title: Evidence for early hematopoietic progenitor cell involvement in acute promyelocytic leukemia.
abstract: Acute promyelocytic leukemia (APL) represents a subtype of acute myeloid leukemia with characteristic morphologic, molecular, and immunophenotypic features. Previous immunophenotypic analyses have shown that leukemic cells in APL typically express the myeloid markers CD33 and CD13 but lack expression of the early hematopoietic progenitor cell antigens CD34 and HLA-DR. We analyzed selected immunophenotypic features of APL by flow cytometry and showed that 7 (41%) of 17 cases contained significant subsets of CD34+ leukemic cells: CD34+ myeloid cells predominated in 2 APL cases. By using a fluorescence-activated cell sorter-fluorescence in situ hybridization approach, we confirmed that the CD34+ cells harbored the t(15;17) translocation characteristic of APL. By using the same experimental approach, CD34+ populations were stratified into primitive CD34+ CD38- and committed CD34+ CD38+ progenitor cell subpopulations; cells in both subsets contained the t(15;17) translocation. The knowledge that APL may be partly or largely CD34+ is important for proper diagnosis. Furthermore, identification of the t(15;17) translocation in CD34+ CD38- blasts indicates that, in at least some cases, the leukemogenic mutation in APL occurs within primitive hematopoietic progenitor cells.
authors.affiliation: Department of Pathology and Laboratory Medicine, Cancer Center Flow Cytometry and Cell Sorting Facility, Philadelphia, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Edwards
authors.forename: M A
authors.initials: MA
authors.lastname: Wasik
authors.forename: J
authors.initials: J
authors.lastname: Finan
authors.forename: R
authors.initials: R
authors.lastname: Rodriguez
authors.forename: J
authors.initials: J
authors.lastname: Moore
authors.forename: M
authors.initials: M
authors.lastname: Kamoun
authors.forename: H
authors.initials: H
authors.lastname: Rennert
authors.forename: J
authors.initials: J
authors.lastname: Bird
authors.forename: P C
authors.initials: PC
authors.lastname: Nowell
authors.forename: K E
authors.initials: KE
authors.lastname: Salhany
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000276:immunology* / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping; D007621:Karyotyping; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014178:Translocation, Genetic; D014212:Tretinoin / Q000627:therapeutic use
chemical_list: D018952:Antigens, CD34; D000970:Antineoplastic Agents; D006684:HLA-DR Antigens; D014212:Tretinoin