title: Characteristics of the phenotypic abnormalities of bone marrow cells in childhood myelodysplastic syndromes and juvenile myelomonocytic leukemia.
abstract: Immunophenotyping of bone marrow (BM) hemopoietic precursors is useful for diagnosis of adult myelodysplastic syndrome (MDS), but data concerning pediatric patients are limited. We analyzed immunophenotypic features of BM cells at diagnosis of children who were referred to the Brazilian Pediatric Cooperative Group of Myelodysplastic Syndromes.
  
  
  
  Diagnosis was based on clinical information, peripheral blood counts, BM cytology and cytogenetics. Patients with Down syndrome were excluded. Children with deficiency anemias or transitory neutropenias were used as controls (CTRLs). Immunophenotyping was performed on an eight-color antibody platform evaluating myelomonocytic maturation and progenitor cells.
  
  
  
  A total of 32 patients were examined: 6 refractory cytopenia of childhood [RCC]; 5 refractory anemia with excess of blasts [RAEB]; 8 refractory anemia with excess of blasts in transformation [RAEB-t]; 13 juvenile myelomonocytic leukemia [JMML] and 10 CTRLs. Median age was 66 months (RCC), 68 months (RAEB/RAEB-t), 29 months (JMML) and 70 months (CTRLs). Median number of phenotypic alterations was 4 (range 1-6) in RCC; 6 (range 2-11) in RAEB/RAEB-t and 6 (range 2-11) in JMML (P = 0.004). The percentage of CD34+/CD117+/CD13+cells was 0.5% (range 0.1-2.8) in RCC; 4.2% (range 0.3-10.1) in RAEB/RAEB-t and 3.7 % (range 0.5-8.6) in JMML cases, compared with 0.7% (0.5-1.2) in CTRLs (P < 0.0005). Aberrancies in antigen expression of myeloid progenitors were seen in 63% of JMML and in 45% of RAEB/RAEB-t. CD34+/CD19+/CD10+cells were decreased or absent in patients compared with age-matched controls. T lymphocytes were decreased in JMML.
  
  
  
  Phenotypic abnormalities were similar to those found in adult MDS. A decrease in B-cell precursors was observed especially in RAEB/RAEB-t. JMML and RAEB showed a similar pattern.
authors.affiliation: Childrens' Cancer Hospital, Barretos Cancer Center, Barretos, SP, Brazil.|Morphology/Flow Cytometry Committee, Brazilian Cooperative Group of Pediatric Myelodysplastic Syndromes (BCG-MDS-PED), Barretos, São Paulo, Brazil.
authors.forename: Anita F
authors.initials: AF
authors.lastname: Oliveira
authors.affiliation: Morphology/Flow Cytometry Committee, Brazilian Cooperative Group of Pediatric Myelodysplastic Syndromes (BCG-MDS-PED), Barretos, São Paulo, Brazil.|Diagnostic Laboratory of Barretos Cancer Center, Barretos, São Paulo, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Tansini
authors.affiliation: Diagnostic Laboratory of Barretos Cancer Center, Barretos, São Paulo, Brazil.|Pediatric Oncology Laboratory, Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos, São Paulo, Brazil.|Molecular Biology Committee, Brazilian Cooperative Group of Pediatric Myelodysplastic Syndromes, Barretos, São Paulo, Brazil.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Vidal
authors.affiliation: Childrens' Cancer Hospital, Barretos Cancer Center, Barretos, SP, Brazil.|Chair of the Brazilian Cooperative Group of Pediatric Myelodysplastic Syndromes, Barretos, São Paulo, Brazil.
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Lopes
authors.affiliation: Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil.
authors.forename: Konradin
authors.initials: K
authors.lastname: Metze
authors.affiliation: Morphology/Flow Cytometry Committee, Brazilian Cooperative Group of Pediatric Myelodysplastic Syndromes (BCG-MDS-PED), Barretos, São Paulo, Brazil.|Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil.
authors.forename: Irene
authors.initials: I
authors.lastname: Lorand-Metze
mesh_terms: D000293:Adolescent; D000328:Adult; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D054429:Leukemia, Myelomonocytic, Juvenile / Q000276:immunology / Q000473:pathology*; D008297:Male; D009190:Myelodysplastic Syndromes / Q000276:immunology / Q000473:pathology*; D010641:Phenotype; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
keywords: B-cell precursors; flow cytometry; juvenile myelomonocytic leukemia; myelodysplastic syndromes