Donor and stem cell source selection in hematopoietic cell transplantation in the Asia-Pacific region: results from...

Donor selection strategies for allogeneic hematopoietic cell transplantation (HCT) have evolved with the increasing use of haploidentical transplantation. However, contemporary patterns of donor and stem cell source selection according to disease category in the Asia-Pacific (AP) region remain insufficiently characterized.

Aggregated data from the APBMT Activity Survey 2022-2023 were analyzed to evaluate donor type and stem cell source distributions for allogeneic HCT. Donors were categorized as HLA-identical sibling, haploidentical (including other related donors), or unrelated donor. Stem cell sources were classified as bone marrow (BM), peripheral blood (PB), cord blood (CB), or mixed graft sources. Malignant and non-malignant diseases were compared, and disease-specific analyses were performed for acute myeloid leukemia, myelodysplastic syndrome/myeloproliferative neoplasms, severe aplastic anemia, and hemoglobinopathy. Sensitivity analyses excluding data from China were conducted.

Donor selection differed between malignant and non-malignant diseases, with haploidentical donors accounting for approximately 45%-60% of allogeneic HCTs, followed by unrelated donors (20%-30%) and HLA-identical sibling donors (15%-25%). Regarding stem cell source, PB was the predominant source across disease categories, accounting for approximately 60%-70% of allogeneic HCTs. BM accounted for approximately 5%-17% of transplants, with somewhat higher use in non-malignant diseases. CB accounted for approximately 10%-12% of transplants in malignant diseases and 3%-4% in non-malignant diseases. These patterns were consistent in disease-specific analyses; however, exclusion of China resulted in a relative decrease in haploidentical transplantation and an increase in unrelated donor use, particularly in malignant diseases, as well as a marked reduction in mixed graft sources with a corresponding increase in bone marrow use. Despite these shifts, the overall predominance of peripheral blood as the stem cell source and the disease-specific trends were maintained.

Across AP region, donor and stem cell source selection for allogeneic HCT demonstrates modest but consistent disease-specific differences, reflecting adaptation of transplantation strategies to disease context in contemporary clinical practice.