Phenotypical Characteristics of Acute Myelocytic Leukemia Associated With the t (8;21) (q22;q22) Chromosomal Abnormality: Frequent Expression of Immature B-Cell Antigen CD19 Together With Stem Cell Antigen CD34

Twenty-three acute myelocytic leukemia (AML) patients with t(8;21) chromosomal abnormality, all classified as M2 (French-American-British [FAB] classification), were investigated. Blas-tic cells from all patients were positive for the stem cell-associated antigens, CD34 and HLA-DR, and the immature myeloid antigens, CD13 and CD33. The nonblastic leukemic cells expressed the more mature myeloid antigens, C D l l b and CD15, with loss of the immature phenotype. The inci-dence of positivities for the stem cell-associated antigens, CD34 and HLA-DR, in t(8;21) AML cells was significantly higher in comparison with those in other AML showing granulocytic differentiation (M2 or M3). AML cells with t(8;21) also showed some phenotypic abnormalities. Fre-0 PRECISELY diagnose acute myelocytic leukemia T (AML), recent hematologic investigations have shown that it is necessary to consider information from variou