Alcohol-associated liver disease-Global epidemiology.

Alcohol-associated liver disease (ALD), as highlighted in this narrative review, is a major public health concern, increasingly impacting global disease burden and premature mortality. In 2019, ALD accounted for the loss of 11 million life-years worldwide. The rising number of deaths and disability-adjusted life-years attributed to ALD, particularly pronounced in the United States, are alarming. Projections suggest that the economic impact of ALD, as seen in the United States, could potentially double by 2040. ALD is increasingly prevalent among younger adults (20-45 y) and has become the leading cause of liver transplantation in both United States and Europe. During the COVID-19 pandemic, the existing trend was further amplified as high-risk drinking patterns coincided with a rise in hospital admissions for alcohol-associated hepatitis and increased ALD-related mortality. The prevalence of ALD is estimated at 3.5% in the general population, 26.0% among hazardous drinkers, and 55.1% among those with alcohol use disorders. Alarmingly, 5-year mortality rates for patients with ALD exceed 50%, with even higher rates in more advanced disease stages. Methodological challenges, such as underreporting, diagnostic difficulties, and variability in registry data quality, complicate the accurate assessment of the impact of ALD. Additionally, the contribution of alcohol to the progression of other liver diseases is often under acknowledged in health care registries, leading to a significant underestimation of its broader implications for liver health. Addressing the growing ALD concern requires robust public health initiatives, heightened awareness, refined diagnostic techniques, and comprehensive epidemiological studies. These measures are vital to tackle the increasing prevalence of ALD and mitigate its extensive impact on individuals and health care systems.

Lipoprotein Z, a hepatotoxic lipoprotein, predicts outcome in alcohol-associated hepatitis.

BACKGROUND AND AIMS: Lipoprotein Z (LP-Z) is an abnormal free cholesterol (FC)-enriched LDL-like particle discovered from patients with cholestatic liver disease. This study aims to define the diagnostic value of LP-Z in alcohol-associated hepatitis (AH) and interrogate the biology behind its formation. APPROACH AND RESULTS: We measured serum levels of LP-Z using nuclear magnetic resonance spectroscopy, a well-established clinical assay. Serum levels of LP-Z were significantly elevated in four AH cohorts compared with control groups, including heavy drinkers and patients with cirrhosis. We defined a Z-index, calculated by the ratio of LP-Z to total apolipoprotein B-containing lipoproteins, representing the degree of deviation from normal VLDL metabolism. A high Z-index was associated with 90-day mortality independent from the Model for End-Stage Liver Disease (MELD) and provided added prognosticative value. Both a Z-index ≤ 0.6 and a decline of Z-index by ≥0.1 in 2 weeks predicted 90-day survival. RNA-sequencing analyses of liver tissues demonstrated an inverse association in the expression of enzymes responsible for the extrahepatic conversion of VLDL to LDL and AH disease severity, which was further confirmed by the measurement of serum enzyme activity. To evaluate whether the FC in LP-Z could contribute to the pathogenesis of AH, we found significantly altered FC levels in liver explant of patients with AH. Furthermore, FC in reconstituted LP-Z particles caused direct toxicity to human hepatocytes in a concentration-dependent manner, supporting a pathogenic role of FC in LP-Z. CONCLUSIONS: Impaired lipoprotein metabolism in AH leads to the accumulation of LP-Z in the circulation, which is hepatotoxic from excessive FC. A Z-index ≤ 0.6 predicts 90-day survival independent from conventional biomarkers for disease prognostication.

