The Precise Relationship Between Model for End-Stage Liver Disease and Survival Without a Liver Transplant

Incorporating Effects of Time Accrued on the Waiting List into Lung Transplantation Survival Models

Rationale: U.S. lung transplant mortality risk models do not account for patients' disease progression as time accrues between mandated clinical parameter updates. Objectives: To investigate the effects of accrued waitlist (WL) time on mortality in lung transplant candidates and recipients beyond those expressed by worsening clinical status and to present a new framework for conceptualizing mortality risk in end-stage lung disease. Methods: Using Scientific Registry of Transplant Recipients data (2015-2020, N = 12,616), we modeled transitions among multiple clinical states over time: WL, posttransplant, and death. Using cause-specific and ordinary Cox regression to estimate trajectories of composite 1-year mortality risk as a function of time from waitlisting to transplantation, we quantified the predictive accuracy of these estimates. We compared multistate model-derived candidate rankings against composite allocation score (CAS) rankings. Measurements and Main Results: There were 11.5% of candidates whose predicted 1-year mortality risk increased by >10% by day 30 on the WL. The multistate model ascribed lower numerical rankings (i.e., higher priority) than CAS for those who died while on the WL (multistate mean; median [interquartile range] ranking at death, 227; 154 [57-334]; CAS median [interquartile range] ranking at death, 329; 162 [11-668]). Patients with interstitial lung disease were more likely to have increasing risk trajectories as a function of time accrued on the WL compared with other lung diagnoses. Conclusions: Incorporating the effects of time accrued on the WL for lung transplant candidates and recipients in donor lung allocation systems may improve the survival of patients with end-stage lung diseases on the individual and population levels.

Superoxide dismutase 2 as a predictor in patients with hepatitis B virus-associated acute-on-chronic liver failure

The prognosis of hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is critical in clinical management. We aimed to assess the prognostic efficacy of superoxide dismutase 2 (SOD2) for 90-day mortality in HBV-ACLF patients. The expression patterns of SOD2 in peripheral blood mononuclear cells (PBMCs) were examined in a derivation set (n = 82) by quantitative real-time polymerase chain reaction (RT-qPCR). The results were further validated in a validation set (n = 35). The expression levels of SOD2 were significantly decreased in the derivation set compared to those with chronic hepatitis B (CHB) or the healthy controls (HCs) (P < 0.001). In HBV-ACLF patients, SOD2 levels were negatively correlated with serum total bilirubin (TBIL) (rs = - 0.43, P < 0.001) and model for end-stage liver disease (MELD) scores (rs =  -  0.22, P = 0.047), but positively correlated with alkaline phosphatase (AKP) (rs = 0.23, P = 0.034). SOD2 was identified as an independent risk factor for 90-day mortality in HBV-ACLF patients (hazard ratio: 0.124, 95% confidence interval: 0.059-0.261, P < 0.001). SOD2 yielded a larger area under the receiver operating characteristic curve (AUROC) than the MELD score in predicting 90-day mortality (0.914 vs. 0.712, P < 0.001). Kaplan-Meier analysis revealed a favorable overall survival (OS) for the SOD2 high expression group compared with the SOD2 low expression group in both the derivation and validation sets (P < 0.001). SOD2 has promising potential as a predictor of 90-day mortality in patients with HBV-ACLF.

Proceedings of the 27th Annual Congress of the International Liver Transplantation Society

After a virtual congress in 2021 and a previous absence in 2020 because of the coronavirus disease 2019 pandemic, the 27th Annual Congress of the International Liver Transplantation Society was held from May 4 to 7, 2022, in a hybrid format in Istanbul, with 1123 (58% on-site) liver transplant professionals from 61 countries attending the meeting. The hybrid format successfully achieved a balance of much yearned-for "in-person interaction" and global online participation. Almost 500 scientific abstracts were presented. In this report, the Vanguard Committee aims to present a summary of key invited lectures and selected abstracts for the liver transplant community.

Fully nonparametric survival analysis in the presence of time-dependent covariates and dependent censoring

In the presence of informative right censoring and time-dependent covariates, we estimate the survival function in a fully nonparametric fashion. We introduce a novel method for incorporating multiple observations per subject when estimating the survival function at different covariate values and compare several competing methods via simulation. The proposed method is applied to survival data from people awaiting liver transplant.

Life expectancy without a transplant for status 1A liver transplant candidates

Status 1A liver transplant candidates are given the highest medical priority for the allocation of deceased donor livers. Organ Procurement and Transplantation Network (OPTN) policy requires physicians to certify that a candidate has a life expectancy without a transplant of less than 7 days for that candidate to be given status 1A. Additionally, candidates receiving status 1A must have one of six medical conditions listed in policy. Using Scientific Registry of Transplant Recipients data from all prevalent liver transplant candidates from 2010 to 2020, we used a bias-corrected Kaplan-Meier model to calculate the survival of status 1A candidates and to determine their life expectancy without a transplant. We found that status 1A candidates have a life expectancy without a transplant of 24 (95% CI 20-46) days-over three times longer than what policy requires for status 1A designation. We repeated the analysis for subgroups of status 1A candidates based on the medical conditions that grant status 1A. We found that none of these subgroups met the life expectancy requirement. Harmonizing OPTN policy with observed data would sustain the integrity of the allocation process.