Faculty Bibliography

BACKGROUND:Multiorgan heart and kidney transplants (HKTx) performed for patients with end-stage heart failure and chronic kidney disease have increased in recent years. However, no established protocols exist on whether a heart and kidney from the same donor should be transplanted in the same operation versus 1-2 days apart. METHODS:Using SRTR data 1993-2023, we compared same-donor HKTx recipients with both transplants performed on the same day ("simultaneous") to recipients with kidney transplants performed within 1 day of the heart transplant ("staged"). We examined differences in weighted post-transplant clinical characteristics using average treatment effect. Post-transplant mortality and graft failure was also assessed using Kaplan-Meier curves and instrumental variable analysis adjusted for recipient characteristics and year of transplant. RESULTS:, p < 0.001). Weighted patient mortality, all cause heart failure (ACHF), and all cause kidney failure (ACKF) 4 years post-transplant were slightly lower for simultaneous versus staged HKTx recipients (17.1% vs. 19.9%, 17.2% vs. 20.1%, 20.8% vs. 24.7%). However, instrumental variable analysis found no meaningful differences in adjusted patient survival, ACHF, or ACKF by HKTx type. CONCLUSION/CONCLUSIONS:Simultaneous HKTx recipients have shorter hospital stays, decreased mortality, and higher rates of graft survival post-transplant compared to staged HKTx recipients, which may reflect favorable patient factors that enable both operations to be performed on the same day rather than an inherent benefit of simultaneous HKTx, given equivalent adjusted patient mortality, ACHF, and ACKF.

BACKGROUND:Kidney transplantation (KT) from donors with human immunodeficiency virus (HIV-1) to recipients with HIV (HIV D+/R+) is noninferior to KT from donors without HIV (HIV D-/R+) with regard to safety. However, there may be differences in posttransplant infections. METHODS:We performed a secondary analysis of the HOPE in Action KT Study (NCT02602262) comparing the time to first clinically relevant infection within 24 months posttransplantation in 99 HIV D+/R+ versus 99 HIV D-/R+. Secondary outcomes included incidence rates, infection-related death, and timing of clinically relevant infection, each stratified by donor HIV status. RESULTS:The cumulative incidence of a clinically relevant infection at 24 months posttransplantation was 73.8% (95% confidence interval [CI]: 63.1%-81.2%) for HIV D+/R+ versus 64.7% (95% CI: 53.0%-73.4%) for HIV D-/R+. Comparing time to first clinically relevant infection in HIV D+/R+ versus HIV D-/R+, the adjusted hazard ratio (aHR) was 1.44 (95% CI: 1.01-2.04) at 24 months posttransplantation; for infections associated with hospitalization, the aHR was not significantly higher (1.21 [95% CI: .78-1.86). There were no significant differences in the number of infections, death from infection, duration, or site of infection between HIV D+/R+ versus HIV D-/R+, though viral infections were numerically more common in HIV D+/R+ (40% vs 35%). CONCLUSIONS:Although there was a statistically significant association between receipt of a kidney from a donor with HIV and time to first clinically relevant infection in the 24 months posttransplantation, there were no differences in infections associated with hospitalization. These data are overall reassuring as this emerging practice expands into clinical care. Clinical Trials Registration. NCT02602262.

INTRODUCTION/BACKGROUND:Elevated concentrations of air pollutants in residential neighborhoods are associated with poorer survival, cognitive, and cardiovascular health among older adults. Older kidney transplant (KT) recipients may be more vulnerable due to chronic immunosuppression and age-related co-morbidities. Therefore, we quantified the associations between pollutant concentrations and post-KT outcomes among older recipients. METHODS:]) were obtained from the Center for Air, Climate and Energy Solutions, and matched by ZIP code and year of KT. We used shared frailty models (cluster = state) to estimate the adjusted hazard ratios (aHR) of mortality and death-censored graft failure (DCGF) and competing risk models with cluster-robust standard errors to estimate the adjusted subhazard ratios (aSHR) of dementia and stroke by pollutant concentrations. RESULTS:concentrations were associated with a 3% (aSHR = 1.03, 95% CI: 1.00-1.07) and 4% higher risk of stroke (aSHR = 1.04, 95% CI: 1.02-1.07), respectively. CONCLUSION/CONCLUSIONS:Residence in neighborhoods with high concentrations of ambient air pollutants can worsen patient and graft survival, as well as increase the risk of stroke among older KT recipients. Early screening and interventions targeting older recipients living in such neighborhoods may be crucial for preserving cognitive and cerebrovascular health, as well as improving longitudinal quality of life.

RATIONALE & OBJECTIVE/UNASSIGNED:exposure and mortality, overall and by race and ethnicity. STUDY DESIGN/UNASSIGNED:Cohort study (2003-2019). SETTING & PARTICIPANTS/UNASSIGNED:National registry for patients with kidney failure. EXPOSURES/UNASSIGNED:), segregation scores (Theil's H method), deprivation scores (American Community Survey), and built environment factors (medically underserved areas [MUA] and urbanicity) by patients' residential ZIP code at dialysis initiation. OUTCOME/UNASSIGNED:All-cause mortality. ANALYTICAL APPROACH/UNASSIGNED:and mortality, overall and stratified by race and ethnicity. RESULTS/UNASSIGNED:< 0.001]). LIMITATIONS/UNASSIGNED:may not reflect individual-level exposures. CONCLUSIONS/UNASSIGNED:and reduce related mortality.

