Post-expiry stability of freeze-dried plasma under field conditions - Can shelf life be extended?

Dried Plasma for Major Trauma: Past, Present, and Future

Uncontrollable bleeding is recognized as the leading cause of preventable death among trauma patients. Early transfusion of blood products, especially plasma replacing crystalloid and colloid solutions, has been shown to increase survival of severely injured patients. However, the requirements for cold storage and thawing processes prior to transfusion present significant logistical challenges in prehospital and remote areas, resulting in a considerable delay in receiving thawed or liquid plasma, even in hospitals. In contrast, freeze- or spray-dried plasma, which can be massively produced, stockpiled, and stored at room temperature, is easily carried and can be reconstituted for transfusion in minutes, provides a promising alternative. Drawn from history, this paper provides a review of different forms of dried plasma with a focus on in vitro characterization of hemostatic properties, to assess the effects of the drying process, storage conditions in dry form and after reconstitution, their distinct safety and/or efficacy profiles currently in different phases of development, and to discuss the current expectations of these products in the context of recent preclinical and clinical trials. Future research directions are presented as well.

Post-Reconstitution Hemostatic Stability Profiles of Canadian and German Freeze-Dried Plasma

Despite the importance of the hemostatic properties of reconstituted freeze-dried plasma (FDP) for trauma resuscitation, few studies have been conducted to determine its post-reconstitution hemostatic stability. This study aimed to assess the short- (≤24 h) and long-term (≥168 h) hemostatic stabilities of Canadian and German freeze-dried plasma (CFDP and LyoPlas) after reconstitution and storage under different conditions. Post-reconstitution hemostatic profiles were determined using rotational thromboelastometry (ROTEM) and a Stago analyzer, as both are widely used as standard methods for assessing the quality of plasma. When compared to the initial reconstituted CFDP, there were no changes in ROTEM measurements for INTEM maximum clot firmness (MCF), EXTEM clotting time (CT) and MCF, and Stago measurements for prothrombin time (PT), partial thromboplastin time (PTT), D-dimer concentration, plasminogen, and protein C activities after storage at 4 °C for 24 h and room temperature (RT) (22-25 °C) for 4 h. However, an increase in INTEM CT and decreases in fibrinogen concentration, factors V and VIII, and protein S activities were observed after storage at 4 °C for 24 h, while an increase in factor V and decreases in antithrombin and protein S activities were seen after storage at RT for 4 h. Evaluation of the long-term stability of reconstituted LyoPlas showed decreased stability in both global and specific hemostatic profiles with increasing storage temperatures, particularly at 35 °C, where progressive changes in CT and MCF, PT, PTT, fibrinogen concentration, factor V, antithrombin, protein C, and protein S activities were seen even after storage for 4 h. We confirmed the short-term stability of CFDP in global hemostatic properties after reconstitution and storage at RT, consistent with the shelf life of reconstituted LyoPlas. The long-term stability analyses suggest that the post-reconstitution hemostatic stability of FDP products would decrease over time with increasing storage temperature, with a significant loss of hemostatic functions at 35 °C compared to 22 °C or below. Therefore, the shelf life of reconstituted FDP should be recommended according to the storage temperature.

Whole blood administration within USCENTCOM

Introduction

Blood product use by the U.S. military has evolved during the conflicts in the U.S. Central Command's area of responsibility to become the preferred resuscitative fluid for damage control procedures. This study evaluates the transition to a whole blood-based trauma system over the past 5 years.

Methods

Patients who received blood product transfusion within USCENTCOM between January 1, 2017, and December 31, 2021, were identified from the Medical Situational Awareness in Theater (MSAT) blood reports. Transfusion recipients were categorized as recipients of whole blood only, component therapy only, or mixed therapy. The type of transfusions, number of recipients, number of available blood products were compared over the 5-year period.

Results

A total of 1762 unique patients were included. Of this population, 220 (12.5%) received whole blood only, 1196 (68.9%) received component therapy, and 346 (19.6%) received mixed therapy. The monthly proportion of individuals receiving whole blood (only or mixed) significantly increased over the 5-year period ( p < .0001). The number of individuals requiring transfusions over this same period decreased significantly ( p < .0001). Individuals receiving component therapy (only or mixed) were transfused component platelets 15.7% of the time. The mean and median number of units required per patient receiving whole blood was 2.39 and 1 unit of blood respectively (IQR 1.0–2.5).

Conclusion

Whole blood use increased significantly within USCENTCOM's AOR secondary to increased supply and low clinical requirement. Without a long-lasting platelet component, component therapy cannot be expected to provide a balanced therapy to casualties in remote locations.

Preserved SARS-CoV-2 neutralizing IgG activity of in-house manufactured COVID-19 convalescent plasma

PURPOSE

In the current study, we aimed to evaluate the neutralizing IgG activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as the coagulation factors of convalescent plasmas which we manufactured in-house without a fast-freezing technique.

METHODS

We collected plasmas from eligible participants who had confirmed certain titers of neutralizing antibodies. The plasmas were frozen and stored in the ordinary biofreezer without a fast-freezing function. The purified-IgG neutralizing activity of 20 samples from 19 participants and the coagulation factors of 49 samples from 40 participants were evaluated before and after freezing.

