Does pressure cause liver cirrhosis? The sinusoidal pressure hypothesis

Body posture can modulate liver stiffness measured by transient elastography: a prospective observational study

BACKGROUND

Non-invasive measurement of liver stiffness (LS), traditionally performed in the supine position, has been established to assess liver fibrosis. However, fibrosis degree is not the sole determinant of LS, necessitating the identification of relevant confounders. One often-overlooked factor is body posture, and it remains unclear whether normal daily postures interfere with LS irrespective of fibrosis. A prospective two-group comparison study was conducted to investigate the relationship between posture and LS.

METHODS

Sixty-two adults participated, divided into two groups: patients with chronic liver disease and healthy controls. Both groups were assessed using transient elastography (TE) under the supine, seated, and standing postures. Randomization was applied to the order of the two upright postures. A two-way mixed ANOVA was conducted to assess the posture-dependence of LS and its variations between two groups.

RESULTS

Results showed that posture differentially affected LS depending on the presence of liver fibrosis. In 31 healthy individuals (baseline LS range: 3.5-6.8 kPa), a transition from the supine (5.0 ± 1.0 kPa) to seated (5.7 ± 1.4 kPa; p = 0.036) or standing (6.2 ± 1.7 kPa; p = 0.002) positions increased LS, indicating liver stiffening. Conversely, in 31 patients with varying fibrosis stages (baseline LS range: 8.8-38.2 kPa), posture decreased LS from the supine (15.9 ± 7.3 kPa) to seated (13.8 ± 6.2 kPa; p < 0.001) or standing (13.9 ± 6.2 kPa; p = 0.001) positions. No significant difference in LS was observed between the seated and standing positions in both groups (control group: 5.7 vs. 6.2 kPa, p = 0.305; patient group: 13.8 vs. 13.9 kPa, p = 1). Additionally, different postures did not elicit significant changes in the success rate (supine, 98.6 ± 4%; seated, 97.6 ± 6%; standing, 99.1 ± 3%; p = 0.258) and IQR/median value (supine, 25 ± 8%; seated, 29 ± 15%; standing, 29 ± 12%; p = 0.117), implying no impact on both measurement feasibility and reliability.

CONCLUSIONS

We demonstrated, for the first time, the feasibility of utilizing upright postures as an alternative measurement protocol for TE. We further unravel a previously unrecognized role of transitioning between different postures to assist the diagnosis of cirrhosis. The findings suggested that daily physiological activity of postural changes suffices to alter LS. Therefore, body positioning should be standardized and carefully considered when interpreting LS.

Cytokeratin-18 is Elevated Prior to Conventional Measures of Liver Disease in Fontan-Associated Liver Disease

The Fontan procedure is used to palliate complex forms of congenital heart disease. This results in adverse hepatic sequelae now known as Fontan-associated liver disease (FALD). Conventional laboratory measures of liver disease do not correlate well with FALD severity. Cytokeratin-18 (CK-18) is a measure of cell death and is sensitive in detecting other causes of liver disease. Our aim was to assess the use of a novel measure of liver disease, CK-18, in Fontan patients. This is a single-center, prospective, cross-sectional study of Fontan patients aged 8-21 years old. We performed ultrasound elastography, echocardiography, magnetic resonance imaging, and serum laboratory testing. Novel laboratory test CK-18 levels in Fontan subjects were compared to healthy age-matched controls. Thirteen Fontan patients were evaluated with a median age 15 years (10, 14), 4 Hypoplastic left heart syndrome, 11 were male, and 5 were symptomatic. Fontan patients had normal AST/ALT, but a significantly elevated liver stiffness by elastography (median 13.4 kPa). Hepatic stiffness by elastography was associated with diastolic-indexed (rho = 0.58, p = 0.04) ventricular volumes. Compared to 10 aged-matched controls, CK-18 was higher in the Fontan group-cleaved CK-18 protein (p < 0.01) and full CK-18 protein, (p = 0.02). CK-18 was positively associated with AST and ALT. Elevated CK-18 levels were found in Fontan patients compared to controls suggesting hepatic cell death even in these relatively healthy Fontan patients. CK-18 was elevated prior to changes in traditional testing. CK-18 may be a useful sensitive marker of liver disease in FALD.

