Chimerism testing (engraftment analysis) is performed for patients who have received a hematopoietic stem cell transplant. The test involves identifying the genetic profiles of the recipient and of the donor and then evaluating the extent of mixture in the recipient’s blood or bone marrow. First, DNA is isolated from the recipient and potential donor before the transplant and analysis is performed to determine whether the genetic markers unique to the donor and the recipient have sufficient power to distinguish the donor from the recipient. Next, after the transplant takes place, the performance of the transplant engraftment is assessed by evaluating the donor versus recipient contribution of white blood cells in post-transplant blood or bone marrow specimens obtained from the recipient.
- The DNA is isolated from the recipient, donor, and post-transplant samples.
- DNA is amplified via the Promega GenePrint24 System which employs methodology commonly used in human identity testing and is accomplished by the analysis of genomic polymorphisms called short tandem repeat (STR) loci.
- The percent donor chimerism is calculated and reported, and a longitudinal plot of historic data is generated for successive post-transplant specimens.