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.

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.

BACKGROUND/UNASSIGNED:A potential long-term complication of living kidney donation in male donors is scrotal swelling on the same side as the nephrectomy, and some undergo surgery to relieve discomfort from the fluid collection. The long-term risk for this outcome attributable to donation is unknown. OBJECTIVE/UNASSIGNED:To evaluate long-term scrotal surgery rates after laparoscopic nephrectomy in male living kidney donors compared with nondonors. DESIGN/UNASSIGNED:Population-based cohort study (2002 to 2024). (ClinicalTrials.gov: NCT06716723). SETTING/UNASSIGNED:Linked administrative health care databases in Ontario, Canada. PARTICIPANTS/UNASSIGNED:898 male living kidney donors who had a laparoscopic nephrectomy were matched in a 1:10 ratio with 8980 male nondonors from the general population. The matching characteristics were age, date of cohort entry, rural residence, income, prior vasectomy, and prior inguinal hernia repair. Participants were followed for a median of 9 years, up to 22 years. MEASUREMENTS/UNASSIGNED:The primary outcome was hospitalization for surgery to address a unilateral scrotal fluid collection. RESULTS/UNASSIGNED:< 0.001). The median time from donation to scrotal surgery was 5.2 years (IQR, 3.3 to 8.4 years); more than 90% of the surgeries were hydrocelectomies and were performed under general anesthesia. Over 20 years, the cumulative incidence was 13.8% in donors versus 0.7% in nondonors. LIMITATION/UNASSIGNED:The precise causal mechanism remains unknown. CONCLUSION/UNASSIGNED:Laparoscopic nephrectomy is associated with a higher risk for subsequent scrotal surgery in male living kidney donors. PRIMARY FUNDING SOURCE/UNASSIGNED:Canadian Institutes of Health Research.

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.

Historically, liver transplant (LT) candidates with human immunodeficiency virus (HIV) have experienced high waitlist mortality. Since the HIV Organ Policy Equity (HOPE) Act expands access to organs from donors with HIV, we assessed the impact of HOPE on LT rate and wait time for this population. We linked data from a multicenter HOPE in Action study to Scientific Registry of Transplant Recipients (February 21, 2019 to June 1, 2024) and used Poisson regression to compare transplant rates among 99 candidates willing to accept HOPE donors (HOPE candidates) to 13 495 candidates with or without HIV not listed as willing to accept HOPE donors (non-HOPE candidates) matched on transplant center. The median time to any deceased donor liver transplant (DDLT) was 2.3 months for HOPE and 1.1 years for non-HOPE candidates. Within 2 years of listing, 90.9% of HOPE versus 58.5% of non-HOPE candidates received a DDLT (P < .001). HOPE was associated with an overall 3.11-fold higher DDLT incident rate ratio (95% CI 2.48-3.88, P < .001). Stratified by model for end-stage liver disease score categories 6 to 14, 15 to 24, 25 to 34, and 35 to 40/status 1; HOPE candidates had 10.12-fold, 5.31-fold, 1.41-fold and 2.90-fold higher DDLT rates, respectively. Willingness to accept livers from donors with HIV improves access to liver transplantation for candidates with HIV.

BACKGROUND:Under the HOPE Act, transplants from donors with HIV to recipients with HIV (HIV D+/R+) have been largely limited to kidney and liver. However, recent modifications to HOPE research guidelines allow broader participation of cardiothoracic programs. METHODS:To quantify potential cardiothoracic HOPE donors, we used SRTR data (3/2016-12/2024) to identify 101,200 donors without HIV and 273 HOPE donors (with true and false positive HIV tests). Using logistic regression, we predicted the probability of having a heart or lung(s) used for transplant among donors without HIV that had a kidney or liver used. We then applied model parameters to HOPE donors that had a kidney or liver used to estimate the number of HOPE donors that might have been cardiothoracic donors if the practice were expanded. RESULTS:Among donors without HIV, cardiothoracic donation was associated with age, cause of death, hepatitis C, hypertension, diabetes, smoking, cardiovascular disease, blood gas, and circulatory death. Applying our model, an estimated 41.0% (N=111), 18.7% (N=51), and 15.2% (N=41) of HOPE donors were potential heart, any lung (single or double), or double-lung donors, as compared to 32.3%, 21.8%, and 18.2% of abdominal organ donors without HIV, respectively. This translated to an annual 13-18 potential heart and 5-8 potential lung transplants (of which 4-6 would be double-lung transplants) from HOPE donors. CONCLUSIONS:If HIV D+/R+ is more widely expanded to cardiothoracic transplantation, 41% of HOPE kidney and liver donors have potential to donate a heart and almost 20% to donate a lung to candidates with HIV.