Faculty Bibliography

RATIONALE & OBJECTIVE:Risk factors for kidney failure are the basis of live kidney donor candidate evaluation. We quantified risk for end-stage kidney disease (ESKD) by the biological relationship of the donor to the recipient, a risk factor that is not addressed by current clinical practice guidelines. STUDY DESIGN:Retrospective cohort study. SETTING & PARTICIPANTS:A cohort of 143,750 US kidney donors between 1987 and 2017. EXPOSURE:Biological relationship of donor and recipient. OUTCOME:ESKD. Donors' records were linked to national dialysis and transplantation registries to ascertain development of the outcome. ANALYTIC APPROACH:Donors were observed over a median of 12 (interquartile range, 6-18; maximum, 30) years. Survival analysis methods that account for the competing risk for death were used. RESULTS:Risk for ESKD varied by orders of magnitude across donor-recipient relationship categories. For Asian donors, risks compared with unrelated donors were 259.4-fold greater for identical twins (95% CI, 19.5-3445.6), 4.7-fold greater for full siblings (95% CI, 0.5-41.0), 3.5-fold greater for offspring (95% CI, 0.6-39.5), 1.0 for parents, and 1.0 for half-sibling or other biological relatives. For black donors, risks were 22.5-fold greater for identical twin donors (95% CI, 4.7-107.0), 4.1-fold for full siblings (95% CI, 2.1-7.8), 2.7-fold for offspring (95% CI, 1.4-5.4), 3.1-fold for parents (95% CI, 1.4-6.8), and 1.3-fold for half-sibling or other biological relatives (95% CI, 0.5-3.3). For white donors, risks were 3.5-fold greater for identical twin donors (95% CI, 0.5-25.3), 2.0-fold for full siblings (95% CI, 1.4-2.8), 1.4-fold for offspring (95% CI, 0.9-2.3), 2.9-fold for parents (95% CI, 2.0-4.1), and 0.8-fold for half-sibling or other biological relatives (95% CI, 0.3-1.6). LIMITATIONS:Insufficient sample size in some race and relationship groups. Absence of data for family history of kidney disease for donors biologically unrelated to their recipients. CONCLUSIONS:Marked differences in risk for ESKD across types of donor-recipient relationship were observed for Asian, black, and white donors. These findings warrant further validation with more robust data to better inform clinical practice guidelines.

RATIONALE AND OBJECTIVE/OBJECTIVE:Compared to recipients of ABO-compatible (ABOc) living donor kidney transplants (LDKT), recipients of ABO-incompatible (ABOi) LDKT have a higher risk of graft loss, particularly in the first few weeks after transplantation. However, the decision to proceed with ABOi LDKT should be based on a comparison of the alternative: waiting for future ABOc LDKT (e.g, through kidney paired exchange) or for a deceased donor kidney transplant (DDKT). We sought to evaluate the patient survival difference between ABOi LDKT and waiting for an ABOc LDKT or an ABOc DDKT. STUDY DESIGN/METHODS:Retrospective cohort study of adults in the Scientific Registry of Transplant Recipients (SRTR) SETTING AND PARTICIPANTS: 808 ABOi LDKT recipients and 2423 matched controls from among 245,158 adult, first-time kidney-only waitlist registrants who did not receive an ABOi LDKT and who remained on the waitlist or received either an ABOc LDKT or an ABOc DDKT, 2002-2017 EXPOSURE: Receipt of ABOi LDKT OUTCOME: Death ANALYTICAL APPROACH: We compared mortality among ABOi LDKT recipients versus a weighted matched comparison population using Cox proportional hazards regression as well as Cox models that accommodated for changing hazards ratios over time. RESULTS:Compared to matched controls, ABOi LDKT was associated with lower survival risk in the first 30 days post-transplant (99.0% vs 99.6%, respectively), but higher survival risk beyond 180 days post-transplant. Patients who received ABOi LDKT had higher survival at 5 and 10 years (90.0% and 75.4% respectively) than similar patients who remained on the waitlist or received ABOc LDKT or ABOc DDKT (81.9% and 68.4% respectively). LIMITATIONS/CONCLUSIONS:No measurement of ABO antibody titers in recipients; eligibility of participants for kidney paired donation is unknown. CONCLUSIONS:Transplant candidates who receive an ABOi LDKT and survive more than 180 days post-transplant experience a long-term survival benefit compared to remaining on the waitlist to potentially receive an ABO compatible kidney transplant.

We represent a group of investigators funded by the National Institutes of Health (R01AI120938, U01AI134591, U01AI138897) to conduct a prospective multicenter study of the landscape of HIV-infected (HIV+) donors and two prospective multicenter trials comparing outcomes between HIV+ recipients of HIV+ and non-HIV+ donor kidneys and livers. These clinical trials are ongoing (NCT02602262, NCT03500315, NCT03734393).