Liver transplantation for non-alcoholic fatty liver disease: indications and post-transplant management

Recent trends and new developments in liver transplantation

Liver transplantation (LT) has been an established treatment for end-staged liver disease for acute, chronic, metabolic diseases and liver cancer. Advanced surgical techniques, refined indications and contraindications for LT, improvements of donor selection, prognostic scorings system and immunosuppressive regimens have contributed to the improved outcomes of liver transplantation. The etiologies of cirrhosis have been shifting from viral hepatitis to metabolic associated fatty liver disease. New indications include peripheral or mass forming bile duct cancer, metastases from bowel cancers or neuroendocrine tumors. Resection and partial liver segments 2-3 transplantation with delayed total hepatectomy has been performed to the limited cases, which was the explored technique of auxiliary partial orthotopic LT. Minimally invasive donor hepatectomy (laparoscopic or robotic) has been increasingly done. In this review are described the recent pressing topics in LT.

Cenicriviroc Suppresses and Reverses Steatohepatitis by Regulating Macrophage Infiltration and M2 Polarization in Mice

The inhibition of hepatic macrophage and Kupfer cell recruitment and activation is a potential strategy for treating insulin resistance and nonalcoholic steatohepatitis (NASH). Cenicriviroc (CVC), a dual C-C chemokine receptor 2 (CCR2) and CCR5 antagonist, has shown antifibrotic activity in murine models of NASH and has been evaluated in clinical trials on patients with NASH. This study investigated the effects of CVC on macrophage infiltration and polarization in a lipotoxic model of NASH. C57BL/6 mice were fed a high-cholesterol, high-fat (CL) diet or a CL diet containing 0.015% CVC (CL + CVC) for 12 weeks. Macrophage recruitment and activation were assayed by immunohistochemistry and flow cytometry. CVC supplementation attenuated excessive hepatic lipid accumulation and peroxidation and alleviated glucose intolerance and hyperinsulinemia in the mice that were fed the CL diet. Flow cytometry analysis revealed that compared with the CL group, mice fed the CL + CVC diet had fewer M1-like macrophages, more M2-like macrophages, and fewer T cell counts, indicating that CVC caused an M2-dominant shift of macrophages in the liver. Similarly, CVC decreased lipopolysaccharide-stimulated M1-like macrophage activation, whereas it increased interleukin-4-induced M2-type macrophage polarization in vitro. In addition, CVC attenuated hepatic fibrosis by repressing hepatic stellate cell activation. Lastly, CVC reversed insulin resistance as well as steatosis, inflammation, and fibrosis of the liver in mice with pre-existing NASH. In conclusion, CVC prevented and reversed hepatic steatosis, insulin resistance, inflammation, and fibrogenesis in the liver of NASH mice via M2 macrophage polarization.

Serum Creatinine as an Independent Predictor of Moderate to Severe Fibrosis in Chinese American Non-obese Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely linked to the obesity epidemic. However, non-obese MASLD (body mass index [BMI] < 25 kg/m2 for Asians) is not uncommon, especially among Asian American populations. Preliminary research has demonstrated sarcopenia, a muscle-wasting syndrome, to be a major risk factor for non-obese Chinese MASLD. This study examined serum creatinine (SCr), a sarcopenia biomarker, and other prominent MASLD biomarkers for their ability to predict moderate to severe fibrosis (≥7.5 kPa or ≥F2 fibrosis) in the Chinese American MASLD population.

METHODS

A total of 296 Chinese American MASLD patients were categorized by BMI and fibrosis severity. As per World Health Organization guidelines for Asians, we identified obese MASLD (BMI ≥ 25 kg/m2) in 191 subjects (64.5%) and non-obese MASLD (BMI < 25 kg/m2) in 105 subjects (35.5%). Multivariate logistic regressions were performed to ascertain which biomarkers served as independent predictors of ≥F2 fibrosis. Wilcoxon signed-rank tests were conducted to compare MASLD cohorts (stratified by gender) and the healthy adult population on SCr distribution.

