The effect of donor characteristics on survival after unrelated donor transplantation for hematologic malignancy.

Publication Type:

Journal Article

Source:

Blood (2015)

Abstract:

There are over 24 million registered adult donors worldwide and the numbers of unrelated donor transplantations are increasing. The optimal strategy for prioritizing among comparably HLA-matched potential donors has not been established. Therefore, the objective of the current analyses was to study the association between donor characteristics (age, sex, parity, cytomegalovirus serostatus, HLA-match and blood group ABO match) and survival after transplantation for hematologic malignancy. The association of donor characteristics with transplantation outcomes was examined using either logistic or Cox regression models, adjusting for patient disease and transplantation characteristics associated with outcomes in two independent datasets, 1988-2006 (N=6349; training cohort) and 2007-2011 (N=4690; validation cohort). All donor-recipient pairs had allele-level HLA typing at HLA-A, -B, -C and -DRB1, the current standard for selecting donors. Results of multivariate analysis adjusting for patient disease and transplantation characteristics showed that survival was better after transplantation of grafts from young donors (aged 18 - 32 years) who were HLA-matched to recipients (p<0.001). These findings were validated for transplantations that occurred between 2007 and 2011. For every 10-year increment in donor age, there is a 5.5% increase in the hazard ratio for overall mortality. Increasing HLA disparity was also associated with worsening survival. Donor age and donor-recipient HLA-match are important when selecting adult unrelated donors. Other donor characteristics such as sex, parity and cytomegalovirus serostatus were not associated with survival. The effect of ABO matching on survival is modest and must be studied further before definitive recommendations can be offered.