Faculty Bibliography

Kidneys from donation after circulatory death (DCD) donors historically had lower recovery and utilization than kidneys from donation after brain death (DBD) donors. However, the organ shortage and advances in organ preservation have increased interest in DCD transplantation. We used OPTN data to study temporal changes in U.S. DCD kidney recovery and transplantation. The percent DCD among kidney donors increased from 21.0% (Era1: 2016-2019) to 30.6% (Era2: 2020-2022) and 42.4% (Era3: 2023-2025). By 2025Q2, more than half (50.4%) of kidney donors were DCDs. Wide variability persisted across eras in percent DCD by recovering OPO (Era1 range: 0%-38%, Era2: 0%-49%, Era3: 0.4%-60%) and by transplanting center (Era1 range: 0%-48%, Era2: 0%-58%, Era3: 0%-60%). Transplanted DCD kidneys in Era3 (vs Era1 & Era2) were more likely to have donor age >60, diabetes, hypertension, obesity, and death due to cardiovascular disease or stroke; 86.8% were pumped. Though the recovered DCD kidney nonuse rate rose from 20.8% (Era1) to 29.9% (Era2) and 35.4% (Era3), nonused DCD kidney donors were age and had more comorbidities in Era 3 compared to earlier eras. Given that half of kidney donors are now DCD, refinements in DCD donor selection and management are needed to optimize recovery and utilization.

As hepatitis C virus (HCV) infection is now curable, HCV-positive donor organs have expanded the deceased donor pool. Using OPTN data, we identified adult kidney, liver, heart, and lung candidates listed between 2016-2025 and evaluated rates of consent to accept HCV antibody-positive (Ab+) and HCV viremic (NAT+) organs. Temporal trends were described, and multilevel modified Poisson regression with center-level random effects was used to estimate adjusted risk ratios for candidate factors and quantify center variation using median incidence rate ratios (MIRR). Rates of consent to accept both HCV Ab+ and NAT+ organs rose over time. By the end of follow-up, consent rates for HCV Ab+ organs were 63.1% for kidney, 80.6% for liver, 73.3% for heart, and 72.1% for lung candidates, and consent rates for NAT+ organs were 44.9%, 70.7%, 50.5%, and 46.1%, respectively. Associations between candidate characteristics and consent were small after adjustment for center, whereas center effects were large. For HCV Ab+ organs, MIRRs were 6.31 (kidney), 2.48 (liver), 2.90 (heart), and 4.36 (lung); for NAT+ organs, MIRRs were even higher, 9.65, 3.19, 4.00, and 7.30, respectively, indicating marked between-center variability. Our analyses suggest that access to HCV-positive organs is influenced more by center practices than patient characteristics.

Disparities in deceased donor liver transplantation (DDLT) may be due to geographic imbalances of organ supply-to-demand ratios and/or center organ acceptance practices. We evaluated the relative contribution of centers versus broader geographic units (DSAs/States/OPTN regions/census divisions) to variability of DDLT rate. Using SRTR data on adult, first-time, non-Status1A, period-prevalent waitlist candidates, we conducted multilevel Poisson regression with center-level and donor service area (DSA)-level intercepts to model DDLT rates across three eras: pre-acuity circles (AC)(5/1/2017-4/30/2019), initial post-AC (2/4/2020-2/3/2022), and recent post-AC (02/04/2022-12/31/2024), adjusting for candidate factors. We calculated center-level and DSA-level median incidence rate ratios (MIRRs) and their relative contributions to total geographic variation. DSA-level MIRR declined from _1.471.52_1.58 to _1.321.37_1.42 to _1.171.23_1.28 from pre-AC to initial post-AC to recent post-AC. The center-level, within-DSA MIRR increased from _1.561.61_1.64 to _1.761.82_1.84 to _1.921.96_2.05 across eras. The DSA-level contribution to total center-level variation declined from 43.7% to 21.5% to 8.4% across eras. Similarly, the contribution of other broad, geographic units (States/OPTN regions/census divisions) to total geographic variation in DDLT rates decreased after AC. Further allocation changes are unlikely to substantially reduce geographic disparities because DDLT rate variation is predominantly driven by center-level differences, which were associated with highly variable advanced preservation practices.