Explainable Boosting Machine approach identifies risk factors for acute renal failure

BACKGROUND

Risk stratification and outcome prediction are crucial for intensive care resource planning. In addressing the large data sets of intensive care unit (ICU) patients, we employed the Explainable Boosting Machine (EBM), a novel machine learning model, to identify determinants of acute kidney injury (AKI) in these patients. AKI significantly impacts outcomes in the critically ill.

METHODS

An analysis of 3572 ICU patients was conducted. Variables such as average central venous pressure (CVP), mean arterial pressure (MAP), age, gender, and comorbidities were examined. This analysis combined traditional statistical methods with the EBM to gain a detailed understanding of AKI risk factors.

RESULTS

Our analysis revealed chronic kidney disease, heart failure, arrhythmias, liver disease, and anemia as significant comorbidities influencing AKI risk, with liver disease and anemia being particularly impactful. Surgical factors were also key; lower GI surgery heightened AKI risk, while neurosurgery was associated with a reduced risk. EBM identified four crucial variables affecting AKI prediction: anemia, liver disease, and average CVP increased AKI risk, whereas neurosurgery decreased it. Age was a progressive risk factor, with risk escalating after the age of 50 years. Hemodynamic instability, marked by a MAP below 65 mmHg, was strongly linked to AKI, showcasing a threshold effect at 60 mmHg. Intriguingly, average CVP was a significant predictor, with a critical threshold at 10.7 mmHg.

CONCLUSION

Using an Explainable Boosting Machine enhance the precision in AKI risk factors in ICU patients, providing a more nuanced understanding of known AKI risks. This approach allows for refined predictive modeling of AKI, effectively overcoming the limitations of traditional statistical models.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: Challenges and Paradigms

Portal hypertension in cirrhosis is defined as an increase in the portal pressure gradient (PPG) between the portal and hepatic veins and is traditionally estimated by the hepatic venous pressure gradient (HVPG), which is the difference in pressure between the free-floating and wedged positions of a balloon catheter in the hepatic vein. By convention, HVPG≥10 mmHg indicates clinically significant portal hypertension, which is associated with adverse clinical outcomes. Nonalcoholic fatty liver disease (NAFLD) is a common disorder with a heterogeneous clinical course, which includes the development of portal hypertension. There is increasing evidence that portal hypertension in NAFLD deserves special considerations. First, elevated PPG often precedes fibrosis in NAFLD, suggesting a bidirectional relationship between these pathological processes. Second, HVPG underestimates PPG in NAFLD, suggesting that portal hypertension is more prevalent in this condition than currently believed. Third, cellular mechanoresponses generated early in the pathogenesis of NAFLD provide a mechanistic explanation for the pressure-fibrosis paradigm. Finally, a better understanding of liver mechanobiology in NAFLD may aid in the development of novel pharmaceutical targets for prevention and management of this disease.

Local fat content determines global and local stiffness in livers with simple steatosis

Fat accumulation during liver steatosis precedes inflammation and fibrosis in fatty liver diseases, and is associated with disease progression. Despite a large body of evidence that liver mechanics play a major role in liver disease progression, the effect of fat accumulation by itself on liver mechanics remains unclear. Thus, we conducted ex vivo studies of liver mechanics in rodent models of simple steatosis to isolate and examine the mechanical effects of intrahepatic fat accumulation, and found that fat accumulation softens the liver. Using a novel adaptation of microindentation to permit association of local mechanics with microarchitectural features, we found evidence that the softening of fatty liver results from local softening of fatty regions rather than uniform softening of the liver. These results suggest that fat accumulation itself exerts a softening effect on liver tissue. This, along with the localized heterogeneity of softening within the liver, has implications in what mechanical mechanisms are involved in the progression of liver steatosis to more severe pathologies and disease. Finally, the ability to examine and associate local mechanics with microarchitectural features is potentially applicable to the study of the role of heterogeneous mechanical microenvironments in both other liver pathologies and other organ systems.

