Riad, Samy M.

Outcomes of kidney-alone transplantation (KAT) in former simultaneous liver-kidney (SLK) transplant candidates after liver waitlist delisting are not well defined. Using Scientific Registry of Transplant Recipients (SRTR) data, we identified adult recipients who underwent KAT between 2005 and 2025 after prior SLK listing (RLD-KAT), which was matched 1:5 to primary KAT recipients without liver disease by age, transplant year, and diabetes status. Patient and graft survival were evaluated using the Kaplan-Meier method and multivariable Cox proportional hazards models. We identified 163 RLD-KAT recipients matched to 815 controls. Unadjusted Kaplan-Meier analyses demonstrated lower patient survival in RLD-KAT (p = 0.020), whereas death-censored and overall graft survival were similar (p > 0.05). In multivariable models, death-censored graft survival (HR 0.89; 95% CI 0.51–1.53), overall graft survival (HR 1.00; 95% CI 0.73–1.36), and patient survival (HR 1.07; 95% CI 0.76–1.5) did not differ significantly. Six RLD-KAT recipients (3.7%) subsequently underwent liver transplantation. Kidney-alone transplantation in prior SLK candidates was associated with acceptable patient and graft outcomes and a low incidence of subsequent liver transplantation.

Key Points Atrial fibrillation after kidney transplantation is common and is associated with poor prognosis. Artificial intelligence applied to 12-lead electrocardiograms pretransplant accurately predicts the risk of new-onset atrial fibrillation in our cohort. High-risk artificial intelligence electrocardiography score was independently associated with increased risk of mortality and allograft failure. Background Incident atrial fibrillation (AF) is common after kidney transplantation (KTx) and is associated with worse clinical outcomes. Artificial intelligence electrocardiography (AI-ECG) algorithms have demonstrated efficacy in predicting risk of new-onset AF in the general population; however, their prognostic value in KTx recipients is relatively unknown. Methods Retrospective analysis was conducted on KTx recipients without AF, with at least one pretransplant ECG between 2011 and 2021 across three tertiary centers in the United States (Mayo Clinic sites in MN, AZ, and FL). A previously validated AI-ECG algorithm estimated the probability of incident AF for each patient. Based on AI-ECG probabilities, patients were categorized into high-risk and low-risk groups, with the optimal AI-ECG score cutoff determined. The incidence of new-onset AF, allograft failure, and mortality was compared between groups. Results Overall, 6246 patients (age 53.5±13.8 years; 58.9% male) were included. Pretransplant AI-ECG probability of AF ≥5% was the optimal cutoff for high risk of incident AF (sensitivity 72%, specificity 62%). High-risk scores were associated with true new-onset AF at 30 days (adjusted hazard ratio [aHR], 2.89; 95% confidence intervals [CI], 2.05 to 4.09; P < 0.001), 3 years (aHR, 2.54; 95% CI, 1.99 to 3.26, P < 0.001), and 5 years post-transplant (aHR, 2.48; 95% CI, 1.99 to 3.09, P < 0.001). High-risk AI-ECG scores were also associated with increased mortality (aHR, 1.56; 95% CI, 1.30 to 1.88, P < 0.001) and overall allograft failure (aHR, 1.50; 95% CI, 1.30 to 1.75, P < 0.001) through the 5-year follow-up. Conclusions This pretransplant AI-ECG parameter identified patients at increased risk of new-onset AF post-KTx and provided prognostic utility. Overall, this easy to obtain tool allows for risk stratification of patients who may benefit from closer monitoring, targeted risk factor modification, and early intervention.

ABSTRACT This study investigated the association between induction type and long‐term outcomes in kidney retransplant recipients who experienced graft loss due to BK virus–associated nephropathy (BKVAN). Using Scientific Registry of Transplant Recipients data (2003–2021), we identified 277 adult kidney‐alone retransplant recipients with BKVAN‐related graft loss and categorized them by induction regimen: depletional ( n = 217) and nondepletional ( n = 60). The groups were similar overall, except the nondepletional cohort had lower panel‐reactive antibodies, a shorter time between transplants, and more live donor kidneys. Kaplan–Meier curves assessed 10‐year recipient and graft survival, and Cox proportional hazards models, adjusted for key donor and recipient factors, evaluated associations between induction type and outcomes. Rates of delayed graft function, one‐year rejection, and estimated glomerular filtration rate were comparable between groups. Ten‐year recipient and death‐censored graft survival did not differ by induction type (recipient survival: HR 1.09; 95% CI 0.43–2.77; p = 0.85; graft survival: HR 0.85; 95% CI 0.24–2.97; p = 0.79). Recurrent BKVAN‐related graft failure occurred only in the depletional group (5 of 217; 2.3%), while rejection‐related graft failure was more common in the nondepletional group (5 of 60; 8.3% vs. 6 of 217; 2.8%). Although these differences did not translate into long‐term graft survival disparities, they highlight the competing risks of viral recurrence and rejection. Thus, clinicians should interpret these results with caution and weigh the risks and benefits of induction choice in retransplant recipients with prior BKVAN, recognizing that this observational study cannot establish causality.

