Key Takeaways

✅ Pseudothrombocytopenia (spurious thrombocytopenia) results from in vitro artifacts including EDTA-dependent and EDTA-independent causes (such as poor mixing of patient sample with anticoagulant in the tube).

✅ EDTA-dependent pseudothrombocytopenia is the phenomenon of a spurious low platelet count due to the presence of agglutinating anti-platelet antibodies that react with platelets in blood anticoagulated with EDTA.

✅EDTA-dependent pseudothrombocytopenia is not a disease, but rather is an in vitro artifact.

✅ Suspect EDTA-dependent pseudothrombocytopenia in a patient with thrombocytopenia when no bleeding is present. 

✅ Confirm diagnosis by demonstrating a) platelet clumps on peripheral smear, and b) normalization of platelet count when blood collected in a non-EDTA containing tube, preferably Na citrate.

✅ Failure to recognize EDTA-dependent pseudothrombocytopenia may lead to unnecessary diagnostic testing and treatment.