Management of Recurrent and De Novo NAFLD/NASH After Liver Transplantation

The impact of county-level food access on the mortality and post-transplant survival among patients with steatotic liver disease

BACKGROUND

The impact of county-level food access on mortality associated with steatotic liver disease, as well as post-liver transplant outcomes among individuals with steatotic liver disease, have not been characterized.

METHODS

Data on steatotic liver disease-related mortality and outcomes of liver transplant recipients with steatotic liver disease between 2010 and 2020 were obtained from the Centers for Disease Control Prevention mortality as well as the Scientific Registry of Transplant Recipients databases. These data were linked to the food desert score, defined as the proportion of the total population in each county characterized as having both low income and limited access to grocery stores.

RESULTS

Among 2,710 counties included in the analytic cohort, median steatotic liver disease-related mortality was 27.3 per 100,000 population (interquartile range 24.9-32.1). Of note, patients residing in counties with high steatotic liver disease death rates were more likely to have higher food desert scores (low: 5.0, interquartile range 3.1-7.8 vs moderate: 6.1, interquartile range, 3.8-9.3 vs high: 7.6, interquartile range 4.1-11.7). Among 28,710 patients who did undergo liver transplantation, 5,310 (18.4%) individuals lived in counties with a high food desert score. Liver transplant recipients who resided in counties with the worst food access were more likely to have a higher body mass index (>35 kg/m2: low food desert score, 17.3% vs highest food desert score, 20.1%). After transplantation, there was no difference in 2-year graft survival relative to county-level food access (food desert score: low: 88.4% vs high: 88.6%; P = .77).

CONCLUSION

Poor food access was associated with a higher incidence rate of steatotic liver disease-related death, as well as lower utilization of liver transplants. On the other hand, among patients who did receive a liver transplant, there was no difference in 2-year graft survival regardless of food access strata. Policy initiatives should target the expansion of transplantation services to vulnerable communities in which there is a high mortality of steatotic liver disease.

Long Term Complications of Immunosuppression Post Liver Transplant

Improvement in immunosuppression has led to a remarkable improvement in short-term and long-term outcomes post-liver transplant (LT). However, with improvements in long-term survival, complications related to immunosuppressive drugs, either directly or indirectly, have also increased. The adverse events could be drug-specific, class-specific, or generic. Calcineurin inhibitors (cyclosporine and tacrolimus) are the backbone of the immunosuppression after LT and the main culprit associated with most of the complications, including renal failure, post-transplant diabetes mellitus (PTDM), and metabolic syndrome. Steroids are also implicated in the development of diabetes, osteoporosis, and metabolic syndrome post-LT. The development of infections and de novo malignancies (DNMs) is a generic effect linked to the overall cumulative immunosuppression. The development of these complications significantly hampers the quality of life and leads to increased morbidity and mortality post-LT. Thus, it is important to minimize the cumulative immunosuppression dose while simultaneously preventing allograft rejection. This review provides up-to-date, comprehensive knowledge of the complications of long-term immunosuppression post-LT along with associated risk factors and strategies to minimize the risk of complications.

Multi-omics network analysis on samples from sequential biopsies reveals vital role of proliferation arrest for Macrosteatosis related graft failure in rats after liver transplantation

To investigate the molecular impact of graft MaS on post-transplant prognosis, based on multi-omics integrative analysis. Rats were fed by methionine-choline deficient diet (MCD) for MaS grafts. Samples were collected from grafts by sequential biopsies. Transcriptomic and metabolomic profilings were assayed. Post-transplant MaS status showed a close association with graft failure. Differentially expressed genes (DEGs) for in-vivo MaS were mainly enriched on pathways of cell cycle and DNA replication. Post-transplant MaS caused arrests of graft regeneration via inhibiting the E2F1 centered network, which was confirmed by an in vitro experiment. Data from metabolomics assays found insufficient serine/creatine which is located on one‑carbon metabolism was responsible for MaS-related GF. Pre-transplant MaS caused severe fibrosis in long-term survivors. DEGs for grafts from long-term survivors with pre-transplant MaS were mainly enriched in pathways of ECM-receptor interaction and focal adhesion. Transcriptional regulatory network analysis confirmed SOX9 as a key transcription factor (TF) for MaS-related fibrosis. Metabolomic assays found elevation of aromatic amino acid (AAA) was a major feature of fibrosis in long-term survivors. Graft MaS in vivo increased post-transplant GF via negative regulations on graft regeneration. Pre-transplant MaS induced severe fibrosis in long-term survivors via activations on ECM-receptor interaction and AAA metabolism.

European Society for Organ Transplantation Consensus Statement on Biomarkers in Liver Transplantation

Currently, one-year survival following liver transplantation (LT) exceeds 90% in large international registries, and LT is considered definitive treatment for patients with end-stage liver disease and liver cancer. Recurrence of disease, including hepatocellular carcinoma (HCC), significantly hampers post-LT outcomes. An optimal approach to immunosuppression (IS), including safe weaning, may benefit patients by mitigating the effect on recurrent diseases, as well as reducing adverse events associated with over-/under-IS, including chronic kidney disease (CKD). Prediction of these outcome measures-disease recurrence, CKD, and immune status-has long been based on relatively inaccurate clinical models. To address the utility of new biomarkers in predicting these outcomes in the post-LT setting, the European Society of Organ Transplantation (ESOT) and International Liver Transplant Society (ILTS) convened a working group of experts to review literature pertaining to primary disease recurrence, development of CKD, and safe weaning of IS. Summaries of evidence were presented to the group of panelists and juries to develop guidelines, which were discussed and voted in-person at the Consensus Conference in Prague November 2022. The consensus findings and recommendations of the Liver Working Group on new biomarkers in LT, clinical applicability, and future needs are presented in this article.

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 hampers early intervention against development of post-LT NASH fibrosis. The 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 liver injury caused by post-LT NASH would yield a unique degradome profile that is predictive of severe post-LT NASH fibrosis, a retrospective analysis of 22 biobanked samples from the Starzl Transplantation Institute (12 with post-LT NASH after 5 years and 10 without) was performed. 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. The plasma degradome profile of post-LT patients yielded 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.

