Clinical significance of phenotypic features of blasts in patients with myelodysplastic syndrome.
Knowledge of the blast phenotype in myelodysplastic syndrome (MDS) would be valuable, as in other malignancies, but remains sparse. This is mainly because MDS blasts are a minor population in clinical samples, making analysis difficult. Thus, for this blast phenotype study, we prepared blast-rich specimens (using a new density centrifugation reagent for harvesting blasts) from blood and marrow samples of 95 patients with various MDS subtypes and 21 patients with acute leukemia transformed from MDS (AL-MDS). Flow cytometry revealed that a high proportion of the enriched blast cells (EBCs) from almost all patients showed an immunophenotype of committed myeloid precursors (CD34(+)CD38(+)HLA-DR(+)CD13(+)CD33(+)), regardless of the disease subtype. The cytochemical reaction for myeloperoxidase was negative in 58% of the cases. Thus, the EBC phenotype is more immature in MDS than in de novo acute myeloid leukemia. MDS EBCs often coexpressed stem cell antigens and late-stage myeloid antigens asynchronously, but rarely expressed T- and B-lymphoid cell-specific antigens. Markers for myeloid cell maturation (CD10 and CD15) were more prevalent on EBCs from low-risk MDS (refractory anemia [RA] and RA with ringed sideroblasts), whereas markers for myeloid cell immaturity (CD7 and CD117) were more prevalent on EBCs from high-risk MDS (chronic myelomonocytic leukemia, RA with excess blasts [RAEB], and RAEB in transformation) and AL-MDS. A shift to a more immature phenotype of EBCs, accompanying disease progression, was also documented by sequential phenotyping of the same patients. Further, CD7 positivity of EBCs was an independent variable for a poor prognosis in MDS. These data represent new, valuable information regarding MDS.
Ogata
Kiyoyuki
K
Division of Hematology, Nippon Medical School, Kyoto, Japan. ogata@nms.ac.jp
Nakamura
Kyoko
K
Yokose
Norio
N
Tamura
Hideto
H
Tachibana
Mikiko
M
Taniguchi
Osamu
O
Iwakiri
Rika
R
Hayashi
Tatsuyuki
T
Sakamaki
Hisashi
H
Murai
Yoshiro
Y
Tohyama
Kaoru
K
Tomoyasu
Shigeru
S
Nonaka
Yasunobu
Y
Mori
Mayumi
M
Dan
Kazuo
K
Yoshida
Yataro
Y
D000208:Acute Disease; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D016022:Case-Control Studies; D002469:Cell Separation / Q000379:methods; D002499:Centrifugation, Density Gradient / Q000379:methods; D018450:Disease Progression; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007938:Leukemia / Q000235:genetics / Q000473:pathology; D008297:Male; D008793:Metrizamide; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000473:pathology*; D010641:Phenotype; D011379:Prognosis; D016019:Survival Analysis
D015703:Antigens, CD; D008793:Metrizamide