Circulating Citrate Is Associated with Liver Fibrosis in Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is associated with mitochondrial damage. Circulating mitochondrial metabolites may be elevated in NAFLD but their associations with liver damage is not known. This study aimed to assess the association of key mitochondrial metabolites with the degree of liver fibrosis in the context of NAFLD and nonalcoholic steatohepatitis (NASH). Cross-sectional analyses were performed on two cohorts of biopsy-proven NAFLD and/or NASH subjects. The association of circulating mitochondrial metabolite concentrations with liver fibrosis was assessed using linear regression analysis. In the single-center cohort of NAFLD subjects (n = 187), the mean age was 54.9 ±13.0 years, 40.1% were female and 86.1% were White. Type 2 diabetes (51.3%), hypertension (43.9%) and obesity (72.2%) were prevalent. Those with high citrate had a higher proportion of moderate/significant liver fibrosis (stage F ≥ 2) (68.4 vs. 39.6%, p = 0.001) and advanced fibrosis (stage F ≥ 3) (31.6 vs. 13.6%, p = 0.01). Citrate was associated with liver fibrosis independent of age, sex, NAFLD activity score and metabolic syndrome (per 1 SD increase: ß = 0.19, 95% CI: 0.03-0.35, p = 0.02). This association was also observed in a cohort of NASH subjects (n = 176) (ß = 0.21, 95% CI: 0.07-0.36, p = 0.005). The association of citrate with liver fibrosis was observed in males (p = 0.005) but not females (p = 0.41). In conclusion, circulating citrate is elevated and associated with liver fibrosis, particularly in male subjects with NAFLD and NASH. Mitochondrial function may be a target to consider for reducing the progression of liver fibrosis and NASH.

Coffee Consumption Is Associated With Lower Liver Stiffness: A Nationally Representative Study.

BACKGROUND & AIMS: Coffee is associated with a reduced risk of liver disease. This association is limited by important sources of confounding such as recall bias, healthy user bias, and indirect measures of liver outcomes or health. We aimed to examine the impact of coffee consumption with liver fibrosis and steatosis in a nationally representative sample. METHODS: We evaluated 4510 subjects 20 years and older from the 2017 to 2018 National Health and Nutrition Examination Survey study who underwent both transient elastography and two 24-hour dietary recall examinations. We tested the associations between liver stiffness measurements (LSM) of 9.5 kpa or greater or controlled attenuation parameter (CAP) and coffee consumption. We used decaffeinated coffee and tea consumption as controls. As a sensitivity analysis, we included all drinks in 1 model, examined the impact of caffeine consumption, and adjusted for the Healthy Eating Index-2015 and sugar-sweetened beverage consumption as separate models. RESULTS: The study sample described was aged 48 ± 0.6 years, 73% were overweight or obese, 10.6% had diabetes, 47.5% reported participation in vigorous physical activity, and 23% drank 2 or more alcoholic drinks per day. After multivariate adjustment, there was no association between coffee and controls with CAP. Subjects who drank more than 3 cups of coffee, but not other drinks, had a 0.9 lower kPa (95% CI, -1.6 to -0.1; P = .03). More than 3 cups of coffee were protective for LSM of 9.5 kpa or higher (odds ratio, 0.4; 95% CI, 0.2-1.0; P = .05). Accounting for all beverages in the same model, only consuming more than 3 cups of coffee remained independently associated with LSM (odds ratio, 0.5; 95% CI, 0.2-0.9; P = .03). Caffeine was not associated significantly with LSM at any dose. Finally, adjusting for sugar-sweetened beverage consumption and Healthy Eating Index-2015, coffee consumption remained associated with a lower LSM. The protective nature of coffee consumption therefore is not attributable to caffeine and persists in participants regardless of their diet quality. CONCLUSIONS: Coffee is associated with lower liver stiffness, but not steatosis, as measured by CAP among US adults.

Genetic Variation in the Mitochondrial Glycerol-3-Phosphate Acyltransferase Is Associated With Liver Injury.

