Comparison of Platelet Clumping and Complete Blood Count Results with Sysmex XT-2000iV in Feline Blood Sampled on EDTA or EDTA plus CTAD (Citrate, Theophylline, Adenosine and Dipyridamole)

Abstract

False thrombocytopenia may result from platelet aggregation, especially in feline ethylenediamine tetra-acetic acid (EDTA) blood specimens. Citrate, theophylline, adenosine and dipyridamole (CTAD) was added to 46 feline EDTA specimens to test its anti-aggregation action. Platelet aggregation was estimated from blood films and a complete blood count was performed with a Sysmex XT-2000iV analyser. Platelet aggregation score was >2 in 11/46 EDTA tubes and only in one EDTA+CTAD specimen. The platelet count was higher in all CTAD-supplemented tubes except one, medians measured by cytometry being 225.5 × 10(9)/l and 249.0 × 10(9)/l in EDTA and EDTA+CTAD, respectively (P = 0.007). Adding CTAD had statistically and analytically significant but moderate effects on other blood variables, the most intense variations being observed for reticulocytes (about 3% higher in EDTA specimens) and reticulocyte indexes. Addition of CTAD to EDTA when sampling feline blood is a useful option to reduce platelet clumping.

Combined and breed‐specific RIs for hematologic, biochemical, and hormonal analytes in Chios and Florina adult rams

“…The mean score of 10 randomly selected oil‐immersion fields at the feathered edge and tail of the blood film was calculated. Platelet clumping was considered significant when the mean score was ≥ 2, as previously suggested …”

Analytical variability of estimated platelet counts on canine blood smears

“…Several methods have been proposed to improve the evaluation of platelet mass, especially in the feline species . Measurement of the plateletcrit (PCT) with the quantitative buffy coat (QBC) IDEXX Vet Autoread hematology analyzer could better evaluate the platelet mass in dogs with macrothrombocytopenia, especially in some canine breeds .…”

“…Measurement of the plateletcrit (PCT) with the quantitative buffy coat (QBC) IDEXX Vet Autoread hematology analyzer could better evaluate the platelet mass in dogs with macrothrombocytopenia, especially in some canine breeds . A scoring system to evaluate platelet mass based on the size of platelet clumps on feline blood smears has also been proposed . However, these methods might only improve the accuracy of platelet counts; the so‐called platelet estimate or estimated platelet count is still recommended to verify the correctness of instrument‐derived platelet counts and to evaluate the platelet mass indirectly.…”

Thrombocytopenia

“…A manual platelet count performed on a blood smear is an easy and cost-effective method to estimate platelet count. 33 On review of peripheral blood smears, a high-powered field (hpf, 100×) should contain 8 to 15 platelets, which corresponds to 120,000 to 225,000/µl (each platelet representing about 15,000/µl). In particular, cats and dogs with inflammatory diseases tend to have platelets that form clumps (especially with traumatic venipuncture) and that may be miscounted by automated analyzers, resulting in a falsely lowered platelet count (Figure 106-1).…”