Liver transplant waitlist removal, transplantation rates and post-transplant survival in Hispanics

Donor-recipient race-ethnicity concordance and patient survival after liver transplantation

INTRODUCTION

We assessed the association between patient survival after liver transplantation (LT) and donor-recipient race-ethnicity (R/E) concordance.

METHODS

The Scientific Registry of Transplant Recipients (SRTR) was retrospectively analyzed using data collected between 2002 and 2019. Only adults without history of prior organ transplant and recipients of LT alone were included. The primary outcome was patient survival. Donors and recipients were categorized into five R/E groups: White/Caucasian, African American/Black, Hispanic/Latino, Asian, and Others. Statistical analyses were performed using Kaplan-Meier survival curves and Cox Proportional Hazards models, adjusting for donor and recipient covariates.

RESULTS

85,427 patients were included. Among all the R/E groups, Asian patients had the highest 5-year survival (81.3%; 95% CI = 79.9-82.7), while African American/Black patients had the lowest (71.4%; 95% CI = 70.3-72.6) (P < 0.001). Lower survival rates were observed in recipients who received discordant R/E grafts irrespective of their R/E group. The fully adjusted hazard ratio for death was statistically significant in African American/Black (aHR 1.07-1.18-1.31; P < 0.01) and in White∕Caucasian patients (aHR 1.00-1.04-1.07; P = 0.03) in the presence of donor-recipient R/E discordance.

CONCLUSION

Disparities in post-LT outcomes might be influenced by biological factors in addition to well-known social determinants of health.

Effect of a Hispanic outreach program on referral and liver transplantation volume at a single center

BACKGROUND

Although Hispanic patients have high rates of end-stage liver disease and liver cancer, for which liver transplantation (LT) offers the best long-term outcomes, they are less likely to receive LT. Studies of end-stage renal disease patients and kidney transplant candidates have shown that targeted, culturally relevant interventions can increase the likelihood of Hispanic patients receiving kidney transplant. However, similar interventions remain largely unstudied in potential LT candidates.

METHODS

Referrals to a single center in Texas with a large Hispanic patient population were compared before (01/2018-12/2019) and after (7/2021-6/2023) the implementation of a targeted outreach program. Patient progress toward LT, reasons for ineligibility, and differences in insurance were examined between the two eras.

RESULTS

A greater proportion of Hispanic patients were referred for LT after the implementation of the outreach program (23.2% vs 26.2%, p = 0.004). Comparing the pre-outreach era to the post-outreach era, more Hispanic patients achieved waitlisting status (61 vs 78, respectively) and received a LT (971 vs 82, respectively). However, the proportion of Hispanic patients undergoing LT dropped from 30.2% to 20.3%. In the post-outreach era, half of the Hispanic patients were unable to get LT for financial reasons (112, 50.5%).

CONCLUSIONS

A targeted outreach program for Hispanic patients with end-stage liver disease effectively increased the total number of Hispanic LT referrals and recipients. However, many of the patients who were referred were ineligible for LT, most frequently for financial reasons. These results highlight the need for additional research into the most effective ways to ameliorate financial barriers to LT in this high-need community.

Survival following liver transplantation: A population-based nested case-control study

BACKGROUND

Liver transplantation is the gold standard treatment for end-stage liver disease. This study evaluates post-transplantation survival compared with the general population by quantifying standardized mortality ratios in a nested case-control study.

METHODS

Controls were noninstitutionalized United States inhabitants from the National Longitudinal Mortality Study. Cases underwent liver transplantation from 1990 to 2007 identified through the Organ Procurement and Transplantation Network database. Propensity matching (5:1, nearest neighbor, caliper 0.1) identified controls based on age, sex, race, and state. The primary endpoint was 10-year survival.

RESULTS

62,788 cases were matched to 313,381 controls. The overall standardized mortality ratio was 2.46 (95% CI ​= ​2.44-2.48). The standardized mortality ratio was higher for males (2.59 vs. 2.25) and Hispanic patients (4.80). Younger patients and those transplanted earlier (1990-1995) had higher standardized mortality ratios.

CONCLUSIONS

Liver recipients have a standardized mortality ratio 2.46 times higher than the general population. Long-term mortality has declined over time.

