Studies on the specificity of human antibodies reacting with GP70 and P15 antigens of baboon endogenous (BaEV) and gibbon ape leukaemia (GaLV) viruses.

Antibodies reacting with gp70 and p15 antigens of baboon endogenous virus (BaEV) and gibbon ape leukaemia virus (GaLV) were detected by radioimmunoprecipitation (RIP) in blood plasma samples of patients with chronic granulocytic leukaemia, acute myeloid leukaemia and with potentially preleukaemic haematological disorders. Anti-gp70 antibodies were found more frequently than anti-p15 antibodies. Digestion of the carbohydrate part of gp70 antigens by glycosidase treatment abrogated the precipitation mediated by IgM antibodies, whereas that mediated by IgG antibodies was not markedly affected. Data suggest that antibodies detected in human plasma samples may have oncovirus specificity, but in considerable part of cases they can be of heterophil nature.