Effects of platelet clumping on platelet concentrations measured by use of impedance or buffy coat analysis in dogs.
OBJECTIVE
To determine whether platelet clumps are homogeneously distributed in blood samples, and whether platelet concentrations (PC) obtained by use of impedance and buffy coat analysis can be considered minimum values when platelet clumps are present.


METHODS
Prospective study.


METHODS
50 blood samples obtained from 30 dogs.


METHODS
10 blood samples containing platelet clumps were used and 10 smears were made from each sample; amount of platelet clumping was graded for all 100 smears. Blood from each of 20 healthy dogs was divided between 2 EDTA tubes before and after platelet clumping was induced by adenosine diphosphate (ADP). The PC for each ADP-treated and untreated sample were measured, using impedance and quantitative buffy coat analyzers.


RESULTS
Platelet clumps were evident in all 100 blood smears, but the amount of clumping varied considerably within some samples. Using the impedance analyzer, the PC of ADP-treated samples were significantly lower and never higher than the PC of untreated samples. Using the buffy coat analyzer, some ADP-treated samples had increased PC; however, significant differences were not detected between treated and untreated samples.


CONCLUSIONS
Platelet clumping was not homogeneous within blood samples. When platelet clumps were identified by direct examination of blood smears, the PC detected by use of the impedance analyzer could be considered minimum values. In contrast, the PC detected by use of the buffy coat analyzer were sometimes increased. Useful information can be obtained by measuring PC in blood with platelet clumps; values obtained by use of impedance can be considered minimums, and values obtained by use of buffy coat analysis may be either minimum values or reasonable estimates of PC.
Koplitz
S L
SL
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65205, USA.
Scott
M A
MA
Cohn
L A
LA
D000244:Adenosine Diphosphate / Q000008:administration & dosage; D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D002469:Cell Separation; D004285:Dogs / Q000097:blood*; D017097:Electric Impedance; D005260:Female; D006405:Hematology / Q000379:methods*; D008297:Male; D010974:Platelet Aggregation / Q000502:physiology*; D010976:Platelet Count / Q000379:methods / Q000662:veterinary*; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D013921:Thrombocytopenia / Q000175:diagnosis / Q000662:veterinary
D000244:Adenosine Diphosphate