BACKGROUND AND AIMS: Most of the genetic basis of chronic liver disease remains undiscovered. APPROACH AND RESULTS: To identify genetic loci that modulate the risk of liver injury, we performed genome-wide association studies on circulating levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin across 312,671 White British participants in the UK Biobank. We focused on variants associated with elevations in all four liver biochemistries at genome-wide significance (P < 5 × 10-8 ) and that replicated using Mass General Brigham Biobank in 19,323 European ancestry individuals. We identified a genetic locus in mitochondrial glycerol-3-phosphate acyltransferase (GPAM rs10787429) associated with increased levels of ALT (P = 1.4 × 10-30 ), AST (P = 3.6 × 10-10 ), ALP (P = 9.5 × 10-30 ), and total bilirubin (P = 2.9 × 10-12 ). This common genetic variant was also associated with an allele dose-dependent risk of alcohol-associated liver disease (odd ratio [OR] = 1.34, P = 2.6 × 10-5 ) and fatty liver disease (OR = 1.18, P = 5.8 × 10-4 ) by International Classification of Diseases, 10th Revision codes. We identified significant interactions between GPAM rs10787429 and elevated body mass index in association with ALT and AST (P = 7.1 × 10-9 and 3.95 × 10-8 , respectively), as well as between GPAM rs10787429 and weekly alcohol consumption in association with ALT, AST, and alcohol-associated liver disease (P = 4.0 × 10-2 , 1.6 × 10-2 , and 1.3 × 10-2 , respectively). Unlike previously described genetic variants that are associated with an increased risk of liver injury but confer a protective effect on circulating lipids, GPAM rs10787429 was associated with an increase in total cholesterol (P = 2.0 × 10-17 ), LDL cholesterol (P = 2.0 × 10-10 ), and HDL cholesterol (P = 6.6 × 10-37 ). Single-cell RNA-sequencing data demonstrated hepatocyte-predominant expression of GPAM in cells that co-express genes related to VLDL production (P = 9.4 × 10-103 ). CONCLUSIONS: Genetic variation in GPAM is associated with susceptibility to liver injury. GPAM may represent a therapeutic target in chronic liver disease.

Severe Hepatic Steatosis by Controlled Attenuation Parameter Predicts Quality of Life Independent of Fibrosis.

BACKGROUND & AIM: Liver fibrosis is associated with poor patient-reported outcomes (PROs), but the impact of steatosis is unknown. We aimed to evaluate the impact of steatosis on PROs independent of liver fibrosis. METHODS: We evaluated the impact of steatosis, measured by Controlled-Attenuation Parameter (CAP) on transient elastography, and PROs using the 2017-2018 National Health and Nutrition Examination Survey (NHANES) database. We used univariate and multivariate logistic and ordinal regression to evaluate categorical CAP score with PROs measuring physical disability, general health and depression. RESULTS: Of 4,509 participants included, 38% had severe steatosis (> 280 dB/m). Those with severe steatosis were older and more likely to be male (56% vs. 43% and 51%). On univariate analysis, severe steatosis was associated with more difficulty walking (P = 0.01), dressing (P = 0.005), lifting objects (P = 0.02), bending (P < 0.001), and moving large objects (P = 0.0006). After multivariate adjustment, severe steatosis remained associated with difficulty lifting objects (odds ratio [OR]: 1.7, 95% confidence interval [CI]: 1.2-2.4, P = 0.01) and difficulty bending (OR: 1.8, 95% CI: 1.2-2.7, P = 0.006). Severe steatosis increased risk of having any of the disabilities (OR: 1.7, 95% CI: 1.2-2.4, P = 0.008) and had higher ordinal disability index (OR: 1.6, 95% CI: 1.2-2.2, P = 0.007). Lastly, severe steatosis was also associated with worse self-perceived health status (OR: 1.5, 95% CI: 1.2-1.9, P = 0.002), while general health compared to one year ago and depression trended toward significance. CONCLUSION: Patients with severe steatosis are at increased risk of physical disability and have worse self-perceived health status independent of liver fibrosis.

Provider Attitudes and Practice Patterns for Direct-Acting Antiviral Therapy for Patients With Hepatocellular Carcinoma.

