Effects of nitric oxide on platelet activation during plateletpheresis and in vivo tracking of biotinylated platelets in humans

Abstract

SNP does not decrease platelet activation during apheresis and subsequent storage, and only a minor proportion of activated (p-selectin+) platelets circulate after transfusion in men. Moreover, biotin labeling of PCs can safely be used in humans for the study of platelet recovery after transfusion, and measuring recovery at 1 hour may lead to an underestimation of the true recovery when activated platelets are transfused.

Biotinylation: A Nonradioactive Method for Labeling of Blood Components

“…There seems to be a protracted sequestration and later release of retransfused (activated) platelets into the circulation, as previously observed for baboon platelets labeled with PKH2, a nonradioactive fluorescent dye [26]. From our data it appears that both time points (after 10 min and 1 h) for the recovery measurements may be too early, because recovery rates of biotinpositive platelets were higher at 24 h. From our previous study [25] we conclude that biotinylation is applicable for platelet recovery studies in humans. As no adverse events were seen in our study even after rechallenge of healthy volunteers with biotin-labeled platelets, there seem to be no apparent contraindications for the use of biotin-labeled platelets in clinical trials.…”

“…We determined platelet recovery of 1-and 5-day-old autologous platelet concentrates (PC) [25]. In the first part of our previous study, 5 subjects underwent plateletpheresis and the PC were stored overnight on a flatbed shaker.…”

“…The activation of platelets induced by biotinylation [25] could be due to either repeated centrifugation or the biotinylation procedure itself. There was only a minor increase (<1%) of P-selectin-positive platelets after transfusion in the circulation.…”

Concurrent measurement of the survival of two populations of rabbit platelets labeled with either two PKH lipophilic dyes or two concentrations of biotin

“…The lipophilic PKH dyes have long alkyl tails that intercalate into the lipid bilayer of cell membranes, as well as polar fluorescent head groups. Others have covalently biotinylated platelets with N-hydroxysuccinimido (NHS) biotin in vivo or in vitro and monitored their survival by flow cytometry after reaction with phycoerythrin (PE)-streptavidin (5,(11)(12)(13)(14)(15). The PKH dyes or biotin can be used to study concurrently the survival of different platelet populations.…”

Effects of the Oral Direct Thrombin Inhibitor Ximelagatran on P-Selectin Expression and Thrombin Generation in Atrial Fibrillation

“…Platelet P-selectin (CD62P) analysis was performed after incubation of citrated blood with fluorescein isothiocyanate-labeled anti-P-selectin antibody (Immunotech, Marseille, France) using flow cytometry (fluorescence-activated cell sorter scan; Becton Dickinson, San Jose, Calif., USA) [20]. An isotopespecific monoclonal antibody was used to set a threshold for positive platelets (IgG1; Immunotech), and the fluorescein-positive number expressed as percentage of total platelets analyzed.…”