title: Diagnostic utility of flow cytometry in low-grade myelodysplastic syndromes: a prospective validation study.
abstract: BACKGROUND
  The diagnosis of myelodysplastic syndromes is not always straightforward when patients lack specific diagnostic markers, such as blast excess, karyotype abnormality, and ringed sideroblasts.
  
  
  METHODS
  We designed a flow cytometry protocol applicable in many laboratories and verified its diagnostic utility in patients without those diagnostic markers. The cardinal parameters, analyzable from one cell aliquot, were myeloblasts (%), B-cell progenitors (%), myeloblast CD45 expression, and channel number of side scatter where the maximum number of granulocytes occurs. The adjunctive parameters were CD11b, CD15, and CD56 expression (%) on myeloblasts. Marrow samples from 106 control patients with cytopenia and 134 low-grade myelodysplastic syndromes patients, including 81 lacking both ringed sideroblasts and cytogenetic aberrations, were prospectively analyzed in Japan and Italy.
  
  
  RESULTS
  Data outside the predetermined reference range in 2 or more parameters (multiple abnormalities) were common in myelodysplastic syndromes patients. In those lacking ringed sideroblasts and cytogenetic aberrations, multiple abnormalities were observed in 8/26 Japanese (30.8%) and 37/55 Italians (67.3%) when the cardinal parameters alone were considered, and in 17/26 Japanese (65.4%) and 42/47 Italians (89.4%) when all parameters were taken into account. Multiple abnormalities were rare in controls. When data from all parameters were used, the diagnostic sensitivities were 65% and 89%, specificities were 98% and 90%, and likelihood ratios were 28.1 and 8.5 for the Japanese and Italian cohorts, respectively.
  
  
  CONCLUSIONS
  This protocol can be used in the diagnostic work-up of low-grade myelodysplastic syndromes patients who lack specific diagnostic markers, although further improvement in diagnostic power is desirable.
authors: Division of Hematology, Department of Medicine, Nippon Medical School, Tokyo, Japan. ogata@nms.ac.jp
authors: Kiyoyuki
authors: K
authors: Ogata
authors: Matteo G
authors: MG
authors: Della Porta
authors: Luca
authors: L
authors: Malcovati
authors: Cristina
authors: C
authors: Picone
authors: Norio
authors: N
authors: Yokose
authors: Akira
authors: A
authors: Matsuda
authors: Taishi
authors: T
authors: Yamashita
authors: Hideto
authors: H
authors: Tamura
authors: Junichi
authors: J
authors: Tsukada
authors: Kazuo
authors: K
authors: Dan
mesh_terms: D000328:Adult; D000368:Aged; D001854:Bone Marrow Cells / Q000378:metabolism; D039481:CD11b Antigen / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D017493:Leukocyte Common Antigens / Q000032:analysis; D016256:Lewis X Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D039481:CD11b Antigen; D019002:CD56 Antigen; D016256:Lewis X Antigen; D017493:Leukocyte Common Antigens