Treatment of acute leukaemia: implications of recent findings in cell biology

Some aspects of the cell biology of normal and leukaemic haematopoietic cells are reviewed. Important points are: (a) normal and possibly also leukaemic stem cells differ from more mature cells in the kinetics as well as in cell surface antigens and other properties; (b) leukaemic cells are subject to a population size control as are normal haematopoietic cells; (c) part of the normal control seems to be chalone feedback regulation of proliferation and maturation rate of precursor cells; (d) evidence is accumulating that C-type oncornaviruses may cause leukaemia in man. Various experimental and established forms of therapy for leukaemia are discussed: No alterative exists to chemotherapy in acute lymphoid leukaemia. Granulocyte chalone may possibly become a valuable adjunct to other types of therapy in acute myeloid leukaemia. Immunotherapy may prove as efficient as maintenance chemotherapy in this disease. So far it has not been possible to synchronize leukaemic and normal cells so as to occupy different positions in the cell cycle. Nor has a forced maturation of human leukaemic cells been effected. Neither bone marrow transplantation nor prophylaxis by vaccination are considered worthwhile procedures for the time being. Anti-viral therapy has been promising in animal experiments, but animal leukaemias are often poor models for the disease in man. Assessment of treatment, using stem cell assays, is advocated.