Risks and side effects of therapy with plasma and plasma fractions.

Transfusion of plasma can lead to adverse reactions or events. Immune-mediated reactions are most common--these include allergic and anaphylactic reactions, transfusion-related acute lung injury (TRALI) and haemolysis. They can range in severity from mild to fatal. Fluid overload and citrate toxicity can occur after rapid or massive transfusion. In developed countries, microbial transmission rates are low because of donor selection and testing. Pathogen reduction processes can be applied to either single-unit components (methylene blue) or plasma pools (solvent-detergent). They have the unwanted effect of reducing some coagulation factors but reduce viral transmission risk even further. Reactions associated with plasma products or fractions also include allergic reactions, although TRALI is rare. Viral transmission risk is very low because of the use of two independent viral inactivation steps. Different products have particular specific unwanted effects: intravenous immunoglobulin has been associated with thrombotic events, renal toxicity and aseptic meningitis; coagulation factors are associated with development of inhibitors and thrombotic events. The risk of transmission of variant Creutzfeldt-Jakob disease in both plasma components and pooled plasma products is as yet unknown. If anything, the low titre of prion infectivity in the blood of an infected individual (approximately 10 infectious units/ml) will be massively diluted by the thousands of units of plasma in the pool. Subsequent manufacturing processes also remove prions from the final product.