title: Fifteen years of external quality assessment in leukemia/lymphoma immunophenotyping in The Netherlands and Belgium: A way forward.
abstract: In 1985, external quality assurance was initiated in the Netherlands to reduce the between-laboratory variability of leukemia/lymphoma immunophenotyping and to improve diagnostic conclusions. This program consisted of regular distributions of test samples followed by biannual plenary participant meetings in which results were presented and discussed. A scoring system was developed in which the quality of results was rated by systematically reviewing the pre-analytical, analytical, and post-analytical assay stages using three scores, i.e., correct (A), minor fault (B), and major fault (C). Here, we report on 90 consecutive samples distributed to 40-61 participating laboratories between 1998 and 2012. Most samples contained >20% aberrant cells, mainly selected from mature lymphoid malignancies (B or T cell) and acute leukemias (myeloid or lymphoblastic). In 2002, minimally required monoclonal antibody (mAb) panels were introduced, whilst methodological guidelines for all three assay stages were implemented. Retrospectively, we divided the study into subsequent periods of 4 ("initial"), 4 ("learning"), and 7 years ("consolidation") to detect "learning effects." Uni- and multivariate models showed that analytical performance declined since 2002, but that post-analytical performance improved during the entire period. These results emphasized the need to improve technical aspects of the assay, and reflected improved interpretational skills of the participants. A strong effect of participant affiliation in all three assay stages was observed: laboratories in academic and large peripheral hospitals performed significantly better than those in small hospitals. © 2015 International Clinical Cytometry Society.
authors.affiliation: Laboratory of Hematology, Department of Laboratory Medicine, Radboud UMC, Nijmegen, The Netherlands.
authors.forename: Frank W M B
authors.initials: FW
authors.lastname: Preijers
authors.affiliation: Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Vincent H J
authors.initials: VH
authors.lastname: van der Velden
authors.affiliation: Laboratory of Hematology, Department of Laboratory Medicine, Radboud UMC, Nijmegen, The Netherlands.
authors.forename: Tim
authors.initials: T
authors.lastname: Preijers
authors.affiliation: Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Rik A
authors.initials: RA
authors.lastname: Brooimans
authors.affiliation: Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Marijt
authors.affiliation: Department of Immunocytology, Sanquin Blood Supply, Amsterdam, The Netherlands.
authors.forename: Christa
authors.initials: C
authors.lastname: Homburg
authors.affiliation: Department of Trials and Statistics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Kees
authors.initials: K
authors.lastname: van Montfort
authors.affiliation: Department of Internal Oncology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Jan W
authors.initials: JW
authors.lastname: Gratama
mesh_terms: D000208:Acute Disease; D001530:Belgium; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007938:Leukemia / Q000473:pathology*; D008223:Lymphoma / Q000175:diagnosis* / Q000473:pathology*; D009426:Netherlands; D011786:Quality Control; D012189:Retrospective Studies
keywords: external quality control; flow cytometry; immunophenotyping; leukemia; lymphoma