Diagnosis of clinical leukosis in cattle and its correlation with bovine leukemia virus antigens using the agar gel immunodiffusion (AGID) test

Abstract

During an 18-month period a total of 317 bovine sera were tested for antibody to bovine leukemia virus (BLV) using the agar gel immunodiffusion (AGID) test. Of these field submissions, 130 (41%) were positive for antibody to BLV and 34 (26%) had a clinical diagnosis of bovine leukosis. A second (AGID) precipitin line was found in tests with sera from five of these cattle. Four cows had grossly enlarged palpable lymph nodes or subcutaneous masses. The two antigens identified in the sera of the 5 cattle were the glycoprotein gp envelope antigen, typically found in cattle exposed to BLV, and the p24 antigen which is part of the virus core. We found that in these 5 cattle with antibodies to both antigens the concentration of antibody to the gp antigen was greater than that of the p24 antigen. The presence of antibody to the p24 viral antigen in cattle with clinical disease and its implication in the confirmation of a diagnosis of bovine leukosis is discussed.