RESULTS

The obese MASLD cohorts had higher rates of ≥F2 fibrosis and type 2 diabetes mellitus compared to their older, non-obese counterparts. For obese MASLD patients, higher age (P < 0.05), increased BMI (P < 0.01), increased AST (P < 0.05), and decreased platelets (P < 0.05) independently predicted ≥F2 fibrosis. For non-obese MASLD patients, lowered SCr (P < 0.05) levels served as the main predictor of ≥F2 fibrosis. Female MASLD patients had markedly lower SCr distributions (P < 0.001) compared to the healthy female population, with 26.8% having SCr levels below the normal range.

CONCLUSIONS

In summary, SCr was the predominant predictor of moderate to severe fibrosis in non-obese Chinese American MASLD patients. The high rate of decreased SCr levels in Chinese American MASLD women suggests that this population may be at higher risk for muscle mass loss, which can lead to liver fat accumulation.

Plasma ALS and Gal-3BP differentiate early from advanced liver fibrosis in MASLD patients

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is estimated to affect 30% of the world's population, and its prevalence is increasing in line with obesity. Liver fibrosis is closely related to mortality, making it the most important clinical parameter for MASLD. It is currently assessed by liver biopsy - an invasive procedure that has some limitations. There is thus an urgent need for a reliable non-invasive means to diagnose earlier MASLD stages.

METHODS

A discovery study was performed on 158 plasma samples from histologically-characterised MASLD patients using mass spectrometry (MS)-based quantitative proteomics. Differentially abundant proteins were selected for verification by ELISA in the same cohort. They were subsequently validated in an independent MASLD cohort (n = 200).

RESULTS

From the 72 proteins differentially abundant between patients with early (F0-2) and advanced fibrosis (F3-4), we selected Insulin-like growth factor-binding protein complex acid labile subunit (ALS) and Galectin-3-binding protein (Gal-3BP) for further study. In our validation cohort, AUROCs with 95% CIs of 0.744 [0.673 - 0.816] and 0.735 [0.661 - 0.81] were obtained for ALS and Gal-3BP, respectively. Combining ALS and Gal-3BP improved the assessment of advanced liver fibrosis, giving an AUROC of 0.796 [0.731. 0.862]. The {ALS; Gal-3BP} model surpassed classic fibrosis panels in predicting advanced liver fibrosis.

CONCLUSIONS

Further investigations with complementary cohorts will be needed to confirm the usefulness of ALS and Gal-3BP individually and in combination with other biomarkers for diagnosis of liver fibrosis. With the availability of ELISA assays, these findings could be rapidly clinically translated, providing direct benefits for patients.

Metabolic dysfunction-associated steatotic liver disease: A silent pandemic

The worldwide epidemiology of non-alcoholic fatty liver disease (NAFLD) is showing an upward trend, parallel to the rising trend of metabolic syndrome, owing to lifestyle changes. The pathogenesis of NAFLD has not been fully understood yet. Therefore, NAFLD has emerged as a public health concern in the field of hepatology and metabolisms worldwide. Recent changes in the nomenclature from NAFLD to metabolic dysfunction-associated steatotic liver disease have brought a positive outlook changes in the understanding of the disease process and doctor-patient communication. Lifestyle changes are the main treatment modality. Recently, clinical trial using drugs that target 'insulin resistance' which is the driving force behind NAFLD, have shown promising results. Further translational research is needed to better understand the underlying pathophysiological mechanism of NAFLD which may open newer avenues of therapeutic targets. The role of gut dysbiosis in etiopathogenesis and use of fecal microbiota modification in the treatment should be studied extensively. Prevention of this silent epidemic by spreading awareness and early intervention should be our priority.