Changings and Challenges in Liver Transplantation for Nonalcoholic Fatty Liver Disease/Steatohepatitis

Liver transplantation for nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) is increasing rapidly worldwide. Compared with alcohol and viral-related liver disease, NAFLD/NASH is more frequently associated with a systemic metabolic syndrome, which significantly affects other organs, requiring multidisciplinary management, in all phases of liver transplant.

NAFLD: A pretransplant and post-transplant conundrum

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Utility and prognostic value of diagnosing MAFLD in patients undergoing liver transplantation for alcohol-related liver disease

BACKGROUND

Recently, the term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed to replace non-alcoholic fatty liver disease (NAFLD). This concept enables diagnosing liver disease associated with metabolic dysfunction in patients with alcohol-related liver disease (ALD), a main indication for liver transplantation (LTx). We assessed MAFLD prevalence in ALD patients undergoing LTx and its prognostic value on post-LTx outcomes.

METHODS

We retrospectively analyzed all ALD patients transplanted at our center between 1990 and August 2020. MAFLD was diagnosed based on the presence or history of hepatic steatosis and a BMI > 25 or type II diabetes or ≥ 2 metabolic risk abnormalities at LTx. Overall survival and risk factors for recurrent liver and cardiovascular events were analyzed by Cox regression.

RESULTS

Of the 371 included patients transplanted for ALD, 255 (68.7%) had concomitant MAFLD at LTx. Median follow-up post-LTx was 72 months (IQR: 34.50-122). Patients with ALD-MAFLD were older at LTx (p = .001), more often male (p < .001) and more frequently had hepatocellular carcinoma (p < .001). No differences in perioperative mortality and overall survival were found. ALD-MAFLD patients had an increased risk of recurrent hepatic steatosis, irrespective of alcohol relapse, but no superimposed risk of cardiovascular events.

CONCLUSIONS

The co-presence of MAFLD at LTx for ALD is associated with a distinct patient profile and is an independent risk factor for recurrent hepatic steatosis. The use of MAFLD criteria in ALD patients might increase awareness and treatment of specific hepatic and systemic metabolic abnormalities before and after LTx.

Indian National Association for Study of the Liver (INASL) Guidance Paper on Nomenclature, Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease globally and in India. The already high burden of NAFLD in India is expected to further increase in the future in parallel with the ongoing epidemics of obesity and type 2 diabetes mellitus. Given the high prevalence of NAFLD in the community, it is crucial to identify those at risk of progressive liver disease to streamline referral and guide proper management. Existing guidelines on NAFLD by various international societies fail to capture the entire landscape of NAFLD in India and are often difficult to incorporate in clinical practice due to fundamental differences in sociocultural aspects and health infrastructure available in India. A lot of progress has been made in the field of NAFLD in the 7 years since the initial position paper by the Indian National Association for the Study of Liver on NAFLD in 2015. Further, the ongoing debate on the nomenclature of NAFLD is creating undue confusion among clinical practitioners. The ensuing comprehensive review provides consensus-based, guidance statements on the nomenclature, diagnosis, and treatment of NAFLD that are practically implementable in the Indian setting.

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

Non-alcoholic fatty liver disease (NAFLD) is currently the fastest growing indication to liver transplantation (LT) in Western Countries, both for end stage liver disease and hepatocellular carcinoma. NAFLD/non-alcoholic steatohepatitis (NASH) is often expression of a systemic metabolic syndrome; therefore, NAFLD/NASH patients require a multidisciplinary approach for a proper pre-surgical evaluation, which is important to achieve a post-transplant outcome comparable to that of other indications to LT. NAFLD/NASH patients are also at higher risk of post-transplant cardiovascular events, diabetes, dyslipidemia, obesity, renal impairment and recurrent NASH. Lifestyle modifications, included diet and physical activity, are key to improve survival and quality of life after transplantation. A tailored immunosuppressive regimen may be proposed in selected patients. Development of new drugs for the treatment of recurrent NASH is awaited.

Factors Impacting Survival in Those Transplanted for NASH Cirrhosis: Data From the NailNASH Consortium

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is the leading indication for liver transplant (LT) in women and the elderly. Granular details into factors impacting survival in this population are needed to optimize management and improve outcomes.

METHODS

Patients receiving LT for NASH cirrhosis from 1997 to 2017 across 7 transplant centers (NailNASH consortium) were analyzed. The primary outcome was all-cause mortality, and causes of death were enumerated. All outcomes were cross referenced with United Network for Organ Sharing and adjudicated at each individual center. Cox regression models were constructed to elucidate clinical factors impacting mortality.

RESULTS

Nine hundred thirty-eight patients with a median follow-up of 3.8 years (interquartile range, 1.60-7.05 years) were included. The 1-, 3-, 5-, 10-, and 15-year survival of the cohort was 93%, 88%, 83%, 69%, and 46%, respectively. Of 195 deaths in the cohort, the most common causes were infection (19%), cardiovascular disease (18%), cancer (17%), and liver-related (11%). Inferior survival was noted in patients >65 years. On multivariable analysis, age >65 (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.04-2.77; P = .04), end-stage renal disease (HR, 1.55; 95% CI, 1.04-2.31; P = .03), black race (HR, 5.25; 95% CI, 2.12-12.96; P = .0003), and non-calcineurin inhibitors-based regimens (HR, 2.05; 95% CI, 1.19-3.51; P = .009) were associated with increased mortality. Statin use after LT favorably impacted survival (HR, 0.38; 95% CI, 0.19-0.75; P = .005).

CONCLUSIONS

Despite excellent long-term survival, patients transplanted for NASH at >65 years or with type 2 diabetes mellitus at transplant had higher mortality. Statin use after transplant attenuated risk and was associated with improved survival across all subgroups, suggesting that careful patient selection and implementation of protocol-based management of metabolic comorbidities may further improve clinical outcomes.

