Incidence and Risks for Nonalcoholic Fatty Liver Disease and Steatohepatitis Post-liver Transplant: Systematic Review and Meta-analysis. Transplantation. 2019;103:e345-e354. [PMID: 31415032 DOI: 10.1097/tp.0000000000002916]

Effect of Immunosuppressive Regimens on Metabolic Dysfunction-associated Fatty Liver Disease Following Liver Transplantation

Background

Metabolic dysfunction-associated fatty liver disease has been linked to negative outcomes in patients with end-stage liver disease following liver transplantation. However, the influence of immunosuppressive regimens on it has not been explored.

Methods

A retrospective analysis was conducted using the preoperative and postoperative data from patients with end-stage liver disease. The study compared three different groups: tacrolimus-based group, sirolimus-based group, and combined tacrolimus- and sirolimus-based regimens. Binary logistic regression analysis was employed to identify risk factors for metabolic dysfunction-associated fatty liver disease.

Results

A total of 171 patients participated in the study, consisting of 127 males and 44 females, with a mean age of 49.6 years. The prevalence of posttransplant metabolic dysfunction-associated fatty liver disease was 29.23%. Among the three groups, there were 111 liver transplant recipients in the tacrolimus-based group, 28 in the sirolimus-based group, and 32 in the combination group. A statistically significant difference was observed in the incidence of metabolic dysfunction-associated fatty liver disease (P < 0.05), whereas the other preoperative and postoperative parameters showed no significant differences. Multivariate analysis revealed that a low-calorie diet (95% confidence intervals: 0.15-0.90, P = 0.021) and a combination of tacrolimus- and sirolimus-based immunosuppressive regimen (95% confidence intervals: 1.01-2.77, P = 0.046) were associated with lower risk of posttransplant metabolic dysfunction-associated fatty liver disease.

Conclusions

Our study indicates that implementing a low-calorie diet and utilizing a combination of tacrolimus- and sirolimus-based immunosuppressive regimen can effectively lower the risk of posttransplant metabolic dysfunction-associated fatty liver disease following liver transplantation.

FibroScan compared to liver biopsy for accurately staging recurrent hepatic steatosis and fibrosis after transplantation for MASH

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) recurrence after liver transplantation (LT) seems unavoidable and gradual. We aimed to evaluate the diagnostic accuracy in the post-LT setting of patients transplanted for metabolic dysfunction-associated steatohepatitis (MASH) of recurrent hepatic steatosis and fibrosis identified with FibroScan, compared to biopsy findings.

METHODS

This prospective cohort study included adults transplanted for MASH between 2010 and 2022 in three LT centres in Spain who underwent FibroScan and biopsy at least 1-year after LT.

RESULTS

In total, 44 patients transplanted for MASH after LT were included. The median time from LT to biopsy and FibroScan was 24.5 (interquartile range [IQR]:16-46) and 26.0 (IQR: 16.8-41.5) months, respectively. The median time between biopsy and FibroScan was 2.0 (IQR: 0-5) months. On FibroScan, significant steatosis was diagnosed in about half of the patients (n = 21, 47.7%), yet advanced fibrosis in only two cases (4.6%). On biopsy, a quarter of biopsied patients (n = 11, 25%) had a MASH diagnosis, two (4.6%) with significant fibrosis and one (2.3%) with cirrhosis. All patients with liver stiffness measurement (LSM) values <8 kPa (n = 35, 79.5%) had a fibrosis stage ≤F1 (negative predictive value = 100%). The combination of post-LT hypertension (odds ratio [OR]: 12.0, 95% confidence interval [CI]: 1.8-80.4, p = .010) and post-LT dyslipidaemia (OR: 7.9, 95% CI: 1.3-47.1, p = .024) with LSM (OR: 1.7, 95% CI: 1.1-2.8, p = .030) was independently associated with MASLD.

CONCLUSIONS

Although biopsy remains the gold standard for detecting fibrosis, our results suggest that LSM values <8 kPa after LT for MASH are strongly correlated with absence of significant/advanced fibrosis.

Maladaptive regeneration and metabolic dysfunction associated steatotic liver disease: Common mechanisms and potential therapeutic targets

The normal liver has an extraordinary capacity of regeneration. However, this capacity is significantly impaired in steatotic livers. Emerging evidence indicates that metabolic dysfunction associated steatotic liver disease (MASLD) and liver regeneration share several key mechanisms. Some classical liver regeneration pathways, such as HGF/c-Met, EGFR, Wnt/β-catenin and Hippo/YAP-TAZ are affected in MASLD. Some recently established therapeutic targets for MASH such as the Thyroid Hormone (TH) receptors, Glucagon-like protein 1 (GLP1), Farnesoid X receptor (FXR), Peroxisome Proliferator-Activated Receptors (PPARs) as well as Fibroblast Growth Factor 21 (FGF21) are also reported to affect hepatocyte proliferation. With this review we aim to provide insight into common molecular pathways, that may ultimately enable therapeutic strategies that synergistically ameliorate steatohepatitis and improve the regenerating capacity of steatotic livers. With the recent rise of prolonged ex-vivo normothermic liver perfusion prior to organ transplantation such treatment is no longer restricted to patients undergoing major liver resection or transplantation, but may eventually include perfused (steatotic) donor livers or even liver segments, opening hitherto unexplored therapeutic avenues.

