Natural antibodies to simian type-C viruses and human retrovirus HTLV in patients with lymphoid malignancies.

Blood plasma samples from adult patients and children with malignant lymphoproliferative diseases were studied for presence of antibodies to primate type-C viruses by membrane immunofluorescence. Antibodies to baboon endogenous virus could be detected in various types of lymphoid leukaemias and lymphomas. Gibbon ape leukaemia virus-specific antibodies were mainly found in B- and O-cell leukaemias and lymphomas. Anti-HTLV antibodies could be detected only in a few cases of T-cell malignancy. There was no evidence of a horizontal transmission of such viruses.