title: Flow cytometry thresholds of myeloperoxidase detection to discriminate between acute lymphoblastic or myeloblastic leukaemia.
abstract: The World Health Organization 2008 Classification emphasizes myeloperoxidase (MPO) detection as sufficient for assigning a blast population to the myeloid lineage. Published MPO positivity thresholds are 10% for flow cytometry (FCM) but 3% for cytochemistry. Here we re-evaluated the FCM-MPO threshold by comparing retrospectively 128 acute lymphoblastic leukaemias and 75 acute myeloid leukaemias without maturation, all assessed by benzidine-based cytochemistry. A 13% threshold was found to be relevant using an isotype control as background-reference (sensitivity 95·1%, specificity 91·7%). Residual normal lymphocytes proved to be an advantageous alternative reference, a threshold of 28% yielding improved 97·4% sensitivity and 96·1% specificity.
authors: Haematology Laboratory, University Hospital of Dijon, Dijon, France.
authors: Julien
authors: J
authors: Guy
authors: Iléana
authors: I
authors: Antony-Debré
authors: Emmanuel
authors: E
authors: Benayoun
authors: Isabelle
authors: I
authors: Arnoux
authors: Chantal
authors: C
authors: Fossat
authors: Magali
authors: M
authors: Le Garff-Tavernier
authors: Anna
authors: A
authors: Raimbault
authors: Michèle
authors: M
authors: Imbert
authors: Marc
authors: M
authors: Maynadié
authors: Francis
authors: F
authors: Lacombe
authors: Marie C
authors: MC
authors: Béné
authors: Orianne
authors: O
authors: Wagner-Ballon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005434:Flow Cytometry / Q000379:methods / Q000592:standards; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis* / Q000201:enzymology; D008875:Middle Aged; D009195:Peroxidase / Q000032:analysis* / Q000378:metabolism; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000201:enzymology; D012372:ROC Curve; D012016:Reference Values; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D009195:Peroxidase