[Is necrotizing vasculitis a disease caused by deposits of circulating immune complexes?]

From findings in serum sickness, it has often been considered that circulating immune complexes play a crucial role in the pathogenesis of experimental necrotizing vasculitis and glomerulonephritis. In reality, most cases of experimental vasculitis might well be due to the formation of immune complexes in situ. Moreover, the role of cell-mediated immunity, still poorly studied, might be important. In humans, the respective roles of circulating immune complexes, immune complexes formed in situ and cell-mediated immunity remain imperfectly known.