Faculty Bibliography

BACKGROUND:Bariatric surgery has long been established as an effective treatment option for obesity and diabetes [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025] and Ogden et al. in JAMA 311(8):806-806, 2025. 10.1001/jama.2014.732]. Recently, GLP-1 Receptor Agonists' (GLP-1RAs) use has expanded as an alternative therapy for weight loss and diabetes management. While GLP1RAs are known to be safe and effective, few have compared long term outcomes of GLP-1RAs versus the "gold standard" of bariatric surgery among Medicare/Medicaid patients, who make up the largest payer group in the U.S. [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025]. METHODS:This was a retrospective, multicenter study of obese, type-2 diabetic patients (T2D) ≥ 18 years old, who initiated weekly injectable semaglutide or tirzepatide or underwent bariatric surgery between January 1st, 2018 to July 31st, 2024. Patients with a baseline BMI ≤ 35, those with prior GLP1-RA use, or any prior bariatric procedure were excluded from analysis. The primary outcome of interest was % total body weight loss 3 months to 3 years post intervention among bariatrics surgery patients vs. GLP1-RA patients (any GLP1-RA prescription and 12 months continuous GLP1-RA prescription). RESULTS:7667 patients were included for analysis (7200 GLP1-RA, 467 bariatric surgery). Bariatric surgery patients were younger (median (IQR): 43 (34, 53) vs. 65 (54, 72); p < 0.001) and more likely to be female (67.5% vs. 60.8%; p < 0.01) and Hispanic (58.7% vs. 19.4%; p < 0.001) while GLP1-RA users were more likely to be white (58.5% vs. 10.7%; p < 0.001). In models adjusting for demographic and clinical characteristics, bariatric surgery was associated with a 22.9% total weight loss 3 years following surgery compared to 2.3% for patients with any GLP1-RA use, and 15.9% vs 2.4% for patients with 12 months consecutive GLP1-RA use (22.9 [21.0-24.8] vs 2.3 [0.5-4.1], 15.9 [6.9-24.9] vs. 2.4 [6.7-11.5]. CONCLUSIONS:Among obese, T2D, publicly insured patients, bariatric surgery was associated with greater weight loss than GLP1-RAs at all measured periods from 3 months to 3 years post op.

IMPORTANCE/UNASSIGNED:Residence in a disadvantaged neighborhood is a key driver of racial and ethnic disparities in the diagnosis and management of chronic diseases; however, its impact on disparities in access to waitlisting and kidney transplantation (KT) is unclear. OBJECTIVE/UNASSIGNED:To examine the association between neighborhood disadvantage and access to waitlisting and KT. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This retrospective cohort study (January 1, 2015, to December 31, 2021) used a US national registry to assess adults (aged ≥18 years) with end-stage kidney disease (ESKD) and adult KT candidates. Statistical analysis was performed in March 2025. EXPOSURE/UNASSIGNED:Residential neighborhood disadvantage score (built environment disadvantage, criminal injustice, education disadvantage, unemployment, housing instability, poverty, social fragmentation, transportation barrier, and wealth inequality) ascertained by American Community Survey and other public data sources. MAIN OUTCOMES AND MEASURES/UNASSIGNED:The adjusted hazard ratios (AHRs) of waitlisting and KT (any KT, live-donor KT [LDKT], and preemptive KT) were assessed across tertiles of the neighborhood disadvantage score using cause-specific hazard models. Interaction terms were used to quantify these aforementioned associations by race and ethnicity. RESULTS/UNASSIGNED:The study included 501 444 adults with ESKD initiating dialysis (mean [SD] age, 63.9 [14.6] years; 293 937 [58.6%] male; 25 790 [5.1%] Asian [Asian American, Native Hawaiian, and Pacific Islander], 133 923 [26.7%] Black, 66 323 [13.2%] Hispanic, and 275 408 [54.9%] White) and 95 068 KT candidates on the waitlist (mean [SD] age, 53.7 [13.0] years; 60 328 [63.5%] male; 6956 [7.3%] Asian, 25 215 [26.5%] Black, 15 685 [16.5%] Hispanic, and 47 212 [49.7%] White). A total of 173 880 adults with ESKD (34.7%) and 26 718 KT candidates (28.1%) resided in high-disadvantage neighborhoods. After adjustment, adults residing in high-disadvantage neighborhoods were less likely to be waitlisted (AHR, 0.71; 95% CI, 0.69-0.72) compared with those in low-disadvantage neighborhoods. Specifically, Asian (AHR, 0.87; 95% CI, 0.80-0.95), Black (AHR, 0.68; 95% CI, 0.66-0.70), Hispanic (AHR, 0.89; 95% CI, 0.86-0.92), and White (AHR, 0.68; 95% CI, 0.66-0.71) adults in high-disadvantage neighborhoods were less likely to be waitlisted compared with White adults in low-disadvantage neighborhoods. Overall, candidates residing in high-disadvantage neighborhoods were less likely to receive any KT (AHR, 0.89; 95% CI, 0.87-0.92), LDKT (AHR, 0.65; 95% CI, 0.62-0.69), and preemptive KT (AHR, 0.62; 95% CI, 0.58-0.67). Notably, Black candidates residing in high-disadvantage neighborhoods were less likely to receive KT (AHR, 0.60; 95% CI, 0.58-0.62), LDKT (AHR, 0.23; 95% CI, 0.21-0.25), and preemptive KT (AHR, 0.22; 95% CI, 0.20-0.25) compared with White candidates in low-disadvantage neighborhoods. CONCLUSIONS AND RELEVANCE/UNASSIGNED:In this cohort study of adults with ESKD and KT candidates, residence in high-disadvantage neighborhoods was associated with reduced access to waitlisting and KT; it also was associated with persistent racial and ethnic disparities in LDKT and preemptive KT. These results suggest that to support equitable access, clinicians and transplant programs should work with social workers and community advocates to implement initiatives (eg, outreach and financial support) that address structural barriers and direct resources to affected neighborhoods.

