title: Acute megakaryoblastic leukemia associated with trisomy 21 demonstrates a distinct immunophenotype.
abstract: BACKGROUND
  Acute megakaryoblastic leukemia (AMKL) is a rare form of acute myeloid leukemia that encompasses three distinct subgroups: children with Down syndrome (DS-AMKL), children without DS (non-DS-AMKL), and adults (adult-AMKL). We hypothesize that the biological differences in the subtypes of AMKL may be reflected in distinct immunophenotypic (IP) features. Our aims were to employ mutiparameter flow cytometry to establish a comprehensive IP spectrum of AMKL in multiple demographic groups and to determine whether the subtypes of AMKL demonstrate distinct immunophenotypes.
  
  
  METHODS
  Thirty-seven AMKL cases were retrieved and subdivided into these three groups. Multiparameter flow cytometry was used to determine and compare the immunophenotypes. Available clinical, cytogenetic, and morphologic data were reviewed to confirm diagnoses.
  
  
  RESULTS
  While there is commonality in the expression pattern for a wide range of myelomonocytic markers in these three subtypes of AMKL, blasts in DS-AMKL were more likely to express CD7 and CD11b than those in non-DS-AMKL and adult-AMKL. Furthermore, blasts in DS-AMKL were more likely to express CD13, CD33, and CD36 than non-DS pediatric AMKL, and showed greater CD56 expression compared with adult AMKL.
  
  
  CONCLUSIONS
  These results indicate that DS-AMKL is related to but immunophenotypically distinct from non-DS-AMKL and adult-AMKL. This distinct immunophenotypic pattern, co-expression of CD7 and CD11b, has practical implications for characterization of AMKL.
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.|ProPath®, Dallas, Texas.
authors.forename: John M
authors.initials: JM
authors.lastname: Peters
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Franklin
authors.initials: F
authors.lastname: Fuda
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.|Department of Pathology, University of Iowa, Iowa City, Iowa.
authors.forename: Nitin J
authors.initials: NJ
authors.lastname: Karandikar
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Prasad
authors.initials: P
authors.lastname: Koduru
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.|Department of Pathology, University of California at San Diego, La Jolla, California.
authors.forename: Huan-You
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Weina
authors.initials: W
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000096:biosynthesis*; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007947:Leukemia, Megakaryoblastic, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged
chemical_list: D015703:Antigens, CD
keywords: Down syndrome; acute megakaryoblastic leukemia; flow cytometry; immunophenotype