Validation of immunoassays for bovine haptoglobin.

Haptoglobin (Hp) is an acute phase protein. The plasma concentration of Hp increases rapidly following tissue damage associated with infection and inflammation. Thus Hp levels could be used as a screening test for organic disease, an objective index of disease activity and response to therapy, or as a sign of microbial infection. Recently, an enzyme-linked immunosorbent assay for bovine Hp was described. We have now developed three different immunoassay formats for bovine Hp and report on their validation and relative value to the diagnosis of bovine disease. Hp levels measured using these three immunoassays were compared and contrasted with results obtained for Hp estimation as measured by the increase in the protection of peroxidase activity against acid inactivation following binding with bovine haemoglobin. The quantitative Hp immunoassays evaluated in the present study are simple, rapid, inexpensive, reproducible, and well suited for both field and laboratory use.