SAT0499 Association between systemic sclerosis and other systemic auto-immune diseases: study in two university hospitals cohorts

Abstract

Introduction: Association between systemic sclerosis (SSc) and another auto-immune systemic disease (AISD) in the same patient seems to be more frequent than each disease's prevalence would explain. The aim of our work was to describe these patients from 2 french cohorts and to compare their characteristics with SSc. Material and Methods: Our study was retrospective observational and bicentric. Patients responding to the 2013 ACR-EULAR scleroderma classification criteria for SSc were screened for concomitant AISD. Patients satisfying 2010 ACR-EULAR diagnostic criteria for rheumatoid arthritis (RA) and/or 2016 ACR-EULAR classification criteria for Gougerot-Sjögren syndrome (GSS) and/or 2012 SLICC systemic lupus erythematosus (SLE) classification criteria were included in our study. Patient, disease, and treatment characteristics were retrospectively retrieved from medical records and were compared to a SSc cohort. Results: A population of 534 SSc patients was studied. Thirty-four (6.4%) patients were identified as having overlap syndrome. There was 21 (62%, prevalence 3.9%) patients with RA, 14 (41%, prevalence 2.6%) with GSS and 4 (12%, prevalence 0.7%) with SLE (5 patients had 2 AISD). There were 24 (71%) limited cutaneous SSc. Median Rodnan was 6 (extreme 0-42), 13 (38%) patients had interstitial pneumonia and 9 (26%) had of lung fibrosis. Three patients had pulmonary arterial hypertension (PAH) confirmed with catheterism. Seventeen patients (50%) had anti-centromere Ab, 11 (32%) had anti-Scl70 Ab whereas none had anti-RNA-polymerase III Ab (searched in 24 patients). Concerning RA patients, 17 (81%) were ACPA-positive and 17 (81%) had erosive disease. Only 6 (29%) were in remission according to Boolean criteria and 13 (62%) had a DAS28-CRP = 3 on accessory salivary gland biopsy and 12 (86%) had positive anti-SSA Ab. In patients with SLE, 3 (75%) had positive anti-DNA Ab and one had a grade IV kidney disease. Three (75%) patients with SLE had a SLICC organ-damage score >= 5 suggesting severe SLE. Compared with our control cohort, patients with overlap syndrome had higher frequency of corticosteroid, immu-nosuppressive therapy and biologic therapy use (85.3% vs 45%; 70.6% vs 31.3%; 52.9 vs 3.8%; p < 0.0001 for all comparisons). Conclusions: Association of SSc and another autoimmune systemic disease is present in more than 6% of patients. These patients might have a more severe disease than usual SSc patients requiring prompt diagnosis and adequate treatment.