Surgical Delay due to Ethylenediaminetetraacetic Acid-Induced Pseudothrombocytopenia

Automated hematology analyzer uses the Coulter principle leading to different cell types based on their size. Despite being rapid and convenient, it can result in spurious outcomes like ethylenediaminetetraacetic acid (EDTA)-induced pseudothrombocytopenia. EDTA-induced pseudothrombocytopenia is an immunologically mediated phenomenon resulting from a change in the configuration of glycoprotein (GP) IIb/IIIa by EDTA. The consequence is an exposure of hidden epitope that reacts with certain autoantibodies resulting in spuriously low platelet counts when the blood samples are evaluated by automated blood analyzers. Although it is a rare cause of thrombocytopenia, if not recognized, it can result in unnecessary investigations and treatments. In this case, EDTA-induced psuedothrombocytopenia delayed laparoscopic cholecystectomy planned for symptomatic cholelithiasis in a 58-year-old male. The presence of large platelet clumps on peripheral smear and normal manual platelet counts confirmed the diagnosis. Pseudothrombocytopenia should be suspected when there is no correlation between clinical and laboratory findings in a patient with a low platelet count. Reperforming counts with other anticoagulants and if necessary, manual count in the peripheral blood smear is suggested.