Background. Living kidney donation (KD) evaluation particularly focuses on glomerular filtration rate (GFR). Assessing GFR in living kidney donors can be done by estimation (eGFR) or measurement (mGFR). This study aims to evaluate the impact of eGFR equations, focusing on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation for donor eligibility screening and the reclassification of donors excluded by eGFR criteria to mGFR assessments. Methods. Retrospective, single-center observational study of 2512 kidney donors evaluated between 2011 and 2023, at the Mayo Clinic. We performed analyses and comparisons of 4 eGFR formulae and 2 mGFR methods in terms of performance, eligibility criteria according to Kidney Disease: Improving Global Outcomes guidelines/age-adjusted criteria, eligibility reclassification, and subgroup analyses. Results. The CKD-EPI 2021 resulted in a higher percentage of patients being eligible for KD (81.4%) and achieved the highest P10 (32%–34%) and P30 (87%–88%) across all mGFR methods. When patients were deemed eligible for donation by any eGFR formula, 95% retained this status on reassessment with mGFR. Conversely, when an eGFR formula classified a patient as ineligible, this was revised to be eligible in about 90% of cases on reassessment with mGFR, with a higher reclassification rate observed when the IoCl was used instead of CrCl. Conclusions. The CKD-EPI 2021 performs best for screening potential KD. If a KD is deemed ineligible by CKD-EPI 2021, there is a high likelihood that they will be reclassified as eligible when assessed with mGFR. This study strongly supports using mGFR in donor evaluations, especially when the eGFR does not meet the criteria to ensure equity of access to being a living donor.

ABSTRACT Background The association between transjugular intrahepatic portosystemic shunt TIPS and waitlist outcomes in simultaneous liver‐kidney (SLK) transplant recipients remains unclear. Methods Between 2003 and 2023, we examined the scientific registry of transplant recipients. All adult candidates with overlapping waiting lists for liver and kidney transplants ( N = 15 087) were analyzed (entire cohort). Candidates without TIPS ( n = 13 980) and with ( n = 1107) were followed through November 30, 2023, and the following outcomes were analyzed: death, SLK transplant, liver‐ or kidney‐alone transplant, or removal from the list. The Aalen–Johansen method was used to calculate the cumulative incidence rates of the outcomes, where the outcomes were considered competing risks. Mixed effects Cox proportional hazard models were used to compare the outcomes by TIPS status. We separately analyzed dialysis‐dependent candidates ( n = 10 370). Results In the entire cohort, the 1‐year cumulative incidence of death in those without TIPS was higher than in those with (12.5% vs. 9%). In the dialysis‐dependent cohort, the 1‐year death incidence was 13.3% versus 8.8% in those without TIPS and those with, respectively. In the multivariable Cox proportional hazard models, TIPS was associated with a 29% lower mortality risk in the entire cohort (HR = 0.71, 95% CI: 0.60–0.84, p < 0.001) and a 33% lower risk of mortality in the dialysis‐dependent cohort. The likelihood of receiving SLK was lower for recipients with TIPS in the univariable analysis. However, this association was attenuated after adjustment. The causes of removal were similar irrespective of TIPS status in both cohorts. Conclusion In this large cohort of SLK candidates, those with TIPS had a better waitlist survival, irrespective of their dialysis requirements before transplantation. Prospective studies are needed to validate these findings.

Key Points Pediatric preemptive kidney transplantation rates in the United States vary by socioeconomic status (SES). The HOUsing-based index of SES, an individual-level SES measure derived from residential addresses, effectively predicts pediatric preemptive kidney transplant rates. Background Preemptive kidney transplantation in children is associated with better patient and graft survival compared with transplants after dialysis. However, preemptive kidney transplantation rates in children remain low. This study aimed to evaluate the effect of socioeconomic status (SES) on preemptive transplantation in children. Methods Our study included 173 Minnesota-resident pediatric kidney transplant recipients (younger than 18 years) transplanted at the University of Minnesota from 2010 to 2020. Using the HOUsing-based index of SES (HOUSES) index, a validated, individual SES measure based on housing units categorized into quartiles (Q1: lower SES; Q2–Q4: higher SES), we applied mixed-effects multivariable logistic models to examine the effects of HOUSES on preemptive kidney transplants and pretransplant dialysis duration. Results Of 173 pediatric kidney transplant recipients, 46 (26.6%) received a preemptive transplant, and of 109 recipients with dialysis duration data, 39 (35.8%) received dialysis for >1 year. After adjusting for age at kidney failure, sex, donor type, insurance type, and underlying cause of kidney failure, we observed significantly lower odds of preemptive transplantation among Q1 recipients compared with Q2–4 recipients (adjusted odds ratio, 0.31; 95% confidence interval, 0.11 to 0.90; P = 0.03). Conclusions Using the HOUSES index, we found significant socioeconomic disparities in preemptive kidney transplantation rates among children.

