Transfusion-related acute lung injury (TRALI) is a serious blood transfusion complication thought to be most commonly caused by a reaction to white blood cell antibodies present primarily in the plasma component of blood products. When transfused, these antibodies sometimes activate a type of white blood cell called a granulocyte, which causes plasma to leak into the lungs, resulting in fluid accumulation – a condition referred to as acute pulmonary edema. Plasma containing blood components obtained from certain donors are thought to carry a higher risk of causing TRALI. Donors who are more likely to have these antibodies include women who have been pregnant and developed these antibodies as a result of exposure to fetal blood and donors who have previously received a transfusion or transplant.
There are currently no screening tests to prevent TRALI, nor is there any single intervention that can eliminate the risk of TRALI. However, some steps to reduce the risk of TRALI are being taken for products that contain high volumes of plasma which may contain antibodies to white blood cells.