To investigate whether patients affected by 1 of the 3 subsets of early systemic sclerosis (SSc; scleroderma), i.e., subset I, Raynaud's phenomenon with SSc marker autoantibodies and typical capillaroscopic findings; subset II, autoantibody positive only; and subset III, capillaroscopy positive only and not satisfying the 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for SSc at admission, differ from each other in the time to satisfy the criteria.
Early SSc patients subdivided into the 3 subsets indicated above consecutively admitted to a rheumatology/angiology center were monitored for 12-102 months (median 36 months). Patients were reevaluated twice yearly to assess whether and when each patient satisfied the new ACR/EULAR classification criteria for SSc. Patients with undifferentiated connective tissue disease (UCTD) served as the comparator group.
During followup, 11 (52.3%) of 21 subset I, 10 (66.6%) of 15 subset II, 0 of 24 subset III, and 0 of 44 UCTD patients satisfied the criteria (P = 0.0001). The difference was significant between early SSc and UCTD patients (P = 0.0001) and, within the group of early SSc patients, between each of the 2 autoantibody-positive subsets (subsets I and II) and the capillaroscopic-positive/autoantibody-negative subset (subset I versus III: P = 0.0001; subset II versus III: P = 0.0009). There was no difference between the 2 autoantibody-positive subsets (P = 0.454). In addition to marker autoantibody positivity, preclinical lung or heart involvement was associated with an increased risk to satisfy the criteria during followup.
Our data demonstrated faster progression of SSc in autoantibody-positive patients, particularly in those with preclinical internal organ involvement at baseline, than in autoantibody-negative patients.