Background: Previous data suggested that the outcomes for liver-alone transplant recipients following transjugular intrahepatic portosystemic shunt (TIPS) insertion were comparable to those without TIPS. This study investigates the association between TIPS and outcomes among simultaneous liver–kidney (SLK) recipients in the United States. Methods: Utilizing the Scientific Registry for Transplant Recipients (SRTR) standard analysis file from 2003 to 2022, we examined 9717 adult SLK recipients, among whom 858 had undergone TIPS before transplantation. Kaplan–Meier curves were generated to assess recipient and death-censored liver and kidney graft survival. Mixed-effects Cox proportional hazard models were employed to analyze the association between TIPS and the outcomes of interest, where the transplant center was treated as a random effect. The models were adjusted for recipient age, sex, MELD score, diabetes, duration of listing, induction, steroid maintenance, hepatitis C status, donor age, donor sex, cold ischemia time, local vs. shipped organs, and allocation era. Results: Overall, the two groups were comparable, with minor differences. Notably, the median liver waiting time was significantly longer in the TIPS group compared to the non-TIPS group (4.1 vs. 2 months, p < 0.001). One-year rejection rates for liver and kidney allografts did not differ significantly between groups. Univariable Cox regression analyses demonstrated no association between TIPS and worse outcomes for recipient, liver, and kidney survival (p = 0.65, p = 0.22, and p = 0.54, respectively). TIPS did not emerge as a predictor of recipient or death-censored liver or kidney graft survival in multivariable models. Conclusion: In this extensive national cohort of SLK transplant recipients, pre-transplant TIPS was not linked to adverse outcomes for recipients or their allografts.

Background. The impact of induction type or high-risk viral discordance on older kidney transplant recipients is unclear. Herein, we analyzed the association between induction type, viral discordance, and outcomes for older recipients. Methods. We analyzed the Scientific Registry of Transplant Recipients standard analysis file for all primary kidney transplant recipients older than 55 y who were transplanted between 2005 and 2022. All transplants were crossmatch negative and ABO-compatible. Recipients were discharged on tacrolimus and mycophenolate ± steroids. Recipients were categorized into 3 groups by induction received: rabbit antithymocyte globulin (r-ATG; N = 51 079), interleukin-2 receptor antagonist (IL-2RA; N = 22 752), and alemtuzumab (N = 13 465). Kaplan-Meier curves were generated for recipient and graft survival, and follow-up was censored at 10 y. Mixed-effect Cox proportional hazard models examined the association between induction type, high-risk viral discordance, and outcomes of interest. Models were adjusted for pertinent recipient and donor characteristics. Results. Induction type did not predict recipient survival in the multivariable model, whereas Epstein-Barr virus high-risk discordance predicted 14% higher mortality (1.14 [1.07-1.21], P < 0.01). In the multivariable model for death-censored graft survival, alemtuzumab, but not IL-2RA, was associated with an increased risk of graft loss (1.18 [1.06-1.29], P < 0.01) compared with r-ATG. High-risk cytomegalovirus discordance predicted 10% lower death-censored graft survival (1.10 [1.01-1.19], P < 0.02). Live donor and preemptive transplantation were favorable predictors of survival. Conclusions. In this large cohort of older transplant recipients, alemtuzumab, but not IL-2RA, induction was associated with an increased risk of graft loss compared with r-ATG. Cytomegalovirus and Epstein-Barr virus high-risk viral discordance portended poor graft and recipient survival, respectively.

Background. Induction choices for kidney-after-heart transplant recipients are variable. We examined the impact of kidney induction types on kidney graft and patient survival in heart transplant recipients. Methods. We analyzed the Scientific Registry of Transplant Recipient database from inception through the end of 2018 to study kidney and patient outcomes in the United States after heart transplantation. We only included recipients who were discharged on tacrolimus and mycophenolate maintenance. We grouped recipients by induction type into 3 groups: depletional (N = 307), nondepletional (n = 253), and no-induction (steroid only) (n = 57). We studied patients and kidney survival using Cox PH regression, with transplant centers included as a random effect. We adjusted the models for heart induction, recipient and donor age, gender, time between heart and kidney transplant, heart transplant indication, HLA mismatches, payor, live-donor kidney, transplant year, dialysis status, and diabetes mellitus at the time of kidney transplant. Results. The 1-y kidney rejection rates and creatinine levels were similar in all groups. The 1-y rehospitalization rate was higher in the depletional group (51.7%) and nondepletional group (50.7%) than in the no-induction group (39.1%) although this was not statistically significant. There were no differences in recipient or kidney survival by kidney induction type. Live-donor kidney was associated with improved patient (hazard ratio, 0.74; 95% confidence interval, 0.54-1.0; P = 0.05) and kidney survival (hazard ratio, 0.45; 95% confidence interval, 0.24-0.84; P = 0.012]. Conclusions. Type of kidney induction did not influence patient or kidney graft survival in heart transplant recipients. No-induction may be the preferred choice due to the lack of clinical benefits associated with induction use.