In response to injury, local inflammatory cells (neutrophil granulocytes and macrophages) secrete a number of cytokines into the bloodstream, most notable of which are the interleukins IL-1, IL-6 and IL-8, and TNF-α.
The liver responds by producing a large number of acute-phase reactants. At the same time, the production of a number of other proteins is reduced; these are therefore referred to as "negative" acute phase reactants.
|Protein||Immune system function|
|C-reactive protein||Opsonin on microbes|
|D-dimer protein||fibrin degradation product|
|Mannose-binding protein||Mannan-binding lectin pathway|
|Alpha 1-antitrypsin||serpin, downregulates inflammation|
|Alpha 1-antichymotrypsin||serpin, downregulates inflammation|
|Fibrinogen, prothrombin, factor VIII, von Willebrand factor, plasminogen||coagulation factors|
|Complement factors||Complement system|
|Ferritin||Binding iron, inhibiting microbe iron uptake|
|Serum amyloid P component (see amyloid)|
|Serum amyloid A|
|Ceruloplasmin||Oxidizes iron, facilitating for ferritin, inhibiting microbe iron uptake|
|Haptoglobin||Bind hemoglobin, inhibiting microbe iron uptake|
|Protein||Immune system function of decrease|
|Transcortin||Decreased binding of cortisol, upregulation of inflammation|
|Retinol binding protein|
Measurement of acute phase proteins, especially C-reactive protein, is a useful marker of inflammation in both medical and veterinary clinical pathology. It correlates with the erythrocyte sedimentation rate (ESR).
They may also indicate liver failure