Post-Liver Transplant Metabolic Syndrome

Non-alcoholic steatohepatitis (NASH) is the second most frequent cause of liver transplantation following alcoholic liver disease. With longer follow-up and increased survival rates, the occurrence rate of the metabolic syndrome is increasing with time among liver transplant recipients. Reappearances of non-alcoholic fatty liver disease after transplantation, both as recurring cases and new instances, are prevalent; nonetheless, the recurrence of fibrosis is minimal. Recognizing populations at elevated risk and enhancing the management of metabolic-related conditions are crucial for maintaining a healthy transplanted organ, particularly considering the prolonged utilization of immunosuppressive treatments. Furthermore, NASH-related cirrhosis patients who had transplant are at a greater risk of cardiovascular, renal events and increased incidence of cancer, necessitating a unique care strategy. This review discusses post-transplant metabolic syndrome, risk factors, pathogenesis, diagnosis, prevention strategy, recurrent and de novo NAFLD and customized immunosuppression.

Reappraisal of Donor Age in Liver Transplantation: NASH as a Potential Target to Safely Utilize Old Liver Grafts

BACKGROUND

With the chronic shortage of donated organs, expanding the indications for liver transplantation (LT) from older donors is critical. Nonalcoholic steatohepatitis (NASH) stands out because of its unique systemic pathogenesis and high recurrence rate, both of which might make donor selection less decisive. The present study aims to investigate the usefulness of old donors in LT for NASH patients.

METHODS

The retrospective cohort study was conducted using the Scientific Registry Transplant Recipient database. The cohort was divided into 3 categories according to donor age: young (aged 16-35), middle-aged (36-59), and old donors (60-). Multivariable and Kaplan-Meier analyses were performed to compare the risk of donor age on graft survival (GS).

RESULTS

A total of 67 973 primary adult donation-after-brain-death LTs (2002-2016) were eligible for analysis. The multivariable analysis showed a reduced impact of donor age on GS for the NASH cohort (adjusted hazard ratio = 1.13, 95% confidence interval, 1.00-1.27), comparing old to middle-aged donors. If the cohort was limited to NASH recipients plus 1 of the following, recipient age ≥60, body mass index <30, or Model of End Stage Liver Disease score <30, adjusted hazard ratios were even smaller (0.99 [0.84-1.15], 0.92 [0.75-1.13], or 1.04 [0.91-1.19], respectively). Kaplan-Meier analysis revealed no significant differences in overall GS between old- and middle-aged donors in these subgroups ( P = 0.86, 0.28, and 0.11, respectively).

CONCLUSIONS

Donor age was less influential for overall GS in NASH cohort. Remarkably, old donors were equivalent to middle-aged donors in subgroups of recipient age ≥60, recipient body mass index <30, or Model of End Stage Liver Disease score <30.

Metabolic-Dysfunction-Associated Steatotic Liver Disease (MASLD) after Liver Transplantation: A Narrative Review of an Emerging Issue

The development of steatotic liver disease after liver transplant (LT) is widely described, and epidemiological data have revealed an increased incidence in recent times. Its evolution runs from simple steatosis to steatohepatitis and, in a small proportion of patients, to significant fibrosis and cirrhosis. Apparently, post-LT steatotic disease has no impact on the recipient's overall survival; however, a higher cardiovascular and malignancy burden has been reported. Many donors' and recipients' risk factors have been associated with this occurrence, although the recipient-related ones seem of greater impact. Particularly, pre- and post-LT metabolic alterations are strictly associated with steatotic graft disease, sharing common pathophysiologic mechanisms that converge on insulin resistance. Other relevant risk factors include genetic variants, sex, age, baseline liver diseases, and immunosuppressive drugs. Diagnostic evaluation relies on liver biopsy, although non-invasive methods are being increasingly used to detect and monitor both steatosis and fibrosis stages. Management requires a multifaceted approach focusing on lifestyle modifications, the optimization of immunosuppressive therapy, and the management of metabolic complications. This review aims to synthesize the current knowledge of post-LT steatotic liver disease, focusing on the recent definition of metabolic-dysfunction-associated steatotic liver disease (MASLD) and its metabolic and multisystemic concerns.

Combination of risk alleles of PNPLA3, TM6SF2, and HSD17B13 of donors can predict recurrence of steatotic liver disease after liver transplantation

AIMS

This study aimed to identify the genetic risk factors from donors or recipients that contribute to postliver transplantation (LT) steatotic liver disease (SLD), focusing on the genetic risk score (GRS) based on single nucleotide polymorphisms (SNPs) in SLD patients.

METHODS

This retrospective study included 55 Japanese SLD recipients and their respective donors. Genotyping of PNPLA3, TM6SF2, and HSD17B13 was undertaken, and the combined GRS was calculated. The relationship between the GRS and the incidence of posttransplant SLD was also evaluated.

RESULTS

The SLD recipients had a high prevalence of post-LT graft steatosis/steatohepatitis (76.4% and 58.2%, respectively). Although the recipients had a high frequency of risk alleles, there was no relationship between the number of risk alleles for each SNP and the incidence of posttransplant SLD. In contrast, an increased number of risk alleles for any SNP in the donor was correlated with high incidence rates of both post-LT steatosis and steatohepatitis. A multivariable analysis showed that a high donor GRS was an independent risk factor for graft steatosis (odds ratio 8.77; 95% CI, 1.94-52.94; p = 0.009). Similarly, a high donor GRS was an independent risk factor (odds ratio 6.76; 95% CI, 1.84-30.78; p = 0.007) for post-LT graft steatohepatitis.