Approach to the Patient With Nonalcoholic Fatty Liver Disease

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes (T2D), causing substantial burden from hepatic and extrahepatic complications. However, endocrinologists often follow people who are at the highest risk of its more severe form with nonalcoholic steatohepatitis or NASH (i.e., T2D or obesity with cardiometabolic risk factors). Endocrinologists are in a unique position to prevent cirrhosis in this population with early diagnosis and treatment.

OBJECTIVE

This work aims to offer endocrinologists a practical approach for the management of patients with NAFLD, including diagnosis, fibrosis risk stratification, and referral to hepatologists.

PATIENTS

(1) An asymptomatic patient with obesity and cardiometabolic risk factors, found to have hepatic steatosis; (2) a patient with T2D and NASH with clinically significant liver fibrosis; and (3) a liver transplant recipient with a history of NASH cirrhosis, with significant weight regain and with recurrent NAFLD on the transplanted organ.

CONCLUSION

NASH can be reversed with proper management of obesity and of T2D. While no agents are currently approved for the treatment of NASH, treatment should include lifestyle changes and a broader use of structured weight-loss programs, obesity pharmacotherapy, and bariatric surgery. Diabetes medications such as pioglitazone and some glucagon-like peptide 1 receptor agonists may also improve liver histology and cardiometabolic health. Sodium-glucose cotransporter-2 inhibitors and insulin may ameliorate steatosis, but their effect on steatohepatitis remains unclear. Awareness by endocrinologists about, establishing an early diagnosis of fibrosis (ie, FIB-4, liver elastography) in patients at high-risk of cirrhosis, long-term monitoring, and timely referral to the hepatologist are all critical to curve the looming epidemic of cirrhosis from NAFLD.

Low-Dose Administration of Cannabigerol Attenuates Inflammation and Fibrosis Associated with Methionine/Choline Deficient Diet-Induced NASH Model via Modulation of Cannabinoid Receptor

Non-Alcoholic Steatohepatitis (NASH) is the progressive form of Non-Alcoholic Fatty Liver Disease (NAFLD). NASH is distinguished by severe hepatic fibrosis and inflammation. The plant-derived, non-psychotropic compound cannabigerol (CBG) has potential anti-inflammatory effects similar to other cannabinoids. However, the impact of CBG on NASH pathology is still unknown. This study demonstrated the therapeutic potential of CBG in reducing hepatic steatosis, fibrosis, and inflammation.

METHODS

8-week-old C57BL/6 male mice were fed with methionine/choline deficient (MCD) diet or control (CTR) diets for five weeks. At the beginning of week 4, mice were divided into three sub-groups and injected with either a vehicle, a low or high dose of CBG for two weeks. Overall health of the mice, Hepatic steatosis, fibrosis, and inflammation were evaluated.

RESULTS

Increased liver-to-body weight ratio was observed in mice fed with MCD diet, while a low dose of CBG treatment rescued the liver-to-body weight ratio. Hepatic ballooning and leukocyte infiltration were decreased in MCD mice with a low dose of CBG treatment, whereas the CBG treatment did not change the hepatic steatosis. The high dose CBG administration increased inflammation and fibrosis. Similarly, the expression of cannabinoid receptor (CB)1 and CB2 showed decreased expression with the low CBG dose but not with the high CBG dose intervention in the MCD group and were co-localized with mast cells. Additionally, the decreased mast cells were accompanied by decreased expression of transforming growth factor (TGF)-β1.

CONCLUSIONS

Collectively, the low dose of CBG alleviated hepatic fibrosis and inflammation in MCD-induced NASH, however, the high dose of CBG treatment showed enhanced liver damage when compared to MCD only group. These results will provide pre-clinical data to guide future intervention studies in humans addressing the potential uses of CBG for inflammatory liver pathologies, as well as open the door for further investigation into systemic inflammatory pathologies.

Lactobacillus reuteri MJM60668 Prevent Progression of Non-Alcoholic Fatty Liver Disease through Anti-Adipogenesis and Anti-inflammatory Pathway

Non-alcoholic fatty liver disease (NALFD) is a disease characterized by liver steatosis. The liver is a key organ involved in the metabolism of fat, protein, and carbohydrate, enzyme activation, and storage of glycogen, which is closely related to the intestine by the bidirectional relation of the gut-liver axis. Abnormal intestinal microbiota composition can affect energy metabolism and lipogenesis. In this experiment, we investigated the beneficial effect of Lactobacillus reuteri MJM60668 on lipid metabolism and lipogenesis. C57BL/6 mice were fed a high-fat diet (HFD) and orally administrated with MJM60668. Our results showed that mice treated with MJM60668 significantly decreased liver weight and liver/body weight ratio, without affecting food intake. Serum levels of ALT, AST, TG, TCHO, and IL-1β in mice fed with MJM60668 were decreased compared to the HFD group. Investigation of gene and protein expression on the lipogenesis and lipid metabolism showed that the expression of ACC, FAS, and SREBP was decreased, and PPARα and CPT was increased. Furthermore, an increase of adiponectin in serum was shown in our experiment. Moreover, serum IL-1β level was also significantly decreased in the treated mice. These results suggested that MJM60668 can strongly inhibit lipogenesis, enhance fatty acid oxidation, and suppress inflammation. Additionally, supplementation of MJM60668 increased the proportion of Akkermansiaceae and Lachnospiracea, confirming a potential improvement of gut microbiota, which is related to mucus barrier and decrease of triglycerides levels.

Metabolic mechanisms for and treatment of NAFLD or NASH occurring after liver transplantation

The rising tide of non-alcoholic fatty liver disease (NAFLD) associated with the obesity epidemic is a major health concern worldwide. NAFLD - specifically its more advanced form, non-alcoholic steatohepatitis (NASH)-related cirrhosis - is now the fastest growing indication for liver transplantation in the USA and Europe. Although the short-term and mid-term overall survival rates of patients who receive a liver transplant for NASH-related cirrhosis are essentially similar to those of patients who receive a transplant for other liver indications, recipients with NASH-related cirrhosis have an increased risk of waiting-list mortality and of developing recurrent liver disease and cardiometabolic complications in the longer term after liver transplantation. This Review provides a brief overview of the epidemiology of NAFLD and NASH and the occurrence of NAFLD or NASH in patients after liver transplantation for NASH and other liver indications. It also discusses the putative metabolic mechanisms underlying the emergence of NAFLD or NASH after liver transplantation as well as optimal therapeutic approaches for recipients of liver transplants, including the management of cardiometabolic comorbidities, tailored immunosuppression, lifestyle changes and pharmacotherapy for NAFLD.

