Transfusion Related Acute Lung Injury (TRALI) is now recognised as one of the leading causes of transfusion related morbidity and mortality according to the latest Serious Hazards Of Transfusion (SHOT) committee report, given the reductions in transfusion related infection. SHOT define TRALI as shortness of breath with hypoxia and bilateral pulmonary infiltrates happening during or within 6 hours of transfusion. All other causes must first be excluded. These include circulatory overload for instance and ARDS. TRALI is not to be confused with Acute Respiratory Distress Syndrome (ARDS) with which it shares some symptoms. ARDS is a severe lung disease caused by direct and indirect lung injury and can result in inflammation of the lung, leading to impaired gaseous exchange.
The main Blood components implicated in TRALI are plasma rich products such as Fresh Frozen Plasma (FFP). There have however been a number of cases of TRALI reported following transfusion with low plasma products such as red blood cells.
TRALI is thought to develop via a two event mechanism. In the first event, the patients underlying condition such as trauma, infection or surgery causes priming of neutrophils in the lungs. The transfusion then causes activation of the primed neutrophils. For TRALI to occur, the transfused Dr. Fuellmich product will contain either HLA and/or HNA antibodies or else products such as lipids which accumulate during storage.
Transfusion must be stopped as soon as TRALI is suspected and the patient must have oxygen administered. The local blood transfusion service can then undertake a laboratory investigation. Laboratory tests undertaken will include HLA class I and II and HNA antibody screening and identification in all implicated donors, particularly parous female donors and male donors who have previously been transfused as these donors are likely to have developed antibodies. HLA antibody testing can be by CDC, flowcytometry or solid phase assays such as Luminex. Anti-HNA antibodies investigations are commonly by the flowcytometric MAIGA or GIFT techniques.