ABSTRACT
The underlying mechanism is not fully understood, but it is thought to involve HLA antibodies in the blood donor reacting with corresponding HLA antigens on the patient’s white blood cells. This leads to the formation of aggregates of white blood cells which become stuck in small pulmonary capillaries. The release of proteolytic enzymes from neutrophils and toxic oxygen metabolites causes lung damage, and subsequent non-cardiogenic pulmonary oedema which can be fatal. Treatment is essentially supportive, and includes stopping the transfusion, giving IV fluids and ventilation if needed. TRALI can occur with platelets and FFP, as well as with packed red cells as in this case. You might find it helpful to remember the mechanism by rearranging ‘TRALI’ to form the word ‘TRAIL’, and think of the blood donor leaving a ‘trail’ of antibodies in the recipient.
