Scientific BackgroundC-reactive protein has several roles associated with host defence such as; promoting agglutination, bacterial capsular swelling, phagocytosis and complement fixation through its calcium-dependent binding to phosphorylcholine. It can interact with DNA and histones and may scavenge nuclear material released from damaged circulating cells. COFACTOR: Binds 2 calcium ions per subunit. C-reactive protein exists as a homopentamer. There are 2 alternatively spliced isoforms. C-reactive protein is found in plasma and its concentration increases greatly during acute phase response to tissue injury, infection or other inflammatory stimuli. It is induced by IL-1 and IL-6.