Management of coagulopathy among patients with cirrhosis undergoing upper endoscopy and paracentesis: Persistent gaps and areas of consensus in a multispecialty Delphi.

Background and Aims Patients with cirrhosis have abnormal coagulation indices such as a high international normalized ratio (INR) and low platelet count, but these do not correlate well with peri-procedure bleeding risk. We sought to develop consensus among the multiple stakeholders in cirrhosis care to inform process measures that can help improve the quality of the peri-procedure management of coagulopathy in cirrhosis. Approach and Results We identified candidate process measures for peri-procedure coagulopathy management in multiple contexts relating to the performance of paracentesis and upper endoscopy. An 11-member panel with content expertise was convened. It included nominees from professional societies for interventional radiology, transfusion medicine, and anesthesia as well as representatives from hematology, emergency medicine, transplant surgery, and community practice. Each measure was evaluated for agreement using a modified Delphi approach (3 rounds of rating) to define the final set of measures. Out of 286 possible measures, 33 measures made the final set. INR testing was not required for diagnostic or therapeutic paracentesis as well as diagnostic endoscopy. Plasma transfusion should be avoided for all paracenteses and diagnostic endoscopy. No consensus was achieved for these items in therapeutic intent or emergent endoscopy. The risks of prophylactic platelet transfusions exceed their benefits for outpatient diagnostic paracentesis and when platelet counts >20,000/mm 3 . It is uncertain whether risks outweigh benefits below 20,000/mm 3 in other contexts. No consensus was achieved on whether it was permissible to continue or stop systemic anticoagulation. Continuous aspirin was permissible for each procedure. Clopidogrel was permissible for diagnostic and therapeutic paracentesis and diagnostic endoscopy. Conclusions We found many areas of consensus that may serve as a foundation for a common set of practice metrics for the peri-procedure management of coagulopathy in cirrhosis.

Spatially resolved immune exhaustion within the alloreactive microenvironment predicts liver transplant rejection.

Allograft rejection is common following clinical organ transplantation, but defining specific immune subsets mediating alloimmunity has been elusive. Calcineurin inhibitor dose escalation, corticosteroids, and/or lymphocyte depleting antibodies have remained the primary options for treatment of clinical rejection episodes. Here, we developed a highly multiplexed imaging mass cytometry panel to study the immune response in archival biopsies from 79 liver transplant (LT) recipients with either no rejection (NR), acute T cell-mediated rejection (TCMR), or chronic rejection (CR). This approach generated a spatially resolved proteomic atlas of 461,816 cells (42 phenotypes) derived from 96 pathologist-selected regions of interest. Our analysis revealed that regulatory (HLADR+ Treg) and PD1+ T cell phenotypes (CD4+ and CD8+ subsets), combined with variations in M2 macrophage polarization, were a unique signature of active TCMR. These data provide insights into the alloimmune microenvironment in clinical LT, including identification of potential targets for focused immunotherapy during rejection episodes and suggestion of a substantial role for immune exhaustion in TCMR.

Evaluation of Induction Immunosuppression and Risk of Incisional Hernia After Liver Transplantation.

INTRODUCTION: Liver transplantation (LT) is a technically complex operation and usually performed on ill patients. A major postoperative morbidity is incisional hernia, occurring in 9.5%-32.4% of cases. There are mixed results in transplant studies regarding potential risk factors. Additionally, the literature is lacking in the relationship between specific immunosuppressive induction agents administered during LT and postoperative incisional hernia. METHODS: A single center, retrospective cohort study of patients who underwent primary LT between 4/2011-1/2018 was conducted. Clinical variables including demographics and comorbidities were reviewed. The primary end point was the development of an incisional hernia following LT. Sub analysis was performed for secondary end points to determine potential risk factors, including immunosuppressive induction agent. RESULTS: Overall, 418 patients met inclusion criteria. At 5 y post-LT, there were 66/271 (24.4%) and 53/147 (36.1%) patients diagnosed with an incisional hernia in the methylprednisolone and basiliximab groups, respectively. After propensity score matching, there was no difference in incisional hernia development between induction agents, P = 0.19. For patients with body mass index ≥30 and postoperative seroma of the abdominal wall, the hazard ratios were 2.67 (95% CI = 1.7, 4.3) and 2.03 (95% CI = 1.1, 3.9), respectively. CONCLUSIONS: Incisional hernia rate after LT was 28.5% at 5 y. Our analysis found that immunosuppressive induction agent at LT was not associated with the development of postoperative incisional hernia. However, preoperative obesity (body mass index ≥30) and postoperative seroma of the abdominal wall were potential risk factors. Further studies are needed to delineate if these risk factors remain across institutions and in alternative settings.