Nonalcoholic Fatty Liver Disease in Living Donor Liver Transplant Recipients: A Histology-Based Study

Background

Recurrent or de novo nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common after liver transplantation (LT) and may be associated with rapid progression to fibrosis; however, there is limited data in this regard after living donor liver transplantation (LDLT).

Material and methods

This is a retrospective study at a high volume LDLT center of all liver biopsies performed in patients with post-transplant NAFLD diagnosed on ultrasound of the abdomen. Liver biopsy was indicated for raised transaminases and/or high liver stiffness on TE. The association between these prebiopsy parameters and inflammation and fibrosis on histology was analyzed. Data are shown as mean ± standard deviation or median (25-75 interquartile range).

Results

The study cohort consisted of 31 males and 3 females, aged 43 ± 10 years. The LT to liver biopsy interval was 44 (28-68) months. The prebiopsy AST and ALT were 71 (38-119) and 66 (50-156), respectively. The histology suggested no nonalcoholic steatohepatitis (NASH) in 7 (20%), borderline NASH in 15 (44%), and NASH in 12 (35%) patients. A total of 15 patients (44%) had stage 1 or stage 2 fibrosis. The proportion of patients having fibrosis was significantly higher in patients with NASH (83%) compared to patients with borderline NASH (33%) or no NASH (none had fibrosis, P = 0.001). Among 18 patients who underwent TE (on FibroScan), liver stiffness was significantly higher in patients with fibrosis [18.1 (9.7-22.5)] than in those without fibrosis [9.7 (4.0-12.7); P = 0.043].

Conclusion

Over a third of the LDLT recipients with post-transplant NAFLD developed NASH, and nearly half, borderline NASH 3-5 years after transplant. Most with established NASH also had fibrosis on histology. Prevention of risk factors and early diagnosis is warranted in these patients.

Current status of liver transplantation for non-B non-C liver cirrhosis and hepatocellular carcinoma

Recently, non-B non-C chronic liver diseases, including alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), have markedly increased worldwide. Liver transplantation (LT) is an effective curative therapy for hepatocellular carcinoma (HCC) as well as decompensated liver cirrhosis. In Japan, where the source of liver grafts is strongly dependent on living donors, efforts have been made to unify the indications for eligibility of HCC patients for LT, leading to the development of 5-5-500 criteria. Along with the expansion of eligibility for LT, the current changing trends in underlying liver diseases of LT recipients, which are related to the rising tide of non-B non-C cirrhosis and HCC, are highlighting the importance of peri-transplant management of patients with various comorbidities. The post-LT prognosis of patients with ALD is significantly affected by de novo malignancies and metabolic syndrome-related complications as well as posttransplant alcohol relapse. NAFLD/NASH patients often suffer from obesity, type 2 diabetes mellitus, and other metabolic syndrome-related disorders, and nonneoplastic factors such as cardiovascular events and recurrence of NAFLD/NASH have a significant impact on post-LT outcomes. Patient management in the peri-transplant period as well as risk assessment for LT are key to improving post-LT outcomes in the era of a growing number of cases of LT for non-B non-C liver diseases.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the past years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato, the Società Italiana di Diabetologia and the Società Italiana dell'Obesità reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure and Istituto Superiore di Sanità. Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources.Level of evidence Level of evidence of recommendations for each PICO question were reported according to available evidence.

Extrahepatic organs in the development of non-alcoholic fatty liver disease in liver transplant patients

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in patients who undergo liver transplantation (LT). Whereas there is huge data on NAFLD, little is known about NAFLD in LT. In this review, we aim to explore extrahepatic organs and their potential mechanisms in the development of NAFLD in LT patients and discuss current limitations in preclinical and clinical scenarios with suggestions for future study.

METHODS

The following keywords, such as NAFLD, NASH, liver transplant, therapy, pathogenesis and biomarkers, were set for literature retrieval. The articles which were published articles in English till 25th June 2020 in PubMed database were included, and there is no limit for the study design type.

KEY CONTENT AND FINDINGS

Following LT, there are significant shifts in the microbiota and farnesoid X receptor may be a potential therapeutic target for NAFLD in LT settings. The roles of probiotics and diet on NALFD remain inconclusive in LT background. Nevertheless, the adipokines and cytokines disorder and local insulin resistance of adipose tissue may contribute to NAFLD process. Bariatric surgeries are promising in controlling de novo and recurrent NAFLD with significant reduction in abdominal adipose tissue, despite the optimal timing is inconclusive in LT cases. Furthermore, circumstantial evidence indicates that miRNA-33a may function as a mediator bridging sarcopenia and NAFLD of post-LT. β-Hydroxy-β-Methyl-Butyrate treatment could improve muscle status in graft recipients and shows protective potential for NAFLD in LT settings.

CONCLUSIONS

Gut, adipose tissue and muscle are intricately intertwined in promoting NAFLD in LT cases. Further animal studies are needed to deepen our understanding of mechanisms in multi-organ crosstalk. High quality clinical trials are warrant for making guidelines and developing management strategies on NAFLD after LT.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

De novo and recurrence of metabolic dysfunction-associated fatty liver disease after liver transplantation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a new acronym adopted from the consensus of international experts. Given the increasing prevalence of MAFLD in pre-transplant settings, de novo and recurrent graft steatosis/MAFLD are common in post-transplant settings. The impact of graft steatosis on long-term outcomes is unclear. The current knowledge of incidence rate, risk factors, diagnosis, long-term outcomes, and management of graft steatosis (both de novo and recurrent) is discussed in this review.

