LAUSR

Skin thickness improves over time in most diffuse cutaneous systemic sclerosis (dcSSc) patients and the use of group level skin score (mRss) as an endpoint is clinical trials can be challenging. We explore the association between individual mRss trajectories and outcome in early dcSSc patients. Subjects with at least one mRss assessment within the first 5 years from onset were included. Random effects models were fitted to evaluate changes in mRss over time and model-predicted individual patient intercepts and slopes were included in Cox regression to assess associations with outcome. Of the 467 patients, 22.7% were male and mean age of disease onset was 45.5 years. Most frequent autoantibodies were anti-Scl70 in 30.2% and anti-RNA polymerase (ARA) in 30.0% of subjects. Average mRss at 12 months from onset was 25 and this declined over time, slowing down with longer disease duration (3.4, 2.7, 1.9 and 1.2 units at years 2, 3, 4 and 5). Higher initial mRss associated with greater subsequent decline (correlation coefficient -0.3). Both higher baseline mRSS (intercept) and slower decline (higher slope) predicted increased risk of death with 8% increase in hazard for every unit higher baseline mRss and 4% increase for every unit higher slope (Table 1). Adjusting for autoantibodies did not change the estimates. ANA+ENA- subjects had the highest risk of death, followed by ATA + (HR 0.91, p = 0.677 v ANA+ENA-), while risk was lowest among ARA+ subjects (HR 0.47, p = 0.002 v ANA+ENA-). Risk of pulmonary complications was associated with rate of change in mRss but not with baseline absolute value. A unit slower yearly decline in mRss increased the hazard of pulmonary fibrosis (PF) by 3.5% and pulmonary hypertension (PH) by 7% (Table 1). The association between mRss and PF disappeared after adjusting for antibody specificities, while the association between skin and PH did not change. Autoantibodies did not show significant association with PH development within this dcSSc cohort. Although at a group level there is an improvement in skin over the initial 5 years, for individual patients, poor outcome for skin predicts increased risk of pulmonary complications and higher mortality. S.I. Nihtyanova None. E.C. Derrett-Smith None. C. Fonseca None. V.H. Ong None. C.P. Denton None.