International Journal of Hematology and Oncology 2023, Vol 33, Num 4 Page(s): 074-084
Impact of HLA-DPB1 Matching in Unrelated Allogeneic Stem Cell Transplantation: Results of Two Centers From Turkey

Bulent KANTARCIOGLU1, Huseyin S. BEKOZ1, Ipek Y. HINDILERDEN2, Demet KIVANC1, Yeliz D. OGRET3, Sevgi K. BESISIK2, Fatma S. OGUZ3, Deniz SARGIN1

1Istanbul Medipol University, Faculty of Medicine, Department of Internal Medicine, Division of Hematology, Istanbul, TURKEY
2Istanbul University, Istanbul Faculty of Medicine, Department of Internal Medicine, Division of Hematology, Istanbul, TURKEY
3Istanbul University, Istanbul Faculty of Medicine, Department of Medical Biology, Istanbul, TURKEY

Keywords: Allogeneic stem cell transplantation, GVHD, Human leukocyte antigen, HLA-DPB1
In this study, we retrospectively examined 34 donor/recipient transplant pairs fully tested for the alleles HLA-A, B, C, DRB1, DQB1 and DPB1 in two different centers in Istanbul, Turkey. HLA-DPB1 disparity in at least one antigen level was 79.6% and only 20.6% of transplant pairs were fully identical for HLA-DPB1, in our study group. Neutrophil and thrombocyte engraftment successfully occurred in the entire study group. When the occurrence of severe (Grade III-IV) aGVHD was taken into account, we have observed that, non-permissive HLA-DPB1 mismatches were a significant factor for development of severe aGVHD (p= 0.019). There was a trend of increasing significance for the gut (p= 0.006) and liver (p: 0.054) aGVHD but not for skin aGVHD in non-permissive HLA-DPB1 mismatched transplantations. In multivariate analysis, non-permissive HLA-DPB1 mismatches remained as an independent factor for severe aGVHD. Our results did not show a significant impact of HLA-DPB1 mismatches on relapse. In survival analysis, both HLADPB1 disparities and non-permissive mismatches showed a decreasing trend of event free and overall survival times. Considering these results during donor selection may improve transplant outcomes in the setting of unrelated ASCT.