Improved access to better HLA-matched hematopoietic cells for allogeneic transplant: analysis of donors and cord blood units selected for Canadian patients in 2018.

BACKGROUND

Patients undergoing hematopoietic cell transplantation (HCT) often require use of an unrelated donor or cord blood unit (CBU). An understanding of evolving practices in graft selection is needed for optimization of donor recruitment and cord blood collection.

STUDY DESIGN AND

METHODS

Each donor workup (WU) requested in 2018 involving a Canadian (CDN) patient and unique donor product or CBU was reviewed (n = 598). Degree of HLA match; product origin (domestic or international [INT]); and non-HLA factors including donor age, sex, cytomegalovirus (CMV), and ABO compatibility were analyzed for WUs that proceeded to transplant (n = 414). We also analyzed changes compared to a similar analysis performed in 2013.

RESULTS

The majority of transplants used matched unrelated donors (MUDs; n = 323; 78%) and were most often young (≤35 years), male, INT donors (n = 136). The proportion of transplants involving MUDs, as opposed to mismatched unrelated donors or CBUs, increased by 12.4% compared with 2013. When young, male, CDN MUDs were identified in patient search reports but not selected, CMV mismatching and ABO incompatibility were most likely to have influenced the decision to use an INT MUD. Consistent with global trends, CBU transplants decreased compared to 2013; however, the degree of HLA matching improved significantly, and 27% of transplanted CBUs were procured from the Canadian Blood Services Cord Blood Bank.

CONCLUSIONS

Access to MUDs and better HLA-matched CBUs by CDN patients has increased since 2013. Ongoing recruitment of young registrants and cord blood donors with diverse HLA haplotypes will support selection of donors with optimal non-HLA characteristics.