Immune complex

Additional recommended knowledge

Weighing the right way

Essential Laboratory Skills Guide

How to quickly check pipettes?

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. Red blood cells carrying C3b-receptors transport C3b-decorated immune complexes to the phagocytes, leave their charge there, mostly in liver and spleen, and return back to the general circulation.

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.

Immune complex deposition is a prominent feature of systemic lupus erythematosus, cryoglobulinemia, rheumatoid arthritis, scleroderma and Sjögren's syndrome.