Autoantibodies coexistence in systemic sclerosis: how to interpret it?

Autoantibodies possibly influence clinical manifestations of systemic sclerosis (SSc). This clinical-serological correlation, associated with the paucity of autoantibodies concomitance, gave rise to the historical paradigm of autoantibodies mutual exclusivity. However, one can question this assumption. Does autoantibodies concomitance mean coexistence of two different entities? On the other hand, if considered a unique disease, is this phenomenon a random event or does it represent a distinct subgroup of patients, with peculiar clinical, pathogenic, and immunogenetic characteristics? The autoantibodies' prevalence in early SSc is high. However, anti-centromere antibody (ACA) and antitopoisomerase 1 antibody (ATA) duplicity is a rare event. Similarly, the ACA, ATA, and anti-RNA polymerase (anti-RNA-P) III coexistence have not been described yet in single patient. In the reported case, with ACA, ATA, and anti-RNA-P III positivity, we have noted early vascular manifestations and late limited cutaneous involvement. This is, to our knowledge, the first report of three concomitant specific autoantibodies in a patient with SSc. We do believe this coexistence represents a rare serologic subgroup of a unique disease, with possible clinical and prognostic value, although this remains to be confirmed.