Background: Although the 2-event pathogenesis of transfusion-related (TR) acute lung injury (ALI) has been accepted as an explanatory model, case reports classically describe patients without other risk factors for ALI. Patients who exhibit another risk factor for the onset of ALI may be neglected as having TRALI, which contributes to underreporting.
Case Report: Two cases of TRALI are reported. The first case is a patient with a hematologic malignancy who experienced ALI within 1 hour after a transfusion of concentrated platelets (PLT), with no other risk factor for ALI present. The second case is a patient with severe sepsis with multiorgan failure who received multiple transfusions during a laparotomy and exhibited ALI perioperatively. The implicated blood components originated from female donors in both cases. Analysis of the plasma of the PLT donor in the first case revealed HLA class I and II antibodies directed against the patient’s antigen. Analysis of the plasma of the fresh-frozen plasma donor in the second case did not reveal antibodies using the techniques available at that time. However, after involvement of this donor in a TRALI reaction in another recipient, HLA II antibodies directed against the antigen of the recipient were detected in the newly available single antigen Luminex technique.
Conclusions: The 2 cases illustrate that TRALI can occur both in the absence and in the presence of another ALI risk factor. Awareness should be increased that all patients exhibiting ALI within 6 hours of a blood transfusion, including possible TRALI, should be reported to the blood bank.

Keywords: perioperative period, Plasma - immunology, HLA Antigens - immunology, Blood Transfusion - adverse effects, Blood Donors, Antibodies - immunology, Acute Lung Injury - physiopathology, Platelet Transfusion - adverse effects, Risk Factors, Time Factors