Effects of in vitro hemodilution of canine blood on platelet function analysis using the PFA-100

Authors

  • Noel Clancey,

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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  • 1 Shelley Burton,

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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  • 1 Barbara Horney,

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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  • 1 Allan MacKenzie,

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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  • 1 Andrea Nicastro,

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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  • and 2 Etienne Côté 2

    1. Departments of 1Pathology and Microbiology and 2Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
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Correspondence
Noel Clancey, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PEI, Canada C1A 4P3
E-mail: nclancey@groupwise.upei.ca

Abstract

Background: The platelet function analyzer (PFA)-100 is a point-of-care instrument previously evaluated in humans and dogs. In both species, artificially prolonged platelet closure time (CT) occurs with anemia. Reliability of the analyzer in dogs becomes a concern when the HCT is between 0.25 and 0.35 L/L.

Objective: The objective of this study was to further define the level of HCT at which CT is prolonged, using in vitro diluted canine blood.

Methods: Citrated whole blood samples were collected from 22 healthy dogs. Initial HCT was determined and autologous platelet-rich plasma was added to samples to achieve HCTs of 0.33, 0.30, and 0.27 L/L. CT was determined in duplicate on the PFA-100 using collagen/adenosine-5′-diphosphate cartridges.

Results: Compared with the initial CT in samples with HCT 0.39–0.54 L/L (CT mean±SD=57.8±5.75 seconds), significantly prolonged CTs were found in hemodiluted samples with HCT 0.33 L/L (61.1±4.64 seconds), 0.30 L/L (64.3±6.79 seconds), and 0.27 L/L (70.8±7.90 seconds) (P=0.029; repeated measures ANOVA).

Conclusion: Although statistical differences were found, further studies are needed to determine the clinical significance of the mild prolongation in CT associated with mild anemia. Until then, dogs with HCTs slightly <0.35 L/L should be evaluated cautiously for platelet dysfunction using the PFA-100.

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