Fatty Liver through the Ages- Non-Alcoholic Steatohepatitis (NASH)

BACKGROUND

The global epidemic of obesity and type 2 diabetes mellitus is the main driver of the growing global prevalence of non-alcoholic fatty liver disease (NAFLD). We aimed to review the current literature on NAFLD and NASH as it impacts children and adults.

METHODS

We performed a literature search on fatty liver specifically non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) among children and adults.

RESULTS

The prevalence of NAFLD in children ranges from 8%-12% while the prevalence in adults ranges 25%-48%. The prevalence of NASH among children with NAFLD is 23% while it ranges from 13% to 65% in the adults. There are similar risk factors for NAFLD among children and adults. However, in children, the diagnostic tests in the studies of NAFLD are limited to elevation of ALT level or a liver biopsy. In adults, additional diagnostic modalities, including non-invasive tests (NITs), have been used. From the spectrum of NAFLD, those with NASH are predominantly at risk of progressive liver disease to cirrhosis and liver-related mortality. NAFLD is associated with impairment of health-related quality of life and substantial economic burden.

CONCLUSION

The comprehensive burden (clinical, HRQL and economic) of NAFLD is high and increasing.

Metabolic associated fatty liver disease and acute-on-chronic liver failure: common themes for common problems

Metabolic associated fatty liver disease (MAFLD) affects 20-30% of the worldwide population and is becoming the most common cause of chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC). MAFLD is the hepatic expression of metabolic dysfunction correlated with a variety of metabolic comorbidities including obesity, dyslipidemia, hypertension and type 2 diabetes (T2DM). Obesity, altered gut permeability, chronic inflammation and dysbiosis related to MAFLD might predispose patients with cirrhosis to the development of acute-on-chronic liver failure (ACLF); however, this relationship remains unclear. ACLF is a syndrome with high short-term mortality, presenting with acute hepatic decompensation associated with organ failures in patients with underlying chronic liver disease with or without an identifiable precipitating event. While this syndrome can occur in any patient with cirrhosis, the increasing prevalence of cirrhosis due to MAFLD is of great concern because, in a recent analysis, MAFLD was the fastest rising cause of cirrhosis associated with ACLF among patients listed for LT in the US. In this review, we will discuss the current knowledge on MAFLD and the development of ACLF.

A prospective longitudinal assessment of de novo metabolic syndrome after liver transplantation

BACKGROUND

De novo metabolic syndrome (MS) is a frequent complication after liver transplantation (LT). The aim of this prospective study is to identify potential risk factors longitudinally associated to post-LT de novo MS. Patients without pre-LT MS who underwent LT between April 2013 and October 2017 were prospectively included. Metabolic variables were collected at LT and at 6, 12 and 24 months post-LT.

RESULTS

63 patients fulfilled the inclusion criteria (76% male, mean age 53.6±9.5 years). The prevalence of de novo MS was 46%, 43% and 49% at 6, 12, and 24 months after LT respectively. Among other MS components, the prevalence of type 2 diabetes, hypertension and hypertriglyceridemia significantly increased after LT. Considering the baseline characteristics at the adjusted analysis, alcoholic liver disease (OR 4.17, 95%CI 1.20-14.51; p = 0.03) and hypertension pre-LT (OR 11.3, 95%CI 1.49-85.46; p = 0.02 were confirmed as independent risk factors of post-LT de novo MS. In the time varying analysis, only eGFR (OR 0.97, 95%IC 0.97-0.98; p<0.0001) was found associated with post-LT de novo MS.

CONCLUSIONS

De novo MS frequently occurs shortly after LT, affecting nearly half of patients at 24 months post-LT. Lifestyle modifications should be recommended starting early post-LT, particularly for patients with established risk factors. This article is protected by copyright. All rights reserved.

Non-alcoholic fatty liver disease: Current therapeutic options

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and has an estimated global prevalence of 25%. NAFLD is found in up to 80% of people with obesity and over 60% of patients with diabetes. Cardiovascular disease is the main cause of mortality, followed by extra-hepatic cancers and then liver-specific complications of cirrhosis and hepatocellular carcinoma. Lifestyle modification remains the primary intervention in NAFLD. Weight loss achieved through dietary modification and exercise can lead to histologic improvement and reversal of metabolic complications. Current drug therapy is limited to pioglitazone and vitamin E; however, several agents are currently under phase III development. This review summarises the current treatment options in NAFLD.

Multidirectional facets of obesity management in the metabolic syndrome population after liver transplantation

The obesity pandemic has resulted in an increasing demand for liver transplantation and has significantly altered the profile of liver transplant candidates in addition to affecting posttransplantation outcomes. In this review, we discuss a broad range of clinical approaches that warrant attention to provide comprehensive and patient‐centred medical care to liver transplant recipients, and to be prepared to confront the rapidly changing clinical challenges and ensuing dilemmas. Adipose tissue is a complex and metabolically active organ. Visceral fat deposition is a key predictor of overall obesity‐related morbidity and mortality. Limited pharmacological options are available for the treatment of obesity in the liver transplant population. Bariatric surgery may be an alternative in eligible patients. The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global concern; NAFLD affects both pre‐ and posttransplantation outcomes. Numerous studies have investigated pharmacological and nonpharmacological management of NAFLD and some of these have shown promising results. Liver transplant recipients are constantly exposed to numerous factors that result in intestinal microbiota alterations, which were linked to the development of obesity, diabetes type 2, metabolic syndrome (MS), NAFLD, and hepatocellular cancer. Microbiota modifications with probiotics and prebiotics bring gratifying results in the management of metabolic complications. Fecal microbiota transplantation (FMT) is successfully performed in many medical indications. However, the safety and efficacy profiles of FMT in immunocompromised patients remain unclear. Obesity together with immunosuppressive treatment, may affect the pharmacokinetic and/or pharmacodynamic properties of coadministered medications. Individualized immunosuppressive regimens are recommended following liver transplantation to address possible metabolic concerns. Effective and comprehensive management of metabolic complications is shown to yield multiple beneficial results in the liver transplant population and may bring gratifying results in improving long‐term survival rates.