What Is Hot and New in Basic and Translational Science in Liver Transplantation in 2023? Report of the Basic and Translational Research Committee of the International Liver Transplantation Society.

The 2023 Joint Annual Congress of the International Liver Transplantation Society, European Liver and Intestine Transplant Association, and Liver Intensive Care Group of Europe were held in Rotterdam, the Netherlands, from May 3 to 6, 2023. This year, all speakers were invited to attend the Congress in person for the first time since the COVID-19 pandemic. The congress was attended by 1159 registered delegates from 54 countries representing 5 continents, with the 10 countries comprising the bulk of the delegates. Of the 647 abstracts initially submitted, 542 were eventually presented at the meeting, coming from 38 countries (mainly North America, Europe, and Asia) and 85% of them (462 abstracts) came from only 10 countries. Fifty-three (9.8%) abstracts, originated from 17 countries, were submitted under the Basic/Translational Scientific Research category, a similar percentage as in 2022. Abstracts presented at the meeting were classified as (1) ischemia and reperfusion injury, (2) machine perfusion, (3) bioengineering and liver regeneration, (4) transplant oncology, (5) novel biomarkers in liver transplantation, (6) liver immunology (rejection and tolerance), and (7) artificial intelligence and machine learning. Finally, we evaluated the number of abstracts commented in the Basic and Translational Research Committee-International Liver Transplantation Society annual reports over the past 5 y that resulted in publications in peer-reviewed journals to measure their scientific impact in the field of liver transplantation.

Immune checkpoint inhibitors in liver transplantation: Current practice, challenges, and opportunities.

Immune checkpoint inhibitors are becoming a mainstay of cancer treatment. While first studied and approved for patients with unresectable disease, due to their efficacy, they are becoming increasingly used in the perioperative period across many cancer types. In patients with HCC, immune checkpoint inhibitors have now become the standard of care in the advanced setting and have shown promising results in the adjuvant setting after liver resection. While these drugs continue to show promise, their role in the peritransplant setting still remains a question. In this review, we explore the current use of this class of medications in patients with HCC, as well as the immunologic role of the pathways that they inhibit. We also identify potential for future research opportunities to better understand the role of these medications.

Technical optimization of spatially resolved single-cell transcriptomic datasets to study clinical liver disease.

Single cell and spatially resolved 'omic' techniques have enabled deep characterization of clinical pathologies that remain poorly understood, providing unprecedented insights into molecular mechanisms of disease. However, transcriptomic platforms are costly, limiting sample size, which increases the possibility of pre-analytical variables such as tissue processing and storage procedures impacting RNA quality and downstream analyses. Furthermore, spatial transcriptomics have not yet reached single cell resolution, leading to the development of multiple deconvolution methods to predict individual cell types within each transcriptome 'spot' on tissue sections. In this study, we performed spatial transcriptomics and single nucleus RNA sequencing (snRNAseq) on matched specimens from patients with either histologically normal or advanced fibrosis to establish important aspects of tissue handling, data processing, and downstream analyses of biobanked liver samples. We observed that tissue preservation technique impacts transcriptomic data, especially in fibrotic liver. Single cell mapping of the spatial transcriptome using paired snRNAseq data generated a spatially resolved, single cell dataset with 24 unique liver cell phenotypes. We determined that cell-cell interactions predicted using ligand-receptor analysis of snRNAseq data poorly correlated with cellular relationships identified using spatial transcriptomics. Our study provides a framework for generating spatially resolved, single cell datasets to study gene expression and cell-cell interactions in biobanked clinical samples with advanced liver disease.

