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A Novel In vitro Model for Studying the Interactions Between Human Whole Blood and Endothelium
Published on: November 21, 2014
Stored red blood cell supernatant facilitates thrombin generation
Joseph Sweeney1, Nicola Kouttab, Jonathan Kurtis
1Transfusion Services, The Miriam Hospital, 164 Summit Avenue, Providence, RI 02906, USA. jsweeney@lifespan.org
Transfusion
|May 6, 2009
Summary
Red blood cell concentrates release microvesicles that express phosphatidylserine and promote thrombin generation. This may explain why stored red blood cells lead to worse clinical outcomes in patients.
Area of Science:
- Transfusion Medicine
- Hematology
- Biochemistry
Background:
- Observational studies link red blood cell (RBC) transfusions to poorer patient outcomes.
- RBC storage age may independently predict adverse clinical outcomes post-transfusion.
Purpose of the Study:
- To investigate the mechanism by which stored RBCs may cause adverse effects.
- To analyze the characteristics of RBC-derived microvesicles (RCMVs) during storage.
Main Methods:
- Studied RBC concentrates over 8 weeks of storage.
- Ultracentrifuged RBC supernatant to isolate RCMVs.
- Analyzed RCMVs for phosphatidylserine (PS) expression via flow cytometry.
- Assessed RCMV procoagulant activity using a modified thromboelastograph (TEG) assay.
Main Results:
- PS expression on RCMVs increased from 50% on Day 1 to 90% by Day 31.
- Four of eight RBC products showed a thrombin facilitation effect after 31 days, shortening TEG R time.
- This procoagulant effect, neutralized by annexin V, was not observed before Day 21.
Conclusions:
- Stored RBCs release RCMVs expressing PS, which can enhance thrombin generation in vitro.
- This mechanism offers a potential explanation for thrombotic or inflammatory effects associated with stored RBC transfusions.
