title: Phenotypic changes in acute myeloid leukaemia: implications in the detection of minimal residual disease.
abstract: OBJECTIVE
  To explore the role of phenotypic changes as possible limiting factors in the immunological detection of minimal residual disease in patients with acute myeloid leukaemia (AML).
  
  
  METHODS
  20 relapses were evaluated, with special attention to changes in the criteria used for the definition of a phenotype as "aberrant". In all cases the same monoclonal antibody and fluorochrome were used at diagnosis and in relapse.
  
  
  RESULTS
  Six out of the 16 patients showed aberrant phenotypes at diagnosis. At relapse, no changes in the aberrant phenotypes were detected in most of the patients; nevertheless, in two of the four patients with asynchronous antigen expression this aberration disappeared at relapse. At diagnosis in both cases there were already small blast cell subpopulations showing the phenotype of leukaemic cells at relapse. Ten out of the 16 cases analysed showed significant changes in the expression of at least one of the markers analysed.
  
  
  CONCLUSIONS
  At relapse in AML the "leukaemic phenotypes" usually remained unaltered, while other phenotypic features--not relevant for distinguishing leukaemic blast cells among normal progenitors--changed frequently; however, they were not a major limitation in the immunological detection of minimal residual disease.
authors.affiliation: Servicio de Hematología, Hospital Clínico Universitario, Salamanca, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Macedo
authors.forename: J F
authors.initials: JF
authors.lastname: San Miguel
authors.forename: M B
authors.initials: MB
authors.lastname: Vidriales
authors.forename: M C
authors.initials: MC
authors.lastname: López-Berges
authors.forename: M A
authors.initials: MA
authors.lastname: García-Marcos
authors.forename: M
authors.initials: M
authors.lastname: Gonzalez
authors.forename: C
authors.initials: C
authors.lastname: Landolfi
authors.forename: A
authors.initials: A
authors.lastname: Orfão
mesh_terms: D000208:Acute Disease; D015703:Antigens, CD / Q000097:blood; D006801:Humans; D016130:Immunophenotyping; D007951:Leukemia, Myeloid / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000276:immunology; D010641:Phenotype; D012008:Recurrence
chemical_list: D015703:Antigens, CD