[New pathogenetic aspects in primary systemic vasculitides].

Primary systemic vasculitides are defined according immunopathological features and the size of the involved vessels. Three anti-neutrophil cytoplasmic autoantibody (ANCA) associated small vessel vasculitides (Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis) can be distinguished from the so-called Non-ANCA-associated vasculitides, i.e. granulomatous vasculitides of large vessels (giant cell arteritis, Takayasu arteritis) and immune complex-mediated vasculitides of medium-sized and small vessels (Polyarteriitis nodosa, Kawasaki disease and Henoch-Schönlein purpura, cryoglobulinemic vasculitis, cutaneous leukocytoklastische angiitis). Predisposing genetic and other endogenous and exogenous factors facilitate the activation of innate immunity and induce persisting inflammatory reactions resulting in different forms of (auto)-immune vasculitides.