engleski

Impact of single nucleotide polymorphisms in the MHC Gamma block on the outcome of unrelated hematopoietic stem cell transplantation

The golden standard in unrelated hematopoietic stem cell transplantation (HSCT) is matching for HLA-A, -B, -C, -DRB1 and -DQB1 alleles. However, this is often not enough to prevent postransplantational complications. MHC haplotype mismatches (MM) have been associated with higher risk of acute graft versus host disease (GvHD). The gamma block (GB) is located in the central MHC region, between HLA-B/C and HLA-DRB/DQB blocks. It contains many inflammatory and immune regulatory genes. The single nucleotide polymorphisms (SNPs) within that block can be considered as markers for MHC haplotype matching. The aim of the research was to test wheatear the MM in the GB impact the outcome of HSCT. Studied group included 30 patients diagnosed with acute myeloid or lymphoblastic leukemia (N=18 and N=12, respectively), transplanted with HLA 10/10 matched unrelated donor (MUD). The pairs were PCR-SSP typed using Gamma Type (GT) assay (Conexio Genomics, Australia) that detects 25 SNPs within GB. Sixteen out of 30 (53.33%) pairs were GT matched (GT-M) while 14 out of 30 pairs (46.67%) were mismatched (GT-MM). The analysis showed no statistically significant difference in overall survival and relapse occurrence in our tested groups. There were also no significant differences in aGvHD incidence between GT-M and GT-MM patients. Although these preliminary results do not support the hypothesis that GT-MM is associated with higher risk of aGvHD and worse HSCT outcome, probably due to the small sample size, further investigation on the larger cohort is needed.

SNP, Gamma block, hematopoietic stem cell

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