoantibodies (ACA- vs. ACA+). At T1, SCTC-DI score was higher in patients with diffuse vs. limited cutaneous subset, and ACA- vs ACA+ (p<0.0001 for both).Multivariable analysis demonstrated that a moderate or severe organ damage (SCTC-DI score >5) at 5 years was positively associated with diffuse cutaneous involvement (p:0.009, OR 4.55, 1.46-14.1), SCTC-DI at T0 (p:0.015, OR 1.34, 1.06-1.70) and at T1 (p:<0.0001, OR 1.65, 1.30-2.07), and negatively associated with ACA+ (p:0.024, OR 0.32, 0.12-0.86), while CCI and male sex showed no association. At 10 years SCTC-DI>5 was associated with diffuse cutaneous involvement (p:0.013, OR 4.30, 1.36-13.7), SCTC-DI at T5 (p:<0.0001, OR 1.67, 1.38-2.01), while SCTC-DI at T0, CCI, male sex and ACA+ had no association.Among 253 patients, 90 (36%) died after >10 years of follow-up. In non-survivors, as compared to survivors, SCTC-DI score was significantly higher at the baseline (T0) and during the entire follow-up (p<0.0001 for every timepoint).Conclusion:At the end of 10-years follow-up (T10), 35% of patients in our cohort had moderate or severe organ damage (SCTC-DI score>5). Diffuse cutaneous involvement was associated with higher SCTC-DI scores at different time points (T5 and T10). Organ damage, quantified by SCTC-DI at different time points, was confirmed as a factor associated with mortality in patients who reached more than 10 years of follow-up.