Detection of a common leukemia-associated antigen in human myelogenous leukemia using immunoperoxidase

The reactivity of a monoclonal antibody (CAMAL-1), raised to a purified leukemia-associated antigen (CAMAL) commonly expressed in or on cells from human myelogenous leukemics has been investigated using an indirect immunoperoxidase staining technique on single cell slide preparations of peripheral blood leucocytes (PBL) or bone marrow (BM) cells. A comparison of reactivity between CAMAL-1 monoclonal antibody (MAb) and rabbit anti-CAMAL serum using this procedure has clarified that differences in reactivities relate to antigen distribution and recognition. The specificity of the CAMAL-1 MAb has been established; most samples from patients with myelogenous leukemia (acute phase or remission and CGL chronic phase) show significantly increased numbers (greater than or equal to 1%) of CAMAL-expressing cells compared to those from normals or individuals with lymphoid leukemias. Evidence is presented that indicates that expression of the CAMAL antigen may represent continued underlying pathology in the acute myelogenous leukemia remission state.