Faculty Bibliography

RATIONALE & OBJECTIVE/OBJECTIVE:Despite substantial growth in the population of older adults with kidney disease, there remains a lack of evidence to guide clinical care for this group. The Kidney Disease and Aging Research Collaborative (KDARC) conducted a Delphi study to build consensus on research priorities for clinical geriatric nephrology. STUDY DESIGN/METHODS:Asynchronous modified Delphi study. SETTING & PARTICIPANTS/METHODS:Clinicians and researchers in the US and Canada with clinical experience and/or research expertise in geriatric nephrology. OUTCOME/RESULTS:Research priorities in geriatric nephrology. ANALYTICAL APPROACH/METHODS:In the first Delphi round, participants submitted free-text descriptions of research priorities considered important for improving the clinical care of older adults with kidney disease. Delphi moderators used inductive content analysis to group concepts into categories. In the second and third rounds, participants iteratively reviewed topics, selected their top 5 priorities, and offered comments used to revise categories. RESULTS:Among 121 who were invited, 57 participants (47%) completed the first Delphi round and 48 (84% of enrolled participants) completed all rounds. After 3 rounds, the 5 priorities with the highest proportion of agreement were: 1) Communication and Decision-Making about Treatment Options for Older Adults with Kidney Failure (69% agreement), 2) Quality of Life, Symptom Management, and Palliative Care (67%), 3) Frailty and Physical Function (54%), 4) Tailoring Therapies for Kidney Disease to Specific Needs of Older Adults (42%), and 5) Caregiver and Social Support (35%). Health equity and person-centricity were identified as cross-cutting features that informed all topics. LIMITATIONS/CONCLUSIONS:Relatively low response rate and limited participation by private practitioners and older clinicians and researchers. CONCLUSIONS:Experts in geriatric nephrology identified clinical research priorities with the greatest potential to improve care for older adults with kidney disease. These findings provide a roadmap for the geriatric nephrology community to harmonize and maximize the impact of research efforts.

BACKGROUND:Highly effective modulator therapies (HEMT) including ivacaftor (IVA) and elexacaftor/tezacaftor/ivacaftor (ETI) have transformed treatment for people with cystic fibrosis (pwCF). However, non-HEMT-responsive mutations are more common in pwCF of non-White race/ethnicity; introduction of HEMT might have exacerbated racial/ethnic disparities in CF care. METHODS:Using the Scientific Registry of Transplant Recipients, we identified all lung transplant candidates and recipients 05/2005-12/2022 and categorized them by diagnosis (CF/non-CF), race/ethnicity (non-Hispanic White/Black/Hispanic) and era [Pre-HEMT (2005-1/30/2012), IVA (1/31/2012-10/30/2019), ETI (10/31/2019-12/31/2022)]. We compared the percentage of patients listed, delisted/died, or transplanted by race/ethnicity and era. RESULTS:34,659 lung transplants were performed: 10,521 pre-HEMT, 15,944 in IVA era, and 7,888 in ETI era. Over the three eras, the percentage of lung recipients with CF of White race decreased (94.5 % to 92.4 % to 78.4 %) and of Black race (1.7 % to 2.4 % to 5.7 %) or Hispanic ethnicity increased (3.5 % to 4.6 % to 14.2 %; p < 0.001). Similarly, among candidates listed for CF over the three eras, the percentage that were of White race decreased (82.0 % vs. 78.6 % vs. 71.0 %) and of Black race (9.2 % vs. 10.0 % vs. 10.3 %) or Hispanic ethnicity increased (6.4 % vs. 8.6 % vs. 13.6 %; p < 0.001). CONCLUSION/CONCLUSIONS:The introduction of HEMT appears to have benefitted CF lung transplant candidates and recipients of Black race or Hispanic ethnicity less than those of White race. This is likely due to the higher prevalence of HEMT-ineligible CFTR mutations among Black and Hispanic patients and underscores the need for therapies aimed at non-HEMT-responsive mutations prevalent in these racial/ethnic populations.

