CLINICAL CHARACTERISTICS AND PROGNOSIS OF PATIENTS WITH SYSTEMIC SCLEROSIS SINE SCLERODERMA: DATA FROM THE INTERNATIONAL EUSTAR DATABASE
Authors: A. Lescoat et al.
SSc sine scleroderma (ssSSc) is a SSc subset characterized by the absence of skin fibrosis and sclerodactyly but with the existence of SSc-associated visceral manifestations. This study aimed to characterise the clinical features of patients with ssSSc.
Patients within the EUSTAR database who had no skin thickening at all visits were compared with patients with lcSSc and dcSSc. 8.8% of the SSc patients had ssSSc. At the inclusion visit, 40.3% of ssSSc patients had puffy fingers, 39.4% had interstitial lung disease (ILD), 1.6% had a history of scleroderma renal crisis. At last available visit, in comparison with lcSSc and dcSSc patients with the same disease duration, ssSSc patients had a lower prevalence of previous or current digital ulcers (28.2% versus 53.1% in lcSSc (P<0.001) and 68.3% in dcSSc (P<0.001)), of joint synovitis (16.9% versus 24.3% in lcSSc (P<0.01) and 30.8% in dcSSc (P<0.0001)), and of elevated sPAP on echocardiogram (15.2% versus 23.9% in lcSSc (P<0.01) and 28.7% in dcSSc (P<0.0001)). By contrast, the prevalence of ILD was almost similar in ssSSc and lcSSc (49.8% and 57.1% (P=0.03)) but significantly higher in dcSSc (75.0%, P<0.0001). Based on forced vital capacity, ILD was less severe in ssSSc in comparison with the other subsets (mean FVC 100% pred) versus 93% in lcSSc and 82% in dcSSc (P<0.0001 for both)). Anti-centromere antibodies were most frequent in ssSSc (61.7% versus 41.9% in lcSSc (P<0.0001) and 16.3% in dcSSc (P<0.0001), whereas the opposite distribution was observed for anti-Scl70 antibodies. Survival was significantly higher in ssSSc patients compared to lcSSc and dcSSc.
This study highlights that the SSc subset without any skin fibrosis accounts for almost 10% of SSc patients. ssSSc patients have, however, significant organ involvement although milder disease severity compared to SSc patients with skin fibrosis.