BACKGROUND & AIMS: Direct-acting antivirals (DAAs) are effective against hepatitis C virus and sustained virologic response is associated with reduced incidence of hepatocellular carcinoma (HCC). However, there is controversy over the use of DAAs in patients with active or treated HCC and uncertainty about optimal management of these patients. We aimed to characterize attitudes and practice patterns of hepatology practitioners in the United States regarding the use of DAAs in patients with HCC. METHODS: We conducted a survey of hepatology providers at 47 tertiary care centers in 25 states. Surveys were sent to 476 providers and we received 279 responses (58.6%). RESULTS: Provider beliefs about risk of HCC recurrence after DAA therapy varied: 48% responded that DAAs reduce risk, 36% responded that DAAs do not change risk, and 16% responded that DAAs increase risk of HCC recurrence. However, most providers believed DAAs to be beneficial to and reduce mortality of patients with complete response to HCC treatment. Accordingly, nearly all providers (94.9%) reported recommending DAA therapy to patients with early-stage HCC who received curative treatment. However, fewer providers recommended DAA therapy for patients with intermediate (72.9%) or advanced (57.5%) HCC undergoing palliative therapies. Timing of DAA initiation varied among providers based on HCC treatment modality: 49.1% of providers reported they would initiate DAA therapy within 3 months of surgical resection whereas 45.9% and 5.0% would delay DAA initiation for 3-12 months and >1 year post-surgery, respectively. For patients undergoing transarterial chemoembolization (TACE), 42.0% of providers would provide DAAs within 3 months of the procedure, 46.7% would delay DAAs until 3-12 months afterward, and 11.3% would delay DAAs more than 1 year after TACE. CONCLUSIONS: Based on a survey sent to hepatology providers, there is variation in provider attitudes and practice patterns regarding use and timing of DAAs for patients with HCC. Further studies are needed to characterize the risks and benefits of DAA therapy in this patient population.

How Would You Manage This Patient With Nonalcoholic Fatty Liver Disease?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

Nonalcoholic fatty liver disease (NAFLD), a common diagnosis in the United States and other developed countries, has been increasing in prevalence. The American Association for the Study of Liver Diseases recently published updated practice guidelines for diagnosing and managing NAFLD, including the following recommendations: Routine screening for NAFLD in high-risk groups is not advised because of uncertainties surrounding test and treatment options, along with a lack of knowledge about cost-effectiveness and long-term benefits. Noninvasive studies, including biomarkers from laboratory tests and liver stiffness measured through elastography, are clinically useful tools for identifying advanced fibrosis in patients with NAFLD. Liver biopsy should be considered in patients with NAFLD who are at increased risk for nonalcoholic steatohepatitis (NASH) or advanced fibrosis. Weight loss of at least 3% to 5% generally reduces NASH, but greater weight loss (7% to 10%) is needed to improve most histopathologic features, including fibrosis. Pharmacologic therapies (such as pioglitazone and vitamin E) should be considered only in patients with biopsy-proven NASH. Patients with NAFLD should not consume heavy amounts of alcohol, although insufficient data exist to provide advice about other levels of alcohol use. Here, 2 clinicians with expertise in this area debate whether to screen for NAFLD in primary care, how to monitor patients with NAFLD, and what interventions should be used to manage this condition.

Baseline Factors Associated With Improvements in Decompensated Cirrhosis After Direct-Acting Antiviral Therapy for Hepatitis C Virus Infection.

