TRALI

Transfusion-Related Acute Lung Injury (TRALI) is characterized by acute non-cardiogenic pulmonary edema and respiratory compromise in the setting of transfusion. The precise mechanism responsible for TRALI is unknown, but it is thought to be triggered by passive transfer of HLA antibodies present in the plasma of the transfused blood product. Less than 5% of TRALI cases are, however, associated with the presence of the causative antibodies in the recipient that react with transfused cellular material.

Donor Screening: Since TRALI has been shown to be associated with the transfusion of blood components containing HLA antibodies, American Association of Blood Banks (AABB) guidelines and standards require that blood collection and transfusion facilities implement interventions to minimize the preparation of high plasma-volume components from donors known to be leukocyte-alloimmunized or at increased risk of leukocyte alloimmunization. Our laboratory offers HLA antibody testing for the purpose of donor screening.

TRALI Evaluation: TRALI has been attributed to donor leukocyte antibodies that are thought to interact with recipient neutrophils, resulting in activation and aggregation in pulmonary capillaries, release of local biologic response modifiers causing capillary leak, and lung injury. Testing plasma samples from the implicated donor(s) and patient for leukocyte antibodies is helpful in evaluation of a suspected TRALI case.

The laboratory uses a panel of color-coded microspheres coated with purified HLA antigens to determine percent reactivity of antibodies present in tested plasma.  Test serum or plasma is first incubated with these coated beads. Any HLA antibodies present in the test serum bind to the antigens on the beads and will be detected fluorescently using a flow analyzer.