Inflammation results in a rapid increase in blood levels of acute phase proteins synthesized by hepatocytes in response to cytokines. Pentraxins, which include C reactive protein (CRP) and serum amyloid P component (SAP), are prototypic acute phase proteins. CRP and SAP are produced by liver epithelial cells and are characterized by a cyclic pentameric structure and calcium-dependent ligand binding. Human serum amyloid A (SAA) is also a major acute-phase protein and precursor to amyloid A protein (AA), which is the major constituent of the fibril deposits of reactive amyloidosis.