title: Extended diagnostic criteria for plasmacytoid dendritic cell leukaemia.
abstract: The diagnosis of plasmacytoid dendritic cell leukaemia (pDCL) is based on the immunophenotypic profile: CD4(+) CD56(+) lineage(neg) CD45RA(+)/RO(neg) CD11c(neg) CD116(low) CD123(+) CD34(neg) CD36(+) HLA-DR(+). Several studies have reported pDCL cases that do not express this exact profile or expressing some lineage antigens that could thus be misdiagnosed. This study aimed to validate pDCL-specific markers for diagnosis by flow-cytometry or quantitative reverse transcription polymerase chain reaction on bone marrow samples. Expression of markers previously found in normal pDC was analysed in 16 pDCL, four pDCL presenting an atypical phenotype (apDCL) and 113 non-pDC - lymphoid or myeloid - acute leukaemia. CD123 was expressed at significantly higher levels in pDCL and apDCL. BDCA-2 was expressed on 12/16 pDCL and on 2/4 apDCL, but was never detected in the 113 non-pDC acute leukaemia cases. BDCA-4 expression was found on 13/16 pDCL, but also in 12% of non-pDC acute leukaemia. High levels of LILRA4 and TCL1A transcripts distinguished pDCL and apDCL from all other acute leukaemia (except B-cell acute lymphoblastic leukaemia for TCL1A). We thus propose a diagnosis strategy, scoring first the CD4(+) CD56(+/-) MPO(neg) cCD3(neg) cCD79a(neg) CD11c(neg) profile and then the CD123(high), BDCA-2 and BDCA-4 expression. Atypical pDCL can be also identified this way and non-pDC acute leukaemia excluded: this scoring strategy is useful for diagnosing pDCL and apDCL.
authors.affiliation: INSERM UMR645, Université of Franche-Comté, Etablissement Français du Sang Bourgogne Franche-Comté, 1 boulevard A. Fleming, Besançon, France. francine.garnache@efs.sante.fr
authors.forename: Francine
authors.initials: F
authors.lastname: Garnache-Ottou
authors.forename: Jean
authors.initials: J
authors.lastname: Feuillard
authors.forename: Christophe
authors.initials: C
authors.lastname: Ferrand
authors.forename: Sabeha
authors.initials: S
authors.lastname: Biichle
authors.forename: Franck
authors.initials: F
authors.lastname: Trimoreau
authors.forename: Estelle
authors.initials: E
authors.lastname: Seilles
authors.forename: Véronique
authors.initials: V
authors.lastname: Salaun
authors.forename: Richard
authors.initials: R
authors.lastname: Garand
authors.forename: Pascale
authors.initials: P
authors.lastname: Lepelley
authors.forename: Marc
authors.initials: M
authors.lastname: Maynadié
authors.forename: Emilienne
authors.initials: E
authors.lastname: Kuhlein
authors.forename: Eric
authors.initials: E
authors.lastname: Deconinck
authors.forename: Sylvie
authors.initials: S
authors.lastname: Daliphard
authors.forename: Laurence
authors.initials: L
authors.lastname: Chaperot
authors.forename: Lucille
authors.initials: L
authors.lastname: Beseggio
authors.forename: Vincent
authors.initials: V
authors.lastname: Foisseaud
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Macintyre
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Bene
authors.forename: Philippe
authors.initials: P
authors.lastname: Saas
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Jacob
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015415:Biomarkers / Q000032:analysis; D002648:Child; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D053650:Interleukin-3 Receptor alpha Subunit / Q000032:analysis; D037181:Lectins, C-Type / Q000032:analysis; D007938:Leukemia / Q000145:classification* / Q000175:diagnosis / Q000276:immunology; D015470:Leukemia, Myeloid, Acute / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000032:analysis; D011971:Receptors, Immunologic / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; C443299:CLEC4C protein, human; D053650:Interleukin-3 Receptor alpha Subunit; C488262:LILRA4 protein, human; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D011971:Receptors, Immunologic; C090851:TCL1A protein, human