Transfusion-Related Immunomodulation

Abstract Blood transfusions are common practice across medical disciplines. With the advent of increased testing, blood components continue being made safer, and they are currently the safest they have ever been. This is not always the case. One entity that has been the reason for concern in the literature for the better part of the last 4 decades is what has been termed as “transfusion-related immunomodulation.” This entity encompasses processes by which the transfused blood leads to changes to the immune responses of the recipient causing a number of possible sequelae. The goal of this chapter is to shed some light at this entity and present the current data indicating the potential elements within blood responsible for either the activation of inflammatory responses or immunosuppression and, in some cases, changes to a recipient's gene expression.