A concise and sophisticated introduction to acute phase proteins has been presented in this comprehensive book. The intensity and speed of alterations in the concentrations of Acute Phase Proteins (APPs), along with their short half-life, infer a crucial function for these proteins in the establishment of host defense. APPs are considered as having routine operations in trapping of micro-organisms and their products, in activating complement, in binding cellular remnants like nuclear fractions, in neutralizing enzymes, scavenging free radicals, and in modulating the host's immune response. Despite a wide range of pro and anti-inflammatory properties attributed to individual APPs, their action during health and disease remains only loosely defined.