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Human Leukocyte Antigen (HLA) Laboratory

The human leukocyte antigen (HLA) complex, located on Chromosome 6q21, comprises genes encode two distinct classes of highly polymorphic cell surface antigen. Class I HLA-A, -B, -C antigens are expressed ubiquitously on nucleated cells, whereas the class II HLA-DR, -DQ, -DP antigens are normally expressed on B cells, monocytes, macrophage, dendritic cells and on activated T cells. An extensive sequence polymorphism is present in the second exon of Class II loci and in the second and third exons of Class I loci. These polymorphic regions encode the peptide-binding groove of the HLA molecules and are important to transplantation, disease susceptibility and drug hypersensitivity.

The Clinical Histocompatibility (HLA) Laboratory at Loyola University Medical Center is accredited by College of American Pathologists (CAP) and American Society of Histocompatibility and Immunogenetics (ASHI). The laboratory provides the state-of-art immunogenetics testing services to support comprehensive transplant programs and other clinical services at Loyola University Medical Center, including:

• Solid organ (Kidney, Liver, Heart, Lung and Pancreas and combined organs) transplantation

• Allogeneic Hematopoietic stem cell/bone marrow  transplantation

• Other clinical purposes: disease associations, drug hypersensitivity and platelet transfusions, etc.

In addition, the laboratory provides the massive educational opportunities including observations, hands-on experiences, lectures and case studies for medical students, residents and fellows in Stritch School of Medicine, Loyola University Chicago. The trainees acquire knowledge on Immunogenetics and transplant immunology in clinical applications during their rotations and selective courses.  

Diversity of HLA molecules represents a major barrier to organ and tissue transplantation between individuals and also has been implicated in susceptibility or resistance to a variety of autoimmune, infectious, and oncologic disorders. HLA typing identifies the unique constellation of HLA antigens for an individual. HLA-class I (A, B, C) and class II (DR, DQ, DP) typing is performed by DNA-based molecular diagnostic techniques.  At the current stage, the laboratory provides low/intermediate HLA typing using PCR-sequence-specific oligonucleotide probe hybridization (SSOP) in house. High resolution HLA typing is sent out now.   

HLA antibody Screening (PRA)

Preformed anti-HLA antibodies are associated with acute rejection of mismatched solid organ and stem cell grafts, failure of platelet transfusions. Patients may become sensitized to HLA antigens through pregnancies, blood transfusions or previous transplantations and develop HLA antibodies. The laboratory performs this test on Luminex phenotype antigen platform that uses a panel of HLA class I and class II antigens isolated from human cell lines coupled to microbeads. These HLA antigens are common and frequent HLA antigens in human populations.  Any HLA antibodies present in the test serum bind to the antigens on the microbeads will be detected by a Luminex analyzer. Results are reported as percentage of panel reactive antibodies (PRA) which indicate the breadth of HLA antibody reactivity in populations and give an estimate of the likelihood of finding a suitable donor.

HLA antibody identification

HLA class I and class II antibody specificity identification is critical in transplant patients. They are tested by Luminex single antigen platform that uses a panel of recombinant allele specific HLA class I and class II antigens coated on microbeads.  Any HLA antibodies present in the test serum bind to the specific HLA single antigens on the microbeads will be detected by a Luminex analyzer.  Thus, HLA class I and class II antibody specificities can be detected accurately. The Class I and Class II antibody screening and identification tests help to identify the most compatible donors for a patient need organ, mismatch stem cell transplantation or platelet transfusion.

Donor Specific HLA antibodies (DSA)
Pre-formed or de novo donor specific antibodies (DSA) is the major risk factor of acute and chronic graft rejection. Using Luminex single antigen platform to accurately detect HLA antibody identification, DSA can be defined for specific donors with the avialbale donor HLA typing. This testing will help clinician to monitor the patient’s under immunomodulation and post-transplant immune status for therapeutic purposes.

T- and B-cell Flow cytometry crossmatch
Crossmatches detect donor specific antibodies by incubating a donor’s lymphocytes with a recipient’s serum. Positive crossmatches detected by flow cytometry suggest the presence of preformed anti-donor antibodies and indicate a risk of acute rejection and damage to the graft. Crossmatch results are interpreted in combination of the patient's disease status, sensitization history, HLA antibody testing and the quality of the donor cells.  

Director, Technical Supervisor and Clinical Consultant
Zeying Du, MD, PhD, D(ABHI)
Phone: 708-216-9028

General Supervisor
Jaishree Patel CHS(ABHI)
Phone: 708-216-3626