Effects of in vitro hemodilution of canine blood on platelet function analysis using the PFA-100
Article first published online: 22 JUN 2009
©2009 American Society for Veterinary Clinical Pathology
Veterinary Clinical Pathology
Volume 38, Issue 4, pages 467–470, December 2009
How to Cite
Clancey, N., Burton, S., Horney, B., MacKenzie, A., Nicastro, A. and Côté, E. (2009), Effects of in vitro hemodilution of canine blood on platelet function analysis using the PFA-100. Veterinary Clinical Pathology, 38: 467–470. doi: 10.1111/j.1939-165X.2009.00162.x
- Issue published online: 1 DEC 2009
- Article first published online: 22 JUN 2009
- platelet function
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.