Mechanotransduction in the pathogenesis of non-alcoholic fatty liver disease

Mechanobiology is a domain of interdisciplinary research that aims to explore the impact of physical force, applied externally or internally, on cell and tissue function, including development, growth, and differentiation. Mechanotransduction is a term that describes how cells sense physical forces (such as compression, stretch, and shear stress), convert them into biochemical signals, and mount adaptive responses integrated by the nucleus. There is accumulating evidence that mechanical forces extensively inform the biological behaviour of liver cells in health and disease. Recent research has elucidated many cellular and molecular mechanisms involved in this process including the pleiotropic control and diverse effects of the paralogous transcription co-activators YAP/TAZ, which play a prominent role in mechanotransduction. The liver sinusoids represent a unique microenvironment in which cells are exposed to mechanical cues originating in the cytoskeleton and at interfaces with adjacent cells, the extracellular matrix, and vascular or interstitial fluids. In non-alcoholic fatty liver disease (NAFLD), hepatocellular lipid accumulation and ballooning, activation of inflammatory responses, dysfunction of liver sinusoidal endothelial cells, and transdifferentiation of hepatic stellate cells into a pro-contractile and pro-fibrotic phenotype have been associated with aberrant cycles of mechanosensing and mechanoresponses. The downstream consequences of disrupted mechanical homeostasis likely contribute to the progression of NAFLD and promote the development of portal hypertension, cirrhosis, and hepatocellular carcinoma. Identification of molecular targets involved in pathogenic mechanotransduction will allow for the development of novel strategies to prevent the progression of liver disease in NAFLD.

In Vitro Models for the Study of Liver Biology and Diseases: Advances and Limitations

In vitro models of liver (patho)physiology, new technologies, and experimental approaches are progressing rapidly. Based on cell lines, induced pluripotent stem cells or primary cells derived from mouse or human liver as well as whole tissue (slices), such in vitro single- and multicellular models, including complex microfluidic organ-on-a-chip systems, provide tools to functionally understand mechanisms of liver health and disease. The International Society of Hepatic Sinusoidal Research (ISHSR) commissioned this working group to review the currently available in vitro liver models and describe the advantages and disadvantages of each in the context of evaluating their use for the study of liver functionality, disease modeling, therapeutic discovery, and clinical applicability.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: Epidemiology, Pathogenesis, and Clinical and Research Implications

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide, affecting up to ~30% of adult populations. NAFLD defines a spectrum of progressive liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma, which often occur in close and bidirectional associations with metabolic disorders. Chronic kidney disease (CKD) is characterized by anatomic and/or functional renal damage, ultimately resulting in a reduced glomerular filtration rate. The physiological axis linking the liver and kidneys often passes unnoticed until clinically significant portal hypertension, as a major complication of cirrhosis, becomes apparent in the form of ascites, refractory ascites, or hepatorenal syndrome. However, the extensive evidence accumulated since 2008 indicates that noncirrhotic NAFLD is associated with a higher risk of incident CKD, independent of obesity, type 2 diabetes, and other common renal risk factors. In addition, subclinical portal hypertension has been demonstrated to occur in noncirrhotic NAFLD, with a potential adverse impact on renal vasoregulation. However, the mechanisms underlying this association remain unexplored to a substantial extent. With this background, in this review we discuss the current evidence showing a strong association between NAFLD and the risk of CKD, and the putative biological mechanisms underpinning this association. We also discuss in depth the potential pathogenic role of the hepatorenal reflex, which may be triggered by subclinical portal hypertension and is a poorly investigated but promising research topic. Finally, we address emerging pharmacotherapies for NAFLD that may also beneficially affect the risk of developing CKD in individuals with NAFLD.

