LONG-TERM SURVIVAL AND PROGNOSTIC FACTORS FOR UNFAVORABLE OUTCOME IN PATIENTS WITH SYSTEMIC SCLEROSIS. A PROSPECTIVE SINGLE-CENTER STUDY

Abstract

Background. Systemic sclerosis (SSc) is a complex chronic autoimmune disease, with an unpredictable evolution and high morbidity and mortality rates. Objective. Evaluation of long-term survival and identification of prognostic factors in patients with systemic sclerosis. Methods. All patients with SSc of the EUSTAR100 center, having at least one visit between 2004 and 2016, were included. Data were analyzed for survival, cause of death, as well as for the following events defining disease worsening: increase in modified Rodnan score (mRSS) with at least 25% and 5 points (compared to baseline visit), decrease with at least 10% (compared to baseline) of predicted forced vital capacity (FVC) and predicted diffusing capacity of the lungs for carbon monoxide (DLCO), and presence of new digital ulcers (DUs). Logistic regression (LR), Cox proportional hazards regression and Kaplan-Meier survival curves were used in univariate and multivariate analysis to study survival and identify prognostic factors. Results. 137 patients were included in the study (89.1% females, mean age ± SD 56.7 ± 12.6 years, disease duration 9.7 ± 7.1 years), with a follow-up duration of up to 19 years. 96 patients had at least one follow-up visit and 66 (not including patients who died earlier than 2 years after the first presentation) had follow-up data at 2 years (± 6 months) after the first visit in the clinic. There were 19 reported deaths (13.9%), 11 attributed to SSc (of whom 8 were due to lung involvement). Risk factors for death were diffuse cutaneous subset and mRSS>14 at baseline (identified by LR adjusted for age and sex), male sex and proteinuria (Cox analysis). While in over half of the patients FVC and mRSS were stable or improved (86% and 96% respectively), and no new DUs occurred (64%), 52% of the patients presented significant worsening of DLCO during the entire follow-up. Risk factors for DLCO worsening at 2 years, by LR adjusted for sex and age, were male sex and diffuse cutaneous subset, while Cox analysis identified only male sex. The only risk factor identified for appearance of new DUs was the history of DUs at the first presentation. Conclusions. SSc often presents an unfavorable disease course, particularly due to lung involvement. Risk factors for disease worsening were male sex, diffuse cutaneous subset, and mRSS>14 at baseline. SSc-related deaths were mainly due to lung involvement, thus underlining the necessity of identifying predictive factors for lung function deterioration at the first presentation.

Keywords

• systemic sclerosis
• prognostic factors
• survival