Cold-stored leukoreduced whole blood: Extending the time between donation and filtration has minimal impact on in vitro quality

Minimal impact of anticoagulant on in vitro whole blood quality throughout a 35-day cold-storage regardless of leukoreduction timing

BACKGROUND

There is increasing interest in leukoreduced whole blood (WB) as a transfusion product for trauma patients. In some jurisdictions, few leukoreduced filters are approved or appropriate for WB leukoreduction and quality information is therefore limited. This study assessed the impact of filtration timing of WB collected in CPDA-1 versus CPD on in vitro quality.

STUDY DESIGN AND METHODS

WB was collected in CPDA-1 or CPD and leukoreduction filtered either after 3-8 h (early) or 18-24 h (late) from stop bleed time. In vitro quality was assessed after filtration and throughout 5 weeks of storage at 4°C. Cell count and hemoglobin levels were determined by hematology analyzer, platelet activation and responsiveness to ADP by surface expression of P-selectin by flow cytometry, hemolysis by HemoCue, and metabolic parameters by blood gas analyzer. Hemostatic properties were assessed by rotational thromboelastometry. Plasma protein activities and clotting times were determined by automated coagulation.

RESULTS

Although there were some data points which showed statistically significant differences associated with anticoagulant choices or the filtration timing, no general trend in inferiority/performance could be discerned. After 35 days' storage, only clotting time, alpha angle and factor II in the early filtration arm comparing anticoagulants and prothrombin time and factor II in the CPDA-1 study arm comparing filtration timing showed a significant difference.

CONCLUSION

In vitro WB quality seems to be independent on the choice of anticoagulant and filtration timing supporting WB hold-times to up to 24 h, increasing operational flexibility for transfusion services.

Sangre total leucorreducida y filtro ahorrador de plaquetas preserva su función hemostática por 21 días: ¿La resucitación hemostática podría ser una realidad en Colombia?

Introducción. La resucitación hemostática es una estrategia para compensar la pérdida sanguínea y disminuir el impacto de la coagulación inducida por trauma. Debido a que la disponibilidad de transfundir una razón equilibrada de hemocomponentes es difícil de lograr en el entorno clínico, la sangre total ha reaparecido como una estrategia fisiológica, con ventajas logísticas, que le permiten ser accesible para iniciar tempranamente la resucitación hemostática. El objetivo de este estudio fue evaluar las propiedades celulares, coagulantes y viscoelásticas de la sangre total almacenada por 21 días. Métodos. Las unidades de sangre total fueron obtenidas de 20 donantes voluntarios sanos. Se procesaron mediante un sistema de leucorreducción ahorrador de plaquetas y fueron almacenadas en refrigeración (1-6°C) sin agitación. Se analizaron los días 0, 6, 11 y 21. Las bolsas fueron analizadas para evaluar las líneas celulares, niveles de factores de coagulación y propiedades viscoelásticas mediante tromboelastografía. Resultados. El conteo eritrocitario y la hemoglobina se mantuvieron estables. El conteo de plaquetas tuvo una reducción del 50 % al sexto día, pero se mantuvo estable el resto del seguimiento. Los factores de coagulación II-V-VII-X, fibrinógeno y proteína C se mantuvieron dentro del rango normal. La tromboelastografía mostró una prolongación en el tiempo del inicio de la formación del coágulo, pero sin alterar la formación final de un coágulo estable. Conclusiones. La sangre total leucorreducida y con filtro ahorrador de plaquetas conserva sus propiedades hemostáticas por 21 días. Este es el primer paso en Colombia para la evaluación clínica de esta opción, que permita hacer una realidad universal la resucitación hemostática del paciente con trauma severo.

Assessment of bacterial growth in leukoreduced cold-stored whole blood supports overnight hold at room temperature prior to filtration: A pilot study

BACKGROUND AND OBJECTIVES

Whole blood (WB) transfusion has regained attention to treat trauma patients. We reported no significant changes in in vitro quality through 21 days of cold storage for leukoreduced WB (LCWB) when time to filtration was extended from 8 to 24 h from collection. This study evaluated the impact of extended WB-hold at room temperature (RT) prior to leukoreduction on proliferation of transfusion-relevant bacteria.

MATERIALS AND METHODS

WB units were spiked with suspensions of Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Listeria monocytogenes prepared in saline solution (SS) or trypticase soy broth (TSB) to a concentration of ~0.2 CFU/ml (N = 6). Spiked units were held at RT for 18-24 h before leukoreduction and cold-stored for 21 days. Bacterial growth was determined on days 2, 7, 14 and 21. In vitro quality of WB inoculated with unspiked diluents was assessed.

RESULTS

K. pneumoniae and S. pyogenes proliferated in WB prior to leukoreduction reaching concentrations ≤10² CFU/ml. These bacteria, however, did not proliferate during the subsequent cold storage. S. aureus did not survive in WB while L. monocytogenes reached a concentration of ~10² CFU/ml by day 21. LCWB in vitro quality was not affected by SS or TSB.

CONCLUSION

Extended WB-hold prior to leukoreduction allowed proliferation of bacteria able to resist immune clearance, although they did not grow to clinically significant levels. While L. monocytogenes proliferated in LCWB, clinically relevant concentrations were not reached by day 21. These data suggest that transfusing LCWB may not pose a significant bacterial contamination safety risk to transfusion patients.