Sleeve gastrectomy prior to liver transplantation is superior to medical weight loss in reducing posttransplant metabolic complications

Strategies to optimize the management of obesity-related metabolic complications after liver transplantation (LT) are needed. We examined the effect of pre-LT sleeve gastrectomy (SG), as compared to medical weight loss (MWL), on post-LT outcomes. This is a cohort study of adults (≥18 years) with medically complicated obesity who were eligible for pre-LT SG and underwent LT from January 1, 2006 to June 1, 2016. Logistic regression models evaluated the association of SG on post-LT diabetes and hypertension, defined as new-onset or progressive disease post-LT. Cox regression models evaluated the association of SG on recurrent and de novo nonalcoholic fatty liver disease (NAFLD). Among 70 LT recipients who were eligible for pre-LT SG, 14 (20%) underwent SG and 56 (80%) underwent MWL only. Mean follow-up was 5.2 years post-LT. The SG cohort sustained higher % total body weight loss at 3 years post-LT (28.9% vs. 5.4%, p < .001). In multivariable analyses, SG was associated with significantly lower risk of post-LT diabetes (OR 0.04, 95% CI 0.00-0.41, p = .01), hypertension (OR 0.15, 95% CI 0.04-0.67, p = .01), and recurrent and de novo NAFLD (HR 0.19, 95% CI 0.04-0.91, p = .04). When compared to MWL, SG resulted in sustained weight loss and significantly lower risk of diabetes, hypertension, and recurrent and de novo NAFLD post-LT.

Nonalcoholic Fatty Liver Disease after Liver Transplant

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the world. The rising prevalence of nonalcoholic steatohepatitis (NASH) has led to a 170% increase in NASH cirrhosis as the listing indication for liver transplantation from 2004 to 2013. As of 2018, NASH has overtaken hepatitis C as an indication for liver transplantation in the USA. After liver transplantation, the allograft often develops recurrent NAFLD among patients with known NASH cirrhosis. In addition to recurrent disease, de novo NAFLD has been reported in patients with other indications for liver transplantation. In this review, we will discuss the risk factors associated with recurrent and de novo NAFLD, natural course of the disease, and management strategies after liver transplantation.

Position paper on liver and kidney diseases from the Italian Association for the Study of Liver (AISF), in collaboration with the Italian Society of Nephrology (SIN)

Liver and kidney are strictly connected in a reciprocal manner, in both the physiological and pathological condition. The Italian Association for the Study of Liver, in collaboration with the Italian Society of Nephrology, with this position paper aims to provide an up-to-date overview on the principal relationships between these two important organs. A panel of well-recognized international expert hepatologists and nephrologists identified five relevant topics: 1) The diagnosis of kidney damage in patients with chronic liver disease; 2) Acute kidney injury in liver cirrhosis; 3) Association between chronic liver disease and chronic kidney disease; 4) Kidney damage according to different etiology of liver disease; 5) Polycystic kidney and liver disease. The discussion process started with a review of the literature relating to each of the five major topics and clinical questions and related statements were subsequently formulated. The quality of evidence and strength of recommendations were graded according to the GRADE system. The statements presented here highlight the importance of strong collaboration between hepatologists and nephrologists for the management of critically ill patients, such as those with combined liver and kidney impairment.

Noninvasive markers of liver steatosis and fibrosis after liver transplantation - Where do we stand?

In the last two decades, advances in immunosuppressive regimens have led to fewer complications of acute rejection crisis and consequently improved short-term graft and patient survival. In parallel with this great success, long-term post-transplantation complications have become a focus of interest of doctors engaged in transplant medicine. Metabolic syndrome (MetS) and its individual components, namely, obesity, dyslipidemia, diabetes, and hypertension, often develop in the post-transplant setting and are associated with immuno-suppressive therapy. Nonalcoholic fatty liver disease (NAFLD) is closely related to MetS and its individual components and is the liver manifestation of MetS. Therefore, it is not surprising that MetS and its individual components are associated with recurrent or "de novo" NAFLD after liver transplantation (LT). Fibrosis of the graft is one of the main determinants of overall morbidity and mortality in the post-LT period. In the assessment of post-LT steatosis and fibrosis, we have biochemical markers, imaging methods and liver biopsy. Because of the significant economic burden of post-LT steatosis and fibrosis and its potential consequences, there is an unmet need for noninvasive methods that are efficient and cost-effective. Biochemical scores can overestimate fibrosis and are not a good method for fibrosis evaluation in liver transplant recipients due to frequent post-LT thrombocytopenia. Transient elastography with controlled attenuation parameter is a promising noninvasive method for steatosis and fibrosis. In this review, we will specifically focus on the evaluation of steatosis and fibrosis in the post-LT setting in the context of de novo or recurrent NAFLD.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Clinical and Genetic Risk Factors of Recurrent Nonalcoholic Fatty Liver Disease After Liver Transplantation

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) has been increasingly reported among recipients of liver transplantation (LT). We aimed to identify clinical and genetic risk factors responsible for the development of early recurrent NAFLD in nonalcoholic steatohepatitis transplant recipients.

METHODS

Forty-six total single nucleotide polymorphisms with known association with NAFLD were tested among both recipient and donor liver samples in 66 LT recipients with nonalcoholic steatohepatitis to characterize influences on NAFLD recurrence at ∼1 year post-LT (median interval from LT to biopsy: 377 days).

RESULTS

Recurrent NAFLD was identified in 43 (65.2%) patients, 20 (30.3%) with mild recurrence, and 23 (34.8%) with moderate to severe NAFLD. On adjusted analysis, change in the body mass index (BMI) (ΔBMI) was significantly associated with NAFLD recurrence, whereas post-LT diabetes mellitus was associated with increased severity of NAFLD recurrence. ADIPOR1 rs10920533 in the recipient was associated with increased risk of moderate to severe NAFLD recurrence, whereas the minor allele of SOD2 rs4880 in the recipient was associated with reduced risk. Similar reduced risk was noted in the presence of donor SOD2 rs4880 and HSD17B13 rs6834314 polymorphism.