BACKGROUND:The iBox is a validated prognostication system that predicts long-term death-censored graft loss in kidney transplant recipients, but its performance in the specific population of African American recipients has not been fully studied. METHODS:We conducted a multicenter study including 3,866 kidney transplant recipients from North America, of whom 1,040 (27%) were African American, to assess the impact of race on the iBox's performance in predicting graft loss. Discrimination, calibration, overall fit and clinical utility were evaluated in the whole cohort and in African American and non-African American recipients. RESULTS:Performance metrics for the prediction of graft loss were similar in both subgroups in terms of discrimination (c-index 0.80 [95% CI: 0.77-0.83] in African American recipients and 0.83 [95% CI: 0.81-0.85] in non-African American recipients, p=0.07), and observed/expected ratios (1.08 [95% CI: 0.95-1.23] and 0.99 [95% CI: 0.88-1.10], respectively, p=0.28). No significant interaction between iBox score values and race was found in multivariable analysis stratified by transplant center (p=0.29 for the interaction term). Results were consistent between subgroups regardless of the equation used to estimate glomerular filtration rate (Kidney Recipient Specific [KRS], CKD-EPI, or MDRD), with small variations in calibration across equations. CONCLUSIONS:The iBox prognostication system showed accurate discrimination, overall fit, and clinical utility up to 7 years post-risk evaluation in African American and non-African American kidney transplant recipients, supporting its robustness in this population.

[This corrects the article DOI: 10.1016/j.lana.2024.100895.].

INTRODUCTION/UNASSIGNED:Older adults with chronic kidney disease (CKD) likely face higher dementia risk because of vascular injury and chronic inflammation, potentially intensified among racially minoritized groups and those in rural or deprived neighborhoods. We quantified this association and examined variation by race and ethnicity, urbanicity, and neighborhood deprivation. METHODS/UNASSIGNED:We identified 211,321 older adults with CKD stages 3 to 5 from the Medicare 5% sample (2010-2022) using International Classification of Diseases (ICD)-9 and/or ICD-10 codes. Zone Improvement Plan (ZIP)-code level urbanicity was defined using Rural-Urban Commuting Area Codes, and neighborhood deprivation was derived from the American Community Survey. We used cause-specific hazard models with time-varying CKD stage (reference = stage 3) to quantify the adjusted hazard ratio (aHR) of dementia and included interaction terms to test the differential effect of these associations by race and/or ethnicity, urbanicity, and neighborhood deprivation. RESULTS/UNASSIGNED:= 0.04). Among older Black (stage 4 aHR: 1.38, 95% CI: 1.28-1.48; stage 5 aHR: 2.01, 95% CI: 1.88-2.15) and Hispanic adults (stage 4 aHR: 1.33, 95% CI: 1.10-1.62; stage 5 aHR: 1.98, 95% CI: 1.67-2.34), stages 4 and 5 were associated with a higher risk of dementia. Among older adults in high-deprivation neighborhoods, stage 5 was associated with a higher risk of dementia (aHR: 1.89, 95% CI: 1.80-1.99). CONCLUSION/UNASSIGNED:CKD stages 4 and 5 were associated with a higher dementia risk, particularly among older Black adults and those in high-deprivation neighborhoods. These findings may inform targeted interventions for early detection and management of cognitive decline in advanced CKD.

