[Use of monoclonal antibodies in the diagnosis of acute leukemia].

Immunological analysis has demonstrated the heterogeneity of acute lymphoblastic leukemia (ALL). The use of classical immunological methods and monoclonal antibodies against human lymphoid cell surface antigens have made it possible to subdivide ALL into five major subclasses: null ALL, common ALL, T-ALL, pre-B-ALL and B-ALL. We have studied in this report 8 cases of adult ALL diagnosed on morphological and cytochemical criteria. Some conventional markers and a panel of monoclonal antibodies have been used to analyse the differentiation of those patients' blast cells. In a second part we report two cases in which myeloid and lymphoid cell markers were observed simultaneously when 22 patients with acute myeloid leukemia were phenotyped according to the French-American-British (FAB) classification system.