Better graft outcomes from offspring donor kidneys among living donor kidney transplant recipients in the United States

A recent study reported that kidney transplant recipients of offspring living donors had higher graft loss and mortality. This seemed counterintuitive, given the excellent HLA matching and younger age of offspring donors; we were concerned about residual confounding and other study design issues. We used Scientific Registry of Transplant Recipients data 2001-2016 to evaluate death-censored graft failure (DCGF) and mortality for recipients of offspring versus nonoffspring living donor kidneys, using Cox regression models with interaction terms. Recipients of offspring kidneys had lower DCGF than recipients of nonoffspring kidneys (15-year cumulative incidence 21.2% vs 26.1%, P <.001). This association remained after adjustment for recipient and transplant factors (adjusted hazard ratio [aHR] =  _0.73 0.77 _0.82 , P <.001), and was attenuated among African American donors (aHR _0.77 0.85 _0.95 ; interaction: P =.01) and female recipients (aHR _0.77 0.84 _0.91 , P <.001). Although offspring kidney recipients had higher mortality (15-year mortality 56.4% vs 37.2%, P <.001), this largely disappeared with adjustment for recipient age alone (aHR =  _1.02 1.06 _1.10 , P =.002) and was nonsignificant after further adjustment for other recipient characteristics (aHR =  _0.93 0.97 _1.01 , P =.1). Kidneys from offspring donors provided lower graft failure and comparable mortality. An otherwise eligible donor should not be dismissed because they are the offspring of the recipient, and we encourage continued individualized counseling for potential donors.