The acute-phase response

Abstract

Inflammation and tissue injury elicit profound changes in the concentrations of several plasma proteins. These proteins are predominantly synthesized in the liver and named acute-phase proteins. The regulatory mechanisms that control this response are highly complex and include the release of various mediators affecting specific subsets of acute-phase genes. Individual mediators can either synergistically enhance or inhibit the effects of other mediators. Binding of mediators to their respective receptors on hepatocytes and transduction of this signal induce changes in acute-phase protein gene expression that are primarily regulated on a transcriptional level. However, under certain conditions post-transcriptional mechanisms may also be involved in this process. Although some acute-phase proteins have been shown to minimize tissue damage, as well as to participate in hemostasis, tissue repair, and regeneration in response to injury, the actual in vivo functions of several acute-phase reactants remain speculative. Measurements of acute-phase protein plasma concentrations can be of diagnostic or prognostic value under certain clinical conditions. Further characterization of the regulatory mechanisms that govern the acute-phase response in vivo could lead to the development of new therapeutic strategies aimed at improving the organism's integrated response to injury.