MPO and vasculitis: NETs release extracellular chromatin with histones and myeloperoxidase (MPO) to trap and kill microbes, ultimately being properly digested.[3,4] In patients with MPO-AAV, soluble NETs in blood and focal NETs in the lesions of crescentic glomerulonephritis were detected.[5] These findings suggest that NET formation triggers an autoimmune response, resulting in ANCA production and the development of vasculitis.