To investigate whether patients affected by one of the 3 subsets of early systemic sclerosis (SSc): subset I, Raynaud's phenomenon with SSc marker autoantibodies and typical capillaroscopic findings; subset II, autoantibody positive only; subset III, capillaroscopy positive only and not satisfying the 2013 ACR/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 above-indicated subsets consecutively admitted to a Rheumatology/ Angiology center were monitored for 12-102 months (median 36). Patients were re-evaluated twice yearly to assess whether and when each patient satisfied the new ACR/EULAR SSc classification criteria. Patients with undifferentiated connective tissue disease (UCTD) served as comparator group.
During follow-up, 11/21 subset I (52.3%), 10/15 subset II (66.6%), 0/24 subset III and 0/44 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 follow-up.