RESULTS

Purified-IgG maintained its neutralizing activities, with the median 50 % inhibitory concentration (IC50) of 10.11 mg/ml (IQR 6.53-18.19) before freezing and 8.90 m g/ml (IQR 6.92-28.27) after thawing (p = 0.956). On the contrary, fibrinogen and factor Ⅷ decreased significantly after freezing and thawing in our environment. No significant temperature deviation was observed during the storage period.

CONCLUSION

Neutralizing IgG activity, which largely contributes to the antiviral activity of convalescent plasma, did not change through our in-house manufacturing, without fastfreezing and storage conditions for more than 200 days. Ordinary freezers without the fast-freezing function are suitable enough to manufacture and store convalescent plasmas. Hospitals or facilities without specified resources could easily collect and store convalescent plasmas in case of upcoming emerging or re-emerging infectious diseases on-demand with appropriate neutralizing antibody levels measurements.

Use of Dried Plasma in Prehospital and Austere Environments

More than 1,000,000 units of lyophilized plasma have been used in France, Germany, and South Africa. Recently, numerous other countries have adopted lyophilized plasma for patients with severe bleeding in prehospital and austere settings.

Retention of hemostatic and immunological properties of frozen plasma and COVID-19 convalescent apheresis fresh-frozen plasma produced and freeze-dried in Canada

BACKGROUND

Randomized clinical trial data show that early plasma transfusion may save lives among trauma patients. Supplying plasma in remote environments is logistically challenging. Freeze-dried plasma (FDP) offers a possible solution.

STUDY DESIGN AND METHODS

A Terumo BCT plasma freeze-drying system was evaluated. We compared pooled frozen plasma (FP) units with derived Terumo BCT FDP (TFDP) units and pooled COVID-19 convalescent apheresis fresh-frozen plasma (CC-AFFP) with derived CC-TFDP units. Parameters measured were: coagulation factors (F) II; V; VII; VIII; IX; XI; XIII; fibrinogen; Proteins C (PC) and S (PS); antithrombin (AT); α₂ -antiplasmin (α₂ AP); ADAMTS13; von Willebrand Factor (vWF); thrombin-antithrombin (TAT); D-dimer; activated complement factors 3 (C3a) and 5 (C5a); pH; osmolality; prothrombin time (PT); and activated partial thromboplastin time (aPTT). Antibodies to SARS-CoV-2 in CC-AFFP and CC-TFDP units were compared by plaque reduction assays and viral protein immunoassays.

RESULTS

Most parameters were unchanged in TFDP versus FP or differed ≤15%. Mean aPTT, PT, C3a, and pH were elevated 5.9%, 6.9%, 64%, and 0.28 units, respectively, versus FP. CC-TFDP showed no loss of SARS-CoV-2 neutralization titer versus CC-AFFP and no mean signal loss in most pools by viral protein immunoassays.

CONCLUSION

Changes in protein activities or clotting times arising from freeze-drying were <15%. Although C3a levels in TFDP were elevated, they were less than literature values for transfusable plasma. SARS-CoV-2-neutralizing antibody titers and viral protein binding levels were largely unaffected by freeze-drying. In vitro characteristics of TFDP or CC-TFDP were comparable to their originating plasma, making future clinical studies appropriate.

Ex vivo hemostatic and immuno-inflammatory profiles of freeze-dried plasma

BACKGROUND

Hemorrhage is a leading cause of preventable death in civilian and military trauma. Freeze-dried plasma is promising for hemostatic resuscitation in remote prehospital settings, given its potential benefits in reducing blood loss and mortality, long storage at ambient temperatures, high portability, and rapid reconstitution for transfusion in austere environments. Here we assess the ex vivo characteristics of a novel Terumo's freeze-dried plasma product (TFDP).

STUDY DESIGN AND METHODS

Rotational thromboelastometry (ROTEM) tests (INTEM, EXTEM, and FIBTEM) were conducted on plasma samples at 37°C with a ROTEM delta-machine using standard reagents and procedures. The following samples were analyzed: pooled plasma to produce TFDP, TFDP reconstituted, and stored immediately at -80°C, reconstituted TFDP stored at 4°C for 24 h and room temperature (RT) for 4 h before freezing at -80°C. Analysis of plasma concentrations of selected cytokines, chemokines, and vascular molecules was performed using a multiplex immunoassay system. One-way ANOVA with post hoc tests assessed differences in hemostatic and inflammatory properties.

RESULTS

No significant differences in ROTEM variables (coagulation time [CT], clot formation time, α-angle, maximum clot firmness, and lysis index 30) between the TFDP-producing plasma and reconstituted TFDP samples were observed. Compared to control plasma, reconstituted TFDP stored at 4°C for 24 h or RT for 4 h showed a longer INTEM CT. Levels of immuno-inflammatory mediators were similar between frozen plasma and TFDP.

CONCLUSIONS

TFDP is equivalent to frozen plasma with respect to global hemostatic and immuno-inflammatory mediator profiles. Further investigations of TFDP in trauma-induced coagulopathy models and bleeding patients are warranted.