Exploring the Multifaceted Landscape of MASLD: A Comprehensive Synthesis of Recent Studies, from Pathophysiology to Organoids and Beyond

Non-alcoholic fatty liver disease (NAFLD) is a widespread contributor to chronic liver disease globally. A recent consensus on renaming liver disease was established, and metabolic dysfunction-associated steatotic liver disease, MASLD, was chosen as the replacement for NAFLD. The disease's range extends from the less severe MASLD, previously known as non-alcoholic fatty liver (NAFL), to the more intense metabolic dysfunction-associated steatohepatitis (MASH), previously known as non-alcoholic steatohepatitis (NASH), characterized by inflammation and apoptosis. This research project endeavors to comprehensively synthesize the most recent studies on MASLD, encompassing a wide spectrum of topics such as pathophysiology, risk factors, dietary influences, lifestyle management, genetics, epigenetics, therapeutic approaches, and the prospective trajectory of MASLD, particularly exploring its connection with organoids.

Exploring the effects of epigallocatechin gallate on lipid metabolism in the rat steatotic liver during normothermic machine perfusion: Insights from lipidomics and RNA sequencing

BACKGROUND

Hepatic steatosis is the leading cause of discarded liver grafts. Defatting steatotic liver grafts using drug combinations during ex vivo normothermic machine perfusion (NMP) has been reported. However, the effectiveness of NMP in reducing fat content using epigallocatechin gallate (EGCG) as a single defatting agent and its effect on lipid metabolism are poorly investigated.

METHODS

In this study, an NMP system was set up to perfuse a steatotic liver from a rat model with 10 mM EGCG. Livers without EGCG served as NMP controls, whereas static cold-preserved livers in the University of Wisconsin medium were used as static cold storage controls. Liver enzyme, reactive oxygen species (ROS), histology, and lipid content assessments were conducted post-perfusion, complemented by lipidomics, RNA sequencing, and western blotting to determine the lipid metabolism changes.

RESULTS

EGCG during NMP reduced hepatocellular injury markers and defatted steatotic liver grafts. Additionally, we observed a significant increase in triglyceride (TG) content in the perfusate post-NMP in the NMP + EGCG group, suggesting TG output from the liver. Furthermore, lipidomics analysis revealed that EGCG primarily affected metabolites involved in glycerophospholipid (GP) and glycerolipid (GL) metabolism. Further, the RNA sequencing indicated the modulation of these metabolic pathways via ECGC, which was associated with the downregulated Lpin1 and Gpat3 expression.

CONCLUSIONS

EGCG defats steatotic livers as a single defatting agent during NMP by promoting GL and GP metabolism via decreasing Lpin1 and Agpat9 levels.

How best to combine liver transplantation and bariatric surgery?-Results from a global, web-based survey

BACKGROUND AND AIMS

Obesity is a growing healthcare challenge worldwide and a significant risk factor for liver failure as seen with non-alcoholic steatohepatitis (NASH). Combining metabolic-bariatric surgery (MBS) with liver transplantation (LT) appears as attractive strategy to treat both, the underlying liver disease and obesity. However, there is an ongoing debate on best timing and patient selection. This survey was designed to explore the current treatment practice for patients with NASH and obesity worldwide.

METHODS

A web-based survey was conducted in 2022 among bariatric and LT surgeons, and hepatologists from Europe, North and South America and Asia.

RESULTS

The survey completion rate was 74% (145/196). The average respondents were 41-50 years (38%), male (82.1%) and had >20 years of clinical experience (42.1%). Centres with a high LT-caseload for NASH were mainly located in the USA and United Kingdom. Almost 30% have already performed a combination of LT with MBS and 49% plan to do it. A majority of bariatric surgeons prefer MBS before LT (77.2%), whereas most of LT surgeons (52%) would perform MBS during LT. Most respondents (n = 114; 80%) favour sleeve gastrectomy over other bariatric techniques. One third (n = 42; 29.4%) has an established protocol regarding MBS for LT candidates.

CONCLUSION

The most experienced centres doing LT for NASH are in the USA and United Kingdom with growing awareness worldwide. Overall, a combination of MBS and LT has already been performed by a third of respondents. Sleeve gastrectomy is the bariatric technique of choice-preferably performed either before or during LT.

