(P-BC-35) Implementation in France of a new method for cryopreserved platelets with minimal post-thaw processing.

Cryopreserved platelets is a component mostly used in case of fresh platelets shortage in overseas islands due to supply issues. The former process to produce cryopreserved platelets involved a centrifugation after thawing to remove the cryopreservation additive solution. Those post-thaw steps last at least 2 hours. To reduce this duration, EFS implemented a new platelet concentrate freezing method.

Study

Design/Methods:

The process which includes a centrifugation step before freezing the platelets and the addition of plasma, to resuspend the platelets and get a final volume suitable for transfusion, was assessed in 4 production sites for residual DMSO, platelet swirling, platelet content and recovery, Mean Platelets Volume (MPV) and pH at different steps: before freezing (T0), immediately after thawing (T1) and 6h after thawing (T2).

Results/Findings:

Results are described in table 1.
The method allow 77% recovery of platelets, show no significant difference in MPV and pH 6h after thawing. The pH is in accordance with French requirements. Mean residual DMSO is 0.8 ± 0.2 g per platelets concentrate (n=20), DMSO content is below the recommended limit of 10g per platelet concentrate⁽¹⁾ and below than the former method 3.5g+/1.3g (n=16). As with the previous method, platelet swirling index (SI) is weak in comparison with fresh platelets; however, SI is higher 6h after thawing than immediately after. The post thawing steps take less than 1h per platelets concentrate. 

 

Conclusions:

The new freezing method was successfully implemented in four production sites. This method allows an easier and quicker response to an emergency request of thawed platelets.