[New aspects of antineutrophil cytoplasmic antibody (ANCA) diagnosis in vasculitis].

Anti-Neutrophil Cytoplasmic Antibodies (ANCA) are a heterogenous group of autoantibodies with a broad spectrum of clinically associated diseases. The diagnostic value is established of Proteinase 3 (PR3)-ANCA for Wegener's granulomatosis (WG) as well as Myeloperoxidase (MPO)-ANCA for microscopic polyangiitis (MPA). Within the last 20 years these antibodies were subject of intensive studies and a growing body of evidence arose for a distinct role of ANCA in the pathogenesis of the ANCA associated vasculitides WG and MPA. Our current concept of whether ANCA directly or indirectly contribute to vascular damage (ANCA-Cytokine-Sequence-Theory) was mainly developed from in vitro studies. It is plausible and it is supported by data from clinical investigations as well as animal models. Nevertheless our knowledge of the etiological and pathogenetic pathways remains incomplete.