Platelet storage in small bags as a model of platelet function in full-sized containers.

Background: Evaluation of additive solutions, storage containers, new collection and storage methods, and other potential modifications is resource intensive, resulting in diversion of platelets away from blood bank inventories and significant time to complete study recruitments. Our goal was to evaluate the feasibility of a small bag for the study of platelet storage, and, by using a standardized respirometry test, separate daily metabolic capacity from observations made in the dynamic storage environment of changing pH, fuels, and end products.

Methods: Single-donor apheresis platelets collected in 100% plasma had small volumes removed to meet secondary processing requirements. Small volumes (23 ± 1.4 mL) were placed in 50-mL bags constructed of platelet storage material, stored 7 days, and assessed with a panel of in vitro assays. Platelet bioenergetics (oxygen consumption and acid production rates) were measured with a respirometer.

Results: The patterns of platelet pH decline, activation, and potency by thrombin generation were consistent with historical reports. Lactate production rates (54.1 ± 11.3 μmol/10¹²plt/h) were significantly correlated with pH decrease, increased activation, and thrombin generation potency by Day 7. Respirometry revealed a reduction of the glycolytic capacity and accumulating damage to the oxidative system for ATP production over storage.

Discussion: Small bags present a storage profile of metabolic changes and activation consistent with historical data for full bag storage. Therefore, this system has promise to provide a platform for scaling experiments of platelet storage in a manner that maximizes platelets collected in research settings and does not compromise availability for patient treatment as exercised in this study.