Circulating immune complexes – reviewing the biological roles in human immune function and exercise

Abstract

Circulating immune complexes (CIC) are formed when antigen (Ag) binds to an antibody (Ab). Each time there is an antibody response, and the antibody meets an antigen, an immune complex (IC) is established. Whilst the formation of immune complexes is an integral component of the immune defence mechanism, excessive immune complex formation can be detrimental to the host in that it can interfere with normal physiological processes. Although initial immune complex formation could be defined as a residual product of an acute-phase inflammatory response, they inevitably play a contributing role through impacting on inflammatory processes and innate/adaptive immune responses. This article provides an overview of immune complex physiology, describes the limited studies that have investigated CIC‘s following exercise and proposes that a comprehensive understanding and interpretation of immune system responses to exercise should take these complexes into consideration.

Keywords: Circulating immune complexes and immune function, CIC, complement activation.