Outcomes in elderly patients undergoing hepatic resection compared to liver transplant for hepatocellular carcinoma

BACKGROUND

Hepatic resection (HR) is an excellent option for patients with hepatocellular carcinoma (HCC). For patients meeting the Milan criteria, a liver transplant (LT) is also a viable option for patients with HCC, especially those with end-stage liver disease. With increasing rates of LTs amongst the elderly, we sought to determine long-term outcomes in patients who underwent HR compared to LTs in this patient population.

METHODS

We queried the national cancer database for elderly patients (≥70 years) diagnosed with HCC between 2004 and 2020. The primary outcome was overall survival (OS) computed using the Kaplan-Meier method and Cox proportional hazard regression. One-to-one propensity score matching was conducted on the basis of clinicodemographic features to account for baseline differences between patients undergoing each procedure.

RESULTS

Of the 5090 patients included, 4674 (91.8%) and 416 (8.2%) patients underwent HR and LT, respectively. Compared with HR patients, patients receiving LT had better OS (p < 0.001) and greater median survival time (65.6 months HR vs. 97.9 months LT, p < 0.001). On multivariable analysis, a LT was independently associated with improved survival (adjusted hazard ratio: 0.61, 95% confidence interval: 0.50-0.76, p < 0.001).

CONCLUSIONS

LT is associated with improved survival for well-selected elderly patients with HCC. Age alone should not be used as the sole parameter for the candidacy of LT in elderly patients.

New Developments and Challenges in Liver Transplantation

Liver disease is increasing in incidence and is the third most common cause of premature death in the United Kingdom and fourth in the United States. Liver disease accounts for 2 million deaths globally each year. Three-quarters of patients with liver disease are diagnosed at a late stage, with liver transplantation as the only definitive treatment. Thomas E. Starzl performed the first human liver transplant 60 years ago. It has since become an established treatment for end-stage liver disease, both acute and chronic, including metabolic diseases and primary and, at present piloting, secondary liver cancer. Advances in surgical and anaesthetic techniques, refined indications and contra-indications to transplantation, improved donor selection, immunosuppression and prognostic scoring have allowed the outcomes of liver transplantation to improve year on year. However, there are many limitations to liver transplantation. This review describes the milestones that have occurred in the development of liver transplantation, the current limitations and the ongoing research aimed at overcoming these challenges.

Evaluation and Management of Nutritional Consequences of Chronic Liver Diseases

Liver diseases are the major predisposing conditions for the development of malnutrition, sarcopenia, and frailty. Recently, the mechanism of the onset of these complications has been better established. Regardless of the etiology of the underlying liver disease, the clinical manifestations are common. The main consequences are impaired dietary intake, altered macro- and micronutrient metabolism, energy metabolism disturbances, an increase in energy expenditure, nutrient malabsorption, sarcopenia, frailty, and osteopathy. These complications have direct effects on clinical outcomes, survival, and quality of life. The nutritional status should be assessed systematically and periodically during follow-up in these patients. Maintaining and preserving an adequate nutritional status is crucial and should be a mainstay of treatment. Although general nutritional interventions have been established, special considerations are needed in specific settings such as decompensated cirrhosis, alcohol-related liver disease, and metabolic-dysfunction-associated fatty liver disease. In this review, we summarize the physiopathology and factors that impact the nutritional status of liver disease. We review how to assess malnutrition and sarcopenia and how to prevent and manage these complications in this setting.

