Immunogenetics Clinical Services
HLA testing is utilized to find the best HLA-matched donor for hematopoietic stem cell transplantation and to investigate clinical problems where HLA is implicated. Clinical HLA testing includes HLA typing, HLA antibody screening and identification, and lymphocyte crossmatching.
HLA Testing for Hematopoietic Stem Cell Transplantation
For a patient in need of an allogeneic hematopoietic stem cell transplant, HLA typing is initially performed on the patient and siblings. If an HLA-matched sibling is not available, an unrelated donor and/or umbilical cord blood search may be initiated. In rare cases where it is indicated, extended family members (e.g., uncles, aunts, nephews, and nieces) may be searched to find a suitably HLA-matched related donor. The HLA laboratory director and supervisor provide consultations to the stem cell transplant team to facilitate an optimal donor search strategy for a given patient.
HLA matching between the recipient and donor is the most important consideration during a donor selection process because the perfect HLA match reduces the risks of graft rejection and acute graft-versus-host-disease. The presence of preformed anti-HLA antibodies against mismatched antigens in the stem cell donor may have adverse effects of graft failure or rejection. Pre-transplant HLA antibody testing and lymphocyte crossmatch may be used to assess these risks.
HLA Typing and HLA Antibody Testing for Other Clinical Applications
HLA is implicated in various clinical conditions including blood transfusion reactions (febrile non-hemolytic transfusion reaction and transfusion-related acute lung injury), platelet transfusion refractoriness, neonatal alloimmune thrombocytopenia, transfusion-related graft-versus-host-disease, and transplantation-related graft-versus-host-disease. HLA testing is used to investigate these complications, and the results can guide appropriate management of the patient.
Certain HLA types are associated with certain diseases (such as ankylosing spondylitis, celiac disease, narcolepsy, and type I diabetes mellitus) and render susceptibility to high risks of reactions with medications such as abacavir and carbamazepine. HLA typing may be performed to assess a patient’s risk for developing the disease or reaction.
Routine Turn-Around-Time (TAT) or STAT Testing
Elective testing is performed within laboratory-established routine TAT. In case of emergency, STAT HLA testing can be requested and performed as determined to be necessary.
The tests commonly performed by the Immunogenetics laboratory include the following:
- HLA-A, B, Cw, DRB1, DQB1 Typing, Low Resolution
- HLA-A, B, Cw, DRB1, DQB1 Typing, High Resolution
- HLA Class I Antibody Screening and Identification
- HLA Class II Antibody Screening and Identification
- Lymphocyte Crossmatch, T-Cells
- Lymphocyte Crossmatch, B-Cells