Issa, Naim

Delayed graft function (DGF) is a frequent complication after deceased donor kidney transplantation, yet its long-term impact remains understudied. Heterogeneous populations, short follow-up, and inadequate control of donor-related factors have limited prior studies. Using the Scientific Registry of Transplant Recipients (2005–2024), we evaluated the association between DGF and long-term graft outcomes, including a mate-kidney (same donor, discordant DGF status) analysis to isolate its independent effect. We identified 103,678 dialysis-dependent deceased donor kidney recipients maintained on tacrolimus and mycophenolate. Mixed-effects Cox models, adjusted for donor, recipient, immunologic, and procurement factors. DGF occurred in 30.1% of recipients and was associated with increased death-censored graft failure (HR 1.40; 95% CI 1.33–1.47) and overall graft failure (HR 1.27; 95% CI 1.23–1.31). DGF recipients had higher rejection rates at 6 (6.0% vs. 4.7%) and 12 months (8.9% vs. 7.3%), longer hospital stay, and higher 1-year rehospitalization. In the mate-kidney analysis (6,818 donors), DGF remained strongly associated with death-censored graft failure (HR 1.58; 95% CI 1.39–1.80) and overall graft failure (HR 1.35; 95% CI 1.25–1.46), confirming the independent effect of DGF. DGF is a strong predictor of adverse long-term outcomes irrespective of rejection and warrants targeted prevention strategies and intensified follow-up.

Obesity is increasingly prevalent among living kidney donor candidates, presenting complex clinical, ethical, and logistical challenges. Although obesity is linked to increased post-donation hypertension, diabetes, proteinuria, and chronic kidney disease, the overall absolute risks are modest and may differ depending on metabolic health and patterns of fat distribution. Current reliance on body mass index alone fails to capture the full spectrum of obesity-related risks, leading to inconsistent donor selection practices and potential inequities. This review examines the pathophysiological mechanisms of obesity-related kidney injury and available evidence on comorbidities and postdonation outcomes related to obesity. We discuss tools for better risk stratification, such as imaging-based adiposity assessment and personalized weight management strategies, and note that some risks may remain after weight loss. Barriers such as rigid body mass index cutoffs, limited access to treatment, and lack of long-term follow-up exacerbate disparities in access to donation. We argue for a shift toward individualized, risk-based evaluation supported by multidisciplinary care. We underscore the importance of donor counseling and advocate for a comprehensive, rather than paternalistic approach to living kidney donor selection. Advancing safe and equitable living donation in the context of rising obesity rates will necessitate revised guidelines, improved access to treatment, and an ongoing commitment to donor well-being.

Background. Delayed graft function (DGF) in deceased-donor kidney transplantation increases morbidity, prolongs hospitalization, and increases healthcare costs. Hypothermic machine perfusion (HMP) has emerged as a promising strategy to reduce DGF; however, large-scale real-world data remain limited. Methods. We performed a retrospective cohort analysis using the Scientific Registry of Transplant Recipients (2014–2024), including adult dialysis-dependent recipients of deceased-donor kidneys preserved using either static cold storage (SCS) or HMP. The primary outcome was DGF, defined as dialysis requirement within 7 d posttransplant. A matched-pairs analysis was conducted using kidneys from the same donor. Results. The overall cohort included 59 859 recipients (46.8% SCS, 53.2% HMP), with 2208 matched pairs identified. In the overall cohort, HMP grafts had longer cold ischemia times and a higher kidney donor risk index. They were more frequently obtained from older and donation after circulatory death donors. Although the overall DGF incidence was higher with HMP (34.4% versus 30.9%, P < 0.001), matched-pairs analysis revealed significantly lower DGF rates with HMP (29.8% versus 36.1%, P < 0.001). Adjusted analyses identified HMP as protective against DGF (overall cohort odds ratio, 0.71; 95% confidence interval, 0.66-0.78; paired cohort OR, 0.68; 95% CI, 0.50-0.93). Additional modifiable risk factors include prolonged cold ischemia time, higher recipient body mass index, and longer dialysis duration. Conclusions. This real-world study demonstrates that HMP is associated with a significant reduction in DGF risk in kidney transplantation compared with SCS, supporting its broader implementation and targeted management of modifiable risk factors.

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.

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.