Circulating Immune Complexes and Glomerulonephritis in a Patient with Congenital Absence of the Third Component of Complement

Abstract

THE third component of complement (C3) is critically involved in host defense and the maintenance of normal immunologic homeostasis.^{1 , 2} It is a central component of both the classical and alternative pathways of complement, and its major cleavage product, C3b, serves as an important serum opsonin.^{1 , 2} Another cleavage product, C3a, is a potent anaphylatoxin that is thought to be important in the initiation of local inflammatory processes.^{1 , 2} Therefore, attention has focused on infection as the major clinical problem in the rare patients with congenital C3 deficiency^{3 4 5 6 7} or marked C3 consumption.^{8 , 9} In the present report, we describe a patient with a congenital . . .