While haploidentical stem cell transfer, using a partially HLA-matched relative as a source of stem cells, may represent an opportunity for patients missing a genotypically matched sibling, alloreactivity due to HLA barriers accounts for negative effects such as graft rejection, graft-versus-host disease or immune dysregulation, also involving changes in genetic information. These factors underlie the reason why, after several months or years, a significant portion of leukemic patients experience disease relapse.
Among the genetic changes that may follow haploidentical HSCT, genomic loss of the mismatched HLA haplotype (HLA LOH) occurs in 33% of post-HSCT patients (Crucitti et al., Leukemia, 2015). due to selective pressure of donor-derived T cells. Loss of HLA heterozygosity confers a selective advantage for leukemic cells that become able to evade the T cell-mediated immune surveillance. This event is sufficient to allow relapse of leukemia.
The new HLA TRACE™ Assays enable detecting the HLA loss events before the onset of a relapse. Results of the monitoring tests may serve as a guidance to determine the most effective therapeutic strategies.
Currently, the HLA TRACE™ Assays comprise a panel of 19 gene markers covering all major HLA loci (A, B, C, DRB1, DQB1, DPB1). This economic and user-friendly method provides an elegant tool for monitoring of multiple HLA loci and non-HLA targets in an efficient, comprehensive and affordable manner.
More information about HLA TRACE™ Assays