Type III (Immune Complex)Reactions IgG antibodies and antigens form complexes that lodge in basement membranes. Basement membrane of blood vessel Immune complexes are deposited in wall Ag of blood vessel. Neutrophils ②Presence of immune Enzymes released complexes activates from neutrophils complement and cause damage to attracts inflammatory endothelial cells cells such as of basement Endothelial. neutrophils. membrane. cell Figure 19.6 • IgG antibodies and antigens form complexes that lodge in basement membranes. Type III (Immune Complex) Reactions Figure 19.6