Endoscopic Bariatric Treatment with Duodenal-Jejunal Bypass Liner Improves Non-invasive Markers of Non-alcoholic Steatohepatitis

Purpose

People with obesity often develop non-alcoholic fatty liver disease (NAFLD) and are at high risk of progression to non-alcoholic steatohepatitis (NASH). Few therapies are effective other than bariatric surgery. We therefore analyzed data from duodenal-jejunal bypass liner (DJBL) patients regarding steatosis, fibrosis, and NASH.

Methods

Consecutive DJBL patients with type 2 diabetes underwent standardized assessments up to device removal at 48 weeks. These included aspartate and alanine transaminase (AST, ALT), controlled attenuation parameter (CAP, for steatosis), and liver stiffness measurement (LSM, for fibrosis). The NAFLD fibrosis score (NFS), fibrosis-4 score (FIB4), and enhanced liver fibrosis (ELF) test were also used to assess fibrosis and the Fibroscan-AST (FAST) score to assess NASH. Mixed models were used and missing data were accounted for with multiple imputation.

Results

Thirty-two patients (18 female, mean age 55.1, mean BMI 40.2 kg/m²) were included. After 48 weeks, the change compared to baseline with 95% CI was a factor 0.74 (0.65 to 0.84) for AST, 0.63 (0.53 to 0.75) for ALT, and a difference of − 0.21 (− 0.28 to − 0.13) for FAST, all with p < 0.001. Fibrosis based on LSM, NFS, and ELF did not change whereas FIB4 exhibited slight improvement. Eight DJBL were explanted early due to device-related complications and eight complications led to hospitalization.

Conclusions

One year of DJBL therapy is associated with relevant improvements in non-invasive markers of steatosis and NASH, but not fibrosis, and is accompanied by a substantial number of complications. Given the lack of alternatives, DJBL deserves further attention.

Graphical abstract

Hydrostatic pressure induces pro-fibrotic properties in hepatic stellate cells via the RhoA/ROCK signaling pathway

Elevated interstitial fluid hydrostatic pressure is commonly observed in diseased livers. We herein examined the hypothesis that hydrostatic pressure induces hepatic stellate cells to acquire pro-fibrotic properties under pathological conditions. Human hepatic stellate cells were exposed to 50 mmHg pressure for 24 hours. Although we observed few changes of cell growth and morphology, PCR array data on the expression of fibrosis-associated genes suggested the acquisition of pro-fibrotic properties. The exposure of hepatic stellate cells to 50 mmHg pressure for 24 hours also significantly enhanced the expression of RhoA, ROCK1, α-SMA, TGF-β₁ , p-MLC and p-Smad2, and this was effectively attenuated by ROCK inhibitor Y-27632. Our ex vivo experimental data suggests that elevated interstitial fluid hydrostatic pressure under pathological conditions may promote liver fibrosis by inducing acquisition of pro-fibrotic properties of hepatic stellate cells through the RhoA/ROCK signaling pathway.

In vitro ballooned hepatocytes can be produced by primary human hepatocytes and hepatic stellate cell sheets

Despite the increasing prevalence of Nonalcoholic steatohepatitis (NASH) worldwide, there is no effective treatment available for this disease. “Ballooned hepatocyte” is a characteristic finding in NASH and is correlated with disease prognosis, but their mechanisms of action are poorly understood; furthermore, neither animal nor in vitro models of NASH have been able to adequately represent ballooned hepatocytes. Herein, we engineered cell sheets to develop a new in vitro model of ballooned hepatocytes. Primary human hepatocytes (PHH) and Hepatic stellate cells (HSC) were co-cultured to produce cell sheets, which were cultured in glucose and lipid containing medium, following which histological and functional analyses were performed. Histological findings showed hepatocyte ballooning, accumulation of fat droplets, abnormal cytokeratin arrangement, and the presence of Mallory–Denk bodies and abnormal organelles. These findings are similar to those of ballooned hepatocytes in human NASH. Functional analysis showed elevated levels of TGFβ-1, SHH, and p62, but not TNF-α, IL-8. Exposure of PHH/HSC sheets to a glucolipotoxicity environment induces ballooned hepatocyte without inflammation. Moreover, fibrosis is an important mechanism underlying ballooned hepatocytes and could be the basis for the development of a new in vitro NASH model with ballooned hepatocytes.