BACKGROUND & AIMS: Treatment with direct-acting antiviral (DAA) agents can reduce Model for End-Stage Liver Disease and Child-Pugh-Turcotte (CPT) scores in patients with decompensated cirrhosis caused by hepatitis C virus. However, many of these patients still die or require liver transplantation. We collected data on baseline features of patients and aimed to develop a scoring system to predict response to DAA therapy. METHODS: We performed a retrospective analysis of data from 4 trials on the effects of sofosbuvir-based therapy in patients with hepatitis C virus-associated decompensated cirrhosis (502 of CPT class B and 120 of CPT class C). In these trials, patients were given 12 or 24 weeks of treatment with ledipasvir, sofosbuvir, and ribavirin or velpatasvir, sofosbuvir, and/or ribavirin, or 48 weeks of treatment with sofosbuvir and ribavirin. We collected demographic, clinical, treatment response, and laboratory data from patients and tested their associations with patient outcomes at 36 weeks. The primary outcome was factors associated with reduction of CPT score to class A. RESULTS: The presence of ascites or encephalopathy, serum level of albumin <3.5 g/dL or alanine aminotransferase <60 U/L, and body mass index >25 kg/m2 were associated with an increased risk of not achieving a reduction in CPT to class A, independent of sustained viral response to therapy. Serum level of albumin <2.8 g/dL and abnormal level of bilirubin were associated with an increased risk of liver transplantation or death. We developed a scoring system based on 5 baseline factors (body mass index, encephalopathy, ascites, and serum levels of alanine aminotransferase and albumin) associated significantly with patient outcomes, which we called the "BE3A score." For patients with scores of 4-5, the hazard ratio for reduction of CPT score to class A was 52.3 (95% confidence interval, 15.2-179.7). CONCLUSIONS: We identified 5 baseline factors (body mass index, encephalopathy, ascites, and serum levels of alanine aminotransferase and albumin) associated with a reduction of CPT score to class A in patients with hepatitis C virus-associated decompensated cirrhosis receiving DAA therapy. We developed a predictive score using these factors, called the BE3A score, which can be used as a shared decision-making tool, quantifying the potential benefits of DAA therapy for patients with decompensated cirrhosis.

Factors That Affect Results of Psychometric Tests to Identify Patients With Minimal Hepatic Encephalopathy.

Of the clinical complications of cirrhosis, hepatic encephalopathy (HE) is the most devastating. HE is a spectrum of reversible cognitive changes ranging from minimal HE (MHE) (mild inattention and deficits of executive function) to overt HE (disorientation to coma). More than 40% of patients with cirrhosis develop HE, which increases mortality, falls, motor vehicle accidents, and has a significant psychosocial impact.1 Early recognition is crucial. Patients with cirrhosis are recommended to receive an assessment for MHE.2.

Distinct roles of ecto-nucleoside triphosphate diphosphohydrolase-2 (NTPDase2) in liver regeneration and fibrosis.

Ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) are cell surface-located transmembrane ecto-enzymes of the CD39 superfamily which regulate inflammation and tissue repair by catalyzing the phosphohydrolysis of extracellular nucleotides and modulating purinergic signaling. In the liver, NTPDase2 is reportedly expressed on portal fibroblasts, but its functional role in regulating tissue regeneration and fibrosis is incompletely understood. Here, we studied the role of NTPDase2 in several models of liver injury using global knockout mice. Liver regeneration and severity of fibrosis were analyzed at different time points after exposure to carbon tetrachloride (CCl4) or 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or partial hepatectomy in C57BL/6 wild-type and globally NTPDase2-deficient (Entpd2 null) mice. After chronic CCl4 intoxication, Entpd2 null mice exhibit significantly more severe liver fibrosis, as assessed by collagen content and histology. In contrast, deletion of NTPDase2 does not have a substantial effect on biliary-type fibrosis in the setting of DDC feeding. In injured livers, NTPDase2 expression extends from the portal areas to fibrotic septae in pan-lobular (CCl4-induced) liver fibrosis; the same pattern was observed, albeit to a lesser extent in biliary-type (DDC-induced) fibrosis. Liver regeneration after partial hepatectomy is not substantively impaired in global Entpd2 null mice. NTPDase2 protects from liver fibrosis resulting from hepatocellular injury induced by CCl4. In contrast, Entpd2 deletion does not significantly impact fibrosis secondary to DDC injury or liver regeneration after partial hepatectomy. Our observations highlight mechanisms relating to purinergic signaling in the liver and indicate possible therapeutic avenues and new cellular targets to test in the management of hepatic fibrosis.

Surface tensiometry of apolipoprotein B domains at lipid interfaces suggests a new model for the initial steps in triglyceride-rich lipoprotein assembly.

