title: Clinical value of the quantitative expression of the three epitopes of CD34 in 300 cases of acute myeloid leukemia.
abstract: OBJECTIVE
  The various epitopes of the CD34 molecule have been classified according to their different sensitivities to enzymatic cleavage by neuraminidase, chymopapain and a glycoprotease from Pasteurella haemolytica. Although monoclonal antibodies have been developed that specifically identify these epitopes, few studies have evaluated the distribution and quantitative expression of such epitopes on leukemic blasts.
  
  
  METHODS
  We report here a prospective multicenter study in which we examined and quantified the expression of the 3 classes of CD34 on fresh leukemic blast cells from 300 cases of acute myeloid leukemia (AML). The binding of monoclonal antibodies was studied by flow cytometry, allowing evaluation of blast cell positivity as well as their mean fluorescence intensity. These quantitative data were made comparable between centers by means of a calibration curve established with the same reagents in all laboratories.
  
  
  RESULTS
  Quantitative expression of class I epitope was significantly higher than that of class II and class III epitopes (p<0.0001). The three classes were more frequently expressed in M0 and M1 and less in M3 and M5. The highest levels of CD34 expression were observed in M2, M0 and M1 and the lowest in M3, M5 and BAL for class II and III. CD34 expression was lower for all classes in cases with a normal karyotype, compared to in cases with structural or numerical abnormalities.
  
  
  CONCLUSIONS
  In cases with a t(9;22) the expression of class I was significantly higher than that of class II and III and the opposite was observed in AML with t(15;17). Moreover, as a whole, a high intensity of class III CD34 appeared to be a marker of good prognosis.
authors.affiliation: Service d'Hématologie biologique, CHU de Dijon, 2 Boulevard Maréchal de Lattre de Tassigny, 21034 Dijon Cedex, France. mmaynadie@chu-dijon.fr
authors.forename: Marc
authors.initials: M
authors.lastname: Maynadié
authors.forename: Luc
authors.initials: L
authors.lastname: Gerland
authors.forename: Serge
authors.initials: S
authors.lastname: Aho
authors.forename: François
authors.initials: F
authors.lastname: Girodon
authors.forename: Michel
authors.initials: M
authors.lastname: Bernier
authors.forename: Corinne
authors.initials: C
authors.lastname: Brunet
authors.forename: Lydia
authors.initials: L
authors.lastname: Campos
authors.forename: Sylvie
authors.initials: S
authors.lastname: Daliphard
authors.forename: Véronique
authors.initials: V
authors.lastname: Deneys
authors.forename: Annie
authors.initials: A
authors.lastname: Falkenrodt
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Jacob
authors.forename: Emilienne
authors.initials: E
authors.lastname: Kühlein
authors.forename: Geneviève
authors.initials: G
authors.lastname: LeCalvez
authors.forename: Philippe
authors.initials: P
authors.lastname: Moskovtchenko
authors.forename: Patrick
authors.initials: P
authors.lastname: Philip
authors.forename: Paule-Marie
authors.initials: PM
authors.lastname: Carli
authors.forename: Gilbert C
authors.initials: GC
authors.lastname: Faure
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Béné
mesh_terms: D000208:Acute Disease; D018952:Antigens, CD34 / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D002138:Calibration; D018572:Disease-Free Survival; D000939:Epitopes / Q000145:classification / Q000276:immunology*; D005434:Flow Cytometry; D005470:Fluorometry; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D016130:Immunophenotyping / Q000295:instrumentation / Q000379:methods; D007951:Leukemia, Myeloid / Q000145:classification / Q000276:immunology* / Q000401:mortality / Q000473:pathology; D015993:Life Tables; D014411:Neoplastic Stem Cells / Q000276:immunology*; D010677:Philadelphia Chromosome; D011379:Prognosis; D011446:Prospective Studies; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D000939:Epitopes