[HLA and transfusion: new approaches with Luminex™ technology].

The major histocompatibility complex is a multigenic system highly polymorphic coding for human leukocyte antigen (HLA) molecules, which are the strongest antigens for immune response and play a major role in allograft rejection. Class I antigens are expressed on almost all nucleated cells and platelets, whereas HLA class II antigens are mostly on antigen presenting cells. During transfusion, anti-HLA antibodies can induce transfusion incidents like fever, transfusion-related acute lung injury TRALI and refractoriness to the platelets transfusion. Identification of HLA class I antibodies is very important to find HLA compatible platelets concentrates. Since the end of 1960s, the complement-dependent microlymphocytotoxicity assay has been the standard internationally recognized method for cross matching and screening of HLA antibodies. It became necessary to improve the test sensitivity because some clinical relevant antibodies were not detected. Sensitive methods appeared in the 1990 s: flow cytometry, enzyme-linked immunosorbent assay and now Luminex™. This latter is the most sensitive method with single HLA antigen panel assays to generate the most informative reactivity pattern of antibodies. The high sensitivity and specificity of the Luminex™ technology performed to screen HLA antibodies allows the best selection of platelets donors. When no compatible concentrates are available for highly immunized recipients, the cross-matching method could be used to select a platelet concentrate.