New treatment strategies in large-vessel vasculitis.

Recent advancements in the understanding of the pathogenesis of large-vessel vasculitis may broaden our currently limited therapeutic possibilities. This review summarizes the available evidence for new treatment strategies in this spectrum of diseases. Interleukin (IL) 6 appears to be an important mediator of the pathology in large-vessel vasculitis. IL-6 is upregulated in inflamed arteries of patients with giant cell arteritis and Takayasu arteritis, and serum levels of this cytokine mirror disease activity. Encouraging preliminary results have been obtained with the IL-6 receptor (IL-6R) antagonist tocilizumab for the treatment of large-vessel vasculitides, including both giant cell arteritis and Takayasu arteritis, and the aortitis of Cogan syndrome and relapsing polychondritis. A small number of patients with Takayasu arteritis and IgG4-related aortitis have also been successfully treated with the B-cell depleting agent rituximab, and some patients with refractory Takayasu arteritis have responded to the immunomodulator leflunomide. The possibility of biologic therapy in large vessel vasculitis has emerged. At this time, better delineation of the immunopathogenic mechanisms of this spectrum of diseases and prospective randomized clinical trials are required to move the field forward and decrease the cumulative glucocorticoid toxicity seen in these disorders.