The Reactivtiy of Leukaemic Cells to HL‐A Typing Sera

Despite the atypical reactions of leukaemic cells in the microcytotoxicity test, it is possible to discern three broad catagories of behaviour. Acute lymphatic leukaemias usually give clear cut results, whereas the antigenic profile in chronic lymphatic leukaemia is obscured by many seemingly ‘extra’antigens. Individuals showing apparent changes of antigens are usually those with acute myeloid leukaemia. The chronic lymphatic leukaemia group was further characterised by always giving positive results with antiserum Reid. The cases of lymphosarcoma studied were divided evenly into those in which the cells behaved in a manner similar to acute lymphatic leukaemia giving unequivocal results, and those similar to chronic lymphatic leukaemia having ‘extra’antigens.