Application of complement-dependent antibody cytotoxicity test for diagnosis of enzootic bovine lymphosarcoma.

Abstract

Complement-dependent antibody cytotoxicity (CDAC) test of peripheral blood lymphocyte (PBL) using monoclonal antibodies against tumor-associated antigen (TAA) expressed on enzootic bovine lymphosarcoma (EBL) cells was evaluated for its usefulness in the diagnosis of EBL. Twenty-seven out of 28 EBL cattle showed cytotoxic index (CI) greater than 31.7 which was considered as minimum value for positive EBL. The CI of PBL and sarcoma cell from solid tumor of one remaining cow was 28.0 and 61.0, respectively. On the other hand, one cow infected with bovine leukemia virus (BLV) but not affected with lymphosarcoma and 9 cattle uninfected with BLV showed less than 31.7 of CI. On the basis of the examination of hemogram, the TAA-positive cells were not always morphologically atypical. Since the TAA-positive cells are circulating in the peripheral blood of EBL cattle, the CDAC test of PBL using monoclonal antibodies is useful for diagnosis of EBL, and will be capable of a diagnostic procedure for aleukemic or subclinical cases of EBL.