[Foetal antigens on leukaemia cells (author's transl)]

An antiserum against human foetal liver cells reacted in in-vitro-cytotoxic test with the leukaemia cells of 6 out of 10 children with acute lymphocytic leukaemias (ALL) and with the lymphoma cells of 1 out 2 children with lymphosarcoma (LS). No cytotoxic reactions were obtained against leukaemia cells of 5 children with acute myelogenic leukaemia (AML), leukaemia cells of 7 adults with chronic lymphocytic leukaemia (CLL), bone marrow cells of 9 children in clinical remission and lymphocytes of normal donors. The cytotoxic activity of the anti-foetalserum was removed by absorption with foetal liver but not with adult liver. The results suggest that foetal antigens may occur on ALL-cells and LS-cells.