Original ArticlesOptimized flow cytometric assay for the measurement of platelet microparticles in plasma: pre-analytic and analytic considerationsKim, H. K.; Song, K. S.; Lee, E. S.; Lee, Y. J.; Park, Y. S.; Lee, K. R.; Lee, S. N.Author Information H. K. Kim, E. S. Lee, Y. J. Lee, Y. S. Park, K. R. Lee and S. N. Lee are with National Cancer Center, Goyang, Gyeonggi, Korea; and K. S. Song is with the Department of Clinical Pathology, Yonsei University College of Medicine, Seoul, Korea. (Received 26 November 2001; revised 25 February 2002; accepted 8 March 2002) Sponsorship: This work was supported by the National Cancer Center Grant N01S1010. Address correspondence to Hyun Kyung Kim, M.D., Hematologic Malignancies Branch, Division of Special Cancers, Research Institute of National Cancer Center, 809, Madu 1-dong, Ilsan-gu, Goyang-si, Gyeonggi-do 411-764, Republic of Korea. Tel: (+82) 31 920 1735; fax: (+82) 31 920 1738; e-mail:[email protected] Blood Coagulation & Fibrinolysis: July 2002 - Volume 13 - Issue 5 - p 393-397 Buy Abstract Platelet microparticles (PMP) are submicroscopic membrane vesicles released by platelets during activation. Flow cytometry is the most widely used method for quantifying PMP, but the optimization of the technical method has not yet been fully evaluated. This study was designed to assess the pre-analytical variables including blood sampling conditions, and to evaluate the analytical variations including effect of the platelet-specific antibodies and quantitative beads, precision, linearity and accuracy in comparison with β-thromboglobulin, which is one of the platelet activation markers. Numbers of PMP collected into citrate–theophylline–adenosine-dipyridamole (CTAD) tubes were increased with time, but to a lesser extent than when collected into sodium citrate tubes. The precision of the PMP assay was relatively high. Excellent linear correlation was observed for dilution linearity. Regarding the platelet-specific antibodies used, anti-CD41a-labeled samples resulted in higher PMP levels than those labeled with anti-CD61 and anti-CD42a. There was no significant difference of PMP counts according to the quantitative beads. The PMP assay is well correlated with β-thromboglobulin levels. Our findings suggest that blood samples for the PMP assay should be collected in a CTAD tube and delayed measurement is not allowed to avoid artefactual platelet activation. The PMP assay can be used successfully as a useful marker of the detection of in vivo platelet activation, provided that pre-analytical and technical points are optimally taken into consideration. © 2002 Lippincott Williams & Wilkins, Inc.