Faculty Bibliography

BACKGROUND:Kidney allograft failure is a common cause of end-stage renal disease. We aimed to develop a dynamic artificial intelligence approach to enhance risk stratification for kidney transplant recipients by generating continuously refined predictions of survival using updates of clinical data. METHODS:In this observational study, we used data from adult recipients of kidney transplants from 18 academic transplant centres in Europe, the USA, and South America, and a cohort of patients from six randomised controlled trials. The development cohort comprised patients from four centres in France, with all other patients included in external validation cohorts. To build deeply phenotyped cohorts of transplant recipients, the following data were collected in the development cohort: clinical, histological, immunological variables, and repeated measurements of estimated glomerular filtration rate (eGFR) and proteinuria (measured using the proteinuria to creatininuria ratio). To develop a dynamic prediction system based on these clinical assessments and repeated measurements, we used a Bayesian joint models-an artificial intelligence approach. The prediction performances of the model were assessed via discrimination, through calculation of the area under the receiver operator curve (AUC), and calibration. This study is registered with ClinicalTrials.gov, NCT04258891. FINDINGS/RESULTS:13 608 patients were included (3774 in the development cohort and 9834 in the external validation cohorts) and contributed 89 328 patient-years of data, and 416 510 eGFR and proteinuria measurements. Bayesian joint models showed that recipient immunological profile, allograft interstitial fibrosis and tubular atrophy, allograft inflammation, and repeated measurements of eGFR and proteinuria were independent risk factors for allograft survival. The final model showed accurate calibration and very high discrimination in the development cohort (overall dynamic AUC 0·857 [95% CI 0·847-0·866]) with a persistent improvement in AUCs for each new repeated measurement (from 0·780 [0·768-0·794] to 0·926 [0·917-0·932]; p<0·0001). The predictive performance was confirmed in the external validation cohorts from Europe (overall AUC 0·845 [0·837-0·854]), the USA (overall AUC 0·820 [0·808-0·831]), South America (overall AUC 0·868 [0·856-0·880]), and the cohort of patients from randomised controlled trials (overall AUC 0·857 [0·840-0·875]). INTERPRETATION/CONCLUSIONS:Because of its dynamic design, this model can be continuously updated and holds value as a bedside tool that could refine the prognostic judgements of clinicians in everyday practice, hence enhancing precision medicine in the transplant setting. FUNDING/BACKGROUND:MSD Avenir, French National Institute for Health and Medical Research, and Bettencourt Schueller Foundation.

Performing third or fourth kidney transplantation (3KT and 4KT) in older patients is rare due to surgical and immunologic challenges. We aimed to analyze and compare the outcomes of younger (18-64 years) and older (≥65 years) recipients of 3KT and 4KT. Between 1990 and 2016, we identified 5816 recipients of 3KTs (153 were older) and 886 recipients of 4KTs (18 were older). The incidences of delayed graft function (24.3% vs. 24.8%, p = .89), primary non-function (3.2% vs. 1.3%, p = .21), 1-year acute rejection (18.6% vs. 14.8%, p = .24), and 5-year death censored graft failure (DCGF) (24.8% vs. 17.9%, p = .06) were not different between younger and older recipients of 3KT. However, 5-year mortality was higher in older recipients (14.0% vs. 33.8%, p < .001) which remained significant after adjustment (aHR = 3.21, 95% CI: 2.59-3.99). Similar patterns were noted in the 4KT cohort. When compared with waitlisted patients, 3KT and 4KT are associated with a lower risk of mortality; aHR = 0.37, 95% CI: 0.33-0.41 and aHR = 0.31, 95% CI: 0.24-0.41, respectively. This survival benefit did not differ by recipient age (younger vs. older, p for interaction = 3KT: .49 and 4KT: .58). In the largest cohort described to date, we report that there is a survival benefit of 3KT and 4KT even among older patients. Although a highly selected cohort, our results support improving access to 3KT and 4KT.

A wide gap between the increasing demand for organs and the limited supply leads to immeasurable loss of life each year. The organ shortage could be attenuated by donors with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). The transplantation of organs from HIV+ deceased donors into HIV+ individuals (HIV D+ /R+) was initiated in South Africa in 2010; however, this practice was forbidden in the USA until the HIV Organ Policy Equity (HOPE) Act in 2013. HIV D+/R+ transplantation is now practiced in the USA as part of ongoing research studies, helping to reduce waiting times for all patients on the waitlist. The introduction of direct acting antivirals for HCV has revolutionized the utilization of donors with HCV for HCV-uninfected (HCV-) recipients. This is particularly relevant as the HCV donor pool has increased substantially in the context of the rise in deaths related to drug overdose from injection drug use. This article serves to review the current literature on using organs from donors with HIV or HCV.

