title: Absolute number of circulating CD34+ cells is abnormally low in refractory anemias and extremely high in RAEB and RAEB-t; novel pathologic features of myelodysplastic syndromes identified by highly sensitive flow cytometry.
abstract: We scored absolute numbers of circulating CD34+ cells by a highly sensitive triple-color flow cytometric analysis using CD45 monoclonal antibody, CD34 monoclonal antibody and propidium iodide. Forty-one patients with MDS (RA: 27, RARS: 1, RAEB: 6, RAEB-t: 3,CMML: 4), 12 patients with aplastic anemia (AA) and 36 age-adjusted normal subjects were studied. RA had significantly decreased numbers of cells expressing CD34 (0.21 +/- 0.29 x 10(6)/l) compared with normal subjects (0.81 +/- 0.36 x 10(6)/l)(P < 0.001). This low number of CD34+ cells in RA resembles the case of AA (0.39 +/- 0.73 x 10(6)/l). In light-scatter analysis, the CD34+ cells of RA patients were distributed mainly in low forward scatter (FSC) (lymphocyte region). In contrast, the CD34+ cell counts were extremely high in patients with RAEB (46.54 +/- 71.37 x 10(6)/l) and RAEB-t (57.00 +/- 52.36 x 10(6)/l) (P < 0.001) and the CD34+ cells were observed in high FSC (blast region).CMML patients showed moderately increased numbers of CD34+ cells (3.69 +/- 4.64 x 10(6)/l). Thus, there was a distinct difference in cell size and number of circulating CD34+ cells between RA and RAEB/RAEB-t. In univariate and multivariate analysis, a high CD34+ cell count (> or = 1.0 x 10(6)/l) was a poor prognostic factor. This method allows one to distinguish RA from other MDS subtypes more reliably than by morphology alone and provides early signs of progression to acute leukemia.
authors.affiliation: Department of Hematology, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fuchigami
authors.forename: H
authors.initials: H
authors.lastname: Mori
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: M
authors.initials: M
authors.lastname: Iwanaga
authors.forename: K
authors.initials: K
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Kuriyama
authors.forename: M
authors.initials: M
authors.lastname: Tomonaga
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000754:Anemia, Refractory, with Excess of Blasts / Q000097:blood* / Q000473:pathology; D018952:Antigens, CD34 / Q000032:analysis*; D005260:Female; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000097:blood* / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D012680:Sensitivity and Specificity
chemical_list: D018952:Antigens, CD34