EDTA-induced platelet aggregation can be avoided by a new anticoagulant also suitable for automated complete blood count.
In vitro EDTA-induced platelet aggregation is a fairly rare event but can have serious clinical consequences producing pseudothrombocytopenia and pseudoleukocytosis. Sixteen specimens with previously recognized EDTA-induced platelet aggregation were collected in a new anticoagulant-antiaggregant mixture containing trisodium citrate 17 mmol/l, pyridoxal 5'-phosphate 11.3 mmol/l and Tris 24.76 mmol/l (CPT mixture) and analyzed at various times after venepuncture with four hematological instruments: Coulter Counter S-Plus STKR, Technicon H6000, Technicon H1 and Ortho ELT-8. In CPT-anticoagulated specimens the signals and instrumental flags of platelet clumping were absent, and the platelet number correlated very well with a microscopic count from a finger stick drawn into Unopette. The complete blood count was very similar in "normal" hematological specimens either collected in K3. EDTA or in CPT, although Technicon H1 and Ortho3 ELT-8 required a suitable calibration for MCV and hematocrit in the latter mixture. Mean platelet volume was stable for up to 24 h only in CPT-collected specimens, if it was measured on a Coulter Counter S-Plus STKR. In routine hematological practice CPT can be an alternative anticoagulant to K3. EDTA, most suitable for automated complete blood count and useful in avoiding EDTA-induced platelet clumping.
Lippi
U
U
Laboratorio di Chimica Clinica e di Ematologia, Ospedale Civile Maggiore, Verona, Italy.
Schinella
M
M
Nicoli
M
M
Modena
N
N
Lippi
G
G
D000925:Anticoagulants / Q000494:pharmacology*; D001772:Blood Cell Count / Q000295:instrumentation / Q000379:methods*; D002951:Citrates / Q000494:pharmacology*; D004338:Drug Combinations / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology*; D005189:False Positive Reactions; D006801:Humans; D007964:Leukocytosis / Q000175:diagnosis; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000494:pharmacology*; D013921:Thrombocytopenia / Q000175:diagnosis; D014325:Tromethamine / Q000494:pharmacology*
D000925:Anticoagulants; D002951:Citrates; D004338:Drug Combinations; D010975:Platelet Aggregation Inhibitors; C064185:pyridoxal phosphate, trisodium citrate, tromethamine drug combination; D014325:Tromethamine; D011732:Pyridoxal Phosphate; D004492:Edetic Acid