Cell-to-Cell Communications in Alcohol-Associated Liver Disease

This review covers some important new aspects of the alcohol-induced communications between liver parenchymal and non-parenchymal cells leading to liver injury development. The information exchange between various cell types may promote end-stage liver disease progression and involves multiple mechanisms, such as direct cell-to-cell interactions, extracellular vesicles (EVs) or chemokines, cytokines, and growth factors contained in extracellular fluids/cell culture supernatants. Here, we highlighted the role of EVs derived from alcohol-exposed hepatocytes (HCs) in activation of non-parenchymal cells, liver macrophages (LM), and hepatic stellate cells (HSC). The review also concentrates on EV-mediated crosstalk between liver parenchymal and non-parenchymal cells in the settings of HIV- and alcohol co-exposure. In addition, we overviewed the literature on the crosstalk between cell death pathways and inflammasome activation in alcohol-activated HCs and macrophages. Furthermore, we covered highly clinically relevant studies on the role of non-inflammatory factors, sinusoidal pressure (SP), and hepatic arterialization in alcohol-induced hepatic fibrogenesis. We strongly believe that the review will disclose major mechanisms of cell-to-cell communications pertained to alcohol-induced liver injury progression and will identify therapeutically important targets, which can be used for alcohol-associated liver disease (ALD) prevention.

Overlooked subclinical portal hypertension in non-cirrhotic NAFLD: Is it real and how to measure it?

Clinical and experimental advances related to the detection, magnitude and pathobiology of subclinical portal hypertension in non-alcoholic fatty liver disease (NAFLD), primarily observed in the presence of non-alcoholic steatohepatitis (NASH), prompt us to revisit current disease paradigms. Hepatic venous pressure gradient (HVPG) has been reported to underestimate portal pressure in NASH-related cirrhosis, while inaccuracy is more likely in non-cirrhotic livers, indicating a potential need for new and preferably non-invasive methods of measurement. Although clinically significant portal hypertension (HVPG ≥10 mmHg) retains its prognostic significance in NASH, subclinical portal hypertension (HVPG 6.0-9.5 mmHg) has been repeatedly detected in patients with NAFLD in the absence of cirrhosis or even significant fibrosis whereas the impact of these findings on disease outcomes remains unclear. Mechanocrine signalling pathways in various types of liver cell reveal a molecular basis for the adverse effects of subclinical portal hypertension and suggest a bidirectional relationship between portal pressure and fibrosis. These findings may guide efforts to improve risk assessment and identify novel therapeutic targets in NAFLD.

Can ultrasound elastography assess liver quality in brain-dead donors and predict early allograft dysfunction after transplantation?

PURPOSE

To evaluate the role of two-dimensional shear wave elastography (2D SWE) in assessing graft quality before liver transplantation and the relationship between donor liver stiffness (LS) and early allograft dysfunction (EAD) after transplantation.

METHODS

Eighty-three donors from January 2018 to December 2018 were involved in this prospective study. Liver stiffness measurements (LSMs) were performed using 2D SWE. The differences in LS values between discarded and transplanted grafts were analyzed. The relationship of donor LS with recipient EAD was also evaluated.

