title: A Leukemia-Associated CD34/CD123/CD25/CD99+ Immunophenotype Identifies FLT3-Mutated Clones in Acute Myeloid Leukemia.
abstract: OBJECTIVE
  We evaluated leukemia-associated immunophenotypes (LAIP) and their correlation with fms-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) gene mutational status in order to contribute a better identification of patients at highest risk of relapse in acute myeloid leukemia (AML).
  
  
  METHODS
  Bone marrow samples from 132 patients with AML were analyzed by nine-color multiparametric flow cytometry. We confirmed the presence of the mutation in diagnostic samples and in sorted cells by conventional RT-PCR and by patient-specific RQ-PCR.
  
  
  RESULTS
  Within the CD34(+) cell fraction, we identified a discrete population expressing high levels of the IL3 receptor α-chain (CD123) and MIC-2 (CD99) in combination with the IL2 receptor α-chain (CD25). The presence of this population positively correlated with the internal tandem duplications (ITD) mutation in the FLT3 gene (r = 0.71). Receiver operating characteristics showed that, within the CD34(+) cell fraction a percentage of CD123/CD99/CD25(+) cells ≥11.7% predicted FLT3-ITD mutations with a specificity and sensitivity of >90%. CD34/CD123/CD99/CD25(+) clones were also detectable at presentation in 3 patients with FLT3 wild-type/NPM1(+) AML who relapsed with FLT3-ITD/NPM1(+) AML. Quantitative real-time PCR designed at relapse for each FLT3-ITD in these three cases confirmed the presence of low copy numbers of the mutation in diagnostic samples.
  
  
  CONCLUSIONS
  Our results suggest that the CD34/CD25/CD123/CD99(+) LAIP is strictly associated with FLT3-ITD-positive cells.
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Daniela F
authors.initials: DF
authors.lastname: Angelini
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy. Laboratorio di Neuro-Oncoematologia, Fondazione Santa Lucia I.R.C.C.S, Rome, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Ottone
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Gisella
authors.initials: G
authors.lastname: Guerrera
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy. Laboratorio di Neuro-Oncoematologia, Fondazione Santa Lucia I.R.C.C.S, Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Lavorgna
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy. Laboratorio di Neuro-Oncoematologia, Fondazione Santa Lucia I.R.C.C.S, Rome, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Cittadini
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Buccisano
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: De Bardi
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gargano
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Maurillo
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Mariadomenica
authors.initials: M
authors.lastname: Divona
authors.affiliation: Laboratorio di Neuro-Oncoematologia, Fondazione Santa Lucia I.R.C.C.S, Rome, Italy. Department of Chemical Biochemistry (Hematology), National University of Rosario, Argentina.
authors.forename: Nélida I
authors.initials: NI
authors.lastname: Noguera
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Maria Irno
authors.initials: MI
authors.lastname: Consalvo
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Borsellino
authors.affiliation: Experimental Neuroscience, Fondazione Santa Lucia, I.R.C.C.S., Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bernardi
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Amadori
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Venditti
authors.affiliation: Neuroimmunology and Flow Cytometry Units, Fondazione Santa Lucia-I.R.C.C.S., Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Battistini
authors.affiliation: Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy. Laboratorio di Neuro-Oncoematologia, Fondazione Santa Lucia I.R.C.C.S, Rome, Italy. francesco.lo.coco@uniroma2.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lo-Coco
mesh_terms: D000071443:12E7 Antigen; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism*; D018952:Antigens, CD34 / Q000378:metabolism*; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D060965:Clonal Evolution; D005260:Female; D005434:Flow Cytometry; D020440:Gene Duplication; D006801:Humans; D016130:Immunophenotyping; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D053650:Interleukin-3 Receptor alpha Subunit / Q000378:metabolism*; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D000090243:Nucleophosmin; D010641:Phenotype; D012372:ROC Curve; D055815:Young Adult; D051941:fms-Like Tyrosine Kinase 3 / Q000235:genetics*
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D053645:Interleukin-2 Receptor alpha Subunit; D053650:Interleukin-3 Receptor alpha Subunit; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; D051941:fms-Like Tyrosine Kinase 3