Automated Analysis of Feline Platelets in Whole Blood, Including Platelet Count, Mean Platelet Volume, and Activation State

Abstract

A new whole-blood flow cytometric method has been developed for counting and sizing platelets in samples from cats, a species in which platelet and red blood cell sizes overlap significantly. The method is a modified version of the two-angle laser light scattering technology used by Bayer H*System hematology analyzers. The new method provided accurate platelet counts and mean platelet volumes (MPV, fl) for cats. The method also measured mean platelet component concentration (MPC, g/dl), a parameter which was shown to be sensitive to platelet activation state, and which decreased in value as activation progressed.

Assessment of platelet function in healthy sedated cats using three whole blood platelet function tests

“…This finding is different from humans, where responses to ADP were lower than responses to COL and AA, and for dogs, where responses to AA appear to have been lower than responses to ADP and COL. 27,33 Furthermore, aggregation responses in our study appear to be lower than responses in dogs and sheep, and only marginally greater than responses in humans, using the same or comparable agonist concentrations. 3,27,32 Cats are considered to have highly aggregable platelets, 35,40 so it was surprising that platelet aggregation responses were not higher compared to other species. Studies in dogs and sheep have demonstrated that aggregation responses can be enhanced by changing agonist concentrations, and similar studies in cats may identify optimal agonist concentrations.…”

Effect of Anticoagulant and Storage Conditions on Platelet Size and Clumping in Healthy Dogs

“…d Samples were considered to have undergone aggregation if at any magnification they displayed at least 3 aggregates, each consisting of $3 platelets. 33,37 The percentage of macroplatelets was calculated following the review of 300 consecutive nonaggregated platelets in the monolayer area with the aid of an ocular micrometer at 1,0003 magnification. For the purpose of the current study, spherical platelets with a diameter $5 mm or elongated platelets with a length $5 mm were considered macroplatelets.…”

Comparison of Manual and Automated Methods for Determining Platelet Counts in Dogs with Macrothrombocytopenia

“…Similar problems with automated analysis are also reported from cats because a significant overlap in size between platelets and red blood cells exists in this species. 15 Interestingly, a recent study demonstrated that a modified flow cytometric method was able to count and size platelets in cats on basis of size and refractive index. 15 That method in addition yielded a new interesting parameter: mean platelet component concentration, which was related to platelet activation state.…”

“…15 Interestingly, a recent study demonstrated that a modified flow cytometric method was able to count and size platelets in cats on basis of size and refractive index. 15 That method in addition yielded a new interesting parameter: mean platelet component concentration, which was related to platelet activation state. 15 The manual estimation of platelet count from blood smear correlated better with the Unopette platelet count than the automated cell counting systems.…”

“…15 That method in addition yielded a new interesting parameter: mean platelet component concentration, which was related to platelet activation state. 15 The manual estimation of platelet count from blood smear correlated better with the Unopette platelet count than the automated cell counting systems. This method, however, also seemed to underestimate the counts at low platelet concentrations, possibly because enlarged platelets tend to be localized in the feathered end of the smear in CKCS with macrothrombocytopenia (Olsen H, unpublished data).…”