How anti-neutrophil cytoplasmic autoantibodies activate neutrophils

OTHER ARTICLES PUBLISHED ON ANCA IN THIS ISSUE Animal models of anti-neutrophil cytoplasmic antibody-associated vasculitis. Clinical and Experimental Immunology 2012, 169: 22937. Summary Neutrophils are pivotal to host defence during infectious diseases. However, activated neutrophils may also cause undesired tissue damage. Ample examples include small-vessel inflammatory diseases (vasculitis) that are associated with anti-neutrophil cytoplasmic autoantibodies (ANCA) residing in the patients' plasma. In addition to being an important diagnostic tool, convincing evidence shows that ANCA are pathogenic. ANCAneutrophil interactions induce important cellular responses that result in highly inflammatory necrotizing vascular damage. The interaction begins with ANCA binding to their target antigens on primed neutrophils, proceeds by recruiting transmembrane molecules to initiate intracellular signal transduction and culminates in activation of effector functions that ultimately mediate the tissue damage.