BACKGROUND/UNASSIGNED:With the introduction of sirolimus as medical therapy for lymphangioleiomyomatosis (LAM), an updated evaluation of LAM lung transplant (LT) outcomes and characterization of peritransplant sirolimus use is needed. METHODS/UNASSIGNED:We identified adult LT recipients from 2005-2021 using the Scientific Registry of Transplant Recipients database and stratified by diagnosis (LAM vs other). Multivariable Cox regression was performed to calculate the adjusted hazard ratio for LAM vs other diagnoses. A pharmacy claims database was linked to provide sirolimus prescription information, and a subgroup analysis comparing outcomes with pre- vs posttransplant sirolimus use was performed. RESULTS/UNASSIGNED: = .003). CONCLUSIONS/UNASSIGNED:This study supports lung transplant as a treatment for severe pulmonary LAM and identifies increased mortality associated with pre-LT sirolimus, though this may be due to uncharacterized baseline differences.

BACKGROUND/UNASSIGNED:Preoperative opioid use (OU) is a strong risk factor for poor postoperative outcomes in other surgical populations but has not been explored in lung transplant (LT) recipients nationally. METHODS/UNASSIGNED:The study identified adult (aged ≥18 years) US lung transplant (LT) recipients from 2011 to 2021 in the Scientific Registry of Transplant Recipients with prescription data through a pharmacy data set. Posttransplantation ventilatory support, infection, and mortality by pretransplantation OU (prescription fill ≤6 months before transplantation) were compared using multivariable regression. RESULTS/UNASSIGNED: = .006). CONCLUSIONS/UNASSIGNED:Pretransplantation OU was the strongest independent risk factor for posttransplantation OU and was associated with greater morbidity and mortality. Reducing pretransplantation and posttransplantation OU could benefit LT recipients and should be explored.

BACKGROUND:Despite excellent outcomes of heart transplants from hepatitis C virus (HCV)-positive donors (D+), many candidates are not listed to even consider HCV D+ offers. METHODS:Using the Scientific Registry of Transplant Recipients, we identified adult (age ≥18 years) heart transplant candidates prevalent on the waitlist between 2018 and March 2023. We compared the likelihood of waitlist mortality or heart transplant by candidate willingness to consider HCV D+ offers using competing risk regression. RESULTS:We identified 19,415 heart transplant candidates, 68.9% of whom were willing to consider HCV D+ offers. Candidates willing to consider HCV D+ offers had a 37% lower risk of waitlist mortality (subhazard ratio [SHR], 0.63; 95% confidence interval [CI], 0.56-0.70; P < .001) than candidates not willing to consider HCV D+ offers, after adjustment for covariates and center-level clustering. Over the same period, heart transplant candidates willing to consider HCV D+ offers had a 21% higher likelihood of receiving a transplant (SHR, 1.21; 95% CI, 1.7-1.26; P < .001). As a result, among candidates willing to consider HCV D+ offers, 74.9% received a transplant and 6.1% died/deteriorated after 3 years, compared to 68.3% and 9.1%, respectively, of candidates not willing to consider HCV D+ offers. Lower waitlist mortality also was observed on subgroup analyses of candidates on temporary and durable mechanical circulatory support. CONCLUSIONS:Willingness to consider HCV D+ heart offers was associated with a 37% lower risk of waitlist mortality and a 21% higher likelihood of receiving a transplant. We urge providers to encourage candidates to list as being willing to consider offers from donors with hepatitis C to optimize their waitlist outcomes and access to transplantation.