BACKGROUND:Transplant waitlist registrants in the United States may be delisted because of receipt of a transplant abroad. Although not universally unethical, "travel for transplantation" poses risks to posttransplant care. To better understand this phenomenon, this study identifies temporal trends, geographic patterns, and demographic factors associated with cross-border transplantation. METHODS:Using Scientific Registry of Transplant Recipients data, we identified 818 US waitlist candidates who were removed because of transplantation abroad between 2010 and 2023. We described recipient characteristics overall, by organ, and by top transplant destinations. We used a Cox regression framework to identify characteristics associated with waitlist removal due to transplantation abroad. RESULTS:Transplants abroad averaged 58.4 per year. Incidence peaked at 80 transplants in 2017, with an upward trend after 2021. Kidney transplants made up 92.1% of cases. The most common destinations were the Philippines (19.8%), India (16.5%), Mexico (9.4%), China (8.4%), and Iran (4.4%). India and Mexico experienced the smallest drop-off during the height of the COVID-19 pandemic 2020-2021. Most recipients were US citizens (65.0%) or residents (23.5%). Female (adjusted hazard ratio [aHR], 0.520.610.71; P < 0.001) and Black candidates (aHR, 0.120.180.26; P < 0.001) were less likely to travel abroad compared with Asian candidates (aHR, 5.927.108.52; P < 0.001). Nonresidents (aHR, 6.708.6911.26; P < 0.001) and, among registrations in 2012 or later, nonresidents who traveled to the United States for transplantation (aHR, 27.2738.9155.50; P < 0.001) had a greater chance of undergoing transplantation abroad. CONCLUSIONS:Understanding patterns of international travel for transplantation is key not only for preventing resource drains from destination countries but also for providing adequate posttransplant care for recipients.

OBJECTIVE:Given frailty and comorbidities that occur with both aging and end-stage kidney disease (ESKD), it is unclear if older patients with ESKD derive the improved survival and kidney transplant (KT) access associated with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). METHODS:Using 2006-2021 USRDS data, we identified 876 patients with RYGB and 1508 patients with SG and compared 5-year mortality by age-group (18-29/30-39/40-49/50-59/60-69/≥ 70 years) to nonsurgical matched controls using 1:3 Mahalanobis distance matching, Kaplan-Meier, and Cox regression. We also compared age-stratified KT incidence between waitlisted patients and controls. RESULTS:) for patients with SG versus controls. CONCLUSIONS:RYGB in older patients with ESKD is associated with increased mortality and lower KT likelihood, whereas SG is associated with decreased mortality and higher KT likelihood compared to nonsurgical matched controls. Choice of bariatric surgery type may play a role in improving survival for older patients with ESKD.