Living-Donor Liver Transplant and Improved Post-Transplant Survival in Patients with Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is the leading indication of liver transplantation (LT) among autoimmune liver disease patients. There is a scarcity of studies comparing survival outcomes between living-donor liver transplants (LDLT)s and deceased-donor liver transplants (DDLTs) in this population. Using the United Network for Organ Sharing database, we compared 4679 DDLTs and 805 LDLTs. Our outcome of interest was post-LT patient survival and post-LT graft survival. A stepwise multivariate analysis was performed, adjusting for recipient age, gender, diabetes mellitus, ascites, hepatic encephalopathy, cholangiocarcinoma, hepatocellular carcinoma, race, and the model for end-stage liver disease (MELD) score; donor' age and sex were also included to the analysis. According to univariate and multivariate analysis, LDLT had a patient and graft survival benefit compared to DDLT (HR, 0.77, 95% CI 0.65-0.92; p < 0.002). LDLT patient survival (95.2%, 92.6%, 90.1%, and 81.9%) and graft survival (94.1%, 91.1%, 88.5%, and 80.5%) at 1, 3, 5, and 10 years were significantly better than DDLT patient survival (93.2%, 87.6%, 83.3%, and 72.7%) and graft survival (92.1%, 86.5%, 82.1%, and 70.9%) (p < 0.001) in the same interval. Variables including donor and recipient age, male recipient gender, MELD score, diabetes mellitus, hepatocellular carcinoma, and cholangiocarcinoma were associated with mortality and graft failure in PSC patients. Interestingly, Asians were more protected than Whites (HR, 0.61; 95% CI, 0.35-0.99; p < 0.047), and cholangiocarcinoma was associated with the highest hazard of mortality (HR, 2.07; 95% CI, 1.71-2.50; p < 0.001) in multivariate analysis. LDLT in PSC patients were associated with greater post-transplant patient and graft survival compared to DDLT patients.

Demographic inequities exist and influence transplant outcomes in liver transplantation for acute alcohol-associated hepatitis

BACKGROUND

Liver transplantation has inherent disparities but data is scarce in liver transplant (LT) candidates with acute alcohol-associated hepatitis (AAH). We aimed to investigate demographic inequities and its impact on survival outcomes among AAH LT candidates.

METHODS

A retrospective analysis using the United Network of Organ Sharing database was conducted between 2000 and 2021. 25 981 LT recipients with alcohol-associated liver cirrhosis and 662 recipients with AAH were included. Waitlisted candidates were also evaluated.

RESULTS

In comparison with alcohol-associated liver cirrhosis, AAH LT recipients were more likely Asian or "other" race and younger. Hispanics demonstrated better graft and patient survival (p < 0.05) but were less likely to be waitlisted and transplanted for AAH than for liver cirrhosis. Women with AAH were more likely to be waitlisted and transplanted. Pre-existing diabetes and male sex were associated with higher graft failure (25% and 8% respectively). Increasing recipient age were 2% more likely to experience negative outcomes. Chronicity of liver disease did not impact graft (p = 0.137) or patient survival (p = 0.145).

CONCLUSION

Our results revealed demographic factors have a significant impact on transplant listing, organ allocation and survival outcomes. Further investigations are imperative to minimize disparities in LT evaluation and provide equity in healthcare.

Primary Sclerosing Cholangitis-Autoimmune Hepatitis Overlap Syndrome: Significant Barriers in Liver Disease Diagnosis and Treatment Experienced by the Latino Community

Overlap syndrome (OS) is a term that comprises the presentation of multiple hepatic disease characteristics in the same patient, such as the presence of autoimmune hepatitis (AIH) features in addition to primary sclerosing cholangitis (PSC) or primary biliary cholangitis (PBC). Standard therapy for AIH is immunosuppression, while ursodeoxycholic acid is the preferred treatment for PBC. Additionally, liver transplantation (LT) may be considered in severe cases. Hispanics have been found to have a higher prevalence of chronic liver disease and develop more complications associated with portal hypertension at the time of listing for LT. Despite being the fastest-growing population in the USA, Hispanics have a higher probability of not receiving an LT due to issues with social determinants of health (SDOH). It has been reported that Hispanics are more likely to be removed from the transplant list. We report a case of a 25-year-old female immigrant from a Latin American developing country who presented with symptoms consistent with worsening liver disease after years of inappropriate workup and late diagnosis due to barriers within the healthcare system. The patient had a history of unresolved jaundice and pruritus and presented with worsening of her previous symptoms and new onset abdominal distention, bilateral leg edema, and telangiectasias. Laboratory and imaging studies confirmed the diagnosis of AIH and primary sclerosing cholangitis (PSC-AIH syndrome). The patient was started on steroids, azathioprine, and ursodeoxycholic acid, showing improvement. Due to her migratory status, she could not receive an appropriate diagnosis and follow up with a single provider or healthcare institution, putting her at increased risk for life-threatening complications. Although medical management is the first step, the probability of future liver transplants exists. The patient is still undergoing liver transplant evaluation and completing a workup since she was found to have an elevated model for end-stage liver disease (MELD) score. Even with the introduction of new scores and policies that aim to reduce disparities in LT, Hispanic patients are still at higher risk of being removed from the waitlist because of death or clinical deterioration compared to non-Hispanics. To this day, Hispanics have the highest percentage of waitlist deaths (20.8%) of all ethnicities and the lowest overall rate for undergoing LT. Understanding and addressing the causes that could contribute to and explain this phenomenon is essential. Increasing awareness of this problem is vital to promote more research on LT disparities.

