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HLA Testing Services

Histocompatibility (HLA)

The human major histocompatibility complex (MHC), or human leukocyte antigen (HLA) complex, comprises several genetic loci on the short arm of chromosome 6. Seven of these loci encode two distinct classes of highly polymorphic cell surface antigens. Class I MHC antigens include HLA-A, HLA-B, and HLA-C, each encoded by a separate locus. Class II MHC molecules include HLA-DR, HLA-DQ, and HLA-DP each having varying degrees of alloimmunity. Many alleles exist for each locus of the Class I and Class II of HLA genes. 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 MHC molecule and are important to disease susceptibility and transplantation.

Clinical Utility:

KCL uses the Sequence Based Typing (SBT) methods, including Next Generation Sequencing (NGS) and Sanger Sequencing, to determine HLA-A, B, C and HLA-DR, DQ high-resolution type for haematopoietic stem cell patients and their selected unrelated donors. In addition, HLA alleles have been implicated in susceptibility or resistance to a variety of autoimmune, infectious, and oncologic disorders. HLA association studies must use typing techniques with high resolution that distinguish the HLA subtypes. Significant associations have been found between the HLA alleles and certain disorders or deficiencies in many disciplines, including rheumatology, nephrology, neurology, endocrinology, gastroenterology, respiratory, ophthalmology, infectious disease, dermatology, immunology and psychology. SBT helps define the possible associated HLA subtypes and is of interest for R & D projects concerned with T cell mediated immune response. Determination of the individual HLA marker is often used diagnostically in immunotherapy and immunomodulation approaches.

Method:

PCR-SSO:
Reverse SSO hybridization is used to determine HLA-A, -B, -C, -DR, -DQ and -DP locus types at an intermediate level of resolution. These tests are used for screening potential bone marrow donors.  If matched, individuals typed at this level of resolution may later require higher resolution testing.
PCR-SSP:
PCR-SSP is also used to determine HLA-A, -B, -C, -DR and DQ locus types. This test is available to obtain intermediate and high resolution HLA typing.  This technology is used in combination with SSO or SBT, as needed, in special cases such as obtaining a higher resolution testing and resolution of various ambiguities.
PCR-SBT:
Sequence Based Typing (SBT) provides a higher resolution HLA typing for HLA-A, -B, -C, -DR, -DQ and -DP locus alleles. The typing obtained by this technology is often used for typing the recipients and donors involved in stem cell transplants.  In addition, this technique provides a comprehensive typing for pharmacologic and disease association studies.
NGS:
Next Generation Sequencing (NGS) provides an ultra-high resolution HLA typing for HLA-A, -B, -C, -DR, -DQ and -DP locus alleles. Additionally, NGS offers the capability of multiplexing the samples which can significantly reduce the turnaround time when HLA typing a large number of samples.  The typing obtained by NGS technology is often used for typing the recipients and donors involved in stem cell transplants as well as for pharmacologic and disease association studies.

Specimen Requirements:

One 5-mL EDTA (purple top) tube or 4 buccal swabs
Other anticoagulants accepted.

Shipping Requirements:

Samples are accepted Monday through Friday. Overnight shipments should be sent Monday through Thursday. Please send samples, at room temperature, along with the completed test requisition to:

Kashi Clinical Laboratories, Inc.
Attention: HLA Laboratory
10101 SW Barbur Blvd, Suite 200
Portland, OR 97219