Apolipoprotein B (apoB) is the principal protein component of triacylglyceride (TAG)-rich lipoproteins, including chylomicrons and very low density lipoprotein, which is the precursor to LDL (the "bad cholesterol"). TAG-rich lipoprotein assembly is initiated by the N-terminal ßα1 superdomain of apoB, which co-translationally binds and remodels the luminal leaflet of the rough endoplasmic reticulum. The ßα1 superdomain contains four domains and is predicted to interact directly with lipids. Using drop tensiometry, we examined the interfacial properties of the α-helical and C-sheet domains and several subdomains to establish a detailed structure-function relationship at the lipid/water interface. The adsorption, stress response, exchangeability, and pressure (Π)-area relationship were studied at both triolein/water and triolein/1-palmitoyl, 2-oleoylphosphatidylcholine/water interfaces that mimic physiological environments. The α-helical domain spontaneously adsorbed to a triolein/water interface and formed a viscoelastic surface. It was anchored to the surface by helix 6, and the other helices were ejected and/or remodeled on the surface as a function of surface pressure. The C-sheet instead formed an elastic film on a triolein/water interface and was irreversibly anchored to the lipid surface, which is consistent with the behavior of amphipathic ß-strands. When both domains were adsorbed together on the surface, the C-sheet shielded a portion of the α-helical domain from the surface, which retained its globular structure. Overall, the unique secondary and tertiary structures of the N-terminal domains of apoB support the intrinsic capability of co-translational lipid recruitment. The evidence presented here allows the construction of a detailed model of the initiation of TAG-rich lipoprotein assembly.

Characterization of circulating microparticle-associated CD39 family ecto-nucleotidases in human plasma.

Phosphohydrolysis of extracellular ATP and ADP is an essential step in purinergic signaling that regulates key pathophysiological processes, such as those linked to inflammation. Classically, this reaction has been known to occur in the pericellular milieu catalyzed by membrane bound cellular ecto-nucleotidases, which can be released in the form of both soluble ecto-enzymes as well as being associated with exosomes. Circulating ecto-nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1/CD39) and adenylate kinase 1 (AK1) activities have been shown to be present in plasma. However, other ecto-nucleotidases have not been characterized in depth. An in vitro ADPase assay was developed to probe the ecto-enzymes responsible for the ecto-nucleotidase activity in human platelet-free plasma, in combination with various specific biochemical inhibitors. Identities of ecto-nucleotidases were further characterized by chromatography, immunoblotting, and flow cytometry of circulating exosomes. We noted that microparticle-bound E-NTPDases and soluble AK1 constitute the highest levels of ecto-nucleotidase activity in human plasma. All four cell membrane expressed E-NTPDases are also found in circulating microparticles in human plasma, inclusive of: CD39, NTPDase 2 (CD39L1), NTPDase 3 (CD39L3), and NTPDase 8. CD39 family members and other ecto-nucleotidases are found on distinct microparticle populations. A significant proportion of the microparticle-associated ecto-nucleotidase activity is sensitive to POM6, inferring the presence of NTPDases, either -2 or/and -3. We have refined ADPase assays of human plasma from healthy volunteers and have found that CD39, NTPDases 2, 3, and 8 to be associated with circulating microparticles, whereas soluble AK1 is present in human plasma. These ecto-enzymes constitute the bulk circulating ADPase activity, suggesting a broader implication of CD39 family and other ecto-enzymes in the regulation of extracellular nucleotide metabolism.

Low vitamin A levels are associated with liver-related mortality: a nationally representative cohort study.

