Search

Nonalcoholic fatty liver disease (NAFLD) affects 25% of adults in the general population and is a disease spectrum ranging from steatosis to nonalcoholic steatohepatitis (NASH) to end-stage liver disease. NAFLD is an independent risk factor for cardiovascular disease, diabetes mellitus, and all-cause mortality, and NASH cirrhosis is a frequent indication for liver transplantation. In persons with human immunodeficiency virus (PWH), chronic liver disease is the second leading cause of non-human immunodeficiency virus-related mortality. Between 20% and 63% of PWH have NASH, and 14% to 63% have NASH with fibrosis. However, little is known about the optimal diagnostic strategies, risk factors for, and treatment of NAFLD in PWH. Here, we review current data on and identify knowledge gaps in the epidemiology, pathophysiology, diagnosis, and management of NAFLD in PWH and highlight priorities for research.

Excess liver fat, called hepatic steatosis, is a leading risk factor for end-stage liver disease and cardiometabolic diseases but often remains undiagnosed in clinical practice because of the need for direct imaging assessments. We developed an abdominal MRI-based machine-learning algorithm to accurately estimate liver fat (correlation coefficients, 0.97-0.99) from a truth dataset of 4,511 middle-aged UK Biobank participants, enabling quantification in 32,192 additional individuals. 17% of participants had predicted liver fat levels indicative of steatosis, and liver fat could not have been reliably estimated based on clinical factors such as BMI. A genome-wide association study of common genetic variants and liver fat replicated three known associations and identified five newly associated variants in or near the MTARC1, ADH1B, TRIB1, GPAM, and MAST3 genes (p < 3 × 10-8). A polygenic score integrating these eight genetic variants was strongly associated with future risk of chronic liver disease (hazard ratio > 1.32 per SD score, p < 9 × 10-17). Rare inactivating variants in the APOB or MTTP genes were identified in 0.8% of individuals with steatosis and conferred more than 6-fold risk (p < 2 × 10-5), highlighting a molecular subtype of hepatic steatosis characterized by defective secretion of apolipoprotein B-containing lipoproteins. We demonstrate that our imaging-based machine-learning model accurately estimates liver fat and may be useful in epidemiological and genetic studies of hepatic steatosis.

Background and aimsNAFLD is increasing in prevalence and will soon be the most common chronic liver disease. Liver stiffness, as assessed by vibration-controlled transient elastography (VCTE), correlates with hepatic fibrosis, an important predictor of liver-related and all-cause mortality. Although liver fat is associated with cardiovascular risk factors, the association between hepatic fibrosis and cardiovascular risk factors is less clear.Approach and resultsWe performed VCTE, assessing controlled attenuation parameter (CAP; measure of steatosis) and liver stiffness measurement (LSM) in 3,276 Framingham Heart Study adult participants (53.9% women, mean age 54.3 ± 9.1 years) presenting for a routine study visit. We performed multivariable-adjusted logistic regression models to determine the association between LSM and obesity-related, vascular-related, glucose-related, and cholesterol-related cardiovascular risk factors. The prevalence of hepatic steatosis (CAP ≥ 290 dB/m) was 28.8%, and 8.8% had hepatic fibrosis (LSM ≥ 8.2 kPa). Hepatic fibrosis was associated with multiple cardiovascular risk factors, including increased odds of obesity (OR, 1.82; 95% CI, 1.35-2.47), metabolic syndrome (OR, 1.49; 95% CI 1.10-2.01), diabetes (OR, 2.67; 95% CI, 1.21-3.75), hypertension (OR, 1.52; 95% CI, 1.15-1.99), and low high-density lipoprotein cholesterol (OR, 1.47; 95% CI, 1.09-1.98), after adjustment for age, sex, smoking status, alcohol drinks/week, physical activity index, aminotransferases, and CAP.ConclusionsIn our community-based cohort, VCTE-defined hepatic fibrosis was associated with multiple cardiovascular risk factors, including obesity, metabolic syndrome, diabetes, hypertension, and high-density lipoprotein cholesterol, even after accounting for covariates and CAP. Additional longitudinal studies are needed to determine if hepatic fibrosis contributes to incident cardiovascular disease risk factors or events.