DISCUSSION

Increased BMI post-LT is strongly associated with NAFLD recurrence, whereas post-LT diabetes mellitus was associated with increased severity of NAFLD recurrence. Both donor and recipient SOD2 rs4880 and donor HSD17B13 rs6834314 single nucleotide polymorphisms may be associated with reduced risk of early NAFLD recurrence, whereas presence of the minor allele form of ADIPOR1 rs10920533 in the recipient is associated with increased severity NAFLD recurrence.

Long-term Management of the Adult Liver Transplantation Recipients

The survival of liver transplantation (LT) recipients has been improved remarkably in short-term. The major causes of mortality in long-term include nonimmunological causes such as cardiovascular, de novo malignancy, chronic kidney disease, and recurrence of primary disease. Rejection-related mortality is rare in the long-term after LT. We discuss nonrejection causes of long-term morbidity/mortality, risk factors, and management strategies in LT recipients. In addition, we discuss osteoporosis, contraception, and pregnancy in LT recipients.

Recurrence of hepatocellular carcinoma following liver transplantation

INTRODUCTION

Hepatocellular carcinoma (HCC) is an increasingly common disease with liver transplant (LT) the best long-term therapy for early stage disease. We will review the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

AREAS COVERED

In this review, we will provide an overview of methods of patient risk stratification in the post-transplant period, the data around surveillance for HCC recurrence, and the evidence for and against post-LT adjuvant treatment strategies. Finally, we will provide data regarding treatment options for patients with HCC recurrence after LT. Using an extensive search of original papers and society guidelines, this paper provides a comprehensive review of the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

EXPERT OPINION

The development of multiple post-transplant prognostic scoring systems have allowed for improved assessment of recurrence risk and stratification of patients. However, the ability to translate this information into surveillance and therapeutic strategies that improve patient outcomes still have to be fully demonstrated. Post-LT immunosuppression strategies have been implemented in order to attempt to reduce this risk. Evidence-based strategies for managing recurrent HCC are evolving. We expect that with further understanding of individual patient characteristics will allow for optimal therapeutic selection.

Metabolic associated fatty liver disease: Addressing a new era in liver transplantation

Metabolic associated fatty liver disease (MAFLD), previously termed non-alcoholic fatty liver disease, is the leading global cause of liver disease and is fast becoming the most common indication for liver transplantation. The recent change in nomenclature to MAFLD refocuses the conceptualisation of this disease entity to its metabolic underpinnings and may help to spur a paradigm shift in the approach to its management, including in the setting of liver transplantation. Patients with MAFLD present significant challenges in the pre-, peri- and post-transplant settings, largely due to the presence of medical comorbidities that include obesity, metabolic syndrome and cardiovascular risk factors. As the community prevalence of MAFLD increases concurrently with the obesity epidemic, donor liver steatosis is also a current and future concern. This review outlines current epidemiology, nomenclature, management issues and outcomes of liver transplantation in patients with MAFLD.

NAFLD and liver transplantation: Disease burden, current management and future challenges

Non-alcoholic fatty liver disease (NAFLD), specifically its progressive form non-alcoholic steatohepatitis (NASH), represents the fastest growing indication for liver transplantation in Western countries. Diabetes mellitus, morbid obesity and cardiovascular disease are frequently present in patients with NAFLD who are candidates for liver transplantation. These factors require specific evaluation, including a detailed pre-surgical risk stratification, in order to improve outcomes after liver transplantation. Moreover, in the post-transplantation setting, the incidence of cardiovascular events and metabolic complications can be amplified by immunosuppressive therapy, which is a well-known driver of metabolic alterations. Indeed, patients with NASH are more prone to developing early post-transplant complications and, in the long-term, de novo malignancy and cardiovascular events, corresponding to higher mortality rates. Therefore, a tailored multidisciplinary approach is required for these patients, both before and after liver transplantation. Appropriate candidate selection, lifestyle modifications and specific assessment in the pre-transplant setting, as well as pharmacological strategies, adjustment of immunosuppression and a healthy lifestyle in the post-transplant setting, play a key role in correct management.

Changing trends of liver transplantation and mortality from non-alcoholic fatty liver disease

The rising tide of non-alcoholic fatty liver disease (NAFLD) associated with the obesity epidemic is a major international health concern. NAFLD is the leading global cause of liver disease with an estimated prevalence of 25% and is the fastest growing indication for liver transplantation (LT). The presence and severity of liver fibrosis is the only histologic predictor of clinical outcomes in this group. NAFLD poses several challenges in the peri-transplant setting including the management of multiple metabolic co-morbidities, post-transplant obesity and cardiovascular risk. However, post-LT outcomes in well-selected NAFLD patients appear similar to non-NAFLD indications, including in the setting of hepatocellular carcinoma (HCC). The rising prevalence of NAFLD may impact potential liver graft donors, which may in-turn adversely affect post-LT outcomes. This review outlines the current epidemiology, natural history and outcomes of NAFLD with a focus on pre- and post-liver transplant settings.

Donor PNPLA3 and TM6SF2 Variant Alleles Confer Additive Risks for Graft Steatosis After Liver Transplantation

BACKGROUND

The rs58542926 polymorphism in transmembrane 6 superfamily member 2 (TM6SF2) is a genetic factor predisposing to nonalcoholic fatty liver disease. We aimed to explore the effect of recipient and donor TM6SF2 rs58542926 genotypes on liver graft fat content after liver transplantation.

METHODS

Steatosis was evaluated in liver biopsies from 268 adult recipients. The influence of recipient and donor TM6SF2 genotypes, patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 genotypes, and nongenetic factors on the steatosis grade assessed 6-30 months after transplantation was analyzed by ordinal logistic regression.