CONCLUSIONS

Donor risk alleles of PNPLA3, TM6SF2, and HSD17B13, rather than recipient risk alleles, have been implicated in the development of posttransplant SLD. The combination of these donor risk alleles into a GRS could predict the development of posttransplant SLD.

The Impact of Metabolic Health and Obesity on Liver Transplant Candidates and Recipients

Poor metabolic health and obesity have significant impacts on the outcomes of patients suffering from chronic liver disease, particularly those with metabolic dysfunction-associated steatotic liver disease. Patients with such comorbidities who require liver transplant evaluation for advancing liver disease or liver failure require special consideration due to increased risk of cardiovascular disease, renal dysfunction, sarcopenic obesity, and cancer. Those who have had a history of prior bariatric surgery pose specific anatomical constraints and may also be at increased risk of alcohol use disorder. Pre-operative risk assessment as well as strict control of metabolic risk factors are essential to reduce intra-operative and post-liver transplant complications. As immunosuppressive therapy exacerbates metabolic dysfunction and risk for cancer, post-liver transplant care must focus on balancing the need to prevent rejection and the impact of progressive metabolic dysfunction in this unique, but growing, patient population.

Prevalence of Liver Steatosis in Tuberous Sclerosis Complex Patients: A Retrospective Cross-Sectional Study

Introduction: Tuberous sclerosis complex (TSC) is a genetic disease caused by pathogenetic variants in either the TSC1 or TSC2 genes. Consequently, the mechanistic target of the rapamycin complex 1 (mTORC1) pathway, a regulator of cell growth, metabolism, and survival, becomes inappropriately activated, leading to the development of benign tumors in multiple organs. The role of mTORC1 in lipid metabolism and liver steatosis in TSC patients has not been well-studied, and clinical data on liver involvement in this population are scarce. Methods: We conducted a retrospective, cross-sectional study to compare liver steatosis in TSC patients with age-, sex-, BMI-, and diabetes status-matched controls. Participants with a definite diagnosis of TSC were recruited from the TSC clinic at UZ Brussel. Liver steatosis was quantified using the fat signal fraction from in-phase and out-of-phase MRI, with a threshold of ≥5% defining the presence of steatosis. We also evaluated the prevalence of liver angiomyolipomata in the TSC group and analyzed risk factors for both liver steatosis and angiomyolipomata. Results: The study included 59 TSC patients and 59 matched controls. The mean fat signal fraction was 4.0% in the TSC group and 3.9% in the controls, showing no significant difference (two-tailed Wilcoxon signed ranks test, p = 0.950). Liver steatosis was observed in 15.3% of TSC patients compared to 23.7% of the controls, which was not statistically significant (two-tailed McNemar test, p = 0.267). Liver angiomyolipomata were identified in 13.6% of the TSC cohort. Conclusions: Our study, describing in detail the liver phenotype of TSC patients, did not reveal a significant difference in the prevalence of MRI-assessed liver steatosis in a large cohort of TSC patients compared to a closely matched control group.

Harnessing Metabolites as Serum Biomarkers for Liver Graft Pathology Prediction Using Machine Learning

Graft injury affects over 50% of liver transplant (LT) recipients, but non-invasive biomarkers to diagnose and guide treatment are currently limited. We aimed to develop a biomarker of graft injury by integrating serum metabolomic profiles with clinical variables. Serum from 55 LT recipients with biopsy confirmed metabolic dysfunction-associated steatohepatitis (MASH), T-cell mediated rejection (TCMR) and biliary complications was collected and processed using a combination of LC-MS/MS assay. The metabolomic profiles were integrated with clinical information using a multi-class Machine Learning (ML) classifier. The model's efficacy was assessed through the Out-of-Bag (OOB) error estimate evaluation. Our ML model yielded an overall accuracy of 79.66% with an OOB estimate of the error rate at 19.75%. The model exhibited a maximum ability to distinguish MASH, with an OOB error estimate of 7.4% compared to 22.2% for biliary and 29.6% for TCMR. The metabolites serine and serotonin emerged as the topmost predictors. When predicting binary outcomes using three models: Biliary (biliary vs. rest), MASH (MASH vs. rest) and TCMR (TCMR vs. rest); the AUCs were 0.882, 0.972 and 0.896, respectively. Our ML tool integrating serum metabolites with clinical variables shows promise as a non-invasive, multi-class serum biomarker of graft pathology.

Protocol liver biopsy predicts graft survival after liver transplantation

BACKGROUND

The use of protocol liver biopsy to monitor liver allograft status remains controversial. There is limited data from modern transplantation populations that includes protocol biopsies to evaluate its value in predicting clinical outcomes.

METHODS

All protocol liver biopsies were identified from 875 patients who underwent liver transplantation at Helsinki University Hospital between 2000 and 2019. Each histologic component was analyzed for its ability to predict long-term outcomes, especially graft survival. We determined the frequency of significant biopsy findings based on the Banff working group definition. Liver function tests (LFTs) and clinical markers were evaluated for their ability to predict significant biopsy findings.

RESULTS

In total, 867 protocol liver biopsies were analyzed. Significant findings were identified in 20.1% of the biopsies. In the first protocol biopsy, steatohepatitis (hazard ratio [HR] 3.504, p = .03) and moderate or severe congestion (HR 3.338, p = .04) predicted graft loss. The presence of cholangitis (HR 2.563, p = .04), necrosis (HR 7.635, p < .001), mild congestion (HR 4.291, p = .009), and significant biopsy finding (HR 2.540, p = .02) predicted inferior death-censored graft survival. While the degree of elevation of LFTs was positively associated with significant biopsy findings, the discrimination was poor (AUC .572-.622). Combined LFTs and clinical risk factors remained suboptimal for discriminating significant biopsy findings (AUC .696).