Excess accumulation of liver fat – termed hepatic steatosis when fat accounts for > 5.5% of liver content – is a leading risk factor for end-stage liver disease and is strongly associated with important cardiometabolic disorders. Using a truth dataset of 4,511 UK Biobank participants with liver fat previously quantified via abdominal MRI imaging, we developed a machine learning algorithm to quantify liver fat with correlation coefficients of 0.97 and 0.99 in hold-out testing datasets and applied this algorithm to raw imaging data from an additional 32,192 participants. Among all 36,703 individuals with abdominal MRI imaging, median liver fat was 2.2%, with 6,250 (17%) meeting criteria for hepatic steatosis. Although individuals afflicted with hepatic steatosis were more likely to have been diagnosed with conditions such as obesity or diabetes, a prediction model based on clinical data alone without imaging could not reliably estimate liver fat content. To identify genetic drivers of variation in liver fat, we first conducted a common variant association study of 9.8 million variants, confirming three known associations for variants in the TM6SF2, APOE , and PNPLA3 genes and identifying five new variants associated with increased hepatic fat in or near the MARC1, ADH1B, TRIB1, GPAM and MAST3 genes. A polygenic score that integrated information from each of these eight variants was strongly associated with future clinical diagnosis of liver diseases. Next, we performed a rare variant association study in a subset of 11,021 participants with gene sequencing data available, identifying an association between inactivating variants in the APOB gene and substantially lower LDL cholesterol, but more than 10-fold increased risk of steatosis. Taken together, these results provide proof of principle for the use of machine learning algorithms on raw imaging data to enable epidemiologic studies and genetic discovery.

Specialty palliative care (PC) is underused for patients with end-stage liver disease (ESLD). We sought to examine attitudes of hepatologists and gastroenterologists about PC for patients with ESLD. We conducted a cross-sectional survey of these specialists who provide care to patients with ESLD. Participants were recruited from the American Association for the Study of Liver Diseases membership directory. Using a questionnaire adapted from prior studies, we examined physicians' attitudes about PC and whether these attitudes varied based on patients' candidacy for liver transplantation. We identified predictors of physicians' attitudes about PC using linear regression. Approximately one-third of eligible physicians (396/1236, 32%) completed the survey. Most (95%) believed that centers providing care to patients with ESLD should have PC services, and 86% trusted PC clinicians to care for their patients. Only a minority reported collaborating frequently with inpatient (32%) or outpatient (11%) PC services. Most believed that when patients hear the term PC, they feel scared (94%) and anxious (87%). Most (83%) believed that patients would think nothing more could be done for their underlying disease if a PC referral was suggested. Physicians who believed that ESLD is a terminal condition (B = 1.09; P = 0.006) reported more positive attitudes about PC. Conversely, physicians with negative perceptions of PC for transplant candidates (B = -0.22; standard error = 0.05; P

BackgroundDyslipidaemia is frequent in non-alcoholic steatohepatitis (NASH); however, it is unclear if improvement in liver histology is associated with favourable changes in cardiovascular disease (CVD) risk.AimsTo evaluate the relationship of NASH resolution and lipoprotein subfraction levels, markers of endothelial dysfunction, and macrophage activation.MethodsOne hundred and seventeen individuals with NASH who participated in the Pioglitazone vs Vitamin E vs Placebo for the Treatment of Nondiabetic Patients with NASH (PIVENS) trial with paired liver biopsies and serum samples available at baseline and after 96 weeks of treatment were included. Participants in the PIVENS trials received vitamin E, pioglitazone, or placebo for 96 weeks. Lipoprotein subfraction levels, intracellular adhesion molecule 1 (ICAM-1), vascular cellular adhesion molecule 1 (VCAM-1), E-selectin, and sCD163 levels were assessed at baseline and week 96 and their relationship with NASH resolution was examined.ResultsFifty-seven individuals had NASH resolution and 60 individuals did not have resolution of NASH. NASH resolution was associated with favourable changes in lipoprotein subfraction levels compared to those without NASH resolution. Individuals with resolution of NASH had a significantly increased mean peak LDL diameter (ratio of geometric means [96 weeks vs baseline] 1.007 vs 0.996, P = 0.004), and higher frequency of LDL phenotype A (58% vs 33%, P = 0.003) at week 96, after adjustment for relevant co-variates including treatment group. No differences in VCAM, ICAM, E-selectin, or sCD163 levels by NASH resolution were found.ConclusionsNASH resolution is associated with favourable changes in a subset of serum lipoprotein levels. More studies are warranted to understand if these favourable changes are associated with decreased risk of CVD.

