EDTA-induced pseudothrombocytopenia

Adverse effects. Haemorrhage occurs but is less of a problem with low doses of heparin it remains a particular risk in patients treated after failed fibrinol5 c therapy for acute myocardial infarction. Platelet transfusion after cessation of abciximab is necessary for refractory or life threatening bleeding. After transfusion, the antibody redistributes to the transfused platelets, reduces the mean level of receptor blockade and improves platelet function. Thrombocytopenia may occur from 1 hour to days after commencing treatment in up to 1% of patients. This necessitates platelet counts at 2-4 hours and then daily if severe, therapy must be stopped and, if necessary, platelets transfused. EDTA-induced pseudothrombocytopenia has been reported and a low platelet count should prompt examination of a blood film for agglutination before therapy is stopped. 

Maniscalchi T, Corbo A, Fighola G, Vaccaro S, Cicatello C, Di Rosa S. EDTA-induced pseudothrombocytopenia. Policlin Sez Med 1996 103 7-12. 

Allerheiligen D, Houston R, Vermedahl B. EDTA-induced pseudothrombocytopenia. J Am Board Fam Pract 1996 9(3) 212-14. 

Foresti V, Parisio E, Tronci M, Casati O, Zubani R, Pedretti D. Pseudothrombocitopenia da EDTA. [EDTA-induced pseudothrombocytopenia.] Recenti Prog Med 1990 81(10) 661-2. 

Germing U, Giagounidis A, Sohngen D, Schneider W. EDTA-induced pseudothrombocytopenia a case report. Z Allgmed 1998 740 891. ... 

EDTA is well recognised to induce pseudothrombocytopenia (PTCP) caused by platelet aggregation and EDTA-dependent antibodies [79, 80 ]. 

Pseudothrombocytopenia, defined as in vitro platelet aggregation in blood anticoagulated with ethylenediaminetetraacetic acid (EDTA), is clinically insignificant, but it must also be differentiated from thrombocytopenia induced by abciximab. In this case, microscopic examination of a peripheral blood smear, along with repeated platelet counts in citrate-anticoagulated blood samples, makes the distinction possible. ... 

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