Finance, race, ethnicity, and spoken language impact clinical outcomes for children with acute liver failure.

BACKGROUND: Pediatric acute liver failure (PALF) is an emergency, necessitating prompt referral and management at an experienced liver transplant center. Social determinants of health (SDOH) drive healthcare disparities and can affect many aspects of disease presentation, access to care, and ultimately clinical outcomes. Potential associations between SDOH and PALF outcomes, including spontaneous recovery (SR), liver transplant (LT) or death, are unknown. This study aims to investigate how SDOH may affect PALF and therefore identify areas for intervention to mitigate unrecognized disparities. METHODS: A retrospective, single-center cohort was analyzed and then compared and validated with data from the multicenter National Institutes of Health PALF Study Group. The single-center review included 145 patients admitted with PALF using diagnostic codes. Medical records were reviewed to extract patient demographics, family structure, inpatient social worker assessments, and clinical outcomes. Data were stratified by outcome. RESULTS: This analysis determined that level of family support (p = .02), caretaker employment (p = .02), patient age, race, and language (p = .01) may impact clinical outcomes. Specifically, the cohort of children that died had the largest proportion of non-English speaking patients with limited support systems and parents who worked full-time. Conversely, patients who underwent LT more often belonged to English-speaking families with a homemaker and extensive support systems. CONCLUSION: This study suggests that SDOH impact PALF outcomes and highlights patient populations facing additional challenges during an already complex healthcare emergency. These associations may indicate unconscious biases held by transplant teams when evaluating waitlist candidacy, as well as barriers to healthcare access. Strategies to better understand the broader applicability of our findings and, if confirmed, efforts to mitigate social disparities, may improve clinical outcomes in PALF.

Impact of Medicaid Expansion on Surgical Care and Outcomes for Hepatobiliary Malignancies.

BACKGROUND: As part of the Patient Protection and Affordable Care Act, some states expanded Medicaid eligibility to adults with incomes below 138% of the federal poverty line. While this resulted in an increased proportion of insured residents, its impact on the diagnosis and treatment of hepatopancreaticobiliary (HPB) cancers has not been studied. STUDY DESIGN: The National Cancer Database (NCDB) from 2010 to 2017 was used. Patients diagnosed with HPB malignancies in states which expanded in 2014 were compared to patients in non-expansion states. Subset analyses of patients who underwent surgery and those in high-risk socioeconomic groups were performed. Outcomes studied included initiation of treatment within 30 days of diagnosis, stage at diagnosis, care at high volume or academic center, perioperative outcomes, and overall survival. Adjusted difference-in-differences analysis was performed. RESULTS: A total of 345,684 patients were included, of whom 55% resided in non-expansion states and 54% were diagnosed with pancreatic cancer. Overall survival was higher in states with Medicaid expansion (HR .90, 95% CI [.88-.92], P < .01). There were also better postoperative outcomes including 30-day mortality (.67 [.57-.80], P < .01) and 30-day readmissions (.87 [.78-.97], P = .02) as well as increased likelihood of having surgery in a high-volume center (1.42 [1.32-1.53], P < .01). However, there were lower odds of initiating care within 30 days of diagnosis (.77 [.75-.80], P < .01) and higher likelihood of diagnosis with stage IV disease (1.09 [1.06-1.12], P < .01) in expansion states. CONCLUSION: While operative outcomes and overall survival from HPB cancers were better in states with Medicaid expansion, there was no improvement in timeliness of initiating care or stage at diagnosis.

