Acute phase protein: Biomarkers of disease in cattle and sheep

Acute phase proteins (APP) such as haptoglobin, serum amyloid A and a, acid glycoprotein are blood proteins which increase in concentration from 10-1000 fold following infection and inflammation. Measurement of APP concentration in serum or plasma can provide useful quantitative diagnostic information on the presence of disease and can be used to monitor responses to therapy. Their use in experimental models of disease has been recognised and can provide a means of studying pathophysiology of disease as well as efficacy of treatment. Elevated concentrations of the APP have been detected in many infectious diseases including mastitis and pneumonia, but they are also raised in metabolic diseases related to the periparturient period in dairy cows. In the future these biomarkers of disease could be an important component of herd health and quality assurance schemes as well as at ante-mortem or post mortem inspection