CONCLUSIONS

Our findings support the use of protocol liver biopsies after liver transplantation since they frequently revealed changes associated with long-term outcomes, even when LFTs were normal.

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.

A Comprehensive Review of Liver Allograft Fibrosis and Steatosis: From Cause to Diagnosis

Despite advances in posttransplant care, long-term outcomes for liver transplant recipients remain unchanged. Approximately 25% of recipients will advance to graft cirrhosis and require retransplantation. Graft fibrosis progresses in the context of de novo or recurrent disease. Recurrent hepatitis C virus infection was previously the most important cause of graft failure but is now curable in the majority of patients. However, with an increasing prevalence of obesity and diabetes and nonalcoholic fatty liver disease as the most rapidly increasing indication for liver transplantation, metabolic dysfunction-associated liver injury is anticipated to become an important cause of graft fibrosis alongside alloimmune hepatitis and alcoholic liver disease. To better understand the landscape of the graft fibrosis literature, we summarize the associated epidemiology, cause, potential mechanisms, diagnosis, and complications. We additionally highlight the need for better noninvasive methods to ameliorate the management of graft fibrosis. Some examples include leveraging the microbiome, genetic, and machine learning methods to address these limitations. Overall, graft fibrosis is routinely seen by transplant clinicians, but it requires a better understanding of its underlying biology and contributors that can help inform diagnostic and therapeutic practices.

Fibrosis and steatosis of the liver graft: Are non-invasive tests useful? A short review

As life expectancy of liver transplanted patients improves, new questions are arising to avoid progressive graft loss. The spectrum of chronic inflammation and fibrosis are known to be important triggers in the alteration of graft function. Liver biopsy remains the gold standard to better understand progressive, normal, and abnormal histological modifications of the graft. In parallel, the interest for metabolic steatosis development in post-transplantation is also growing. Long-term survival of these patients involves the management of comorbidities including metabolic syndrome and cardiovascular diseases. Early detection of altered graft parenchyma, and monitoring of its evolution are undoubtedly essential. Non-invasive methods including transient elastography and fibrosis biomarkers are attractive tools to avoid drawbacks and complications of liver biopsy. Accuracy of these methods are well-known in a pre-transplantation setting, but evidence is lacking in post-transplantation setting. We review current knowledge of progressive liver fibrosis and steatosis development after transplantation and non-invasive methods of their assessment.

NASH After Liver Transplantation: Impact of Immunosuppression

Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the common causes of cirrhosis and hepatocellular carcinoma (HCC) and is a leading indication for liver transplantation (LT). Patients with NAFLD-related cirrhosis and HCC are at high risk for the development of recurrent NAFLD after LT. NAFLD can also develop de novo post-transplantation in patients subjected to LT for other indications. Besides the pretransplant presence of various components of metabolic syndrome (MS) use of immunosuppressive agents in the post-LT setting forms one of the major drivers for the development of post-LT NAFLD. Individual components of conventional immunosuppressive regimens (corticosteroids, calcineurin inhibitors, and m-TOR inhibitors) are all implicated in the development of post-LT metabolic derangement and follow unique mechanisms of action and degree of disturbances. The development of cardiovascular risk is associated with post-LT NAFLD, although graft outcomes do not seem to be influenced only by the presence of post-LT NAFLD. Measures in consonance with the management of NAFLD, in general, including lifestyle modifications and control of metabolic risk factors, hold true for post-LT NAFLD. Tailoring immunosuppression strategies with early corticosteroid withdrawal and calcineurin inhibitor minimization balancing against the risk of graft rejection constitutes important nuances in the individualized management of post-LT NAFLD.

Pharmaceutical Strategies to Improve Druggability of Potential Drug Candidates in Nonalcoholic Fatty Liver Disease Therapy

Nonalcoholic fatty liver disease (NAFLD) has become globally prevalent and is the leading cause of chronic liver disease. Although NAFLD is reversible without medical intervention in the early stage, the condition could be sequentially worsened to nonalcoholic steatohepatitis (NASH) and, eventually, cirrhosis and hepatic cancer. The progression of NAFLD is related to various factors such as genetics, pre-disposed metabolic disorders, and immunologic factors. Thankfully, to date, there have been accumulating research efforts and, as a result, different classes of potent drug candidates have been discovered. In addition, there have also been various attempts to explore pharmaceutical strategies to improve the druggability of drug candidates. In this review, we provided a brief overview of the drug candidates that have undergone clinical trials. In the latter part, strategies for developing better drugs are discussed.

Liver Transplantation 2023: Status Report, Current and Future Challenges

Liver transplantation offers live-saving therapy for patients with complications of cirrhosis and stage T2 hepatocellular carcinoma. The demand for organs far outstrips the supply, and innovations aimed at increasing the number of usable deceased donors as well as alternative donor sources are a major focus. The etiologies of cirrhosis are shifting over time, with more need for transplantation among patients with alcohol-associated liver disease and nonalcoholic/metabolic fatty liver disease and less for viral hepatitis, although hepatitis B remains an important indication for transplant in countries with high endemicity. The rise in transplantation for alcohol-associated liver disease and nonalcoholic/metabolic fatty liver disease has brought attention to how patients are selected for transplantation and the strategies needed to prevent recurrent disease. In this review, we present a status report on the most pressing topics in liver transplantation and future challenges.

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.