BackgroundCoinfection with human immunodeficiency virus (HIV) accelerates hepatitis C virus (HCV)-related liver fibrosis. Macrophages are triggered during both viral infections and are critical in liver inflammation/fibrogenesis. Liver fibrosis strongly associates with serum soluble CD163 (sCD163, a macrophage activation marker); comprehensive evaluation in HIV/HCV coinfection is lacking.MethodsWe retrospectively analyzed sCD163 (enzyme-linked immunosorbent assay) and hepatic CD163 (immunofluorescent CD163/CD68 costaining) in patients infected with HIV/HCV, HCV, or HIV, pre- and post-antiviral therapy.ResultssCD163 was significantly higher in HIV/HCV compared to either monoinfection, and decreased following successful antiviral therapy, although did not fully normalize. In HIV/HCV, sCD163 was associated with necroinflammation, Ishak fibrosis scores, and noninvasive fibrosis scores. We observed a novel trend whereby sCD163 levels progressively increase with increasing Ishak fibrosis score, peaking at stage 4, above which levels plateaued. Periportal CD163+ macrophage frequency was also higher with increasing fibrosis score. When stratified by fibrosis stage, sCD163 levels were higher in HIV/HCV than HCV but only in individuals with mild to moderate fibrosis.ConclusionsIn HIV/HCV, increasing sCD163 levels accompanied periportal CD163+ macrophage enrichment in mild to moderate fibrosis, but not in established cirrhosis, suggesting that sCD163 is a dynamic biomarker of fibrogenesis rather than accumulated fibrosis. Our findings implicate HIV-related macrophage activation in accelerated fibrosis progression in HIV/HCV coinfection.

Nonalcoholic fatty liver disease (NAFLD) is a spectrum comprised of isolated steatosis, nonalcoholic steatohepatitis (NASH), advanced fibrosis, and cirrhosis. The majority of NAFLD subjects do not have NASH and do not carry a significant risk for liver-related adverse outcomes (cirrhosis and mortality). Globally, the prevalence of NAFLD is approximately 25%. In Asia, a gradient of high to low prevalence rates is noted from urban to rural areas. Given the prevalence of NAFLD, the clinical and economic burden of NAFLD and NASH can be substantial. With increasing recognition of NASH as an important liver disease, the diagnosis of NASH still requires a liver biopsy that is suboptimal. Although liver biopsy is the most accurate modality to diagnose and stage the severity of NASH, this method suffers from being invasive, costly, associated with potential complications, and plagued with interobserver variability of individual pathological features. A number of noninvasive modalities to diagnose NASH and stage liver fibrosis are being developed. These modalities include predictive models (NAFLD fibrosis score) and serum biomarkers such as enhanced liver fibrosis (ELF). Other tests are based on radiological techniques, such as transient elastography (TE) or magnetic resonance elastography (MRE), which are used to estimate liver stiffness as a potential surrogate of hepatic fibrosis. Although a dynamic field of research, most of these diagnostic modalities have area under the curve ranging between 0.76 and 0.90%, with MRE having the best predictive performance. In summary, developing safe and easily accessible noninvasive modalities to accurately diagnose and monitor NASH and associated fibrosis is of utmost importance in clinical practice and clinical research. These tests are not only important to risk stratify subjects at the greatest risk for progressive liver disease, but also to serve as appropriate surrogate endpoints for therapeutic clinical trials of NASH. (Hepatology 2018;68:349-360).

