Kidney transplants from living donors who were biologically related to their recipients had a higher rate of allograft failure compared with transplants from unrelated donors, investigators reported in JAMA Network Open.
Among 72,980 living transplant donors and recipients (median donor age, 41 years; 60% female; 69% White), 59% of donors and recipients were biologically related and 41% were not. Related pairs had fewer HLA mismatches (median 3 vs 5). Still, recipients of kidneys donated from relatives had a significant 5% overall higher risk for death-censored allograft failure after adjustment for HLA mismatches, donor and recipient characteristics, and transplant era, S. Ali Husain, MD, MPH, of Columbia University Medical Center in New York City, and colleagues reported. This association persisted in recipients without cystic kidney disease. When stratified by donor race, however, the association persisted only for transplants from related Black donors. In a fully adjusted model, a transplant from a related Black donor was significantly associated with a 12% increased risk for death-censored allograft failure.
Whether genetic factors or socioeconomics underlie the increased risk requires further study, according to Dr. Husain’s team. The investigators suggested a higher proportion of related donors may have APOL1 risk variants. Systolic blood pressure, smoking, and body mass index could not be accounted for, which is a limitation.
In an accompanying editorial, Daryl Thornton, MD, MPH, of the Center for Reducing Health Disparities at Case Western Reserve University in Cleveland, Ohio, discussed the importance of examining the effect of socioeconomic disadvantages.
“To better understand the disparities found in transplantation outcomes, we need to incorporate data on the socioeconomic factors that donors and recipients face on a daily basis individually and within their communities,” Dr. Thornton wrote. “Area-based measures can be linked with robust data collected directly from individuals to help design effective, tailored interventions and policies to eliminate these disparities.”