Detection of cell-associated antigen in a blast crisis of chronic myeloid leukemia by the cytotoxic test with xenogeneic antibodies

An antimyeloblastic immune serum (AMS) was prepared by immunizing horses with white blood cells (WBC) from a patient with chronic myeloid leukemia (CML) in the blast crisis stage. The serum was exhausted in relation to antibodies against red and white blood cells of healthy donors. The AMS continued to have a cytotoxic action on blast cells from the blood of 20 of the 42 patients with CML in the blast crisis stage. The AMS did not react with WBC from the blood of patients with CML in the chronic phase or from patients with other forms of leukemia. Morphological observations indicate that the above-mentioned immune serum cam be used to identify antigen associated with myeloblasts from the blood of patients with CML in the blast crisis stage.