Abstract

The reactivity of five monoclonal antibodies J5, OKB-cALLA, Nu-N1, Nu-N2 and VIL-A1 against the common acute lymphoblastic leukaemia (common-ALL) antigen (glycoprotein 100, CD10); was investigated by indirect immunofluorescence in cell suspensions, and by immunoperoxidase in cytocentrifuge slides of ALL, chronic B cell lymphoproliferative disorders, and plasma cell dyscrasias. The five monoclonal antibodies gave similar positive results with both techniques only in samples of ALL. J5 was positive in variable degrees by immunofluorescence in the majority of B cell disorders examined but this was not confirmed by immunoperoxidase. OKB-cALLA reacted in a similar way to J5 in both techniques, although with a lower percentage of cells by immunofluorescence. Nu-N1, Nu-N2, and VIL-A1 were mainly negative when tested by both immunofluorescence and immunoperoxidase in B cell disorders other than ALL and therefore seemed to be more specific for the diagnosis of common-ALL.