RESULTS

Our results suggest that the donor LS values were higher in discarded grafts than in transplanted grafts (24.0 ± 10.9 kPa vs 10.0 ± 2.6 kPa, p < 0.001). LSM failed in one donor. According to multivariate logistic regression analysis, the donor LS values ≥10.9 kPa (odds ratio [OR] 4.042, 95% confidence interval [CI] 1.133-14.421, p = 0.031), BMI (OR 1.287, 95% CI 1.025-1.616, p = 0.030) and INR (OR 6.703, 95% CI 1.338-33.589, p = 0.021) were independently associated with EAD.

CONCLUSION

Donor LSM conducted by 2D SWE might represent an effective quantitative method to evaluate graft quality. Donor LS might predict recipient EAD after liver transplantation.

Effects of Lipid Deposition on Viscoelastic Response in Human Hepatic Cell Line HepG2

Hepatic steatosis is associated with various liver diseases. The main pathological feature of steatosis is the excessive lipid accumulation. Ultrasound has been extensively used for the diagnosis of hepatic steatosis. However, most ultrasound-based non-invasive methods are still not accurate enough for cases with light lipid infiltration. One important reason is that the extent to which lipid infiltration may affect mechanical properties of hepatocytes remains unknown. In this work, we used atomic force microscope and in vitro dose-dependent lipid deposition model to detect the quantitative changes of mechanical properties under different degrees of steatosis in a single-cell level. The results show that hepatic cells with lipid deposition can be treated as linear viscoelastic materials with the power law creep compliance and relaxation modulus. Further analysis showed that even slight accumulation of lipid can lead to measurable decrease of stiffness and increased fluidity in liver cells. The accurate detection of viscoelastic properties of hepatocytes and the analysis methods may provide novel insights into hepatic steatosis grading, especially in the very early stage with reversible liver lesion. The application of viscoelasticity index for grading fat deposition might be a new detection indicator in future clinical diagnosis.

Synapomorphic features of hepatic and pulmonary vasculatures include comparable purinergic signaling responses in host defense and modulation of inflammation

Hepatosplanchnic and pulmonary vasculatures constitute synapomorphic, highly comparable networks integrated with the external environment. Given functionality related to obligatory requirements of "feeding and breathing," these organs are subject to constant environmental challenges entailing infectious risk, antigenic and xenobiotic exposures. Host responses to these stimuli need to be both protective and tightly regulated. These functions are facilitated by dualistic, high-low pressure blood supply of the liver and lungs, as well as tolerogenic characteristics of resident immune cells and signaling pathways. Dysregulation in hepatosplanchnic and pulmonary blood flow, immune responses, and microbiome implicate common pathogenic mechanisms across these vascular networks. Hepatosplanchnic diseases, such as cirrhosis and portal hypertension, often impact lungs and perturb pulmonary circulation and oxygenation. The reverse situation is also noted with lung disease resulting in hepatic dysfunction. Others, and we, have described common features of dysregulated cell signaling during liver and lung inflammation involving extracellular purines (e.g., ATP, ADP), either generated exogenously or endogenously. These metabokines serve as danger signals, when released by bacteria or during cellular stress and cause proinflammatory and prothrombotic signals in the gut/liver-lung vasculature. Dampening of these danger signals and organ protection largely depends upon activities of vascular and immune cell-expressed ectonucleotidases (CD39 and CD73), which convert ATP and ADP into anti-inflammatory adenosine. However, in many inflammatory disorders involving gut, liver, and lung, these protective mechanisms are compromised, causing perpetuation of tissue injury. We propose that interventions that specifically target aberrant purinergic signaling might prevent and/or ameliorate inflammatory disorders of the gut/liver and lung axis.

Non-invasive Biomarkers of Liver Inflammation and Cell Death in Response to Alcohol Detoxification

Introduction

Alcohol-related liver disease (ALD) represents the most common liver disease worldwide, however, the underlying molecular mechanisms are still poorly understood. Namely centrilobular inflammation and programmed cell death are characteristic to ALD and it remains to be elucidated why they persist despite the absence of alcohol.

