The immunological classification of leukaemia based on a rapid microcytotoxicity test.

We describe a rapid, accurate, and reproducible cytotoxic antibody test for the immunological classification of leukaemia. Well characterized heteroantisera and monoclonal antibodies were distributed in a microcytotoxicity tray referred to as a leukaemia screening tray (LST). Leukaemia cells were tested for the presence of Ia-like, 'blast', thymocyte, common acute lymphoblastic leukaemia (cALL), and acute myeloblastic leukaemia (AML) antigens. Utilizing this technique, T ALL could be distinguished from non-T ALL, ALL and AML could be differentiated, the myeloid blast crisis of chronic myelogenous leukaemia (CML) could be distinguished from the lymphoid blast crisis, and the T lymphocyte and B lymphocyte lymphoid leukaemias were readily identified. It has been shown that subclassification of leukaemia according to surface markers, as described here, offers considerable improvement in the diagnosis and treatment of leukaemia over the classical morphological methodologies. Because the test can be completed in 2 hr and unlimited amounts of monoclonal antibodies are available, the LST or similar tests should become universally available in the future to supplement morphological data and replace other lengthy enzyme and rosetting tests.