International standardization of acute phase proteins.

Acute phase proteins (APPs) such as haptoglobin, serum amyloid A and pig major acute phase protein are plasma proteins that increase in concentration following infection, inflammation, or trauma. The circulating concentrations of these proteins in pigs and cattle can provide an objective measure of the health status of an animal and are increasingly being used as markers of animal health and welfare. Plasma concentrations of APPs are related to the severity of the underlying condition, and provide a ready means of evaluating both the presence and extent of disease. Haptoglobin, for example, has been used to identify both clinical and subclinical disease in animals, and for objectively monitoring antibiotic therapy in experimentally infected animals. Interpretative benefit can be further enhanced by the "acute phase index", derived from a mathematical formula that uses both positive- and negative-reacting APPs. Research suggests that in the future, assays for APPs will be used routinely to assess animal health, optimize production rates, monitor antibiotic therapy, detect diseases such as mastitis in dairy cows, and assess the health of animals at slaughter. These applications have considerable benefit for human food safety. Before APP assays can be applied in animal production on a worldwide basis, however, the calibration of assay methods must be harmonized to ensure that results obtained in the laboratory or on the farm are universally comparable and of consistent quality. In February 2000 the European Commission Directorate General Research Concerted Action was established to fulfill the task of international standardization of APPs. The Concerted Action Group consists of a network of 14 institutions representing 9 European countries. In this report, the background and goals of the Concerted Action Group, and scientific presentations from the group's first colloquium are described. In addition, the progress of the group to date and the standardization plan for the full 30-month duration of the Concerted Action are summarized.