The role of sodium citrate during extended cold storage of platelets in platelet additive solutions

Abstract

Background Cold‐stored platelets are increasingly being used to treat bleeding. Differences in manufacturing processes and storage solutions can affect platelet quality and may influence the shelf life of cold‐stored platelets. PAS‐E and PAS‐F are approved platelet additive solutions (PAS) in Europe and Australia, or the United States respectively. Comparative data are required to facilitate international transferability of laboratory and clinical data. Study Design and Methods Single apheresis platelets from matched donors (n = 8) were collected using the Trima apheresis platform and resuspended in either 40% plasma/60% PAS‐E or 40% plasma/60% PAS‐F. In a secondary study, platelets in PAS‐F were supplemented with sodium citrate, to match the concentration in PAS‐E. Components were refrigerated (2–6°C) and tested over 21 days. Results Cold‐stored platelets in PAS‐F had a lower pH, a greater propensity to form visible (and micro‐) aggregates, and higher activation markers compared to PAS‐E. These differences were most pronounced during extended storage (14–21 days). While the functional capacity of cold‐stored platelets was similar, the PAS‐F group displayed minor improvements in ADP‐induced aggregation and TEG parameters (R‐time, angle). Supplementation of PAS‐F with 11 mM sodium citrate improved the platelet content, maintained the pH above specifications and prevented aggregate formation. Discussion In vitro parameters were similar during short‐term cold storage of platelets in PAS‐E and PAS‐F. Storage in PAS‐F beyond 14 days resulted in poorer metabolic and activation parameters. However, the functional capacity was maintained, or even enhanced. The presence of sodium citrate may be an important constituent in PAS for extended cold storage of platelets.

Bacterial Contamination of Platelet Products

“…Nevertheless, implementation and usage of these units may not decrease the platelet product wastage at the destination facility [ 73 ]. Use of sodium citrate as a buffer in the platelet additive solution maintains the activity of cold stored platelet concentrates without sacrificing yield [ 74 ]. Perhaps the one variable to be considered in these platelet units is that body mass index (BMI) influences the degree of activation since donors with higher BMI had platelets with a lower activation capability and lower overall platelet numbers after cold storage and subsequent transfusion [ 75 ].…”

In vitro Hemostatic Functions of Cold-Stored Platelets

“…In summary, despite all efforts made in the last decades, it is still difficult to draw a final conclusion on the impact of cold storage on platelet functions since the information obtained from different studies are limited to the specific platelet preparation procedure, product composition (like plasma volume or additive solutions) and storage condition used for performing the study. In Tables 1 and 2, we reported the most common sources of platelets as well as additive solutions used for PCs, respectively [44‒52]. In this context, a global standardization of all steps involved in both processes, production and storage, might be extremely helpful to clarify the discrepancies observed until now and take the final decision on the use of CSPs for clinical application.…”