Nonalcoholic fatty liver disease (NAFLD) and its progressive form non-alcoholic steatohepatitis (NASH), are rapidly becoming among the top causes of cirrhosis, hepatocellular carcinoma, and indications for liver transplantation. Other than lifestyle modification through diet and exercise, there are currently no other approved treatments for NASH/NAFLD. Although weight loss can be effective, it is difficult to achieve and sustain. In contrast, bariatric surgery can improve metabolic conditions associated with NAFLD, and has been shown to improve liver histology. To have approved regimens for the treatment of NASH/NAFLD, several issues must be addressed. First, all stakeholders must agree on the most appropriate clinical trial endpoints for NASH. Currently, resolution of NASH (without worsening fibrosis) or reduction of fibrosis stage (without worsening NASH) are the accepted endpoints by the regulatory authorities. It is important to recognize the prognostic implication of histologic features of NASH. In this context, although histologic NASH has been associated with advanced fibrosis, it is not an independent predictor of long-term mortality. In contrast, there are significant data to suggest that fibrosis stage is the only robust and independent predictor of liver-related mortality. In addition to the primary endpoints, several important secondary endpoints, including noninvasive biomarkers, long-term outcomes, and patient-reported outcomes must be considered. In 2018, a few phase 3 clinical trials for the treatment of NASH have been initiated. Additionally, a number of phase 2a and 2b clinical trials targeting different pathogenic pathways in NASH are in the pipeline of emerging therapies.ConclusionOver the next 5 years, some of these regimens are expected to provide potential new treatment options for patients with NASH/NAFLD. (Hepatology 2018;68:361-371).

BackgroundBiomarkers to predict the presence and severity of subclinical cardiovascular disease (CVD) in nonalcoholic fatty liver disease (NAFLD) are lacking.Methods3876 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), without known chronic liver disease underwent baseline non-contrast cardiac CT, with NAFLD defined by validated liver:spleen ratio (L:S)  0. Randomly-selected subgroups underwent detailed inflammatory marker testing, including LpPLA2 mass (N = 2951), activity (N = 3020), high-sensitivity C-reactive protein (hsCRP; N = 3849), and interleukin-6 (IL-6; N = 3764). Among those with NAFLD, we estimated the prevalence of CAC > 0 and CAC > 100 for each SD biomarker increase, using multivariable log-binomial regression models adjusted for cardiometabolic risk factors.ResultsSeventeen percent (N = 668) of participants met the criteria for NAFLD. NAFLD participants were younger (mean age 61 ± 10 vs. 63 ± 10 years, p  0 (PR = 1.06 [1.00-1.11]), or CAC > 100 (PR = 1.09 [1.02-1.17]). In contrast, circulating LpPLA2 mass/activity and hsCRP were not associated with either the prevalence or severity of subclinical CVD (all p > .05).ConclusionIn a large, multi-ethnic population with NAFLD, IL-6 is independently associated with the prevalence and severity of subclinical atherosclerosis. Further research into the longitudinal effects of NAFLD on progressive CVD will determine whether IL-6 is a marker or mediator of NAFLD-related atherosclerosis.

