Transfusion-related acute lung injury

Transfusion -related acute lung injury ( transfusion related acute lung injury, TRALI; obsolete: transfusion- associated nichtkardiogenes pulmonary edema) is an acute disease of the lungs that occurs after transfusion of blood products and is one of the most serious transfusion side effects.

The TRALI is defined as acute respiratory distress that occurs within six hours after a blood transfusion, with pulmonary infiltrates (pulmonary edema) in the chest x-ray and no signs of heart failure due to volume overload as the cause.

The incidence in Germany is specified for red blood cell concentrates ( after the introduction of leukocyte depletion ) with at 1:1,000,000, for therapeutic single plasma and platelet concentrates it is 1-10:100.000 ( hemotherapy guidelines of the German Medical Association 2010). The mortality rate is about 10%. or up to 25% ( cross-section guidelines blood component therapy the German Medical Association 2008). TRALI was first described in 1951.

Causes

Antibodies directed against white blood cells ( granulocytes ) of the receiver and mainly with fresh frozen plasma ( FFP) and platelet concentrates are transfused are blamed as the main cause of TRALI. The antibodies bind to human leukocyte antigens ( HLA) class I and human neutrophil antigens ( HNA) of granulocytes. This agglutinate then, are activated and can no longer pass through the pulmonary capillaries in the sequence. Through the release of oxygen radicals and enzymes on the permeability ( permeability ) is increased in lung vessels, blood plasma occurs and forms of pulmonary edema.

As antibody - independent triggering mechanism are still biologically active lipids ( phosphatidylcholines ) known to be transmitted by blood products and also can activate granulocytes. The clinical course of these so-called non-immunogenic TRALI is generally milder.

Clinic

TRALI typically manifests itself as acute episodes of shortness of breath (dyspnea ), often accompanied by low blood pressure (hypotension ), and fever. In the X-ray image of the thorax ( chest X-ray ) may occur as a result of significant infiltrates of pulmonary edema, which are in discrepancy with the clinical picture often. Often there is also a waste of leukocytes in the blood picture.

A differentiation from acute respiratory distress syndrome ( ARDS) other cause is the basis of the clinical picture usually not possible.

Diagnostics

The diagnosis is made ​​on the clinical picture associated with a transfusion and the chest X-ray absorption. The most important differential diagnosis, cardiogenic pulmonary edema due to an overload of the circuit through the transfusion volume ( transfusion -associated circulatory overload, TACO ), left ventricular pump function is often limited ( echocardiography), the cardiac silhouette changed ( chest X-ray ) and brain natriuretic peptide increased.

The preserves are administered immunologically examined for HNA and HLA antibodies.

Therapy

For treatment, patients receive oxygen. The indication for intubation and mechanical ventilation is made early, this can be decisive for the course. The benefit of corticosteroids is not secured, the gift is still partially practiced. The other (possibly intensive care ) therapy is symptomatic. The recovery is rapid in most cases.

Prevention

On the transfusion products dispenser whose blood products could be identified as a trigger will be omitted in the following.

Most TRALI cases are transmitted by transfusion of FFP donors that were sensitized in multiple pregnancies against leukocyte antigens and have established appropriate antibodies. Mitigating risks, therefore, is the use of blood products derived from women without previous pregnancies or only of men, which, due to the scarcity of stored blood but takes place only restricted in practice.

Routine testing of all donors to the corresponding antibody is not required and is usually not carried out for economic reasons.