Critical contribution of the interleukin-6/signal transducer and activator of transcription 3 axis to vasculopathy associated with systemic sclerosis.

Reflecting the critical role of interleukin (IL)-6 in systemic sclerosis (SSc), tocilizumab, an anti-IL-6 receptor antibody, is currently under a global phase III trial against skin sclerosis of this disease. We here demonstrate that the IL-6/signal transducer and activator of transcription 3 axis is broadly activated in various cell types in the lesional skin of SSc patients irrespective of disease subtypes, especially in endothelial cells. Importantly, 12 monthly infusions of tocilizumab improved nailfold capillary changes as well as skin sclerosis in a patient with diffuse cutaneous SSc. The present findings suggest a potential disease-modifying effect of tocilizumab on SSc vasculopathy.