Effect of bedside filtration on aggregates from cold‐stored whole blood–derived platelet‐rich plasma and apheresis platelet concentrates

Abstract

Background The current approach to manufacture cold‐stored platelets (CSP) replicates that of room temperature–stored platelets (RSP). However, this production method is associated with aggregate formation in CSP, a major pitfall that leads to significant wastage. We hypothesized that isolating platelets from whole blood as platelet‐rich plasma (PRP) and storing them at a lower concentration reduces aggregates and that conventional bedside transfusion filtration removes CSP aggregates. Methods We collected platelets from healthy humans by apheresis (AP) and by phlebotomy, from which we generated platelet‐rich plasma (PRP). We split each AP and PRP platelets into two equal aliquots, storing one at 22°C (RT‐PRP and RT‐AP) and the other at 4°C (4C‐PRP and 4C‐AP). We evaluated platelets on day 0 and day 7 of storage. After storage, we measured platelet counts, aggregates, and other key characteristics before and after filtration by a bedside filter. Results After storage, the 4C‐AP platelet counts decreased significantly. 4C‐PRP preserved glucose better and prevented a significant increase in lactate contrary to 4C‐AP. Filtration led to significantly lower platelet counts in both 4C‐PRP and 4C‐AP but not in their RT counterparts. Post filtration, we observed 50% fewer aggregates only in 4C‐AP, whereas 4C‐PRP showed an unexpected but significant increase in aggregates. Testing confirmed activation during storage but filtration did not further activate platelets. Conclusion We provide evidence that 4C‐PRP is an alternative to 4C‐AP and that bedside filters reduce aggregates from 4C‐AP. Further studies are needed to evaluate the hemostatic potential of 4C‐PRP and the management of aggregates.

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

“…There is also a lack of international consensus regarding acceptability of components containing aggregates (in the context of RT storage), where some institutes issue components containing low numbers of and/or small aggregates 49 . The rationale supporting this approach is that the aggregates would be removed at the time of transfusion by the bedside filter; 49 which has recently been shown to be appropriate for cold‐stored apheresis platelet components 50 . In contrast, other institutes, including Lifeblood, do not issue platelet components containing visible aggregates 49 .…”

“…49 The rationale supporting this approach is that the aggregates would be removed at the time of transfusion by the bedside filter; 49 which has recently been shown to be appropriate for cold-stored apheresis platelet components. 50 In contrast, other institutes, including Lifeblood, do not issue platelet components containing visible aggregates. 49 Clearly, more research is required to understand the significance of aggregates, particularly in the context of cold-stored platelets.…”

Cold temperature induces a TRPM8-independent calcium release from the endoplasmic reticulum in human platelets

“…We employed a gating strategy that excluded the TRPM8 (FITC) intensity of the unstained ( Fig 2A ) and secondary-only control samples ( Fig 2B ), to identify the TRPM8-positive population ( Fig 2C ). The samples were run on Amnis Imagestream Mk II (Luminex Corp, Austin, TX) image flow cytometer as described before [ 55 , 56 ]. Briefly, the samples were acquired using the 60X magnitude objective and the following channels: the bright field (Ch01), the SSC (Ch06), FITC (Ch02), and APC (Ch11).…”

Cold temperature induces a TRPM8-independent calcium release from the endoplasmic reticulum in human platelets

“…We employed a gating strategy that excluded the TRPM8 (FITC) intensity of the unstained (Figure 2 A) and secondary-only control samples (Figure 2 B), to identify the TRPM8-positive population (Figure 2 C). The samples were run on Amnis Imagestream Mk II (Luminex Corp, Austin, TX) image flow cytometer as described before (55) (56). Briefly, the samples were acquired using the 60X magnitude objective and the following channels: the bright field (Ch01), the SSC (Ch06), FITC (Ch02), and APC (Ch11).…”