What stuff is this! A historical perspective on fibrinoid necrosis

The salient features of systemic vasculitis are endothelial swelling, inflammatory infiltrates, and fibrinoid necrosis of the arterial wall. Of these three, the concept of fibrinoid necrosis is undoubtedly the most elusive. Is it really necrosis, defined as unprogrammed cell death, that we are looking at? And does the adjective 'fibrinoid', meaning fibrin-like, cover its most important attribute? In early case reports on systemic vasculitis the term was used with caution, but over the years it has grown in status to become the most characteristic histopathological manifestation of systemic vasculitis in patients with anti-neutrophil cytoplasmic antibodies (ANCA), suggesting that the clue to the auto-immune mechanisms that damage the vessel wall lies in the necrotic lesion. But what is this assumption based on? This review discusses the history of fibrinoid necrosis in vasculitis, focusing on the ideas that have been postulated over the years regarding this lesion. Special attention will be paid to its occurrence in the kidney in systemic vasculitis.