Spectrum of Reactivity with Three Monoclonal Antibodies-MHM6(CD23), L30(CD24) and UCHB1-in B-Cell Leukaemias

Cells from patients with a range of B-cell leukaemias have been investigated for reactivity with three monoclonal antibodies-MHM6 (CD23), L30 (CD24) and UCHB1. Cells in suspension were studied by indirect immunofluorescence and fixed cells in cytospin preparations by an indirect immunoperoxidase technique. Positive results with CD23 were obtained in two thirds of patients with chronic lymphocytic leukaemia in contrast to one quarter of cases of other mature B-lineage leukaemias and lymphomas; cells of acute lymphoblastic leukaemia gave negative results. L30 (CD24) had a wide spectrum of reactivity within the B-lineage with negative reactions being common only in hairy cell leukaemia and multiple myeloma/plasma cell leukaemia. UCHB1 was most frequently and most strongly positive in prolymphocytic leukaemia. Our observations suggest that these reagents, in particular L30 (CD24) and MHM6 (CD23), provide useful additional information in the differential diagnosis of B-lineage lymphoproliferative disorders.