Post‐transfusion recovery of function of 5‐day stored platelet concentrates

Abstract

Platelets show a rapid reduction in their responsiveness to aggregating agents during storage for transfusion, but little is known about reversal of this defect in vivo after transfusion. In this study, fresh and stored platelets from the same donor (n = 12) were labelled with 111In or 51Cr, respectively, mixed, and simultaneously infused. Blood samples were taken for up to 5 d post-infusion, and the functional behaviour of the labelled platelets ex vivo was measured by retention on glass bead columns, and by whole blood aggregability to ADP, epinephrine and ristocetin. Aggregation was determined by filtering aggregated samples through a column of cotton wool to remove the aggregates, and quantitated as per cent decrease in radioactive counts. The study showed that, although infused radiolabelled 5 d stored platelets had a significantly lower aggregability towards ADP and epinephrine immediately (1 h) after infusion (32% and 29%, respectively, of fresh platelet values), a complete restoration to fresh platelet levels was found 24-72 h post-infusion, with no further change observed over the ensuing 5 d with either fresh or stored labelled platelets. A slightly (6-9%) lower adhesion to both uncoated and collagen-coated beads was found for the stored platelets throughout the 5 d period of study post-infusion. In conclusion, these studies show that, with ex vivo testing, platelets stored for 5 d quickly recovered adhesion and aggregability capabilities similar to that of fresh platelets, suggesting that the functional lesion developed during storage is quickly and completely reversed after infusion.

The storage lesion of platelets: ultrastructural and functional aspects

“…A desensitization of the signal transduction pathways and lack of as yet unidentified components from the blood plasma are presumed to be responsible for these defects [20,70]. In several experiments, the addition of fresh plasma immediately prior to the in vitro function tests was found to improve the reactivity of stored platelets to weak agonists [20,63]. Besides serving as a simple energy supply, the fresh plasma might have compensated for the above-mentioned unidentified components that had been lost during storage.…”

“…Finally, the partial reversibility of the storage lesion should be stressed again: Addition of fresh plasma after storage results in improved reactivity in in vitro stimulation tests [20,70], and transfused platelets that were stored for 5 days recover aggregation characteristics similar to those of fresh platelets 24-71 h after transfusion [63]. Additionally, endocytosis of a variety of substances from the blood plasma and their incorporation into storage granules may restore the contents of the storage compartments after transfusion [30-33, 43, 89], thereby allowing the stored platelets to regain relatively normal function after transfusion [73].…”

Refrigeration and cryopreservation of platelets differentially affect platelet metabolism and function: a comparison with conventional platelet storage conditions

“…35 While this differential aggregation response is interesting, the value of these results for predicting transfusion outcomes remains to be established, as in vitro PLT function, particularly ADP responsiveness, appears to "recover" upon transfusion. [60][61][62] As such, TEG was used to provide a more global measure of hemostasis. The MA (clot strength) provides information on the functional contribution of PLTs.…”

Enhanced platelet responsiveness due to chilling and its relation to CD40 ligand level and platelet–leukocyte aggregate formation

“…These results are consistent with the findings of PRP and whole blood aggregation, and release reaction in response to ADP, suggesting that the cold temperature of 48C enhances the responsiveness of platelet for agonists. This may be supported by several studies performed by keeping platelets at cold temperature [4,34,35].…”