Acute Phase Proteins in Dairy Cows and Sows During the Periparturient Period

Abstract

Acute phase proteins have been used as biomarkers of diseases for decades in human medicine, but have been relatively under-utilised in the veterinary medicine. Over recent years, significant progress has been made in studies on acute phase response in farm animal medicine, including the detection, measurement and application of acute phase proteins as biomarkers of diseases in both cattle and pigs. Acute phase proteins are blood proteins primarily synthesized by hepatocytes as part of the acute phase response. The acute phase response is a complex systemic early-defense system activated by impaired homeostasis, trauma, tissue injury, infection, inflammation, stress or neoplasia (Cray et al., 2009). This response leads to a range of metabolic activities and alterations in a wide variety of biochemical processes. One of the most important metabolic changes during the acute phase response is the strongly increased or decreased production and secretion of some plasma proteins from the liver, the acute phase proteins (Murata et al., 2004). Although non-specific, the acute phase response serves as a core of the innate immune reactions involving physical and molecular barriers and responses with the goal to prevent infection, clear potential pathogens, and contribute to the resolution and healing processes (Petersen et al., 2004). Much of the recent attention on the assessment of acute phase proteins in farm animals has resulted not only from the advances described above, but also because they have been recognized as valuable markers of diseases. As indicators of inflammation, the assays of acute phase proteins provide valuable additional information to more traditional haematological and biochemical investigations (Skinner et al., 1991; Eckersall, 2000). Application of acute phase protein analyses in disease investigations also in farm animals has shown that it has a major diagnostic contribution to make in the evaluation of various inflammatory, as well as non-inflammatory diseases (Gruys et al., 2005). In the clinical field, acute phase proteins may serve as non-specific indicators of health status and surveillance of animals at the herd level. In the last decade, emphasis has been laid also on the application of blood test for acute phase reactants to monitor animals suffering from specified classes of diseases. However, the behavior of acute phase proteins in some disease, as well as physiological conditions, e.g. during the reproduction cycle of cows and sows,