Transcriptomic changes in liver transplant recipients with non-alcoholic steatohepatitis indicate dysregulation of wound healing

Background

Non-alcoholic steatohepatitis (NASH) has become a leading indication for liver transplantation. However, it often recurs in the graft and can also arise de novo in individuals transplanted for other indications. Post-transplant NASH (PT-NASH) is more aggressive and leads to accelerated fibrosis. The mechanistic basis of PT-NASH has not yet been defined and no specific therapeutic strategies are currently available.

Methods

Here, we profiled the transcriptomes of livers with PT-NASH from liver transplant recipients to identify dysregulated genes, pathways, and molecular interaction networks.

Results

Transcriptomic changes in the PI3K-Akt pathway were observed in association with metabolic alterations in PT-NASH. Other significant changes in gene expression were associated with DNA replication, cell cycle, extracellular matrix organization, and wound healing. A systematic comparison with non-transplant NASH (NT-NASH) liver transcriptomes indicated an increased activation of wound healing and angiogenesis pathways in the post-transplant condition.

Conclusion

Beyond altered lipid metabolism, dysregulation of wound healing and tissue repair mechanisms may contribute to the accelerated development of fibrosis associated with PT-NASH. This presents an attractive therapeutic avenue to explore for PT-NASH to optimize the benefit and survival of the graft.

Hepatic Outcomes of Nonalcoholic Fatty Liver Disease Including Cirrhosis and Hepatocellular Carcinoma

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and represents a significant cause of cirrhosis and hepatocellular carcinoma (HCC). Almost 20% of patients with NAFLD and advanced fibrosis develop cirrhosis, of which 20% can progress to decompensated liver stage. Although patients with cirrhosis or fibrosis continue to have a high risk for HCC progression, growing evidence shows that NAFLD-HCC can develop even in the absence of cirrhosis. Current evidence characterizes NAFLD-HCC primarily as a condition with late presentation, lower response to curative therapy, and poor prognosis.

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.

Hepatic steatosis after liver transplantation: a systematic review and meta-analysis

NAFLD can occur after liver transplantation (LT), as recurrence or de novo hepatic steatosis (HS). We aimed to evaluate the literature on prevalence, risk factors, and prognosis of post-LT HS. Systematic review with meta-analysis through a search on: PUBMED, Scopus, and Web-of-Science, from inception until the September 30, 2021. Forty studies were included, representing 6979 patients. The post-LT HS prevalence was 39.76% (95% CI, 34.06-45.46), with a rising kinetics (11.06% increase per decade, p =0.04), and a geographical distribution (15.10% more prevalent in American continent compared with Europe and Asia). Recurrent HS was up to 5-fold more likely than de novo HS [OR: 5.38 (2.69-10.76)]. Metabolic disturbances were stronger risk factors in the post-LT recipient [obesity: OR: 4.62 (3.07-6.96); metabolic syndrome: OR: 3.26 (2.03-5.25)] as compared with pre-LT recipients, with the exception of diabetes mellitus, which doubled the risk at any set [pre-LT diabetes mellitus: OR: 2.06 (1.58-2.68); post-LT diabetes mellitus: OR: 2.12 (1.73-2.59)]. Donor factors were not the relevant risk factors for post-LT HS and the only immunosuppressive drug associated with increased risk was sirolimus [OR: 1.68 (1.07-2.64)]. The prevalence of post-LT steatohepatitis was 28.82% (19.62-38.03) and the strongest risk factor was pre-LT NAFLD. Limited outcomes data suggest that post-LT HS did not increase the risk for liver cirrhosis or mortality in these studies. Two out of 5 patients submitted to LT will develop post-LT HS, being recurrent HS more common than de novo HS. Diabetes mellitus and post-LT metabolic syndrome are the strongest risk factors for HS and baseline NAFLD for steatohepatitis. All transplanted patients should be enrolled in lifestyle interventions to prevent post-LT metabolic syndrome, and sirolimus should be avoided in high-risk patients.

NAFLD: A pretransplant and post-transplant conundrum

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Combined liver transplantation and sleeve gastrectomy: Report of a brief-interval staged approach

Pretransplantation bariatric surgery in patients with high Model for End-Stage Liver Disease (MELD) score is fraught with risks. Bariatric surgery after liver transplantation (LT) may be complicated by surgical adhesions but could have advantages if performed at the time of transplantation. We investigated a method of brief-interval staging combining LT and sleeve gastrectomy (SG). LT recipients with a body mass index (BMI) > 40 kg/m 2 received an SG during the same hospitalization as the LT (LT/SG), at the same time as a planned brief-interval return to the operating room for biliary anastomosis. Differences in intraoperative attributes of the LT (Stage 1) versus SG (Stage 2) procedures were analyzed using Wilcoxon signed-rank test with significance p  < 0.05 and compared with patients with obesity having a two-stage LT without SG. A total of 14 cases {median MELD score 33 (interquartile range [IQR], 18-40)} were compared with 28 controls; 60% were critically ill prior to surgery with mechanical ventilation, vasopressors, or continuous renal replacement therapy. Median interval between procedures was 16.1 (IQR, 12.5-22.7) hours for cases and 12.2 (IQR, 11.1-16.6) hours for controls, p  = 0.27. Median BMI at LT/SG was 47.0 (IQR, 41.7-51.3) kg/m 2 versus 38.1 (IQR, 35.7-39.8) kg/m 2 for controls, p  < 0.001. At 1 year, median excess body weight loss was 74.0% (IQR, 46.2%-78.7%) in cases and 15.8% (IQR, -5.4% to 62.6%) in controls, p  = 0.13; total weight loss was 38.1% (IQR, 23.9-42.9) in cases versus 7.7% (IQR, -2.4% to 27.6%) for controls, p  = 0.03. Graft survival at 1 year was 92.9% for cases and 89.3% for controls with similar early postoperative outcomes. This proof-of-concept study revealed that a brief-interval SG during LT is feasible in patients with high MELD and resulted in sustained weight loss at 1 year with similar graft survival. Further studies are needed to determine an optimal strategy.

