In October of 2025, Versiti announced the launch of a new, more sensitive test to monitor post-transplant chimerism, which is when both donor and recipient cells are present in a patient after a transplant.
Following a blood or bone marrow transplant (allogeneic hematopoietic cell transplantations), patients are usually monitored by DNA-based chimerism testing to track the proportion of donor and recipient cells in the bone marrow or peripheral blood.
High levels of donor cells are a sign of transplant success and detection of even low levels of recipient hematopoietic cells means that the transplant may have complications or is failing, making post-transplant chimerism an important element of patient care.
The outcomes of allogeneic cellular therapies can also be monitored with this highly sensitive testing.
Versiti Diagnostic Laboratories have been providing chimerism and engraftment testing to transplant and cell therapy centers for more than 30 years, but this new testing incorporates a more accurate and sensitive next generation sequencing (NGS) methodology.
David Dinauer, portfolio manager at Versiti, says, “The old method compared about a dozen markers in the genome of the donor and the recipient, and it didn’t include every chromosome, so it had limitations. This new NGS method uses more than 200 markers across all autosomal chromosomes, making it more sensitive and accurate, even with lower amounts of DNA.”
Although the old method Dinauer refers to has long been the industry standard, Senior Director of the Histocompatibility and Immunogenetics Lab, Jennifer Schiller, PhD, F(ACHI), indicates that Versiti is an early adopter of NGS for multiple applications including both HLA genotyping and chimerism testing.
“There are other HLA labs that use an NGS methodology for post-transplant chimerism monitoring, but typically only academic centers performing testing for their own local programs,” she says. “The Versiti HLA lab is on the cutting-edge offering NGS methodology for transplant patient diagnostics more broadly.”
Another advantage of the NGS assay is that it has a lower limit of detection, meaning that it can detect small amounts of recipient cell DNA, potentially detecting disease relapse earlier in the disease process.
“The earlier a patient’s doctor can see changes in a post-transplant patient, the better,” Schiller says.“Another example of one of the benefits of this new methodology, sometimes a patient has a transplant, experiences a relapse, and then gets a second transplant, but some original donor cells from the first transplant are still around. Interpretation of three mixed genomes using the NGS-based assay is much easier and more accurate in these cases.”
With the adoption of next generation sequencing for chimerism testing, Versiti continues to lead in advancing transplant diagnostics, helping clinicians detect changes sooner, which may improve outcomes for patients who depend on accurate tests.