PURPOSE/OBJECTIVE:In October 2018, the OPTN changed adult heart transplant (HT) allocation policy, increasing the number of adult candidates that had higher priority than pediatric candidates, potentially disadvantaging pediatric waitlist registrants. METHODS:To understand the impact of this policy change, we used SRTR data to identify 1469 pre-policy (7/2016-9/2018) and 2901 (10/2018-12/2022) post-policy pediatric (< 18 years) HT registrants. We quantified mortality and transplant risks using weighted cause-specific hazard models, and then using weighted competing risks regression. We further stratified these analyses by age to understand risks for those in direct competition with adults for organs (≥ 12 years). RESULTS:, p = 0.02). Post policy, 1-year transplant rate did not change in those < 12years (68.2%-71.0%, p = 0.77), but in those ≥ 12years, transplant rate increased (77.3%-81.0%, p = 0.003). CONCLUSIONS:Mortality on the waitlist decreased and access to HT for pediatric registrants did not decline following the 2018 policy change. The decreased mortality rate may reflect changes in patient casemix and/or improved patient care. Continued surveillance is important in ensuring equity in pediatric, and adult, HT.

Graft failure and recipient death with functioning graft are important competing outcomes after kidney transplantation. Risk prediction models typically censor for the competing outcome thereby overestimating the cumulative incidence. The magnitude of this overestimation is not well described in real-world transplant data. This retrospective cohort study analyzed data from the European Collaborative Transplant Study (n = 125 250) and from the American Scientific Registry of Transplant Recipients (n = 190 258). Separate cause-specific hazard models using donor and recipient age as continuous predictors were developed for graft failure and recipient death. The hazard of graft failure increased quadratically with increasing donor age and decreased decaying with increasing recipient age. The hazard of recipient death increased linearly with increasing donor and recipient age. The cumulative incidence overestimation due to competing risk-censoring was largest in high-risk populations for both outcomes (old donors/recipients), sometimes amounting to 8.4 and 18.8 percentage points for graft failure and recipient death, respectively. In our illustrative model for posttransplant risk prediction, the absolute risk of graft failure and death is overestimated when censoring for the competing event, mainly in older donors and recipients. Prediction models for absolute risks should treat graft failure and death as competing events.

The adoption of large language models (LLMs) in healthcare demands a careful analysis of their potential to spread false medical knowledge. Because LLMs ingest massive volumes of data from the open Internet during training, they are potentially exposed to unverified medical knowledge that may include deliberately planted misinformation. Here, we perform a threat assessment that simulates a data-poisoning attack against The Pile, a popular dataset used for LLM development. We find that replacement of just 0.001% of training tokens with medical misinformation results in harmful models more likely to propagate medical errors. Furthermore, we discover that corrupted models match the performance of their corruption-free counterparts on open-source benchmarks routinely used to evaluate medical LLMs. Using biomedical knowledge graphs to screen medical LLM outputs, we propose a harm mitigation strategy that captures 91.9% of harmful content (F1 = 85.7%). Our algorithm provides a unique method to validate stochastically generated LLM outputs against hard-coded relationships in knowledge graphs. In view of current calls for improved data provenance and transparent LLM development, we hope to raise awareness of emergent risks from LLMs trained indiscriminately on web-scraped data, particularly in healthcare where misinformation can potentially compromise patient safety.

BACKGROUND/UNASSIGNED:For patients with alpha-1 antitrypsin (AAT) deficiency, AAT augmentation therapy can be an important part of care. However, for those who require a lung transplant (LT), there is currently only limited information to guide the use of AAT augmentation therapy post-LT. METHODS/UNASSIGNED:We identified all LT recipients from 2011-2021 in the Scientific Registry of Transplant Recipients with an AAT deficiency diagnosis. We categorized recipients by use of AAT augmentation therapy post-LT and compared their baseline characteristics using Fisher's exact test and Wilcoxon rank-sum tests. We used Kaplan-Meier analyses and estimated the average treatment effect (ATE) of post-LT AAT augmentation therapy on mortality and all-cause graft failure (ACGF). The ATE measures the observed effect we would see if everyone in the population received the intervention as opposed to just a subset. RESULTS/UNASSIGNED: = 0.02, log-rank test). CONCLUSIONS/UNASSIGNED:In our study, the use of augmentation therapy post-LT was associated with improved survival. Confirmatory prospective studies should be considered to inform post-LT AAT therapy guidelines.