title: Flow cytometric assessment of CD15+CD117+ cells for the detection of minimal residual disease in adult acute myeloid leukaemia.
abstract: There is little information available regarding immunophenotypic monitoring of minimal residual disease (MRD) in acute myeloid leukaemia (AML). We investigated leukaemic cells co-expressing CD15 and CD117 (CD15+CD117+) in 72 adult AML cases at diagnosis. In 22 cases (31%) with various AML subtypes, more than 5% of leukaemic cells showed the CD15+CD117+ phenotype (range 5.22-55.48%). These 22 cases were younger and had a higher complete remission (CR) rate than the other AML cases, but the CD15+CD117+ cell percentage at diagnosis showed no correlation with the CR duration among the 72 cases. The CD15+CD117+ cell percentage showed a range of 0.00-0.08% in bone marrow cells from 10 haematologically normal subjects. We also investigated CD15+CD117+ cells in sequential bone marrow samples from 17 AML patients who achieved CR and who had had more than 5% CD15+CD117+ leukaemic cells at diagnosis. Because the CD15+CD117+ cell percentage varied among these AML cases, we calculated the percentage of MRD ¿MRD% = [CD15+CD117+ cells (%) in each sequential marrow sample] / [CD15+CD117+ cells (%) at diagnosis of the corresponding case] x 100¿. A high MRD% after 10 months of CR was significantly associated with a short CR duration (P = 0.0004), whereas continuation of a well-reduced MRD% was associated with a long CR duration. The leukaemic cells conserved the CD15+CD117+ phenotype in all of the eight cases who relapsed. Flow cytometric monitoring of CD15+CD117+ cells is simple and can be applied to a substantial fraction of AML cases. This monitoring may be useful for predicting relapse of adult AML.
authors.affiliation: Third Department of Internal Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Ogata
authors.forename: E
authors.initials: E
authors.lastname: An
authors.forename: K
authors.initials: K
authors.lastname: Dan
mesh_terms: D000328:Adult; D000368:Aged; D001854:Bone Marrow Cells / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007951:Leukemia, Myeloid / Q000276:immunology*; D016256:Lewis X Antigen / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis* / Q000276:immunology; D019009:Proto-Oncogene Proteins c-kit / Q000276:immunology*; D012008:Recurrence
chemical_list: D016256:Lewis X Antigen; D019009:Proto-Oncogene Proteins c-kit