We investigated early systemic sclerosis (SSc) (that is, Raynaud's phenomenon with SSc marker autoantibodies and/or typical capillaroscopic findings and no manifestations other than puffy fingers or arthritis) versus undifferentiated connective tissue disease (UCTD) to identify predictors of short-term disease evolution.
Thirty-nine early SSc and 37 UCTD patients were investigated. At baseline, all patients underwent clinical evaluation, B-mode echocardiography, lung function tests and esophageal manometry to detect preclinical alterations of internal organs, and were re-assessed every year. Twenty-one early SSc and 24 UCTD patients, and 25 controls were also investigated for serum endothelial, T-cell and fibroblast activation markers.
At baseline, 48.7% of early SSc and 37.8% of UCTD patients had at least one preclinical functional alteration (P > 0.05). Ninety-two percent of early SSc patients developed manifestations consistent with definite SSc (that is, skin sclerosis, digital ulcers/scars, two or more teleangectasias, clinically visible nailfold capillaries, cutaneous calcinosis, X-ray bibasilar lung fibrosis, X-ray esophageal dysmotility, ECG signs of myocardial fibrosis and laboratory signs of renal crisis) within five years versus 17.1% of UCTD patients (X2 = 12.26; P = 0.0005). Avascular areas (HR = 4.39 95% CI 1.18 to 16.3; P = 0.02), increased levels of soluble IL-2 receptor alpha (HR = 4.39; 95% CI 1.03 to 18.6; P = 0.03), and of procollagen III aminopropeptide predicted disease evolution (HR = 4.55; 95% CI 1.18 to 17; P = 0.04).
Most early SSc but only a few UCTD patients progress to definite SSc within a short-term follow-up. Measurement of circulating markers of T-cell and fibroblast activation might serve to identify early SSc patients who are more likely to develop features of definite SSc.