Aims

To study the effects of alcohol withdrawal in a cohort of heavy drinkers and the role of cirrhosis by using non-invasive biomarkers such as cytokines, apoptotic and angiogenic markers.

Methods

Caspase 3-cleaved M30, M65, cytokines (IL-6, IL-8), tumor necrosis factor alpha (TNF-α), transforming growth factor (TGF-β) and vascular endothelial growth factor (VEGF) were measured in 114 heavy drinkers. The role of alcohol detoxification was investigated in 45 patients. The liver histology was available in 23 patients. Fibrosis stage and steatosis were assessed by measuring liver stiffness (LS) and controlled attenuation parameter (CAP) in all patients using transient elastography (FibroScan, Echosens, Paris). Mean observation interval between the measurements was 5.7 ± 1.4 days (mean + -SD).

Results

Patients consumed a mean of 204 ± 148 g/day alcohol with a heavy drinking duration of 15.3 ± 11.0 years. Mean LS was 20.7 ± 24.4 kPa and mean CAP was 303 ± 51 dB/m. Fibrosis distribution was F0-38.1%, F1-2-31%, F3-7.1 and F4-23.9%. Apoptotic markers M30 and M65 were almost five times above normal. In contrast, TNF- α a, IL-8 and VEGF were only slightly elevated. Patients with manifest liver cirrhosis (F4) had significantly higher levels of M30, M65, IL-6 and IL-8. Histology features such as hepatocyte ballooning, Mallory-Denk bodies, inflammation and fibrosis were all significantly associated with elevated LS, and serum levels of TNF-alpha, M30 and M65 but not with CAP and other cytokines. During alcohol detoxification, LS, transaminases, TGF- β, IL-6, IL-8 and VEGF decreased significantly. In contrast, no significant changes were observed for M30, M65 and TNF- α and M30 even increased during detoxification in non-cirrhotic patients. Profibrogenic cytokine TGF-beta and pro-angiogenic cytokine VEGF showed a delayed decrease in patients with manifest cirrhosis.

Conclusion

Patients with alcohol-related cirrhosis have a pronounced apoptotic activity and a distinct inflammatory response that only partly improves after 1 week of alcohol detoxification. Alcohol withdrawal may represent an important approach to better dissect the underlying mechanisms in the setting of alcohol metabolism.

Effect of breath holding at the end of the inspiration and expiration phases on liver stiffness measured by 2D-MR elastography

PURPOSE

Evaluate the effect of breath holding at the end of the inspiration and expiration phases on the measurement of liver stiffness by 2D-MR elastography (MRE).

METHODS

The study included 61 subjects, of which 31 subjects were pathologically confirmed liver fibrosis patients [liver fibrosis group (LFG)] and 30 healthy subjects [healthy group (HG)]. MRE was used to measure the liver stiffness of subjects in inspiration breath-hold (IBH) and expiration breath-hold (EBH) states.

RESULTS

In IBH and EBH states, the liver stiffness measured by MRE was not significantly different in the HG (P = 0.125, > 0.05), while the LFG showed a significant difference (P <0.001). Also, a significant difference was observed between the change values in the mild/moderate fibrosis group (MFG) and advanced fibrosis group (AFG) (P = 0.005, < 0.05).

CONCLUSIONS

The liver stiffness values in patients with liver fibrosis were affected by breath-holding states. The higher the stage of liver fibrosis, the greater the change in liver stiffness values, but no significant difference was observed between liver stiffness values in healthy subjects under the two breath-holding conditions. Different breath-holding states are factors influencing liver fibrosis stiffness measured by MRE, which should be given due attention in both clinical and research contexts.

