Diagnostic utility of flow cytometry in low-grade myelodysplastic syndromes: a prospective validation study.
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.
Ogata
Kiyoyuki
K
Division of Hematology, Department of Medicine, Nippon Medical School, Tokyo, Japan. ogata@nms.ac.jp
Della Porta
Matteo G
MG
Malcovati
Luca
L
Picone
Cristina
C
Yokose
Norio
N
Matsuda
Akira
A
Yamashita
Taishi
T
Tamura
Hideto
H
Tsukada
Junichi
J
Dan
Kazuo
K
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
D039481:CD11b Antigen; D019002:CD56 Antigen; D016256:Lewis X Antigen; D017493:Leukocyte Common Antigens