Purpose: Non-alcoholic fatty liver disease (NAFLD) prevalence and severity may be higher in people with human immunodeficiency virus (HIV) than the general population, and vary with sex and age. We explored NAFLD characteristics by gender. Methods: Adult transgender women (TW), cisgender women (CW), and cisgender men (CM) with HIV on antiretroviral therapy and without other known causes of liver disease underwent screening for NAFLD (2017–2020). Circulating factors associated with NAFLD were measured. Hepatic steatosis and fibrosis were assessed using transient elastography by controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), respectively. Analysis of variance/Wilcoxon testing compared normally/non-normally distributed variables, respectively. Logistic regression evaluated factors associated with CAP and LSM. Results: Participants (n=194) had median age 48 years and body mass index 28.3 kg/m2; 42% were CM, 37% TW, and 21% CW; 95% were non-white; and 16% had diabetes, 40% dyslipidemia, and 49% hypertension. NAFLD prevalence was 59% using CAP ≥248 dB/m (≥S1 steatosis), 48% using CAP ≥260 dB/m (≥S2 steatosis), and 32% using CAP ≥285 dB/m (≥S3 steatosis). Compared to CM and CW, TW had the highest median CAP scores, were more likely to have ≥S2 steatosis, and had the highest insulin resistance, interleukin-6, and fetuin-A values. TW off versus on gender-affirming hormone therapy (GAHT) had slightly higher median CAP scores. Conclusion: TW on GAHT had less hepatic steatosis than TW not on GAHT, although overall NAFLD severity was greater than expected for TW compared to CM and CW. The effects of estrogen supplementation and androgen deprivation on liver health in TW require further study. [ABSTRACT FROM AUTHOR]

Background and aimsNonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) are growing in prevalence in the USA. Existing data on the relationship between OSA and NAFLD are conflicting and limited by the use of various histologic definitions of nonalcoholic steatohepatitis (NASH). Using a robust definition of NASH in a large, well-characterized cohort, we sought to evaluate whether OSA was associated with NASH and advanced fibrosis.MethodsTwo hundred and thirteen subjects undergoing weight loss surgery were queried for OSA and then underwent liver biopsy. NASH was defined, as recommended by the American Association for the Study of Liver Disease, by the presence of all of the following: >5 % macrovesicular steatosis, lobular inflammation, and hepatocyte ballooning. NAFLD activity score (NAS) was also determined for each subject.ResultsSubjects with OSA had significantly higher alanine and aspartate aminotransferase levels than subjects without OSA (ALT 54.1 vs. 37.7 U/L, P = 0.0007; AST 31.7 vs. 20.5 U/L, P = 0.0007). OSA was associated with the presence of NASH, and this remained significant after adjusting for age, gender, race, and diabetes mellitus (P = 0.03 OR 2.01; 95 %, 1.05-3.87). Steatosis grade, lobular inflammation grade, NAS score, and fibrosis stage were all significantly associated with the presence of OSA and remained so after adjustment.ConclusionsOSA is associated with elevated aminotransferase levels, the presence of NASH, and advanced NASH histology. Further studies are needed to evaluate the impact of OSA treatment on NASH.

BackgroundNonalcoholic steatohepatitis (NASH) carries an increased risk of cardiovascular disease (CVD) relative to the general population. We sought to evaluate whether differences in lipoprotein subfractions in obese patients with and without NASH contributes to this difference in CVD risk.FindingsIon mobility analysis was performed on 78 individuals with obesity undergoing weight loss surgery. All individuals had standard of care liver biopsies performed during surgery. Patients with NASH had significantly smaller peak LDL diameter (P = 0.02, 219.0 Å vs. 222.6 Å), and levels of IDL2 (P = 0.01, 104. nmol/L vs. 133.4 nmol/L) and HDL2b (P = 0.05, 676.7 nmol/L vs. 880.1 nmol/L) compared to those without NASH. NASH patients had significantly higher LDL-IVb levels than those without NASH (P = 0.02, 49.0 nmol/L vs. 37.1 nmol/L).The inverse association of LDL peak diameter with NASH remained significant after adjustment for diabetes (P = 0.02). HDL2b levels were inversely correlated with hepatocyte ballooning and NASH and these remained significant after adjustment for diabetes (P = 0.0017 and P = 0.007, respectively). IDL2 levels were inversely correlated with NASH, hepatocyte ballooning and fibrosis stage but these were not significant after adjustment for diabetes.ConclusionsThe lipoprotein subfraction profile in subjects with NASH is characterized by small peak LDL diameter, reduced HDL2b levels and elevated LDL-IVb levels. These changes may contribute to the increased CVD seen in patients with NASH.