Pig-MAP, porcine acute phase proteins and standardisation of assays in Europe

Abstract

The pattern of plasma proteins changes greatly following infection, inflammation or tissue injury. The concentration of some proteins referred to as acute phase proteins (APPs) significantly increases within hours or days after the onset of these processes. In contrast, the concentration of other proteins, such as albumin (Alb), called negative acute phase proteins, decreases. APPs have been extensively studied in man and rat, but less so in other species. In recent work, the APPs have been characterised in pigs in response to inflammation following turpentine injection. The concentrations of C reactive protein (CRP) and haptoglobin (Hp) increase 5–7 times 48 h after the injection. Porcine Alb, α-lipoprotein, fetuin and transferrin were negative APP. Finally, the concentration of α1-acid glycoprotein and α1-protease inhibitor (α1-antitrypsin) did not change significantly during the inflammation. In addition to CRP and Hp, a serum α2-globulin was observed to be the major acute phase (MAP) protein in pigs. Pig-MAP is a new mammalian plasma protein, which is the pig counterpart of a recently cloned human serum protein denominated PK-120 or IHRP. Pig-MAP shows promise as a prominent positive APP and has been shown to be a good marker of different pig pathologies.