Main factors influencing long-term outcomes of liver transplantation in 2022

Liver transplant (LT) outcomes have markedly improved in the recent decades, even if long-term morbidity and mortality are still considerable. Most of late deaths are independent from graft function and different comorbidities, including complications of metabolic syndrome and de novo neoplasms, seem to play a key role in determining long-term outcomes in LT recipients. This review discusses the main factors associated with late mortality and suggests possible strategies to improve long-term management and follow-up after liver transplantation. In particular, the reduction of drug toxicity, the use of tools to identify high-risk patients, and setting up a multidisciplinary team also for long-term management of LT recipients may further improve survival after liver transplantation.

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.

Collagen matrix scaffolds: Future perspectives for the management of chronic liver diseases

Approximately 1.5 billion chronic liver disease (CLD) cases have been estimated worldwide, encompassing a wide range of liver damage severities. Moreover, liver disease causes approximately 1.75 million deaths per year. CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process, cell death, over deposition of extracellular matrix proteins, and dysregulated regeneration. Overall, these processes impair the correct function of this vital organ. Cirrhosis and liver cancer are the main complications of CLD, which accounts for 3.5% of all deaths worldwide. Liver transplantation is the optimal therapeutic option for advanced liver damage. The liver is one of the most common organs transplanted; however, only 10% of liver transplants are successful. In this context, regenerative medicine has made significant progress in the design of biomaterials, such as collagen matrix scaffolds, to address the limitations of organ transplantation (e.g., low donation rates and biocompatibility). Thus, it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Evaluation of an Abnormal Liver Panel After Liver Transplantation

Abnormal liver tests are common after liver transplantation. The differential diagnosis depends on the clinical context, particularly the time course, pattern and degree of elevation, and donor and recipient factors. The perioperative period has distinct causes compared with months and years after transplant, including ischemia-reperfusion injury, vascular thrombosis, and primary graft nonfunction. Etiologies seen beyond the perioperative period include biliary complications, rejection, infection, recurrent disease, and non-transplant-specific causes. The evaluation begins with a liver ultrasound with Doppler as well as appropriate laboratory testing and culminates in a liver biopsy if the imaging and laboratory testing is unrevealing.

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.

Bariatric surgery for non-alcoholic fatty liver disease: Indications and post-operative management

The prevalence of obesity and metabolic consequences such as nonalcoholic fatty liver diseases (NAFLD) has become a crucial health problem. Lifestyle modifications, especially weight loss, effectively reduces liver injury in NAFLD patients. However, adherence to lifestyle changes is very low in the clinical setting. Bariatric surgery can improve metabolic components and cause long-term weight loss. Therefore, bariatric surgery could serve as an attractive treatment option for NAFLD patients. This review integrates data about the benefits of bariatric surgery on NAFLD but also describes the potential pitfalls.

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.

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.

Inevitability of disease recurrence after liver transplantation for NAFLD cirrhosis

Background & Aims

Liver transplantation (LT) is the only available treatment for end-stage non-alcoholic fatty liver disease (NAFLD) (related decompensated cirrhosis and/or hepatocellular carcinoma). The aim of our study was to evaluate the risk of disease recurrence after LT and the factors influencing it.

Method

This retrospective multicenter study included adults transplanted for NAFLD cirrhosis between 2000 and 2019 in 20 participating French-speaking centers. Disease recurrence (steatosis, steatohepatitis and fibrosis) was diagnosed from liver graft biopsies.

Results

We analyzed 150 patients with at least one graft liver biopsy available ≥6 months after transplantation, among 361 patients transplanted for NAFLD. The median (IQR) age at LT was 61.3 (54.4-64.6) years. The median follow-up after LT was 4.7 (2.8-8.1) years. The cumulative recurrence rates of steatosis and steatohepatitis at 5 years were 80.0% and 60.3%, respectively. Significant risk factors for steatohepatitis recurrence in multivariate analysis were recipient age at LT <65 years (odds ratio [OR] 4.214; p = 0.044), high-density lipoprotein-cholesterol <1.15 mmol/L after LT (OR 3.463; p = 0.013) and grade ≥2 steatosis on the graft at 1 year after LT (OR 10.196; p = 0.001). The cumulative incidence of advanced fibrosis (F3-F4) was 20.0% at 5 years after LT and significant risk factors from multivariate analysis were metabolic syndrome before LT (OR 8.550; p = 0.038), long-term use of cyclosporine (OR 11.388; p = 0.031) and grade ≥2 steatosis at 1 year after LT (OR 10.720; p = 0.049). No re-LT was performed for NAFLD cirrhosis recurrence.

Conclusion

Our results strongly suggest that recurrence of initial disease after LT for NAFLD is inevitable and progressive in a large proportion of patients; the means to prevent it remain to be further evaluated.

