Measurement of Platelet's Count in different Anticoagulants should be Performed in Each Routine Blood Test

Introduction: Platelets are anucleate cells that play a crucial role in primary haemostasis. In addition, they also play a role in inflammation and immunity by expressing Toll-like receptors and binding endotoxins (i.e., LPS). Platelets can also interact with heparin by binding to the GPIIIa. A previous study showed that platelet counts is similar in all anticoagulants, except heparin. The aim of this study was to assess the clinical importance of evaluating the Platelet's Analyzed Number in Different Anticoagulants (PANDA-test).

Methods: PANDA test consists in the collection of peripheral blood samples into EDTA and heparin using S-Monovette tubes and the measurement of the mean platelet number using an automated counter. In this study, we analyzed blood samples of more than 1000 patients with chronic inflammatory gastrointestinal diseases and also of healthy volunteers.

Results and Discussion: In more than 80% of the patients, platelet's count was significantly lower in heparin-blood compared to EDTA-blood due to the presence of LPS-loaded platelets as a consequence of intestinal LPS translocation in these patients. Indeed, platelets containing LPS have a lower threshold to be aggregated in presence heparin which explain the low number of platelets in heparin- compared to EDTA-blood. Ex vivo addition of endotoxin induced a remarkable decrease in platelet count in heparin-blood of the control group but not in patient's group, where platelets could be previously saturated by LPS circulating in blood.

Conclusion: PANDA test is a reliable tool for screening endotoxin-loaded platelets and can be used as a diagnostic biomarker for increased intestinal permeability. Our results support the importance of performing PANDA as a routine blood test.