Transfusion reaction

Prompt recognition of an immune-mediated transfusion reaction is fundamental to improving patient outcome.

Immune-mediated transfusion reactions can be classified as acute or delayed. Acute reactions occur within 24 hours of transfusion and include acute haemolytic, febrile non-haemolytic, allergic, and transfusion-related acute lung injury (TRALI). Delayed reactions occur days to weeks after the transfusion and include delayed haemolytic transfusion reactions, transfusion-associated graft-versus-host disease, and post-transfusion purpura.

Although infrequent, non-immune transfusion reactions, including haemolysis, transfusion-associated sepsis, and circulatory overload, should be considered in the differential diagnosis.

Acute haemolytic transfusion reactions are most often the result of clerical error. Identification is critical because of the high probability of a second patient receiving the wrong blood product at the same time.

Treatment depends upon the type of transfusion reaction. Although pretransfusion prophylactic paracetamol and diphenhydramine are often routinely administered, there is little evidence to support this practice.

This topic will mainly address immune-mediated transfusion reactions, which comprise an array of distinct adverse clinical responses to transfusion. They are mediated by the interaction of recipient antibodies to foreign antigens contained in any allogeneic blood products. Acute immune-mediated transfusion reactions occur immediately following, or within 24 hours of, transfusion. They include acute haemolytic, febrile non-haemolytic, allergic (with or without anaphylaxis), and transfusion-related acute lung injury (TRALI). Delayed immune-mediated transfusion reactions occur within days to weeks of transfusion and include delayed haemolytic transfusion reaction, graft-versus-host disease, and post-transfusion purpura.