Plasma and Plasma Protein Product Transfusion: A Canadian Blood Services Centre for Innovation Symposium

The effect of convalescent plasma therapy on the rate of nucleic acid negative conversion in patients with persistent COVID-19 test positivity

Objective

This study investigates the association between convalescent plasma therapy and the negative conversion rate in patients with persistent COVID-19 test positivity.

Method

A retrospective analysis was conducted on patients with severe or mild to moderate COVID-19 whose viral nucleic acid tests remained positive for over 30 days. Patients were categorized into two groups: those who administered convalescent plasma therapy and those who were not. Data collected included information on therapy strategies used (convalescent plasma, corticosteroids, interferons, etc.), patients' demographic characteristics, comorbidities, therapeutic medications, and nucleic acid testing results. Patients in the convalescent plasma therapy group were matched 1:2 ratio with those in the non-convalescent plasma therapy group. Cumulative negative conversion rates on the fifth, tenth, and fifteenth days post-therapy initiation were analyzed as dependent variables. Independent variables included therapy strategies, demographic characteristics, comorbidities, and therapeutic medication usage. Univariate analysis was conducted, and factors with a p-value (P) less than 0.2 were included in a paired Cox proportional hazards model.

Results

There was no statistically significant difference in the cumulative negative conversion rate between the convalescent plasma therapy group and the non-convalescent plasma therapy group on the fifth, tenth, and fifteenth days. Specifically, on day the fifth, the negative conversion rate was 41.46% in the convalescent plasma therapy group compared to 34.15% in the non-convalescent plasma therapy group (HR: 1.72, 95% CI: 0.82-3.61, P = 0.15). On the tenth day, it was 63.41% in the convalescent plasma therapy group and 63.41% in the non-convalescent plasma therapy group (HR: 1.25, 95% CI: 0.69∼2.26, P = 0.46). On the fifteenth day, the negative conversion rate was 85.37% in the convalescent plasma therapy group and 75.61% in the non-convalescent plasma therapy group (HR: 1.19, 95% CI: 0.71-1.97, P = 0.51).

Conclusion

Our finding does not support the hypothesis that convalescent plasma therapy could accelerate the time to negative conversion in patients who consistently test positive for COVID-19.

A Concise Synopsis of Current Literature and Guidelines on the Practice of Plasma Transfusion

Evidence-based indications for plasma transfusion are limited, and much of the clinical practice relies on expert opinion. This article highlights key studies, meta-analyses, and guidelines for plasma transfusion in adults. The goal is to limit non-evidence-based plasma transfusion that is outside of clinical guideline, because as with all transfusions, the administration of plasma is not without risk. Any intended potential benefit must be appraised against the real risks associated with transfusion. Moving forward, the practice of plasma transfusion would benefit greatly from randomized controlled trials to update and expand the existing guidelines.

Red blood cells, still vital after all these years: Commentary on Canadian Blood Services' International Symposium 2017

Canadian Blood Services (CBS), Canada's national blood transfusion service, has for many years sponsored an annual conference, for the education and awareness of interested participants, showcasing the latest evidence-based understanding of both basic science and clinical issues in transfusion medicine and science. The 15th iteration of this symposium took place September 9, 2017 and focused on some of the vital aspects of red blood cells (RBC), in line with the" 3Rs" concept, namely the provision of the Right red blood cell (RBC) product to the Right patient at the Right time. Presentations touched upon: the evolution of blood banking in North America; the monocyte monolayer assay as a predictor of post-transfusion hemolysis; hemoglobin-based oxygen carriers; RBC alloimmunization; serological approaches to complex RBC antibody problems; randomized clinical trials related to the age of stored RBC; RBC genotyping; pathophysiology, prevention and treatment of hemolytic disease of the fetus and newborn (HDFN); and testing and timing in perinatal serology. This commentary provides summaries of all speakers' presentations annotated with relevant references. Special thanks are due to all contributors for their praiseworthy approaches in sharing their experiences and knowledge on this interesting scientific/clinical and management theme.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Blood-Borne Pathogens: A Canadian Blood Services Centre for Innovation Symposium

Testing donations for pathogens and deferring selected blood donors have reduced the risk of transmission of known pathogens by transfusion to extremely low levels in most developed countries. Protecting the blood supply from emerging infectious threats remains a serious concern in the transfusion medicine community. Transfusion services can employ indirect measures such as surveillance, hemovigilance, and donor questioning (defense), protein-, or nucleic acid based direct testing (detection), or pathogen inactivation of blood products (destruction) as strategies to mitigate the risk of transmission-transmitted infection. In the North American context, emerging threats currently include dengue, chikungunya, and hepatitis E viruses, and Babesia protozoan parasites. The 2003 SARS and 2014 Ebola outbreaks illustrate the potential of epidemics unlikely to be transmitted by blood transfusion but disruptive to blood systems. Donor-free blood products such as ex vivo generated red blood cells offer a theoretical way to avoid transmission-transmitted infection risk, although biological, engineering, and manufacturing challenges must be overcome before this approach becomes practical. Similarly, next generation sequencing of all nucleic acid in a blood sample is currently possible but impractical for generalized screening. Pathogen inactivation systems are in use in different jurisdictions around the world, and are starting to gain regulatory approval in North America. Cost concerns make it likely that pathogen inactivation will be contemplated by blood operators through the lens of health economics and risk-based decision making, rather than in zero-risk paradigms previously embraced for transfusable products. Defense of the blood supply from infectious disease risk will continue to require innovative combinations of surveillance, detection, and pathogen avoidance or inactivation.

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A symposium on blood-borne pathogens was held September 26, 2015, in Toronto, Canada.

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Transmission-transmitted infections remain a threat to the blood supply.

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The residual risk from established pathogens is small; emerging agents are a concern.

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Next generation sequencing and donor-free blood are not yet practical approaches.

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Pathogen inactivation technology is being increasingly used around the world.

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Health economic concerns will likely guide future advances in this area.