INTRODUCTION/BACKGROUND:The United States Organ Procurement and Transplantation Network mandates collection of 6-month, 1-year, and 2-year post-donation follow-up data on living kidney donors (LKDs), but many centers struggle to meet these requirements. This study investigated whether providing a financial incentive (mailed gift card) could increase patient compliance with LKD follow-up. METHODS:A parallel, non-blinded, 1:1 superiority randomized control trial of LKDs was conducted at two centers from March 2017 to February 2021. The control arm received standard of care (SOC): instructions to complete the mandated LKD follow-up consisting of a health questionnaire and laboratory measurements at 6 months, 1 year, and 2 years post-donation. The intervention arm received SOC and was mailed a $25 gift card for each timely completed follow-up. Compliance rates were compared at each timepoint using Poisson regression. RESULTS:at 2 years). Similarly, no differences were observed in compliance with clinical follow-up, laboratory follow-up, or individual questions or lab values. CONCLUSION/CONCLUSIONS:Mailed gift cards did not improve patient compliance with LKD follow-up requirements; such interventions may be counterproductive among LKDs. Further research is needed to investigate and address barriers to completing LKD follow-up. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov identifier: NCT03090646.

BACKGROUND/UNASSIGNED:; environmental injustice) by racial/ethnic segregation (social injustice) on dementia diagnosis in ESKD. METHODS/UNASSIGNED:concentrations (annualized and matched to older adults' residential ZIP code at dialysis initiation) and by segregation scores (Theil's H method). FINDINGS/UNASSIGNED:and segregation. INTERPRETATION/UNASSIGNED:experienced an increased risk of dementia; this risk was particularly pronounced among individuals in high segregation and predominantly minority neighborhoods. Environmental and social injustices likely drive racial and ethnic disparities in dementia for older adults with ESKD, underscoring the need for interventions and policies to mitigate these injustices. FUNDING/UNASSIGNED:National Institutes of Health.

Xenotransplantation of genetically-modified pig kidneys offers a solution to the scarcity of organs for end-stage renal disease patients.¹ We performed a 61-day alpha-Gal knock-out pig kidney and thymic autograft transplant into a nephrectomized brain-dead human using clinically approved immunosuppression, without CD40 blockade or additional genetic modification. Hemodynamic and electrolyte stability and dialysis independence were achieved. Post-operative day (POD) 10 biopsies revealed glomerular IgM and IgA deposition, activation of early complement components and mesangiolysis with stable renal function without proteinuria, a phenotype not seen in allotransplantation. On POD 33, an abrupt increase in serum creatinine was associated with antibody-mediated rejection and increased donor-specific IgG. Plasma exchange, C3/C3b inhibition and rabbit anti-thymocyte globulin (rATG), completely reversed xenograft rejection. Pre-existing donor-reactive T cell clones expanded progressively in the circulation post-transplant, acquired an effector transcriptional profile and were detected in the POD 33 rejecting xenograft prior to rATG treatment. This study provides the first long-term physiologic, immunologic, and infectious disease monitoring of a pig-to-human kidney xenotransplant and indicates that pre-existing xenoreactive T cells and induced antibodies to unknown epitope(s) present a major challenge, despite significant immunosuppression. It also demonstrates that a minimally gene-edited pig kidney can support long-term life-sustaining physiologic functions in a human.

We sought to understand the potential impacts of a rapidly evolving donor pool on the annual recalibration of the kidney donor profile index (KDPI). Using OPTN data, we examined the kidney donor risk index (KDRI) among deceased kidney donors recovered 2011-2024. We mimicked the OPTN's annual re-mapping process to measure the KDRI-to-KDPI calibration drift and used Cox regression to translate this drift into all-cause graft failure rate differences. The 50th/75th/95th KDRI percentile among recovered donors rose from 1.19/1.47/2.0 in 2011 to 1.40/1.77/2.36 in 2024. For donors with the same KDRI, the KDPI assigned in 2024 was as much as 13 points lower than the KDPI assigned in 2012. Holding other factors constant, the KDRI-KDPI calibration shift equated to 7 years of increased age (65 vs. 58) for KDPI 86% donors. Five-year graft failure risk was 9% higher (RR: _1.0871.093_1.097) for a kidney assigned a KDPI of 86% in 2024 versus 2012. Organ recovery practices have changed. The relationship between KDPI and organ quality has become a moving target, complicating shared decision-making and altering the meaning of allocation policy thresholds. Alternative solutions to annually remapping KDPI, such as establishing a fixed reference cohort or migrating away from KDPI, could be considered.