Impact and implications

Non-alcoholic fatty liver disease (NAFLD) is a growing indication for liver transplantation, but the analysis of disease recurrence, based on graft liver biopsies, has been poorly studied. Cumulative incidences of steatosis, steatohepatitis and NAFLD-related significant fibrosis recurrence at 5 years were 85.0%, 60.3% and 48.0%, respectively. Grade ≥2 steatosis on graft biopsy at 1 year (present in 25% of patients) is highly predictive of recurrence of steatohepatitis and advanced fibrosis: bariatric surgery should be discussed in these patients specifically.

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.

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.

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.

Growing challenge of post-liver transplantation non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease, cirrhosis, and hepatocellular carcinoma worldwide, with an estimated prevalence of 25%. Post-liver transplantation (LT) recurrent or de novo hepatic steatosis is a common complication in recipients, irrespective of transplantation indication. Risk factors for graft steatosis mainly include obesity, immunosuppression, donor steatosis, and genetic factors. Liver transplant recipients are at high risk of developing insulin resistance, new-onset diabetes, and post-transplantation metabolic syndrome that is highly associated with immunosuppressive treatment. Post-LT NAFLD is often underdiagnosed due to the poor sensitivity of most routine imaging methods. The gold standard for the diagnosis of hepatic steatosis is liver biopsy, which is, however, limited to more complex cases due to its invasive nature. There is no approved pharmacotherapy in NAFLD. Lifestyle modification remains the cornerstone in NAFLD treatment. Other treatment strategies in post-LT NAFLD include lifestyle modifications, pharmacotherapy, bariatric surgery, and tailored immunosuppression. However, these approaches originate from recommendations in the general population, as there is scarce data regarding the safety and efficacy of current management strategies for NAFLD in liver transplant patients. Future prospective studies are required to achieve tailored treatment for these patients.

Hepatocellular Carcinoma Due to Nonalcoholic Fatty Liver Disease: Current Concepts and Future Challenges

Obesity has been labeled as the global pandemic of the 21st century, resulting from a sedentary lifestyle and caloric excess. Nonalcoholic fatty liver disease (NAFLD), characterized by excessive hepatic steatosis, is strongly associated with obesity and metabolic syndrome and is estimated to be present in one-quarter of the world population, making it the most common cause of the chronic liver disease (CLD). NAFLD spectrum varies from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. The burden of NAFLD has been predicted to increase in the coming decades resulting in increased rates of decompensated cirrhosis, hepatocellular carcinoma (HCC), and liver-related deaths. In the current review, we describe the pathophysiology of NAFLD and NASH, risk factors associated with disease progression, related complications, and mortality. Later, we have discussed the changing epidemiology of HCC, with NAFLD emerging as the most common cause of CLD and HCC. We have also addressed the risk factors of HCC development in the NAFLD population (including demographic, metabolic, genetic, dietary, and lifestyle factors), presentation of NAFLD-associated HCC, its prognosis, and the issue of HCC development in non-cirrhotic NAFLD. Lastly, the problems related to HCC screening in the NAFLD population, the remaining challenges, and future directions, especially the need to identify the high-risk individuals, will be discussed. We will conclude the review by summarizing the clinical evidence for treating fibrosis and preventing HCC in those at risk with NAFLD-associated HCC.

Personalizing Diabetes Management in Liver Transplant Recipients: The New Era for Optimizing Risk Management

Post-transplant diabetes mellitus (PTDM) is a significant contributor to morbidity and mortality in liver transplant recipients (LTRs). With concurrent comorbidities and use of various immunosuppression medications, identifying a safe and personalized regimen for management of PTDM is needed. There are many comorbidities associated with the post-transplant course including chronic kidney disease, cardiovascular disease, allograft steatosis, obesity, and de novo malignancy. Emerging data suggest that available diabetes medications may carry beneficial or, in some cases, harmful effects in the setting of these co-existing conditions. Sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide 1 receptor agonists have shown the most promising beneficial results. Although there is a deficiency of LTR-specific data, they appear to be generally safe. Effects of other medications are varied. Metformin may reduce the risk of malignancy. Pioglitazone may be harmful in patients combatting obesity or heart failure. Insulin may exacerbate obesity and increase the risk of developing malignancy. This review thoroughly discusses the roles of these extra-glycemic effects and safety considerations in LTRs. Through weighing the risks and benefits, we conclude that alternatives to insulin should be strongly considered, when feasible, for personalized long-term management based on risk factors and co-morbidities.

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.

A Comprehensive Review on the Risk of Metabolic Syndrome and Cardiovascular Disease after Liver Transplantation

Survival rates after liver transplantation have increased dramatically over the past 20 years. Cardiovascular disease is the most common extra-hepatic cause of mortality in the long-term post liver transplant. This is intimately linked with both the higher pre-existing rates of metabolic syndrome in these patients as well as increased propensity to develop de novo metabolic syndrome post-transplant. This unfavorable metabolic profile that contributes to cardiovascular disease is multifactorial and largely preventable. This review explores metabolic syndrome and cardiovascular disease and their contributory factors post liver transplantation to highlight areas for potential intervention and thus reduce the significant morbidity and mortality of patients due to metabolic syndrome and cardiovascular disease.

Prevalence of fatty liver disease after liver transplantation and risk factors for recipients and donors

INTRODUCTION AND OBJECTIVES

Fatty liver disease (FLD) may develop in liver transplant recipients. We investigated the recipient and donor risk factors for FLD development after liver transplantation (LT).

METHODS

A total of 108 liver transplant recipients (54 men [50.0%]; median age, 52 [20-68] years) treated from 2011-2020 was enrolled. Three recipients died at < 3 months as a result of infection or blood flow impairment, and were excluded from the long-term FLD study. On evaluation of 88 prospective living donors, fatty liver was observed in 21. The prevalence and risk factors for FLD and survival were evaluated.

