ACUTE MYELOBLASTIC-LEUKEMIA (ANLL-M2) WITH T(8-21)(Q22-Q22) VARIANT EXPRESSING LYMPHOID BUT NOT MYELOID SURFACE-ANTIGENS WITH A HIGH NUMBEROF G-CSF RECEPTORS

Leukemic cells from an 8-year-old girl with ANLL-M2 expressed precurso r B-cell antigen CD19, but none of the myeloid antigens CD11b, CD13, C D14 and CD33. After culture, the cells expressed CD11b and CD13. The c ells carried a high number of granulocyte colony-stimulating factor (G -CSF) receptors. In chromosome analysis, metaphase cells were obtained only in the case of culture with G-CSF. The karyotype was a variant o f t(8;21)(q22;q22). Southern blot analysis revealed rearrangement of t he AML1 gene located on chromosome 21. These observations may suggest that even without myeloid surface antigens and with precursor B-cell a ntigen, ANLL-M2 with t(8;21)(q22;q22) has apparent myeloid characteris tics.