Transfusion-related acute lung injury (TRALI)

When to suspect this adverse reaction

Acute onset of fever, chills, dyspnoea, tachypnoea, tachycardia, hypotension, hypoxaemia and noncardiogenic bilateral pulmonary oedema leading to respiratory failure during or within six hours of transfusion.
TRALI has been implicated in transfusion of plasma-containing components (red cells, platelets and plasma).

TRALI is one of the most common cause of transfusion-associated fatalities. The true incidence is unknown but is reported to occur in about 1:10,000 units transfused.

Usual causes

Various mechanisms have been proposed for the pathogenesis of TRALI. The most widely held view is that passive transfer of human leucocyte antigen (HLA) or human neutrophil antigen (HNA) antibodies in the donor’s plasma are directed against recipient leucocyte antigens. The resulting antigen-antibody reaction activates neutrophils in the lung microcirculation, releasing oxidases and proteases that damage blood vessels and make them leak.
Biological response modifiers (BRM), such as biologically active lipids can accumulate in some cellular components during storage and may be responsible for TRALI in susceptible patients.


TRALI has many clinical features in common with fluid overload or cardiogenic pulmonary oedema and therefore careful clinical assessment is required.

Acute haemolytic reaction or transfusion-associated sepsis may have similar initial clinical findings. A direct antiglobulin test (DAT), full blood count and repeat ABO group may be indicated.
A chest X-ray will show bilateral interstitial infiltrates.
Once TRALI is clinically suspected, test the donor and recipient serum for HLA and HNA antibodies and perform a HLA type on the recipient. If these antibodies are present, it supports diagnosis of TRALI.

TRALI testing is specialised, so please contact Lifeblood for further support and provide the following details: 

  • observations and symptoms and time of onset of symptoms, and
  • management of the suspected TRALI.

A Lifeblood doctor may contact you for further clarification.

Collect blood samples and send them to the nearest Lifeblood tissue typing laboratory. The samples should be labelled “TRALI investigations” and kept and sent at room temperature.
Please send: 

  • patient pre-transfusion serum, and
  • patient post-transfusion samples: 12 mL serum (clot) and 12 mL EDTA or ACD.

What to do

Stop the transfusion immediately and follow other steps for managing suspected transfusion reactions.

Provide cardiovascular and airway support. Administer supplemental oxygen and employ ventilation as necessary. Diuretics are not beneficial.

This may become a medical emergency; support blood pressure and maintain an open airway.

Advise your Transfusion Service Provider to contact Lifeblood,  so we can quarantine and test related components from the same donor and prevent TRALI in other recipients.

Reducing the risk of antibody-mediated TRALI

To reduce the risk of antibody-mediated TRALI, donors with a possibility of having HLA or HNA antibodies either because of a history of pregnancy or transfusion, are not used for plasma components or apheresis platelets.
The below are two significant changes Lifeblood has made as part of its TRALI Risk Reduction Strategy.
1. Male-only plasma
Only blood or plasma from male donors is used in the manufacture of clinical plasma components such as fresh frozen plasma (FFP) or cryoprecipitate.
2. Apheresis platelets collected from male donors
To further reduce the TRALI risk associated with apheresis platelets, Lifeblood has moved to a plateletpheresis panel comprised of cisgender male donors only.