RESULTS

After LT, 28 of 105 recipients (26.7%) developed FLD. FLD was more common in patients with a high body mass index (BMI) and dyslipidemia (both p < 0.01), primary nonalcoholic steatohepatitis (p = 0.02), after living-donor LT (p = 0.03) and everolimus (EVL) use (p = 0.08). Factors predictive of FLD included EVL use and a high BMI (hazard ratios = 3.00 and 1.34; p = 0.05 and p < 0.01, respectively). Sixteen donors lost 6.5 kg (range: 2.0-16.0 kg) of body weight prior to LT. However, there were no cases of primary non-function, which did not affect the FLD prevalence. Development of FLD did not have a negative impact on LT outcome; the 5-year survival rate was 92.6%.

CONCLUSIONS

Recipient factors were more important than donor factors for FLD onset after LT.

Non-alcoholic Fatty Liver Disease and Steatohepatitis: Risk Factors and Pathophysiology

Non-alcoholic fatty liver disease (NAFLD) and its progressive subtype non-alcoholic steatohepatitis (NASH) are the most prevalent liver diseases, often leading to hepatocellular carcinoma (HCC). This review aims to describe the present knowledge of the risk factors responsible for the development of NAFLD and NASH. I performed a literature review identifying studies focusing on the complex pathogenic pathway and risk factors of NAFLD and steatohepatitis. The relationship between NAFLD and metabolic syndrome is well established and widely recognized. Obesity, dyslipidemia, type 2 diabetes, hypertension, and insulin resistance are the most common risk factors associated with NAFLD. Among the components of metabolic syndrome, current evidence strongly suggests obesity and type 2 diabetes as risk factors of NASH and HCC. However, other elements, namely gender divergences, ethnicity, genetic factors, participation of innate immune system, oxidative stress, apoptotic pathways, and adipocytokines, take a leading role in the onset and promotion of NAFLD. Pathophysiological mechanisms that are responsible for NAFLD development and subsequent progression to NASH are insulin resistance and hyperinsulinemia, oxidative stress, hepatic stellate cell (HSC) activation, cytokine/adipokine signaling pathways, and genetic and environmental factors. Major pathophysiological findings of NAFLD are dysfunction of adipose tissue through the enhanced flow of free fatty acids (FFAs) and release of adipokines, and altered gut microbiome that generate proinflammatory signals and cause NASH progression. Understanding the pathophysiology and risk factors of NAFLD and NASH; this review could provide insight into the development of therapeutic strategies and useful diagnostic tools.

How will NAFLD change the liver transplant landscape in the 2020s?

Liver steatosis is the hepatic manifestation of the metabolic syndrome, and is now the leading cause of chronic liver disease worldwide. The treatment of metabolic cirrhosis with liver failure and/or hepatocellular carcinoma is liver transplantation (LT). During the past decade, metabolic cirrhosis represented an increasing cause for LT, especially in the United States. At listing, patients with metabolic cirrhosis are older, with numerous cardiovascular (CV) and renal comorbidities, and this requires multidisciplinary pre-transplant assessment. After LT, 5-year survival is similar to other indications. The leading causes of death are infectious, cancers and CV. The recurrence of the initial disease is very frequent, and a significant part of the patients progress towards graft cirrhosis. No specific immunosuppressive regimen is recommended, but the toxicity profiles must probably be taken into account. In these patients, the only etiological treatment is that of obesity, in the absence of specific therapy for non-alcoholic steatohepatitis. The place of bariatric surgery has to be defined, probably sleeve gastrectomy, in a stable patient, 6-12 months after LT.

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.

Non-alcoholic steatohepatitis in liver transplant recipients diagnosed by serum cytokeratin 18 and transient elastography: A prospective study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) seem common after liver transplantation.

AIM

To investigate incidence and predictors of NAFLD and NASH by employing noninvasive testing in liver transplant recipients, namely controlled attenuation parameter (CAP) and the serum biomarker cytokeratin 18 (CK-18). We also evaluated the diagnostic accuracy of CK-18 and CAP compared to liver histology.

METHODS

We prospectively recruited consecutive adult patients who received liver transplant at the McGill University Health Centre between 2015-2018. Serial measurements of CK-18 and CAP were recorded. NAFLD and NASH were diagnosed by CAP ≥ 270 dB/m, and a combination of CAP ≥ 270 dB/m with CK-18 > 130.5 U/L, respectively. Incidences and predictors of NAFLD and NASH were investigated using survival analysis and Cox proportional hazards.

RESULTS

Overall, 40 liver transplant recipients (mean age 57 years; 70% males) were included. During a median follow-up of 16.8 mo (interquartile range 15.6-18.0), 63.0% and 48.5% of patients developed NAFLD and NASH, respectively. On multivariable analysis, after adjusting for sex and alanine aminotransferase, body mass index was an independent predictor of development of NAFLD [adjusted hazard ratio (aHR): 1.21, 95% confidence interval (CI): 1.04-1.41; P = 0.01] and NASH (aHR: 1.26, 95%CI: 1.06-1.49; P < 0.01). Compared to liver histology, CAP had a 76% accuracy to diagnose NAFLD, while the accuracy of CAP plus CK-18 to diagnose NASH was 82%.

CONCLUSION

NAFLD and NASH diagnosed non-invasively are frequent in liver transplant recipients within the first 18 mo. Close follow-up and nutritional counselling should be planned in overweight patients.