This study of SARS-CoV-2 mRNA vaccination in 14 persons with HIV (PWH) demonstrated uniformly high anti-SARS-CoV-2 receptor binding domain (RBD) antibody titres after two doses, despite varied titres after a single dose. The majority of vaccine reactions were mild and no adverse events occurred.

Importance:Traditionally, liver transplant (LT) for alcohol-associated liver disease (ALD) requires 6 months of abstinence. Although early LT before 6 months of abstinence has been associated with decreased mortality for decompensated ALD, this practice remains controversial and concentrated at a few centers. Objective:To define patient, allograft, and relapse-free survival in early LT for ALD, and to investigate the association between these survival outcomes and early vs standard LT. Design, Setting, and Participants:This cohort study analyzed all patients with ALD who underwent their first LT at a single academic referral center between October 1, 2012, and November 13, 2020. Patients with known pretransplant hepatocellular carcinoma, hepatitis B or C, or an alternative cause of liver failure were excluded. Follow-up period was defined as the time from LT to the most recent encounter with a transplant center or death. Exposures:The exposure of interest was early LT, which was defined as less than 180 days of pre-LT abstinence. Standard LT was defined as 180 days or more of pre-LT abstinence. Patients were separated into early LT and standard LT by time from abstinence to LT. Main Outcomes and Measures:The outcomes were patient, allograft, relapse-free, and hazardous relapse-free survival for patients who underwent early LT or standard LT. These groups were compared by log-rank testing of Kaplan-Meier estimates. Hazardous relapse was defined as binge, at-risk, or frequent drinking. Abstinence was reassessed at the most recent follow-up visit for all patients. Results:Of the 163 patients with ALD included in this study, 88 (54%) underwent early LT and 75 (46%) underwent standard LT. This cohort had a mean (SD) age at transplant of 52 (10) years and was predominantly composed of 108 male patients (66%). Recipients of early LT vs standard LT were younger (median [interquartile range (IQR)] age, 49.7 [39.0-54.2] years vs 54.6 [48.7-60.0] years; P < .001) and had a higher median (IQR) Model for End-stage Liver Disease score at listing (35.0 [29.0-39.0] vs 20.0 [13.0-26.0]; P < .001). Both recipients of early LT and standard LT had similar 1-year patient survival (94.1% [95% CI, 86.3%-97.5%] vs 95.9% [95% CI, 87.8%-98.7%]; P = .60), allograft survival (92.7% [95% CI, 84.4%-96.7%] vs 90.5% [95% CI, 81.0%-95.3%]; P = .42), relapse-free survival (80.4% [95% CI, 69.1%-88.0%] vs 83.5% [95% CI, 72.2%-90.6%]; P = .41), and hazardous relapse-free survival (85.8% [95% CI, 75.1%-92.2%] vs 89.6% [95% CI, 79.5%-94.9%]; P = .41). Conclusions and Relevance:Adherence to the 6-month rule was not associated with superior patient survival, allograft survival, or relapse-free survival among selected patients. This finding suggests that patients with ALD should not be categorically excluded from LT solely on the basis of 6 months of abstinence, but rather alternative selection criteria should be identified that are based on need and posttransplant outcomes.

Vaccine-induced SARS-CoV-2 antibody responses are attenuated in solid organ transplant recipients (SOTRs) and breakthrough infections are more common. Additional SARS-CoV-2 vaccine doses increase anti-spike IgG in some SOTRs, but it is uncertain whether neutralization of variants of concern (VOCs) is enhanced. We tested 47 SOTRs for clinical and research anti-spike IgG, pseudoneutralization (ACE2 blocking), and live-virus neutralization (nAb) against VOCs before and after a third SARS-CoV-2 vaccine dose (70% mRNA, 30% Ad26.COV2.S) with comparison to 15 healthy controls after two mRNA vaccine doses. We used correlation analysis to compare anti-spike IgG assays and focused on thresholds associated with neutralizing activity. A third SARS-CoV-2 vaccine dose increased median anti-spike (1.6-fold) and receptor-binding domain (1.5-fold) IgG, as well as pseudoneutralization against VOCs (2.5-fold versus Delta). However, IgG and neutralization activity were significantly lower than healthy controls (p<0.001); 32% of SOTRs had zero detectable nAb against Delta after third vaccination. Correlation with nAb was seen at anti-spike IgG >4 AU on the clinical assay and >10^4 AU on the research assay. These findings highlight benefits of a third vaccine dose for some SOTRs and the need for alternative strategies to improve protection in a significant subset of this population.