Time from apheresis platelet donation to cold storage: Evaluation of platelet quality and bacterial growth

Abstract

Background Cold storage reduces posttransfusion survival of platelets; however, it can improve platelet activation, lower risk of bacterial contamination, and extend shelf‐life compared to room temperature (RT) storage. To facilitate large‐scale availability, manufacturing process optimization is needed, including understanding the impact of variables on platelet potency and safety. Short time requirements from collection to storage is challenging for large blood centers to complete resuspension and qualify platelets for production. This study evaluated the impact of time from platelet component collection to cold storage on in vitro properties and bacterial growth. Study design and methods Double‐apheresis platelet components were collected from healthy donors, suspended in 65% PAS‐III/35% plasma, and split into 2 equal units. One unit was placed into cold storage within 2 h and the other unit after 8 h. Eight matched pairs were evaluated for 12 in vitro parameters. Twenty‐four matched pairs were evaluated with 8 bacterial strains tested in triplicate. Samples were tested throughout 21 days of storage. Results In vitro properties were not different between 2 and 8 h units, and trends throughout storage were similar between arms. Time to cold storage did not significantly impact bacterial growth, with <1 log10 difference at all timepoints between units. Discussion Our studies showed that extending time to cold storage from 2 to 8 h from collection did not significantly increase the bacterial growth, and the platelet component quality and function is maintained. The ability to extend the time required from collection to storage will improve blood center logistics to feasibly produce CSPs.

Gamma and X‐ray irradiation do not affect the in vitro quality of refrigerated apheresis platelets in platelet additive solution (PAS‐E)

“…This timeframe is considered acceptable to balance logistics, while minimizing the potential for bacterial growth and maintaining platelet quality parameters. 45 Furthermore, to align with our current practices for bacterial contamination screening, irradiation was applied once the platelets had been in the refrigerator for 2 days (at least 36 h from collection), rather than prior to refrigeration. While the intent was not to specifically warm the platelets prior to irradiation, the platelets were out of the fridge for approximately 35 min, as both irradiation and bacterial contamination sampling was performed together.…”

“…The platelet components were transported from our metropolitan donation centers to the processing center and refrigerated within 8 h of collection. This timeframe is considered acceptable to balance logistics, while minimizing the potential for bacterial growth and maintaining platelet quality parameters 45 . Furthermore, to align with our current practices for bacterial contamination screening, irradiation was applied once the platelets had been in the refrigerator for 2 days (at least 36 h from collection), rather than prior to refrigeration.…”

Postoperative Transfusions after Administration of Delayed Cold-stored Platelets versus Room Temperature Platelets in Cardiac Surgery: A Retrospective Cohort Study

“…5–7,19 In addition, cold-stored platelets appear to be more resistant to bacterial growth than room temperature platelets up to 21 days of cold storage. 2,20,21 These properties have led to a growing interest in apheresis- derived cold-stored platelet concentrates in bleeding patients (mostly trauma), since the introduction of a Food and Drug Administration variance in 2015 and a renewed interest in studying their clinical efficacy and safety in actively bleeding patients in other clinical areas. 12,17,18…”

“…[5][6][7]19 In addition, cold-stored platelets appear to be more resistant to bacterial growth than room temperature platelets up to 21 days of cold storage. 2,20,21 These properties have led to a growing interest in apheresis-derived cold-stored platelet concentrates in bleeding patients (mostly trauma), since the introduction of a Food and Drug Administration variance in 2015 and a renewed interest in studying their clinical efficacy and safety in actively bleeding patients in other clinical areas. 12,17,18 Although few studies have evaluated cold-stored platelets clinically, those that have generally demonstrate comparable early post-transfusion efficacy in actively bleeding patients with no significant safety concerns and consistently demonstrate a decreased post-transfusion circulation time.…”

Cold storage alters the immune characteristics of platelets and potentiates bacterial‐induced aggregation

“…Additionally, cold-stored platelets have been approved for limited use by the US Food and Drug Administration (FDA) [1,2], and delayed cold storage has been implemented in some blood centres to counter pandemic-induced shortages [3]. Overall, cold storage better preserves the in vitro haemostatic function of platelets and lowers the risk of bacterial proliferation [4,5], compared to conventional roomtemperature (RT) storage [6][7][8][9][10][11].…”