Living Donor Liver Transplantation for Hepatocellular Carcinoma Within and Outside Traditional Selection Criteria: A Multicentric North American Experience.

OBJECTIVE: To evaluate long-term oncologic outcomes of patients post-living donor liver transplantation (LDLT) within and outside standard transplantation selection criteria and the added value of the incorporation of the New York-California (NYCA) score. BACKGROUND: LDLT offers an opportunity to decrease the liver transplantation waitlist, reduce waitlist mortality, and expand selection criteria for patients with hepatocellular carcinoma (HCC). METHODS: Primary adult LDLT recipients between October 1999 and August 2019 were identified from a multicenter cohort of 12 North American centers. Posttransplantation and recurrence-free survival were evaluated using the Kaplan-Meier method. RESULTS: Three hundred sixty LDLTs were identified. Patients within Milan criteria (MC) at transplantation had a 1, 5, and 10-year posttransplantation survival of 90.9%, 78.5%, and 64.1% versus outside MC 90.4%, 68.6%, and 57.7% ( P = 0.20), respectively. For patients within the University of California San Francisco (UCSF) criteria, respective posttransplantation survival was 90.6%, 77.8%, and 65.0%, versus outside UCSF 92.1%, 63.8%, and 45.8% ( P = 0.08). Fifty-three (83%) patients classified as outside MC at transplantation would have been classified as either low or acceptable risk with the NYCA score. These patients had a 5-year overall survival of 72.2%. Similarly, 28(80%) patients classified as outside UCSF at transplantation would have been classified as a low or acceptable risk with a 5-year overall survival of 65.3%. CONCLUSIONS: Long-term survival is excellent for patients with HCC undergoing LDLT within and outside selection criteria, exceeding the minimum recommended 5-year rate of 60% proposed by consensus guidelines. The NYCA categorization offers insight into identifying a substantial proportion of patients with HCC outside the MC and the UCSF criteria who still achieve similar post-LDLT outcomes as patients within the criteria.

Summary of a consensus conference on heart-liver transplantation.

Patients with severe heart disease may have coexisting liver disease from various causes. The incidence of combined heart-liver transplant (CHLT) is increasing as more patients with congenital heart disease survive to adulthood and develop advanced heart failure with associated liver disease from chronic right-sided heart or Fontan failure. However, the criteria for CHLT have not been established. To address this unmet need, a virtual consensus conference was organized on June 10, 2022, endorsed by the American Society of Transplantation. The conference represented a collaborative effort by experts in cardiothoracic and liver transplantation from across the United States to assess interdisciplinary criteria for liver transplantation in the CHLT candidate, surgical considerations of CHLT, current allocation system that generally results in the liver following the heart for CHLT, and optimal post-CHLT management. The conference served as a forum to unify criteria between the different specialties and to forge a pathway for patients who may need dual organ transplantation. Due to the continuing shortage of available donor organs, ethical issues related to multiorgan transplantation were also debated. The findings and consensus statements are presented.

CHALF Score: A Novel Tool to Rapidly Risk Stratify Children in Need of Liver Transplant Evaluation During Acute Liver Failure.

