title: Clonal evolution of blasts in an elderly patient with CD56(+) relapsed acute promyelocytic leukemia.
abstract: We describe an elderly patient with acute promyelocytic leukemia (APL), whose leukemic cells expressed CD56 antigen at relapse but not at diagnosis. Chromosome analysis revealed that blasts with t(8;15;17)(q24.1;q22;q11.2) increased from 4 of 20 cells (20%) at first relapse to 10 of 14 cells (71.4%) at second relapse. In addition, the positivity for CD56 expression on blasts judged by flow cytometric analysis using CD45 blast gating was also increased from 14.2% at first relapse to 75% at second relapse. Although conventional chemotherapy was performed for the initial disease and the first relapse, relapse developed again. Therefore, three courses of intensive postremission chemotherapy including concurrent administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) with cytarabine were performed after achievement of complete remission (CR) by the treatment with all-trans-retinoic acid (ATRA). Although PML-RARalpha mRNA was not detectable by reverse transcription polymerase chain reaction (RT-PCR), a third relapse occurred. This case demonstrated clonal evolution from a CD56(-) to a CD56(+) blast population and provided further support for the suggestion that CD56 expression might be an unfavorable prognostic factor in t(15;17) APL.
authors.affiliation: Division of Hematology, Third Department of Internal Medicine, Iwate Medical University School of Medicine, Morioka, Japan. shigei@iwate.med.ac.jp
authors.forename: Shigeki
authors.initials: S
authors.lastname: Itoh
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sugawara
authors.forename: Sanae
authors.initials: S
authors.lastname: Enomoto
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ono
authors.forename: Hideharu
authors.initials: H
authors.lastname: Numaoka
authors.forename: Taiju
authors.initials: T
authors.lastname: Utsugisawa
authors.forename: Kazunori
authors.initials: K
authors.lastname: Murai
authors.forename: Yoji
authors.initials: Y
authors.lastname: Ishida
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kuriya
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D019002:CD56 Antigen / Q000032:analysis*; D002869:Chromosome Aberrations; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D002898:Chromosomes, Human, Pair 8; D003561:Cytarabine / Q000008:administration & dosage; D005260:Female; D005434:Flow Cytometry; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage; D006801:Humans; D007621:Karyotyping; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics / Q000276:immunology* / Q000473:pathology*; D011379:Prognosis; D011994:Recombinant Proteins / Q000008:administration & dosage; D012008:Recurrence; D012074:Remission Induction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014178:Translocation, Genetic
chemical_list: D000970:Antineoplastic Agents; D019002:CD56 Antigen; D011994:Recombinant Proteins; D003561:Cytarabine; D016179:Granulocyte Colony-Stimulating Factor