High fragmentation in platelet concentrates impacts the activation, procoagulant, and aggregatory capacity of platelets.

Platelets are transfused to patients to prevent bleeding. Since both preparation and storage can impact the hemostatic functions of platelets, we studied platelet concentrates (PCs) with different initial composition in regard to platelet fragmentation and its impact on storage-induced changes in activation potential. Ten whole blood derived PCs were assessed over 7 storage days. Using flow cytometry, platelet (CD41+) subpopulations were characterized for activation potential using activation markers (PAC-1, P-selectin, and LAMP-1), phosphatidylserine (Annexin V), and mitochondrial integrity (DiIC What is the context?● Platelets are necessary to prevent and stop bleeding.● Conditions associated with a low platelet count in the circulation, such as during chemotherapy treatment for hematologic cancer, can result in life-threatening bleeding. To prevent this, platelets from blood donors are transfused to these patients.● The collection and preparation of platelet concentrates and subsequent storage before transfusion can affect the ability of the platelets to prevent bleeding.● In this study, we investigated platelet concentrates prepared from whole blood and how their activation capacity was affected by the preparation and storage period.What is new?● We found that the platelet concentrates contained mainly low activated platelets of normal size, but also smaller platelets and platelet fragments.● Unlike normal-sized platelets, small platelets and fragments exhibited hallmarks that are characteristic of pre-activation.● Some platelet concentrates contained a relatively high proportion of small platelets and fragments already directly following preparation.● Investigating several platelet activation markers, we found that platelet concentrates containing a high proportion of small platelets and platelet fragments showed lower activation capacity throughout the storage period.