ABSTRACT
Albumin solutions derived from human plasma have demonstrated clinical benefit as intravenous fluid therapy in clinical settings such as liver disease, sepsis, intensive care, and surgery. For all plasma-derived medicinal products, there is potential risk from pathogens, including relevant blood-borne viruses, emerging viruses, and prion proteins. To minimize the risk of transmissible infections, production of human albumin solutions includes rigorous donor selection and plasma testing, and effective pathogen removal and inactivation methods such as fractionation and pasteurization. Compliance with international pharmacopeial standards for purity and prekallikrein activator and aluminum content are crucial, as is post-marketing pharmacovigilance for the continuous monitoring of adverse events. This review focuses on the effectiveness of manufacturing methods in the production of plasma-derived albumin, to ensure the safety of hyperoncotic solutions for volume expansion. We evaluated evidence identified through online database (PubMed) searches and from unpublished sources, on the manufacturing and pathogen safety of plasma-derived albumin solutions. The results confirmed the already established and evolving pathogen reduction capacity of the reviewed manufacturing methods. Up to date post-marketing pharmacovigilance data and log10 reduction factors for known and emerging pathogens during albumin production are included. Towards the goal of ever-increasing clinical safety, potential areas of improvement, such as compliance rates for completion of donor health questionnaires, are also discussed. Taken together, the current manufacturing and pathogen reduction steps result in albumin products of greater purity than previous-generation products, with a high margin of pathogen safety against known and emerging pathogens, such as severe acute respiratory syndrome-associated coronavirus 2.
ABSTRACT
Analysis of convalescent plasma derived from individuals has shown that IgG3 has the most important role in binding to SARS-CoV-2 antigens; however, this has not yet been confirmed in large studies, and the link between binding and neutralization has not been confirmed. By analyzing plasma pools consisting of 247-567 individual convalescent donors, we demonstrated the binding of IgG3 and IgM to Spike-1 protein and the receptor-binding domain correlates strongly with viral neutralization in vitro. Furthermore, despite accounting for only approximately 12% of total immunoglobulin mass, collectively IgG3 and IgM account for approximately 80% of the total neutralization. This may have important implications for the development of potent therapies for COVID-19, as it indicates that hyperimmune globulins or convalescent plasma donations with high IgG3 concentrations may be a highly efficacious therapy.