Immunological reactions secondary to blood transfusion.

Multiply injured patients are at risk of developing the systemic inflammatory response syndrome, which may involve multiple organ failure, infections/sepsis, longer hospital stay and mortality. These systemic complications have been associated with immunological changes in which several components of the immune system have been implicated. Recent studies have shown that blood transfusions may increase these changes. The immunomodulating effects of packed red blood cells have been identified and attributed to contaminating leukocytes and inflammatory mediators in the supernatant liquid. This review will outline immunological consequences of allogeneic blood transfusion, with a special focus on trauma cases.