(P-BC-36) Implementation in France of an alternative method for producing Plasma, Fresh Frozen, Pathogen-Reduced (PR)with previously thawed plasma.

Background/Case Studies: Plasma, Fresh Frozen, Pathogen-Reduced (PR) is prepared from pools of 5 ABO identical whole blood
donations using amotosalen/UVA light (INTERCEPT™ Blood System) pathogen inactivation. This process requires the
use of fresh plasma derived from whole blood and to perform pooling, PR and freezing within a timeframe of 19 hours
after collection. It’s challenging to get enough ABO identical donations, especially for the AB group.To overcome this time
restriction and to produce more AB units, EFS implement an alternative method authorized by ANSM in January 2022.

Study

Design/Methods: This study aims to assess impact on coagulation factors in the plasma pools during the implementation of this alternative process.
This method consists in freezing the plasma within 24 hours of collection, then after a storage period at a
temperature < - 25 ° C not exceeding 34 weeks, to carry out rapid thawing. A pooling step of 5 ABO identical plasma is
added and treatment with amotosalen and UVA occurred. Then plasmas are refreezing, within 6h after thawing, for
storage < -25°C. Only group A, B and AB plasmas are concerned. After storage period, plasmas are thawed and pooled
then coagulation factors are measured (n=90) before (T1), and after PR and refreezing/additional storage/ thawing step
(T2; plasma ready for issuing and transfusion).

Results/Findings: As expected, a decrease in coagulation factors between T1 and T2 is noticed (table 1). The final plasmas, ready
for issuing and transfusion, contains a mean of 74% of initial FVIII and 88% of initial fibrinogen. However, both FVIII and
fibrinogen for all units remain above French requirements.

Table 1: plasmas results (n=90)

Coagulation factors requirements N=90	Pool of thawed plasma, before PR (T1)	Plasma, Fresh Frozen, PR after 1 to 14 days of storage at ≤-25°C (T2)	Percentage of retention
FVIII (IU/ml) Spec. ≥ 0.50 UI/ml (for >70% of units)	1.05 ± 0.15	0.78 ± 0.12	74 ± 4%
Fibrinogen (g/L) Spec. ≥ 2.0 g/L (for >70% of units)	2.86 ± 0.26	2.54 ± 0.23	88 ± 3%

Conclusions: The new method is successfully implemented in three production sites and will allow to
increase EFS stock in AB pooled Fresh Frozen, Pathogen-Reduced (PR) Plasma. Even if the method includes a thawing
step, plasmas are in accordance with the quality requirements and it allows a more efficient organization for production.
However, this method is not validated for group O plasma which implies to maintain two production lines.