[Pathogenic role of antimyeloperoxidase antibodies]

Antimyeloperoxidase antibodies are a variety of antineutrophil cytoplasm antibodies (Anca), which can be detected in systemic small-sized vessel vasculitides such as microscopic polyangiitis, Wegener's granulomatosis and Churg-Strauss syndrome. Antimyeloperoxidase antibodies have been also associated with the development of lung fibrosis. Their pathogenic role has been well established, both in vitro and in vivo. These autoantibodies can activate neutrophils and trigger their oxidative burst leading to the release of free oxygen species and cytotoxic proteins. The oxidative burst is deleterious for the endothelium. Another mechanism by which antimyeloperoxidase may act is the activation of myeloperoxydase leading to an increased production of hypochlorous acid, which is highly toxic for the endothelial cells. These mechanisms contribute to the development of vasculitis.