TRANSFUSION RELATED ACUTE LUNG INJURY CAUSED SOLELY BY CLASS II HLA ANTIBODIES : 3 CASES.

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TRANSFUSION RELATED ACUTE LUNG INJURY CAUSED SOLELY BY CLASS II HLA ANTIBODIES : 3 CASES.
Vaughan Carter FIBMS , Gary Cavanagh MPhil , Anatole Lubenko PhD , C. Jane Matthews, PhD and Catherine E. Chapman, MD . Newcastle upon Tyne United Kingdom, National Blood Service, Histocompatibility and Immunogenetics and Leeds United Kingdom, National Blood Service, Stem Cell Immunology .

We report three cases of transfusion related acute lung injury (TRALI) in which the only demonstrable allospecific antibodies were directed against class II antigens.
TRALI is a serious and potentially fatal hazard of blood transfusion, usually associated with patient specific HLA or granulocyte alloantibodies in transfused blood products. Most reports have implicated HLA class I antibodies and granulocyte antibodies as the main causes of TRALI. However, currently, there is growing evidence that class II antibodies may also be involved.
Patients and relevant donors are tested for anti-HLA class I and II by CDC and ELISA and for granulocyte, lymphocyte and monocyte antibodies by flow cytometry (GLAM assay). Patients are HLA typed and crossmatching performed when possible.
We have identified three cases in which the clinical picture was consistent with TRALI and the only identifiable alloantibodies in donor sera were directed against HLA class II. In two of the cases the antibodies were well characterised and the patients had the antigenic targets for the specific antibodies detected. In the third case the donor had multi-specific class II antibodies. We have also identified five further TRALI cases in which donor class II antibodies were present in conjunction with HLA class I and/or granulocyte antibodies.
Our findings show that TRALI can be caused by antibodies against HLA class II in the absence of any other detectable alloreactive antibodies. In addition, class II antibodies may be involved in TRALI in combination with other alloantibodies. Class II antibodies appear to be important causative agents in TRALI and should not be overlooked when investigating this condition.