Complement C3 Deposition on Endothelial Cells Revealed by Flow Cytometry.

The three pathways of the complement system converge toward the cleavage of the central complement component C3 into its activated fragments, with C3b being able to bind covalently to the activating surface. The endothelial cells are among the major targets for complement attack in pathological conditions, as the atypical hemolytic uremic syndrome. Therefore, study of complement C3 deposition on endothelial cells by flow cytometry is a sensitive test to measure complement activation. This test can be used as a research or clinical tool to test complement activation induced by patients' sera or to test the functional consequences of newly discovered complement mutations as well as different triggers of endothelial cells injury.