Pseudothrombocytopenia

Q: Which of the following drug can cause pseudothrombocytopenia? 

A) glycoprotein IIb/IIIa inhibitors 
B) Heparin
C) Acetaminophen 
D) Piperacillin 
E) Vancomycin 


Answer:  A

The objective of the above question is to highlight the main causes of pseudothrombocytopenia.

The usual anticoagulant used in phlebotomy tubes is ethylenediaminetetraacetic acid (EDTA). Many times in vitro platelet clumping may occur by ethylenediaminetetraacetic acid (EDTA)-dependent agglutinins. In such suspected scenarios, a blood sample should be sent in different anticoagulants based tubes after consulting laboratory personnel.

The most difficult situation is the use of glycoprotein IIb/IIIa inhibitors after acute coronary events. Although it is true that glycoprotein IIb/IIIa inhibitors can itself cause true thrombocytopenia but by default, any thrombocytopenia without any clinical finding with the use of glycoprotein IIb/IIIa inhibitors be read as pseudothrombocytopenia, as it may cause in vitro clumping of platelets.

Other major causes of pseudothrombocytopenia are insufficiently anticoagulated specimen and large size platelets (giant platelets) read as white blood cells by an automated counter.

#hematology
#cardiology
#pharmacology
#laboratory-medicine


Reference:

Bizzaro, Nicola Pathology - PSEUDOTHROMBOCYTOPENIA - Journal of the RCPA: 2009 - Volume 41 - Issue - p 34