Diabetes and Metabolic Disorders: Their Impact on Cardiovascular Events in Liver Transplant Patients

Cardiovascular diseases are currently one of the most important causes of morbidity and mortality in liver transplant patients over the long term. Therefore, evaluating prognostic factors for cardiovascular events (CVEs) in this population is essential for taking preventive measures. The aim of this study was to identify the impact of diabetes and other metabolic disorders on CVEs in liver transplant patients. Three hundred fifty-six liver transplant recipients who survived at least 6 months after surgery were enrolled. Patients were followed for a median time of 118 months (12-250 months). All cardiovascular events were carefully recorded and detailed in the patients' charts. Demographic data, diabetes, hypertension, dyslipidemia, weight changes, and a diagnosis of metabolic syndrome both before and after transplantation were noted to assess their possible relationship with CVE. The presence of a diagnosis of metabolic-associated fatty liver disease (MAFLD) was also evaluated. Immunosuppressive therapy was included in the analysis. Diabetes mellitus (DM), especially when present before transplantation, was strongly associated with CVEs (hazard risk HR 3.10; 95% confidence interval CI: 1.60-6.03). Metabolic syndrome was found to be associated with CVEs in univariate analysis (HR 3.24; 95% CI: 1.36-7.8), while pretransplantation and de novo MAFLD were not. Immunosuppressive therapy had no influence on predisposing transplanted patients to CVEs during follow-up. Further prospective studies may be useful in investigating the risk factors for CVEs after liver transplantation and improving the long-term survival of transplant patients.

The plasma degradome reflects later development of NASH fibrosis after liver transplant

Although liver transplantation (LT) is an effective therapy for cirrhosis, the risk of post-LT NASH is alarmingly high and is associated with accelerated progression to fibrosis/cirrhosis, cardiovascular disease, and decreased survival. Lack of risk stratification strategies hamper liver undergoes significant remodeling during inflammatory injury. During such remodeling, degraded peptide fragments (i.e., 'degradome') of the ECM and other proteins increase in plasma, making it a useful diagnostic/prognostic tool in chronic liver disease. To investigate whether inflammatory liver injury caused by post-LT NASH would yield a unique degradome profile, predictive of severe post-LT NASH fibrosis, we performed a retrospective analysis of 22 biobanked samples from the Starzl Transplantation Institute (12 with post-LT NASH after 5 years and 10 without). Total plasma peptides were isolated and analyzed by 1D-LC-MS/MS analysis using a Proxeon EASY-nLC 1000 UHPLC and nanoelectrospray ionization into an Orbitrap Elite mass spectrometer. Qualitative and quantitative peptide features data were developed from MSn datasets using PEAKS Studio X (v10). LC-MS/MS yielded ∼2700 identifiable peptide features based on the results from Peaks Studio analysis. Several peptides were significantly altered in patients that later developed fibrosis and heatmap analysis of the top 25 most significantly-changed peptides, most of which were ECM-derived, clustered the 2 patient groups well. Supervised modeling of the dataset indicated that a fraction of the total peptide signal (∼15%) could explain the differences between the groups, indicating a strong potential for representative biomarker selection. A similar degradome profile was observed when the plasma degradome patterns were compared being obesity sensitive (C57Bl6/J) and insensitive (AJ) mouse strains. Both The plasma degradome profile of post-LT patients yields stark difference based on later development of post-LT NASH fibrosis. This approach could yield new "fingerprints" that can serve as minimally-invasive biomarkers of negative outcomes post-LT.

Liver fibrosis and MAFLD: the exploration of multi-drug combination therapy strategies

In recent years, the prevalence of metabolic-associated fatty liver disease (MAFLD) has reached pandemic proportions as a leading cause of liver fibrosis worldwide. However, the stage of liver fibrosis is associated with an increased risk of severe liver-related and cardiovascular events and is the strongest predictor of mortality in MAFLD patients. More and more people believe that MAFLD is a multifactorial disease with multiple pathways are involved in promoting the progression of liver fibrosis. Numerous drug targets and drugs have been explored for various anti-fibrosis pathways. The treatment of single medicines is brutal to obtain satisfactory results, so the strategies of multi-drug combination therapies have attracted increasing attention. In this review, we discuss the mechanism of MAFLD-related liver fibrosis and its regression, summarize the current intervention and treatment methods for this disease, and focus on the analysis of drug combination strategies for MAFLD and its subsequent liver fibrosis in recent years to explore safer and more effective multi-drug combination therapy strategies.