Microparticles in stored canine RBC concentrates



Maureen A. McMichael, Department of Veterinary Clinical Sciences, University of Illinois at Urbana-Champaign, 1008 West Hazelwood Dr., Urbana, IL 61802, USA

E-mail: mmcm@illinois.edu



Transfusion of RBC concentrates may cause adverse effects in the recipient, particularly when stored > 2 weeks. Prestorage removal of WBCs and platelets (leukoreduction, LR) improves clinical outcome in the human recipient. As blood ages during storage, progressive alterations in the structure and function of the cells occur. Changes in cell membranes may lead to formation of microparticles (MPs) in stored blood.


The aim of the study was to quantify MP concentration in supernatants from canine RBC concentrates from 11 clinically healthy dogs.


Whole blood units (= 11) were collected and randomized either to be stored without LR (= 5), or to be subject to prestorage LR (= 6). Whole blood was processed for the generation of RBC concentrates, from which aliquots were aseptically collected weekly for 5 weeks. Supernatants from the concentrates were evaluated for phosphatidylserine-expressing MPs by flow cytometry using staining with Annexin-V-phycoerythrin.


Microparticle counts were similar between non-LR and LR units on storage days 0 and 7, but were significantly higher in non-LR units on days 14, 21, 28, and 35. MPs increased during the 35-day storage by a mean (SD) of 1.8 (1.4)-fold in LR units and 5.5 (3.1)-fold in non-LR units.


There was marked formation of phosphatidylserine-expressing MPs during storage beyond 7 days in canine RBC concentrates. Prestorage LR attenuated the generation of MPs.