Transplant Services

Labcorp employs DNA-based methods to perform HLA typing of Class I (A, B, C) and Class II (DR, DQ, DP) loci. Labcorp uses a diverse network of technology and sequencing platforms to achieve desired resolution.

Common HLA Genotyping Resolutions

Antigen Recognition Domain (ARD) level resolution is accomplished with short range sequencing and reports a minimum of G-Group resolution. Common and Well Documented (CWD) level resolution resolves all common nulls and reports high resolution as an allele and/or approved high resolution code. Long-Range Sequencing provides the broadest gene coverage and alleles can be reported at up to four (4) field resolution.

Sample Reports

Next Generation Sequencing (NGS) technology increases the resolution of the HLA typing, while offering a more economical genotyping approach compared to conventional sequencing methods. Labcorp offers NGS typing of all major HLA loci in both ARD/(G-Group) and long read formats, providing options to achieve better resolution, turn-around time, and cost.¹

Alternative short read technologies may suffer from typing ambiguities when heterozygotes include similar alleles. Labcorp’s technology allows for the rapid resolution of these G-Group ambiguities.

For the highest resolution needs, Labcorp offers third generation long-read sequencing. For HLA class I loci, this assay sequences the entire gene in a single read, eliminating nearly all ambiguities. For Class II loci, the long-read assay covers exons 2, 3 and 4, as well as the intervening intron sequences. Labcorp’s long-read NGS assay provides up to four (4) field resolution and may be reported as an expanded result containing variants within the coding region and polymorphic differences in the non-coding region. All alleles containing differences in gene expression are captured in the final result.

Labcorp also offers other sequencing methods to expedite turnaround time. For more information please contact your Labcorp representative or call customer service at 800-533-1037 or by email at [email protected].

Post-transplant complications have been linked to the presence of pre-existing HLA antibodies.²

HLA antibody testing detects the antigens in a human leukocyte antigen (HLA) panel that react with a patient’s serum. Labcorp reports calculated panel reactive antibodies (CPRA) which estimate the percentage of potential donors in the population that express one or more of the unacceptable HLA antigens to which a patient has been sensitized.³

HLA Class I/Class II antibody screening is a qualitative assay that can be used as a means of assessing whether a patient is sensitized to HLA antigens.⁴ HLA Class I/Class II C1q binding analysis can be performed using single antigen beads to determine which anti-HLA antibodies can bind complement.⁵

Clinical Indications

Testing of individuals in need of either an organ transplant or hematopoietic cell transplant.^3,6 Testing of high-risk individuals who may have developed anti-HLA antibodies due to pregnancy, blood transfusion, or previous organ grafts.⁶ Identification of donor specific antibodies (DSA) in the recipient to assist in donor screening and selection.⁶ Post-transplant monitoring for the development of donor-specific HLA antibodies.⁷

Sample Reports

Transplant Engraftment Monitoring (Chimerism testing)

Chimerism testing is based on the detection and comparison of alleles at multiple loci in the recipient after transplantation. Labcorp routinely uses 16 loci for detecting differences between recipient and donor, and if the recipient and donor have few or no differences based on routine testing, more loci are available for testing. This testing is informative in most donor/recipient pairs except identical twins. The methodology uses polymerase chain reaction (PCR) to amplify short tandem repeats (STR) of DNA. Cell sorting for post-engraftment monitoring is offered to help physicians evaluate specific cell subpopulations. Cell sorting is available for T cells (CD3), Myeloid cells (CD33/CD66b) and Natural Killer Cells (CD56). Labcorp can also customize assays for other requested cell subpopulations.

In the example below, the pre-transplant patient (bottom) shows two DNA alleles, 20 and 22. The donor (top) has alleles 21 and 25. Samples taken from the patient after transplant (center) show a mixture of both donor and patient alleles in the CD3 cells, indicating chimerism. The percentage of donor cells is reported — in this case the CD3 cells are 57% donor and the CD33/CD66b cells are 100% donor. The progress of a stem cell transplant can be monitored periodically after transplant, aiding in the diagnosis of disease relapse, graft failure, or successful transplant.

Sample engraftment monitoring results

Donor alleles are located at the top of the illustration, the post-transplant CD3 and CD33/CD66b cell fractions are located in the middle, and the bottom panel shows the recipient’s pre-transplant alleles.

Killer Immunoglobulin-like Receptors (KIR): The function of natural killer cells in the immune response is regulated by killer immunoglobulin-like receptors (KIR). These receptors interact with class I HLA antigens on the cell surface to prevent or activate killing of the target cell. KIR genotyping analysis may be useful in some stem cell transplants because KIR matching or mismatching can mediate a graft-versus-leukemia effect when the cancer cells are under-expressing HLA class I antigens.

ImmuKnow®: ImmuKnow provides information about the immune suppression status of a transplant patient. This assay measures the ATP response of stimulated CD4+ peripheral blood lymphocytes.

Apolipoprotein L1 Risk Variants: The two apolipoprotein L1 gene (APOL1) risk variants (referred to as G1 and G2), found predominantly in African Americans, have been associated with worse allograft survival in kidney transplantation.¹¹ The homozygous expression of the wild type variant observed in this case has been associated with lower risk of early failure after transplantation compared to kidneys from donors with heterozygous or homozygous expression of the higher risk variants.

Sample Reports

Private Donor Testing

For patients in need of a stem cell transplant, the most pressing need it to find a suitable donor. 

In most cases, family members are screened first Labcorp's Family and Friends program can provide human leukocyte antigen (HLA) typing for potential donors at an affordable price. For more information about setting up a Family and Friends Account, contact Labcorp's histocompatibility customer service Monday through Friday from 8:00am to 6:00pm (EST) and can be reached at 800-533-1037 or by email at [email protected].

Patient Service Centers

• Network of nearly 2,000 patient service centers
  • Labcorp can accommodate donor collections throughout the country and can support remote collection with buccal swab kits for self-collection.
  • Strategically located sites throughout the United States to provide convenient access to specimen collection services

Quality Assurance

• Our staff is committed to providing a professionalenvironment during the specimen collection process.
• Cost effective solutions for screening and confirmatory typing of patients and donors
• Fully licensed and accredited: CAP, ASHI, ISO 17025, CLIA
• Network-wide quality control analysis
• Standardized laboratory technology and protocols
• Internal and external proficiency testing program