Platelet function under high‐shear conditions from platelet concentrates

Abstract

BACKGROUND: Platelet (PLT) collection and storage affect the functional capacity of PLTs in PLT concentrates (PCs). Therefore, PLTs' functional quality should be studied before transfusion. STUDY DESIGN AND METHODS: PCs (n = 15) were collected by a standard apheresis procedure (Trima, Gambro BCT) and were stored for 7 days. Samples were taken to assess PLT adhesion and aggregate formation by a cone and plate analyzer (Impact-R, DiaMed) on Days 1, 3, 5, and 7 after harvesting. This device allows testing PLT function under high-shear stress close to physiologic conditions. Concomitantly, P-selectin expression and the residual responsiveness to TRAP-6 were determined by flow cytometry. RESULTS: PLT adhesion, as measured by surface coverage, decreased during the entire observation period; likewise, the size of aggregates was significantly lower on Days 5 and 7 compared to Day 1 (p < 0.02). P-selectin expression increased from Day 5 to Day 7 (p < 0.04), whereas TRAP-6-inducible expression remained stable until Day 5 of storage and decreased significantly on Day 7 (p = 0.04). CONCLUSIONS: Our results show that high-shearinduced PLT adhesion and aggregation on the polystyrene surface deteriorate upon storage, suggesting decreased PLT function in vivo. Thus, the Impact-R may be a useful tool to assess the functional capacity of PLTs under various PLT harvesting and storage procedures. P latelet (PLT) transfusions are used to prevent or treat bleeding episodes in patients with thrombocytopenia, for example, after high-dose chemotherapy. The process of PLT collection and storage may affect the functional capacity of PLTs in PLT concentrates (PCs). Therefore, a variety of in vitro methods have been extensively investigated for their validity and feasibility to test and guarantee the function of PLTs that were prepared for their transfusion.1 Results from in vitro tests were correlated with the corrected count increment (CCI) of PLTs 1 or 24 hours after transfusion to estimate the validity of these tests clinically. 2-4Although the CCI is most often used to estimate the success of PLT transfusions, it does not always correlate with PLT survival.1 Very few in vitro tests performed on PLTs from PCs, however, correlate with PLT viability after their transfusion to healthy individuals, 4,5 and these tests have not been further validated after transfusion to thrombocytopenic patients. Further, the CCI does not evaluate PLTs' hemostatic activity. Thus, in vitro evaluation of PLT function in PCs is desirable before transfusion. According to the European guidelines, only the pH must be measured (6.4-7.4) and the swirling phenomenon must be demonstrated after 5 days of storage. This device allows evaluation of PLT function under close to physiologic conditions in a whole-blood assay. PLT adhesion and aggregation can be determined in anticoagulated blood under arterial flow conditions wherein a cone and plate viscometer induces laminar flow with a uniform shear stress over a plastic plate by the rotating cone. Results can then be e...

Usefulness of delta value of platelet parameters on ADVIA 120 for the functional reactivity of stored platelets

“…However, Cardigan et al (21) reported that the reactivity of platelets to stimuli such as physiological agonists, rather than the glycoprotein expression without agonists, might be a better predictor of in vivo platelet transfusion efficacy. Recently, several studies have reported on CD62P expression in agonist-stimulated platelets for the evaluation of platelet function in platelet products (8)(9)(10)(11)(12)(13)(14)(15). However, agonist-induced expression of CD62P by flow cytometry analysis is not easy to use routinely.…”

“…Currently, agonist-induced expression of CD62P, or other markers, has been investigated in several studies to determine platelet function in platelet products (8)(9)(10)(11)(12)(13)(14)(15), because the functional reactivity of platelets could be used to predict platelet transfusion efficacy. However, agonist-induced expression of CD62P by flow cytometry analysis has some disadvantages, including the expense of the equipment and reagents, and the difficulty of the associated procedures.…”

Platelet adhesion changes during storage studied with a novel method using flow cytometry and protein-coated beads

“…The collagen beads did not change in percentage of beads with adhering platelets, but did increase the amount of platelets adhering to each bead during the first 7 days of storage. There are few studies on platelet adhesion during storage and they vary in the method of platelet preparation, storage length and storage media, making direct comparisons difficult, as all these factors affect platelet function [6,7,[9][10][11]. Furthermore these studies have tested platelets in presence of added red blood cells which could also influence their results.…”

“…One reason is that current available methods are time consuming, complicated to use, and require large sample volumes. The adhesion capacity of stored platelets has been studied using perfusion chambers [6][7][8] or cone and-plate devices [9,10]. These methods require the presence of red blood cells, which complicates the analysis of PCs and introduces a potential source of non-specific and unpredictable effects [8,9,11].…”

Platelet aggregation and quality control of platelet concentrates produced in the Amazon Blood Bank

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