A new approach for rapid and reliable enumeration of circulating endothelial cells in patients

Jaco Kraan, Michiel Strijbos, Anieta Sieuwerts, John Foekens, Michael den Bakker, Kees Verhoef, Stefan Sleijfer, Jan willem Gratama

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40 Citations (Scopus)


. Background broken vertical bar Mature circulating endothelial cells (CECs) are surrogate markers of endothelial damage/dysfunction. A lack of standardized assays and consensus on CEC phenotype has resulted in a wide variation of reported CEC numbers (41300 per mL). Objectives broken vertical bar Given the need for a quick, reliable, robust and validated CEC assay at an affordable price, we present a novel approach to enumerate CECs using a multi-parameter flow cytometric (FCM) method without immunological pre-enrichment. Methods broken vertical bar CECs were defined as CD34+, CD45neg, CD146+ and DNA+ events based on the immunophenotype of endothelial cells from vein-wall dissections. As CECs express high levels of CD34, we based our assay on absolute CD34 counts after analyzing all CD34 positive events in a total blood volume of 4 mL needed for a precise enumeration of CECs at a frequency of < 1 cell mu L-1. Results broken vertical bar The endothelial origin of CECs was confirmed by morphology, immunohistochemistry and gene expression. The new FCM assay was tested in parallel with a validated assay (i.e. CellSearch (R)). CEC levels ranged from 4 to 79 CEC mL-1 in healthy individuals and were significantly higher in patients with advanced solid malignancies (P = 0.0008) and in patients with hematological malignancies (P < 0.0001). Conclusions broken vertical bar This flow cytometric method should be useful as a fast and economical assay to enumerate and characterize CECs.
Original languageUndefined/Unknown
Pages (from-to)931-939
Number of pages9
JournalJournal of Thrombosis and Haemostasis
Issue number5
Publication statusPublished - 2012

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