HLA Testing andPost-Transplant Monitoring
Our Transplant Services and Expertise
Solid Organ Transplant Services
Versiti’s Histocompatibility Laboratory supports solid organ transplant programs with:
- HLA Class I and II typing to identify the best available donor
- Detection and identification of HLA antibodies to inform donor selection and monitor post-transplant reactions
- Crossmatching to confirm donor–recipient compatibility
These services help clinicians balance immunologic risk, allocate organs efficiently, and support desensitization protocols when needed.
Hematopoietic Cell Transplant (HCT) Services
For allogeneic HCT, Versiti provides:
- High-resolution typing by NGS for HLA Class I and Class II to help identify the best available donor for a patient in need of a stem cell transplant
- Unique related donor HLA haplotype screening by short tandem repeat (STR) assay
- Expert HLA antibody identification and monitoring for sensitized patients and haploidentical transplants
- KIR genotyping to aid in selection of the best donor for particular cases
- Post-transplant chimerism testing for engraftment and relapse monitoring
- HLA Loss of Heterozygosity (LOH) for post-transplant relapse characterization
- Erythroid chimerism test to monitor sickle cell disease transplant patients
Therapeutic Apheresis and Cellular Therapy Services
Versiti supports patients with therapeutic apheresis services and cellular therapy collections that accelerate treatments as an extension of your patient’s care team. Learn more about our services.
Our Chimerism Testing Process
Indications for Testing
- Monitor hematopoietic reconstitution following allogenic bone marrow transplantation
- Monitor effects of post-transplant therapies
- Monitor for potential disease relapse
- Monitor outcomes of allogeneic cellular therapies
- Measure chimerism in cellular subpopulations
- Identify the presence of maternal cells in newborns (e.g. SCID patients)
Chimerism by Next Generation Sequencing (NGS) Testing
Versiti’s Chimerism by NGS testing takes advantage of hundreds of single nucleotide polymorphisms (SNPs) found on all human autosomal chromosomes as well as the high data output of next generation sequencing (NGS) to provide sensitive and reliable results to monitor the relative amounts of recipient and donor cells present post-transplant. In technical validation studies NGS based chimerism testing has been found to provide more sensitive results and earlier detection of mixed chimerism in post-transplant monitoring compared to STR/VNTR based assays.
Test Method & Analysis
Chimerism testing is performed using 202 biallelic SNPs across 22 autosomes that are used to uniquely identify recipient and donor cells in the sample. PCR amplification and next generation sequencing is performed and analysis of the informative markers identified in pre-transplant samples enables relative quantification of recipient and donor cells.
This test is performed in two parts:
- Pre-transplant Analysis determines which markers can be used to uniquely identify recipient and donor alleles.
- Post-transplant Analysis establishes relative amounts of recipient and donor DNA.
Enriched Cell Populations
Enriched cell populations can also be used to monitor patients following hematopoietic stem cell transplant for more precise detection of changes in transplant dynamics. Testing for the following cell subtypes is available:
| Cell Marker | Cell Subset |
| CD3 | T cells |
| CD19 | B cells |
| CD33 (incl. CD66b) | Myeloid cells |
| CD56 | Natural Killer cells |