Transfusion-related acute lung injury due to HLA-A2-specific antibodies in recipient and NB1-specific antibodies in donor blood

Transfusion-related acute lung injury (TRALI) is a hazardous but little-known complication of blood transfusion, characterized by non-cardiogenic lung oedema after blood transfusion. Leucoagglutinating antibodies in the donor plasma are considered to play a central role in the pathogenesis of TRALI but no recommended procedure currently exists for their detection, and most of them have not yet been well characterized. Serum samples of two patients who have developed TRALI within 30 min of blood transfusion and the sera of the involved blood donors were investigated for leucocyte antibodies by granulocyte immunofluorescence, granulocyte agglutination and lymphocytotoxicity assays using typed test cells. Suspected specificities of the detected antibodies were confirmed by a luminoimmunoblot assay and the antigen capture assay MAIGA. One case was associated with granulocyte agglutinating anti-HLA-A2 antibodies in the recipient's (i.e. patient's) own blood and the other with donor-related non-agglutinating antibodies directed against the granulocyte-specific antigen NB1. Leucocyte incompatibility between donor and recipient was shown in both cases by crossmatching and typing of the incompatible cells for the appropriate antigen. The results show that TRALI is associated not only with donor- but also with recipient-related leucocyte antibodies. In addition to leucoagglutinating antibodies, non-agglutinating granulocyte-specific antibodies can be also involved. For immunodiagnosis, sera from both must be investigated by a combination of granulocyte and lymphocyte (HLA) antibody screening tests and leucocyte incompatibility verified by crossmatching.