@article{oai:niigata-u.repo.nii.ac.jp:00006589, author = {Aoki, Sadao and Nomoto, Nobuhiko and Maruyama, Souichi and Shinada, Shoji and Shibata, Akira}, issue = {4}, journal = {Acta medica et biologica, Acta medica et biologica}, month = {Dec}, note = {Phenotypes of leukemic cells can be determined through dual staining with pairs of FITC-labeled and PE-labeled monoclonal antibodies using a laser flow cytometer. Hybrid acute leukemia (HAL) was diagnosed when leukemic cells expressed 2 or more lymphoid markers and at least on myeloid marker simultaneously. Based on this criteria, nineteen out of 72 cases with untreated acute leukemia were diagnosed as HAL, 15 of 29 (51%) patients with acute lymphoblastic leukemia and 4 of 43 (9%) patients with acute non-lymphocytic leukemia were diagnosed as having HAL. We classified these HAL cells into 4 types by the following items. Type I: leukemic cells expressing only CD33 and 2 or more B-cell antigens; Type II: only CD33 and 2 or more T-cell antigens; Type III: two myeloid antigens (CD13, CD33) and 2 or more B-cell antigens; and Type IV: at least 2 of 3 myeloid antigens (CD13, CD33), peroxidase) and 2 or more T-cell antigens. There were 7 Type I cases and 3 Type II cases. These two types were thought to be ALL accompanied with positive CD33 alone, which meant a weak specificity as a myeloid marker. There were 6 Type III cases and 3 Type IV cases. Types III and IV were regarded as definite HAL since they had both myeloid and lymphoid antigens distinctly. The incidence of definite HAL among 72 acute leukemias was 12.5%.}, pages = {169--174}, title = {Criteria and Classification of Hybrid Acute Leukemia in 72 Acute Leukemias Based Mainly on Flow Cytometric Analysis}, volume = {39}, year = {1991} }