Reactivity of antisera to antigens of C-type viruses with leucocytes from patients with acute leukaemia

Abstract

A number of previous studies have suggested that certain C-type viruses from non-human primates are associated with acute leukaemia in humans. The present study sought to examine this association further by detection of antigens related to these viruses on the surface of acute leukaemia cells. Antisera against the whole viruses or the major internal protein of simian sarcoma, endogenous baboon and Rauscher viruses were tested against mononuclear cells from patients with acute leukaemia at various stages of their disease in 51Cr release leucocyte dependent cytotoxic assays. A high proportion of the patients had antigens related to these viruses detectable on their blood leucocytes at some stage in their disease whereas with one exception blood leucocytes from non-leukaemic subjects did not. The expression of these antigens did not show a close relation to the number of blast cells in blood detected on morphological grounds. Antigens related to the non-human primate viruses were detected on mononuclear cells from bone marrow samples of several non-leukaemic patients which indicated they were not specifically associated with leukaemia. Antigens related to the Rauscher virus were detected on cells of practically all bone marrow samples tested. These results suggest that assays to detect these antigens would be of limited usefulness to monitor disease activity in patients with acute leukaemia. Their expression on blood leucocytes however appeared strongly associated with acute leukaemia and further studies to assess the prognostic and epidemiological significance of detection of these antigens appears warranted.