RESULTS

The presence of the TM6SF2 c.499A allele in the donor (P = 0.014), PNPLA3 c.444G allele in the donor (P < 0.001), posttransplant body mass index (P < 0.001), and serum triglycerides (P = 0.047) independently predicted increased liver fat content on multivariable analysis, whereas noncirrhotic liver disease, as an indication for liver transplantation, was associated with lower risk of steatosis (P = 0.003). The effects of the donor TM6SF2 A and PNPLA3 G alleles were additive, with an odds ratio of 4.90 (95% confidence interval, 2.01-13.00; P < 0.001), when both minor alleles were present compared with an odds ratio of 2.22 (95% confidence interval, 1.42-3.61; P = 0.002) when only one of these alleles was present.

CONCLUSIONS

The donor TM6SF2 c.499A allele is an independent risk factor of liver graft steatosis after liver transplantation that is additive to the effects of donor PNPLA3 c.444G allele.

De novo and recurrent liver disease

Decompensated cirrhosis due to nonalcoholic steatohepatitis (NASH), and autoimmune liver diseases (AILD) are the most common indications for liver transplantation (LT). AILD include autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). NASH and AILD share some peculiarities as they can recur in the new graft, compromising the quality of life, and graft and patient survival. De novo NASH or AIH connotes the development of these liver diseases in patients transplanted for other indications. The diagnosis of recurrent or de novo liver disease usually requires a liver biopsy aside from recurrent PSC, which can be diagnosed with compatible imaging studies and exclusion of other causes of biliary strictures. The treatment of recurrent NASH is lifestyle modifications aiming for weight loss. Recurrent and de novo AIH is usually treated with corticosteroids with or without azathioprine. Recurrent PBC should be treated with ursodeoxycholic acid. There are no proven treatment options for recurrent PSC. Patients with graft failure should be considered for repeat LT. Future investigations should use standardized diagnostic criteria for each disease, seek diagnostic biomarkers, and evaluate treatments that improve outcomes.

Mechanisms of nonalcoholic fatty liver disease and implications for surgery

Background

Nonalcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in both adults and children worldwide. Understanding the pathogenic mechanisms behind NAFLD provides the basis for identifying risk factors, such as metabolic syndrome, pancreatoduodenectomy, and host genetics, that lead to the onset and progression of the disease. The progression from steatosis to more severe forms, such as steatohepatitis, fibrosis, and cirrhosis, leads to an increased number of liver and non-liver complications.

Purpose

NAFLD-associated end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC) often require surgery as the only curative treatment. In particular, the presence of NAFLD together with the coexisting metabolic comorbidities that usually occur in these patients requires careful preoperative diagnosis and peri-/postoperative management. Bariatric surgery, liver resection, and liver transplantation (LT) have shown favorable results for weight loss, HCC, and ESLD in patients with NAFLD. The LT demand and the increasing spread of NAFLD in the donor pool reinforce the already existing lack of donor organs.

Conclusion

In this review, we will discuss the diverse mechanisms underlying NAFLD, its implications for surgery, and the challenges for patient management.

Post-transplant diabetes mellitus and preexisting liver disease - a bidirectional relationship affecting treatment and management

Liver cirrhosis and diabetes mellitus (DM) are both common conditions with significant socioeconomic burden and impact on morbidity and mortality. A bidirectional relationship exists between DM and liver cirrhosis regarding both etiology and disease-related complications. Type 2 DM (T2DM) is a well-recognized risk factor for chronic liver disease and vice-versa, DM may develop as a complication of cirrhosis, irrespective of its etiology. Liver transplantation (LT) represents an important treatment option for patients with end-stage liver disease due to non-alcoholic fatty liver disease (NAFLD), which represents a hepatic manifestation of metabolic syndrome and a common complication of T2DM. The metabolic risk factors including immunosuppressive drugs, can contribute to persistent or de novo development of DM and NAFLD after LT. T2DM, obesity, cardiovascular morbidities and renal impairment, frequently associated with metabolic syndrome and NAFLD, may have negative impact on short and long-term outcomes following LT. The treatment of DM in the context of chronic liver disease and post-transplant is challenging, but new emerging therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium–glucose cotransporter 2 inhibitors (SGLT2i) targeting multiple mechanisms in the shared pathophysiology of disorders such as oxidative stress and chronic inflammation are a promising tool in future patient management.

Management of metabolic syndrome and cardiovascular risk after liver transplantation

Cardiovascular events are the second most prevalent cause of non-hepatic mortality in liver transplant recipients. The incidence of these events is projected to rise because of the growing prevalence of non-alcoholic steatohepatitis as a transplant indication and the ageing population of liver transplant recipients. Recipients with metabolic syndrome are up to four times more likely to have a cardiovascular event than recipients without, therefore prevention and optimal treatment of the components of metabolic syndrome are key in reducing the risk of these events. Although data on the treatment of metabolic comorbidities specifically in liver transplant recipients are scarce, there is detailed guidance from learned societies that mostly mirrors the guidance for patients at increased cardiovascular risk in the general population. In this Review, we discuss the management of the components of metabolic syndrome following liver transplantation and provide practical stepwise guidance. We also emphasise the need for adequately powered studies for the treatment of metabolic comorbidities in liver transplant recipients.

Nonalcoholic steatohepatitis recurrence after liver transplant

Nonalcoholic steatohepatitis (NASH) is the fastest growing indication for liver transplant (LT)worldwide and is deemed to be the foremost indication in the near future. Recurrence of NASH can occur post LT and has been observed to be a common phenomenon. Baseline metabolic co-morbidities and worsening of metabolic profile post LT are the principal drivers of NASH recurrence. Liver biopsy remains the gold standard for establishing the diagnosis. However, noninvasive methods including transient elastography (TE) and magnetic resonance imaging (MRI) seem to be promising. The implications of recurrent NASH on post LT outcomes, graft steatosis, progression to fibrosis, overall survival, and cardiovascular associations warrant careful evaluation. Control of metabolic parameters and weight gain along with tailored immunosuppression remain the cornerstone of management. Extrapolation of the ever-increasing armamentarium of NASH pharmacotherapy specifically in this population of recurrent NAFLD remains a challenge for the future.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.