title: A whole blood model of thrombocytopenia that controls platelet count and hematocrit.
abstract: In patients with thrombocytopenia, it can be difficult to predict a patient's bleeding risk based on platelet count alone. Platelet reactivity may provide additional information; however, current clinical assays cannot reliably assess platelet function in the setting of thrombocytopenia. New methods to study platelet reactivity in thrombocytopenic samples are needed. In this study, we sought to develop a laboratory model of thrombocytopenia using blood from healthy subjects that preserves the whole blood environment and reproducibly produces samples with a specific platelet count and hematocrit. We compared the activation state of unstimulated and agonist-stimulated platelets in thrombocytopenic samples derived from this method with normocytic controls. Whole blood was diluted with autologous red blood cell concentrate and platelet-poor plasma, which were obtained via centrifugation, in specific ratios to attain a final sample with a predetermined platelet count and hematocrit. P-selectin exposure and GPIIbIIIa activation in unstimulated platelets and platelets stimulated with collagen-related peptide (CRP) or adenosine diphosphate (ADP) in thrombocytopenic samples and the normocytic control from which they were derived were quantified by flow cytometry. Our methodology reliably produced thrombocytopenic samples with a platelet count ≤50,000/μL and an accurately and precisely controlled hematocrit. P-selectin exposure and GPIIbIIIa activation on unstimulated platelets or on ADP- or CRP-stimulated platelets did not differ in thrombocytopenic samples compared to normocytic controls. We describe a new method for creating thrombocytopenic blood that can be used to better understand the contributions of platelet number and function to hemostasis.
authors: Medical Sciences Institute, PO Box 2178, Milwaukee, WI, 53201, USA. rachel.bercovitz@bcw.edu.
authors: R S
authors: RS
authors: Bercovitz
authors: Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, USA.
authors: M K
authors: MK
authors: Brenner
authors: Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, USA.
authors: D K
authors: DK
authors: Newman
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D002352:Carrier Proteins / Q000494:pharmacology; D002498:Centrifugation; D005434:Flow Cytometry / Q000379:methods*; D006400:Hematocrit; D006474:Hemorrhagic Disorders / Q000097:blood / Q000209:etiology*; D006801:Humans; D066298:In Vitro Techniques; D019007:P-Selectin / Q000032:analysis; D010455:Peptides / Q000494:pharmacology; D015539:Platelet Activation / Q000187:drug effects; D010976:Platelet Count; D010979:Platelet Function Tests; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000032:analysis; D015203:Reproducibility of Results; D013921:Thrombocytopenia / Q000097:blood* / Q000150:complications
chemical_list: D002352:Carrier Proteins; D019007:P-Selectin; D010455:Peptides; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C435908:collagen-related peptide; D000244:Adenosine Diphosphate
keywords: Blood platelets; Flow cytometry; Platelet activation; Platelet aggregation; Thrombocytopenia