An immune complex is the combination of an epitope with an antibody directed against that epitope. After an antigen-antibody reaction, the immune complexes are in turn processed by proteases or ingested by phagocytes.

Immune complexes may themselves cause disease when they are deposited in organs, e.g. in certain forms of vasculitis. This is the third form of hypersensitivity in the Gell-Coombs classification.

Immunology