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

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.

Past meets present: Reviving 80-year-old Canadian dried serum from World War II and its significance in advancing modern freeze-dried plasma for prehospital management of haemorrhage

During World War II, Charles H. Best utilized Charles R. Drew's plasma isolation and drying technique to lead Canada's initiative to provide dried serum as a means of primary resuscitation for British casualties on the frontlines. Serum was likely utilized over plasma for its volume expansion properties without the risk of clotting during prolonged storage. We reconstituted dried serum from 1943 and discovered intact albumin, as well as anti-thrombin, plasminogen, protein C and protein S activity. Proteomic analysis identified 71 proteins, most prominent being albumin, and positive for hepatitis B by serological testing. Transmission of blood-borne diseases ended the programme, until modern advances in testing and pathogen reduction revived this technology. We tested the latest iteration of Canadian freeze-dried plasma (FDP), which was stored for 4 years, and demonstrated that its clotting capacity remained equivalent to fresh frozen plasma. We recommend that FDP is a strong alternative to contemporary prehospital resuscitation fluids (e.g. normal saline/lactated Ringer's) in managing prehospital haemorrhage where whole blood is unavailable.

Plasma: indications, controversies, and opportunities

Plasma is overused as a blood product worldwide; however, data supporting appropriate use of plasma is scant. Its most common utilization is for treatment of coagulopathy in actively bleeding patients; it is also used for coagulation optimization prior to procedures with specific coagulation profile targets. A baseline literature review in PUBMED and Google Scholar was done (1 January 2000 to 1 June 2023), utilizing the following search terms: plasma, fresh frozen plasma, lyophilized plasma, indications, massive transfusion protocol, liver disease, warfarin reversal, cardiothoracic surgery, INR < 2. An initial review of the titles and abstracts excluded all articles that were not focused on transfusional medicine. Additional references were obtained from citations within the retrieved articles. This narrative review discusses the main indications for appropriate plasma use, mainly coagulation factor replacement, major hemorrhage protocol, coagulopathy in liver disease, bleeding in the setting of vitamin K antagonists, among others. The correlation between concentration of coagulation factors and INR, as well as the proper plasma dosing with its volume being weight-based, is also discussed. A high value approach to plasma utilization is supported with a review of the clinical situations where plasma is overutilized or unnecessary. Finally, a discussion of novel plasma products is presented for enhanced awareness.

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.

Novel blood derived hemostatic agents for bleeding therapy and prophylaxis

PURPOSE OF REVIEW

Hemorrhage is a major cause of preventable death in trauma and cancer. Trauma induced coagulopathy and cancer-associated endotheliopathy remain major therapeutic challenges. Early, aggressive administration of blood-derived products with hypothesized increased clotting potency has been proposed. A series of early- and late-phase clinical trials testing the safety and/or efficacy of lyophilized plasma and new forms of platelet products in humans have provided light on the future of alternative blood component therapies. This review intends to contextualize and provide a critical review of the information provided by these trials.

RECENT FINDINGS

The beneficial effect of existing freeze-dried plasma products may not be as high as initially anticipated when tested in randomized, multicenter clinical trials. A next-generation freeze dried plasma product has shown safety in an early phase clinical trial and other freeze-dried plasma and spray-dried plasma with promising preclinical profiles are embarking in first-in-human trials. New platelet additive solutions and forms of cryopreservation or lyophilization of platelets with long-term shelf-life have demonstrated feasibility and logistical advantages.

SUMMARY

Recent trials have confirmed logistical advantages of modified plasma and platelet products in the treatment or prophylaxis of bleeding. However, their postulated increased potency profile remains unconfirmed.