INTRODUCTION: Vitamin A, a fat-soluble vitamin that includes retinol and carotenoids, is implicated in liver fibrosis, whereas its deficiency has been associated with various liver diseases and higher overall mortality. This study aims to determine the relationship between levels of vitamin A species and liver fibrosis, as well as liver-related mortality in the population of the US. METHODS: A total of 12,299 participants from the National Health and Nutrition Examination Survey III (NHANES III) were analyzed to provide nationally representative estimates of the relationship between the levels of vitamin A species and liver fibrosis measured by Fibrosis-4 (FIB-4) index and liver-related mortality. RESULTS: A low blood level of retinol, but not other retinoid derivatives, was associated with significant liver fibrosis after adjustment for demographics, anthropometric measurements, medical history, retinol, and carotene intakes. Compared with vitamin D and E, retinol deficiency demonstrated much stronger associations with a high FIB-4 score. Individuals with known risks of chronic liver disease (CLD) and the lowest pentile of retinol levels had ORs of 3.12 (95% CI, 1.64-5.91) for possible fibrosis and 19.7 (95% CI, 5.71-67.7) for likely fibrosis, and an HR of 7.76 (95% CI, 1.19-50.5) for liver-related mortality compared with those in the highest retinol-level pentile. These relationships were more pronounced among individuals with known risks of chronic liver disease than without. CONCLUSIONS: A low circulating retinol level is associated with liver fibrosis and liver-related mortality in chronic liver disease. This relationship is potentially driven by a mechanistic link rather than the malabsorption of fat-soluble vitamins and may be leveraged for disease prognostication and have therapeutic implications.

Multicellular Liver Organoids: Generation and Importance of Diverse Specialized Cellular Components.

Over 40,000 patients in the United States are estimated to suffer from end-stage liver disease and acute hepatic failure, for which liver transplantation is the only available therapy. Human primary hepatocytes (HPH) have not been employed as a therapeutic tool due to the difficulty in growing and expanding them in vitro, their sensitivity to cold temperatures, and tendency to dedifferentiate following two-dimensional culture. The differentiation of human-induced pluripotent stem cells (hiPSCs) into liver organoids (LO) has emerged as a potential alternative to orthotropic liver transplantation (OLT). However, several factors limit the efficiency of liver differentiation from hiPSCs, including a low proportion of differentiated cells capable of reaching a mature phenotype, the poor reproducibility of existing differentiation protocols, and insufficient long-term viability in vitro and in vivo. This review will analyze various methodologies being developed to improve hepatic differentiation from hiPSCs into liver organoids, paying particular attention to the use of endothelial cells as supportive cells for their further maturation. Here, we demonstrate why differentiated liver organoids can be used as a research tool for drug testing and disease modeling, or employed as a bridge for liver transplantation following liver failure.

Advancing diagnosis and management of liver disease in adults through exome sequencing.

BACKGROUND: Whole-exome sequencing (WES) is an effective tool for diagnosis in patients who remain undiagnosed despite a comprehensive clinical work-up. While WES is being used increasingly in pediatrics and oncology, it remains underutilized in non-oncological adult medicine, including in patients with liver disease, in part based on the faulty premise that adults are unlikely to harbor rare genetic variants with large effect size. Here, we aim to assess the burden of rare genetic variants underlying liver disease in adults at two major tertiary referral academic medical centers. METHODS: WES analysis paired with comprehensive clinical evaluation was performed in fifty-two adult patients with liver disease of unknown etiology evaluated at two US tertiary academic health care centers. FINDINGS: Exome analysis uncovered a definitive or presumed diagnosis in 33% of patients (17/52) providing insight into their disease pathogenesis, with most of these patients (12/17) not having a known family history of liver disease. Our data shows that over two-thirds of undiagnosed liver disease patients attaining a genetic diagnosis were being evaluated for cholestasis or hepatic steatosis of unknown etiology. INTERPRETATION: This study reveals an underappreciated incidence and spectrum of genetic diseases presenting in adulthood and underscores the clinical value of incorporating exome sequencing in the evaluation and management of adults with liver disease of unknown etiology. FUNDING: S.V. is supported by the NIH/NIDDK (K08 DK113109 and R01 DK131033-01A1) and the Doris Duke Charitable Foundation Grant #2019081. This work was supported in part by NIH-funded Yale Liver Center, P30 DK34989.