HLA Antibody Testing

Patients may become sensitized to HLA antigens through pregnancies, blood transfusions or transplantations and develop HLA antibodies. The presence of these pre-formed anti-HLA antibodies may lead to acute or chronic graft rejection or failed platelet transfusion. When present in blood donors, HLA antibodies may passively transfer to recipients and lead to development of transfusion-related acute lung injury (TRALI). HLA antibodies can be identified and characterized using various techniques.

Antibody Screening and Identification: Patients facing transplant surgery or platelet transfusion need to be tested for the presence of anti-HLA antibodies. HLA Class I and Class II antibody screening and identification tests are performed to help identify the most compatible donors for a patient in need of platelet transfusion or transplantation who may have developed allogeneic HLA antibodies. In addition, these tests help clinicians to monitor the patient’s post-transplant/transfusion immune status for therapeutic purposes.

Antibody Screening: HLA Class I and Class II antibody screening is also used in testing plasma samples from the implicated blood donors and patients for leukocyte antibodies in evaluation of a suspected TRALI case. In addition, blood donors known to be leukocyte-alloimmunized or at increased risk of leukocyte alloimmunization are tested for HLA antibodies.

Method

Antibody Identification: The Single Antigen assay is used for the confirmation of antibody specificity suggested by a previous screening test. Microbeads coated with purified Class I or Class II HLA antigens are used to detect HLA antibodies present in the test serum that will bind to the antigens on these beads. The reaction pattern of the test serum is detected fluorescently using a flow analyzer.

Antibody Screening: The laboratory uses a panel of color-coded microspheres coated with purified HLA antigens to determine percent reactivity of antibodies present in tested plasma.  Test serum or plasma is first incubated with these coated beads. Any HLA antibodies present in the test serum bind to the antigens on the beads and will be detected fluorescently using a flow analyzer.

Specimen and Shipping Requirements