[Rheumatology -- Part 3. Research news concerning epidemiology, diagnosis, and therapy of primary systemic vasculitides].

Antineutrophil cytoplasmic autoantibody-(ANCA-)associated vasculitides, immune complex-mediated vasculitides and granulomatous arteritides of unknown etiology belong to the group of primary systemic vasculitides. Numerous in vitro and in vivo studies have underscored the role of ANCA in the pathogenesis of ANCA-associated vasculitides (Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome) in the meantime. Whereas the pathogenicity of myeloperoxidase (MPO) ANCA has been supported by data from various animal models in the past, the in vivo pathogenicity of proteinase 3 (PR3) ANCA has been demonstrated in an animal model only recently. Other studies showed an altered T-cell response in Wegener's granulomatosis. Hepatitis C virus-(HCV-)associated cryoglobulinemic vasculitis is mediated by immune complexes. Recent data suggest that the HCV core particles concentrated in the cryoprecipitate apparently play a role in the interaction of cryoglobulin and endothelial cells and neutrophil granulocytes. Data from the European Vasculitis Study Group (EUVAS) demonstrate the efficacy of azathioprine in maintaining remission in ANCA-associated vasculitides on the basis of large patient numbers. Biologicals play an increasing role in the treatment of refractory vasculitis.