Sex Disparities in Outcome of Patients with Alcohol-Related Liver Cirrhosis within the Eurotransplant Network—A Competing Risk Analysis

Alcohol use disorder (AUD) is one of the most important risk factors for the development of alcohol-related liver cirrhosis (ALC). Importantly, psychiatrists are an integral part of the interdisciplinary care for patients with AUD and ALC. The aim of the current study was to investigate whether sex influences the outcome within this group of patients. For this purpose, data of all registrations for liver transplantations due to ALC within the Eurotransplant region from 2010 to 2019 were analyzed for sex disparities using competing risk models and in-between group comparisons. Relevant sex differences in registration numbers (24.8% female) and investigated outcomes were revealed. Risk ratios for a positive outcome, i.e., transplantation (0.74), and those of adverse outcomes, i.e., removal from waiting list (1.44) and death on waiting list (1.10), indicated a relative disadvantage for female patients with ALC. Further, women listed for liver transplantations were significantly younger than their male counterparts. Notably, sex disparities found in registration and outcome parameters were independent of differences found in the prevalence of AUD and liver transplantations. Further research is necessary to identify the underlying mechanisms and establish strategies to ensure equity and utility in liver transplantations due to ALC.

A scoping review of inequities in access to organ transplant in the United States

Background

Organ transplant is the preferred treatment for end-stage organ disease, yet the majority of patients with end-stage organ disease are never placed on the transplant waiting list. Limited access to the transplant waiting list combined with the scarcity of the organ pool result in over 100,000 deaths annually in the United States. Patients face unique barriers to referral and acceptance for organ transplant based on social determinants of health, and patients from disenfranchised groups suffer from disproportionately lower rates of transplantation. Our objective was to review the literature describing disparities in access to organ transplantation based on social determinants of health to integrate the existing knowledge and guide future research.

Methods

We conducted a scoping review of the literature reporting disparities in access to heart, lung, liver, pancreas and kidney transplantation based on social determinants of health (race, income, education, geography, insurance status, health literacy and engagement). Included studies were categorized based on steps along the transplant care continuum: referral for transplant, transplant evaluation and selection, living donor identification/evaluation, and waitlist outcomes.

Results

Our search generated 16,643 studies, of which 227 were included in our final review. Of these, 34 focused on disparities in referral for transplantation among patients with chronic organ disease, 82 on transplant selection processes, 50 on living donors, and 61 on waitlist management. In total, 15 studies involved the thoracic organs (heart, lung), 209 involved the abdominal organs (kidney, liver, pancreas), and three involved multiple organs. Racial and ethnic minorities, women, and patients in lower socioeconomic status groups were less likely to be referred, evaluated, and added to the waiting list for organ transplant. The quality of the data describing these disparities across the transplant literature was variable and overwhelmingly focused on kidney transplant.

Conclusions

This review contextualizes the quality of the data, identifies seminal work by organ, and reports gaps in the literature where future research on disparities in organ transplantation should focus. Future work should investigate the association of social determinants of health with access to the organ transplant waiting list, with a focus on prospective analyses that assess interventions to improve health equity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01616-x.

Access to liver transplantation for minority populations in the United States

PURPOSE OF REVIEW

Racial disparities in access to liver transplantation have been known since the National Transplant Act of 1980. Since the inception of the Final Rule in 2000, the United Network of Organ Sharing has sought to ensure the equitable distribution of donor livers. Despite several measures aimed to improve access for vulnerable populations, disparities in outcomes are still prevalent throughout the liver transplant (LT) evaluation, while on the waitlist, and after liver transplantation.

RECENT FINDINGS

Blacks and Hispanics are underrepresented on the LT list and have an increased waitlist mortality rate compared to Whites. Additionally, Blacks have a significantly higher risk of posttransplant mortality.

SUMMARY

Ongoing efforts are necessary to eliminate inequities in transplant access. Strategies such as policy implementation and increasing diversity in the healthcare workforce may prove efficacious in creating change.

Statistical methods versus machine learning techniques for donor-recipient matching in liver transplantation

Donor-Recipient (D-R) matching is one of the main challenges to be fulfilled nowadays. Due to the increasing number of recipients and the small amount of donors in liver transplantation, the allocation method is crucial. In this paper, to establish a fair comparison, the United Network for Organ Sharing database was used with 4 different end-points (3 months, and 1, 2 and 5 years), with a total of 39, 189 D-R pairs and 28 donor and recipient variables. Modelling techniques were divided into two groups: 1) classical statistical methods, including Logistic Regression (LR) and Naïve Bayes (NB), and 2) standard machine learning techniques, including Multilayer Perceptron (MLP), Random Forest (RF), Gradient Boosting (GB) or Support Vector Machines (SVM), among others. The methods were compared with standard scores, MELD, SOFT and BAR. For the 5-years end-point, LR (AUC = 0.654) outperformed several machine learning techniques, such as MLP (AUC = 0.599), GB (AUC = 0.600), SVM (AUC = 0.624) or RF (AUC = 0.644), among others. Moreover, LR also outperformed standard scores. The same pattern was reproduced for the others 3 end-points. Complex machine learning methods were not able to improve the performance of liver allocation, probably due to the implicit limitations associated to the collection process of the database.