Complement is an important component of the innate immune system that is crucial for
defense from microbial infections and for clearance of immune complexes and injured cells.
In normal conditions complement is tightly controlled by a number of fluid-phase and cell
surface proteins to avoid injury to autologous tissues. When complement is hyperactivated,
as occurs in autoimmune diseases or in subjects with dysfunctional regulatory proteins, it
drives a severe inflammatory response in numerous organs. The kidney appears to be …