Amanda Vinson1, Tom Skinner2, Bryce Kiberd3, David Clark1, Karthik Tennankore1. 1. Division of Nephrology, Department of Medicine, Nova Scotia Health Authority, Halifax, NS, Canada. 2. Department of Urology, Nova Scotia Health Authority, Halifax, NS, Canada. 3. Faculty of Medicine, Dalhousie University, Halifax, NS, Canada.
Abstract
BACKGROUND: The impact of weight mismatch between donors and recipients (D-R) undergoing living-donor kidney transplant (LDKT) versus weight-matched deceased donor kidney transplant (DDKT) is not established. AIM: To determine whether absolute weight mismatch between D-R affects graft survival following LDKT and how this relates to graft outcomes with DDKT when D-R are weight matched. MATERIALS & METHODS: We used multivariable Cox proportional hazards models and the Scientific Registry of Transplant Recipients to determine the association of weight-mismatched D-R (>50 kg, 30-50 kg or 10-30 kg ((D < R); (D > R) and <10 kg (D = R)) with death-censored graft failure in US LDKT recipients from 2006 to 2017. We also explored outcomes relative to weight-matched DDKT and finally, the impact of combined D-R weight-sex mismatch. RESULTS: In LDKT, the risk of graft loss was highest in the setting of D < R (HR 1.28, 95% CI 1.05-1.56 for >50 kg difference relative to D = R); however, this was still lower risk than weight-matched DDKT. D-R sex and combined weight-sex mismatch were only important for male recipients (HR 1.47, 95% CI 1.27-1.71 for a male recipient >30 kg larger than their female donor, relative to weight-matched male donor-male recipient). This remained superior to weight-sex-matched DDKT however. CONCLUSION: D-R weight-sex mismatch is important in LDKT; however, graft survival remains superior to proceeding with matched DDKT. Optimizing D-R matching in LDKT could be facilitated through a national kidney-paired donation registry. LDKT weight-sex mismatch should not be deferred in favor of DDKT.
BACKGROUND: The impact of weight mismatch between donors and recipients (D-R) undergoing living-donor kidney transplant (LDKT) versus weight-matched deceased donor kidney transplant (DDKT) is not established. AIM: To determine whether absolute weight mismatch between D-R affects graft survival following LDKT and how this relates to graft outcomes with DDKT when D-R are weight matched. MATERIALS & METHODS: We used multivariable Cox proportional hazards models and the Scientific Registry of Transplant Recipients to determine the association of weight-mismatched D-R (>50 kg, 30-50 kg or 10-30 kg ((D < R); (D > R) and <10 kg (D = R)) with death-censored graft failure in US LDKT recipients from 2006 to 2017. We also explored outcomes relative to weight-matched DDKT and finally, the impact of combined D-R weight-sex mismatch. RESULTS: In LDKT, the risk of graft loss was highest in the setting of D < R (HR 1.28, 95% CI 1.05-1.56 for >50 kg difference relative to D = R); however, this was still lower risk than weight-matched DDKT. D-R sex and combined weight-sex mismatch were only important for male recipients (HR 1.47, 95% CI 1.27-1.71 for a male recipient >30 kg larger than their female donor, relative to weight-matched male donor-male recipient). This remained superior to weight-sex-matched DDKT however. CONCLUSION: D-R weight-sex mismatch is important in LDKT; however, graft survival remains superior to proceeding with matched DDKT. Optimizing D-R matching in LDKT could be facilitated through a national kidney-paired donation registry. LDKT weight-sex mismatch should not be deferred in favor of DDKT.