Tissue Typing

The Tissue Typing Laboratory provides:

• Cell-bound platelet antibody testing
• Granulocytic antibody testing
• HLA Class I and HLA Class II molecular typing for solid organ and bone marrow transplantation
• HLA-B27 testing for disease association
• Narcolepsy-associated antigen testing
• Serum platelet antibody testing

The serum platelet antibody test and the cell-bound platelet autoantibody test (enzyme-linked immunoassay methods) can be used to detect autoantibodies (such as those seen in idiopathic thrombocytopenic purpura) or alloantibodies such as those in refractory or alloimmunized patients. The cell-bound test is frequently positive in autoimmune thrombocytopenia.

The HLA-B27 test detects the presence or absence of the HLAB27 antigen. HLA-B27 is a major histocompatibility complex Class I molecule. There is a strong association between the presence of the HLA-B27 antigen and an increased incidence of ankylosing spondylitis as well as several other disorders.

Narcolepsy-associated antigen testing is performed to determine if the patient is positive or negative for the allele DQB1*0602. The test is performed using polymerase chain reaction (PCR)-SSP. The absence of the strongly associated DQB1*0602 is very strong evidence that the patient does not have narcolepsy.

The granulocyte antibody test by the indirect immunofluorescence method detects antibodies to white blood cells which are a frequent cause of nonhemolytic, febrile transfusion reactions and may also be involved in autoimmune neutropenia. The test cannot distinguish between allo- and autoantibodies.

HLA Class I and HLA Class II are performed using molecular typing methods for solid organ and bone marrow transplantation. The matching of both Class I and Class II antigens of donor/recipient pairs results in better graft survival for most solid organ transplants and less alloimmunization in the recipient. Linkage disequilibrium exists between some diseases and their association with specific Class I and Class II antigens.