The relapse in leukemia after an allogeneic transplant of hematopoietic stem cells is due, in many cases, to the recipient cells, causing a state of mixed chimerism. When an increase in the level of chimerism is detected during post-transplant monitoring, it is important to determine if there is a HLA loss in the recipient cells to determine an adequate treatment.
The study of HLA loss can potentially be applied to all transplants with HLA mismatches. When the donor and the recipient are HLA haploidentical, they are frequently mismatched for HLA-A, -C and -DPB1.
GenDx studies 10 HLA-KMR markers targeting some of the most frequent alleles of HLA-A, -C, and -DPB1 (5 specific assays for HLA-A, 2 specific for HLA-C and 3 specific for HLA-DPB1), the loci that most frequently do not match in unrelated or haploidentical HSCT, allowing to find an informative marker of HLA loss.