What is the Complement Cascade?

The Complement Cascade an important part of both the innate and adaptive immune systems. The majority of circulating complement is produced by the liver however complement synthesized in the kidney is likely to have an important role in local injury.  There are several different pathways of complement activation involved in different forms of renal disease, such as the alternative pathway in atypical hemolytic uremic syndrome (aHUS) and C3 Glomerulopathy (C3G), and the classical pathway in lupus nephritis.

Abnormalities in the alternative pathway of complement in C3G patients may be detected in the laboratory. The figure below displays the relative location of these proteins. Included also in this figure for reference are the proteins that may be blocked by some of the emerging therapeutics.