BACKGROUND: Pediatric acute liver failure (PALF) can require emergent liver transplantation (LT, >25%) or lead to death (~15%). Existing models cannot predict clinical trajectory or survival with native liver (SNL). We aimed to create a predictive model for PALF clinical outcomes based on admission variables. METHODS: A retrospective, single-center PALF cohort (April 2003 to January 2022) was identified using International Classification of Disease codes, selected using National Institutes of Health PALF Study Group (PALFSG) criteria, and grouped by clinical outcome (SNL, LT, or death). Significant admission variables were advanced for feature selection using least absolute shrinkage and selection operator regression with bootstrapping (5000×). A predictive model of SNL versus LT or death was created using logistic regression and validated using PALFSG data. RESULTS: Our single-center cohort included 147 patients (58% SNL, 32% LT, 10% expired), while the PALFSG validation cohort included 492 patients (50% SNL, 35% LT, 15% expired). Admission variables associated with SNL included albumin (odds ratio [OR], 16; P < 0.01), ammonia (OR, 2.37; P < 0.01), and total bilirubin (OR, 2.25; P < 0.001). A model using these variables predicted SNL versus LT or death with high accuracy (accuracy [0.75 training, 0.70 validation], area under the curve [0.83 training, 0.78 validation]). A scaled score (CHLA-acute liver failure score) was created that predicted SNL versus LT or death with greater accuracy (C statistic 0.83) than Pediatric End-Stage Liver Disease (C statistic 0.76) and admission liver injury unit (C statistic 0.76) scores. CONCLUSIONS: The CHLA-acute liver failure score predicts SNL versus LT or mortality in PALF using admission laboratories with high accuracy. This novel, externally validated model offers an objective guide for urgent referral to a pediatric LT center.

Review of pediatric combined heart-liver transplantation: A roadmap to success.

BACKGROUND: Combined heart-liver transplantation (CHLT) is a promising technique to address end stage organ failure in patients with concomitant heart failure and chronic liver disease. While most experience with CHLT has involved adult patients, the expanding population of children born with univentricular congenital heart disease who underwent the Fontan procedure and develop Fontan-associated liver disease (FALD) has emerged as a growing indication for pediatric CHLT. METHODS: Currently, CHLT is performed at a select subset of experienced transplant centers, especially in the pediatric population. RESULTS: While technically demanding, CHLT may offer survival benefit when compared to heart transplant alone with decreased rejection of both synchronous allografts and equivalent outcomes with respect to waitlist time and post-operative complications. Limitations in the technique can be attributed to need for an appropriate multidisciplinary care center, challenges with donor organ availability and allocation, and the complexity associated with patient selection and peri-operative management. CONCLUSION: In this review, we summarize the history of CHLT, discuss patient selection, and highlight key facets of peri-operative care in the pediatric population.

Psychosocial evaluation of living liver donors-State of current practices in the United States.

We surveyed living donor liver transplant programs in the United States to describe practices in the psychosocial evaluation of living donors focused on (1) composition of psychosocial team; (2) domains, workflow, and tools of the psychosocial assessment; (3) absolute and relative mental health-related contraindications to donation; and (4) postdonation psychosocial follow-up. We received 52 unique responses, representing 33 of 50 (66%) of active living donor liver transplant programs. Thirty-one (93.9%) provider teams included social workers, 22 (66.7%) psychiatrists, and 14 (42.4%) psychologists. Validated tools were rarely used, but domains assessed were consistent. Respondents rated active alcohol (93.8%), cocaine (96.8%), and opioid (96.8%) use disorder, as absolute contraindications to donation. Active suicidality (97%), self-injurious behavior (90.9%), eating disorders (87.9%), psychosis (84.8%), nonadherence (71.9%), and inability to cooperate with the evaluation team (78.1%) were absolute contraindications to donation. There were no statistically significant differences in absolute psychosocial contraindications to liver donation between geographical areas or between large and small programs. Programs conduct postdonation psychosocial follow-up (57.6%) or screening (39.4%), but routine follow-up of declined donors is rarely conducted (15.8%). Psychosocial evaluation of donor candidates is a multidisciplinary process. The structure of the psychosocial evaluation of donors is not uniform among programs though the domains assessed are consistent. Psychosocial contraindications to living liver donation vary among the transplant programs. Mental health follow-up of donor candidates is not standardized.

Technical optimization of spatially resolved single-cell transcriptomic datasets to study clinical liver disease.

