Antibody to bovine leukemia virus in sera from leukemic patients.

A new cell line, persistently infected with Bovine Leukemia Virus (BLV), was obtained by co-cultivation of lymphocytes from adult leukemic bovine with normal calf kidney cells. The presence of BLV was demonstrated directly in the lymphocytes and in the new cell line by electron microscopy, and by ELISA of cell extracts. An immunoperoxidase staining technique was used for detection of BLV-infected cells at each new passage of the line, in order to confirm the persistence of viral infection. Fixed preparations of infected cells were used to study human sera for the presence of specific antibody to BLV. Human sera were collected from different groups of patients, and a specific antibody response to BLV was detected in only 3 out of 33 sera from leukemic patients. No positivity was detected in control sera.