Interplay of Donor-Recipient Relationship and Donor Race in Living Liver Donation in the United States

Introduction: Living liver donation improves survival of end-stage liver disease (ESLD) patients. Yet, it continues to represent a small proportion of United States (U.S.) liver transplantation with existing racial disparities. We investigated the interplay of donor-recipient relationship and donor race to understand donor subgroups with no significant increase.

Methods: We studied 4407 living liver donors in the U.S. from January 1, 2012, to December 31, 2022 (median age = 36 years, and 59% were biologically related to the recipient). We quantified the change in the number of donors per 3-year increment using negative binomial regression (incidence rate ratio [IRR]), stratified by donor-recipient relationship and race/ethnicity.

Results: Among biologically related donors, the observed annual number of White donors increased from 146 to 253, Hispanic donors from 18 to 53, and Black donors decreased from 11 to 10. Among unrelated donors, White donors increased from 65 to 221, Hispanic donors from 4 to 25, and Black donors from 3 to 11. For the IRR of biologically related donors aged <40 and ≥40 years, White donors increased by 18% and 22%; Hispanic donors increased by 25% and 54%; and Black donors did not change. Likewise, the IRR of unrelated donors aged <40 and ≥40 years, White donors increased by 48% and 55%; Hispanic donors increased by 52% and 65%; and Black donors did not change.

Conclusions: While biologically related donors represent the majority of donors, unrelated donors have substantially risen in recent years, primarily driven by White donors. Although the rate of unrelated donations increased among Hispanic donors, the absolute number remains very small (≤25 donors/year). Interventions are needed to increase education among Hispanic and Black communities to grow unrelated living liver donations across race/ethnicity.