INTRODUCTION/BACKGROUND:Biological parental donations provide the best option for many pediatric recipients, yielding unique immunological benefits that may enable minimization of immunosuppression in transplanted children. However, living related maternal donation in the postpartum period may introduce an increased risk of donor complications due to the physiological changes of pregnancy and childbirth, and the optimal timing of postpartum living donation is unknown. METHODS:Using US national registry data, we characterized donor and recipient outcomes for pediatric living donor liver transplants performed between 2004 and 2022 where a biological mother donated to a child ≤ 24 months old. RESULTS:Our study population included 256 donor-recipient pairs, with biliary atresia representing the most common indication for transplantation (68.0%). Donors had a median [IQR] age of 30 [25, 34] years, and the median [IQR] time from birth to donation was 9.0 [6.8, 13.0] months. 6.3% of donors experienced a biliary or other complication. When stratifying by donors who donated ≤ 6 vs. > 6 months postpartum, we found no significant differences in donor complications or readmission. Stratified analyses were also comparable for recipient mortality, graft survival, and rejection-free survival. Donors ≤ 6 months postpartum (n = 64) were more likely to experience reoperation than mothers who donated > 6 months postpartum (n = 192) (6.2% vs. 1.0%, p = 0.04). CONCLUSIONS:While maternal living donor liver transplantation is safe for most donors, there is a higher risk of reoperation when donation is performed ≤ 6 months postpartum. Surgeons should be aware that these donors are a higher risk population, requiring discussion upon consent and warranting close post-operative monitoring.

BACKGROUND:As a 6-month waiting period is required to receive exception points to prioritize patients with hepatocellular carcinoma (HCC) for liver transplantation, prompt addition to the waitlist is critical in access to LT. METHODS:Using Epic Cosmos data on patients with HCC referred for LT 1/2018-10/2024, we used modified Poisson regression to calculate rates of waitlisting. Center-level and individual (socioeconomic, geographic, and insurance) factors were measured among those who progressed. RESULTS:Among 11,422 HCC patients referred for LT at 70 centers, with median age 63 [IQR: 58, 68], 71.5% initiated evaluation and, of those who began evaluation, 57.6% were waitlisted for LT. Of those referred, patients who were older (age 70+ vs. 51-60; RR 0.77, 95% CI: 0.65-0.90, p < 0.001), on Medicaid (0.83, 95% CI: 0.71-0.97, p = 0.02), never-married (0.82, 95% CI: 0.73-0.91, p < 0.001), or low SES (Q4: 0.87, 95% CI: 0.77-0.97, p = 0.002) had lower rates of waitlisting. Among waitlisted patients, median time from referral was 3.3 months [IQR: 2.0, 5.3]. Despite adjustment for patient level covariates, there was high center-level variation in rate of waitlisting within 12 months; 13% of centers listed patients at a rate ≥ 20% below the national median. CONCLUSION/CONCLUSIONS:Only a fraction of referred patients with HCC are waitlisted for LT. High variation in access to waitlisting based on non-clinical factors suggests barriers to waitlisting that must be addressed. Centers should focus on interventions to reduce barriers to waitlisting in patients with HCC.

BACKGROUND:Care coordination between primary care providers and nephrologists is crucial for preemptive kidney transplantation (KT), which confers health advantages over KT after dialysis. Residence in areas with limited primary care (Medically Underserved Areas [MUAs]/Health Professional Shortage Areas [HPSAs]) and nephrology access may differentially affect preemptive listing/KT. OBJECTIVE:To quantify access to preemptive KT by residence in limited primary care/nephrology access areas. DESIGN/METHODS:Retrospective cohort study from the US national registry. PARTICIPANTS/METHODS:A total of 353,636 adult KT candidates (age ≥ 18) listed between 2005-2020. EXPOSURES/METHODS:ZIP-code level MUA and HPSA information (HRSA), and distance to nearest nephrologist (CMS; urbanicity-specific thresholds for "far" from nephrologists: suburban, > 5.8 km; urban, > 2.3 km; small town, > 19.4 km; rural, > 25.2 km). MAIN MEASURES/METHODS:Poisson regression with robust variance estimator quantified adjusted prevalence ratios (aPRs) of preemptive listing, and cause-specific hazards models quantified adjusted hazard ratios (aHRs) of preemptive KT by MUAs/HPSAs/distance to nephrologists. Interaction terms quantified differences in the aforementioned associations by race and ethnicity/neighborhood urbanicity/socioeconomic determinants. KEY RESULTS/RESULTS: < 0.05). Lastly, there were no associations between distance to nephrologists and preemptive listing/KT. CONCLUSIONS:Limited primary care access may impede KT access. Greater investment in primary care within MUAs/HPSAs, addressing geographic/linguistic barriers, and improved nephrology care coordination may increase transplant equity. CLINICAL TRIAL NUMBER/BACKGROUND:Not applicable.