Single cell and spatially resolved 'omic' techniques have enabled deep characterization of clinical pathologies that remain poorly understood, providing unprecedented insights into molecular mechanisms of disease. However, transcriptomic platforms are costly, limiting sample size, which increases the possibility of pre-analytical variables such as tissue processing and storage procedures impacting RNA quality and downstream analyses. Furthermore, spatial transcriptomics have not yet reached single cell resolution, leading to the development of multiple deconvolution methods to predict individual cell types within each transcriptome 'spot' on tissue sections. In this study, we performed spatial transcriptomics and single nucleus RNA sequencing (snRNASeq) on matched specimens from patients with either histologically normal or advanced fibrosis to establish important aspects of tissue handling, data processing, and downstream analyses of biobanked liver samples. We observed that tissue preservation technique impacts transcriptomic data, especially in fibrotic liver. Deconvolution of the spatial transcriptome using paired snRNASeq data generated a spatially resolved, single cell dataset with 24 unique liver cell phenotypes. We determined that cell-cell interactions predicted using ligand-receptor analysis of snRNASeq data poorly correlated with celullar relationships identified using spatial transcriptomics. Our study provides a framework for generating spatially resolved, single cell datasets to study gene expression and cell-cell interactions in biobanked clinical samples with advanced liver disease.

Spatially resolved immune exhaustion within the alloreactive microenvironment predicts liver transplant rejection.

Allograft rejection is a frequent complication following solid organ transplantation, but defining specific immune subsets mediating alloimmunity has been elusive due to the scarcity of tissue in clinical biopsy specimens. Single cell techniques have emerged as valuable tools for studying mechanisms of disease in complex tissue microenvironments. Here, we developed a highly multiplexed imaging mass cytometry panel, single cell analysis pipeline, and semi-supervised immune cell clustering algorithm to study archival biopsy specimens from 79 liver transplant (LT) recipients with histopathological diagnoses of either no rejection (NR), acute T-cell mediated rejection (TCMR), or chronic rejection (CR). This approach generated a spatially resolved proteomic atlas of 461,816 cells derived from 98 pathologist-selected regions of interest relevant to clinical diagnosis of rejection. We identified 41 distinct cell populations (32 immune and 9 parenchymal cell phenotypes) that defined key elements of the alloimmune microenvironment (AME), identified significant cell-cell interactions, and established higher order cellular neighborhoods. Our analysis revealed that both regulatory (HLA-DR+ Treg) and exhausted T-cell phenotypes (PD1+CD4+ and PD1+CD8+ T-cells), combined with variations in M2 macrophage polarization, were a unique signature of TCMR. TCMR was further characterized by alterations in cell-to-cell interactions among both exhausted immune subsets and inflammatory populations, with expansion of a CD8 enriched cellular neighborhood comprised of Treg, exhausted T-cell subsets, proliferating CD8+ T-cells, and cytotoxic T-cells. These data enabled creation of a predictive model of clinical outcomes using a subset of cell types to differentiate TCMR from NR (AUC = 0.96 ± 0.04) and TCMR from CR (AUC = 0.96 ± 0.06) with high sensitivity and specificity. Collectively, these data provide mechanistic insights into the AME in clinical LT, including a substantial role for immune exhaustion in TCMR with identification of novel targets for more focused immunotherapy in allograft rejection. Our study also offers a conceptual framework for applying spatial proteomics to study immunological diseases in archival clinical specimens.

Impact of gut microbiota on liver transplantation.

The gut microbiota has been gaining attention due to its interactions with the human body and its role in pathophysiological processes. One of the main interactions is the "gut-liver axis," in which disruption of the gut mucosal barrier seen in portal hypertension and liver disease can influence liver allograft function over time. For example, in patients who are undergoing liver transplantation, preexisting dysbiosis, perioperative antibiotic use, surgical stress, and immunosuppressive use have each been associated with alterations in gut microbiota, potentially impacting overall morbidity and mortality. In this review, studies exploring gut microbiota changes in patients undergoing liver transplantation are reviewed, including both human and experimental animal studies. Common themes include an increase in Enterobacteriaceae and Enterococcaceae species and a decrease in Faecalibacterium prausnitzii and Bacteriodes, while a decrease in the overall diversity of gut microbiota after liver transplantation.