Aspects of transition cow metabolomics-Part II: Histomorphologic changes in the liver parenchyma throughout the transition period, in cows with different liver metabotypes and effects of a metaphylactic butaphosphan and cyanocobalamin treatment

The aims of this study were to evaluate histopathologic changes during the transition period, describe the histopathological features of the metabotypes identified in Part I (Schären et al., 2021b), and investigate effects of a metaphylactic treatment with butaphosphan and cyanocobalamin (BCC) on the liver parenchyma. Eighty German Holstein cows (mean 305-d production: 10,957 kg, range: 6,480-15,193 kg; mean lactation number: 3.9, range: 2-9) from a commercial dairy farm in Saxony, Germany, were enrolled in a randomized, prospective, triple-blinded study. Two groups received a treatment with BCC (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin, Catosal, Bayer Animal Health, n = 20 each) and one group a placebo treatment (NaCl 0.9%, n = 40). Liver biopsy specimens were collected 14 d antepartum (AP) and 7, 28, and 42 d postpartum (PP), routinely processed for histologic examination, and stained with hematoxylin and eosin, Sudan III, periodic acid-Schiff, and picrosirius red stains. The sections were assessed for fat and glycogen content and degenerative, inflammatory, fibrotic, and proliferative changes. The statistical analysis included the effects of the sampling day, the lactation number, the treatment, and the metabotype (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP status). There was mild to moderate fat infiltration in the liver of 37% of cows in the last 2 wk AP, and moderate to severe fat infiltration in 66% of cows in the first days PP. The degree of fat infiltration increased from 2 wk AP until the end of the first week PP, and then decreased until the end of the study period, at which time about 25% of cows had moderate to severe fatty infiltration. Lipidosis was positively correlated with the severity of liver cell degeneration, and negatively correlated with the degree of glycogen deposits. Complete glycogen depletion of hepatocytes was not observed in cows, even in the presence of severe hepatic lipidosis. Moderate to severe lymphocytic hepatitis was seen in 39% of cows throughout the study period, and cows with lactation numbers 5 or greater had perisinusoidal fibrosis more often than younger cows. Severe fibrosis and cirrhosis of the liver did not occur. Metabotype B animals exhibited a higher chance of fatty infiltration, lower glycogen storage, and perisinusoidal fibrosis and for this metabotype positive correlations were calculated between increased fat deposition in the liver and marked glycogen depletion, and increased degenerative, inflammatory, fibrotic, and proliferative changes of hepatic tissue. For the treatment with BCC, no significant effect was observed. In summary, during the transition period, the liver of dairy cows is characterized by fat accumulation and glycogen depletion and histologic signs of hepatitis and hepatocyte degeneration. These histomorphologic changes were accentuated in animals exhibiting little alterations in their liver metabolome profile across the transition period (metabotype B) and support the assumption of a decreased grass silage quality as a causative factor.

Study on correlation between coagulation indexes and disease progression in patients with cirrhosis

OBJECTIVE

To inquire into the significance of coagulation indexes in the progression of cirrhosis.

METHODS

A total of 108 patients with cirrhosis treated in our hospital were collected as the research group (RG), and 105 healthy people who underwent concurrent physical examination were selected as the control group (CG). The coagulation indexes of all the participants were tested to determine their significance in cirrhosis progression.

RESULTS

Compared with the CG, prothrombin time (PT), activated partial thrombin time (APTT) and thrombin time (TT) in the RG were statistically prolonged, while fibrinogen (FIB) was notably decreased (P<0.05). With the increase of Child-Pugh score, PT, APTT and TT prolonged and FIB reduced gradually (P<0.05). The coagulation indexes of patients were correlated with Child-Pugh score (P<0.05). Patients in the RG showed markedly higher alanine aminotransferase (ALT), total bilirubin (TBil), total bile acid (TBA), mean platelet volume (MPV), platelet distribution width (PDW) and platelet-large cell ratio (P-LCR), with notably lower albumin (ALB), prealbumin (PA), platelet count (PLT) and coagulation factors compared with the CG. As the Child-Pugh score increased, the ALT, TBil, TBA, MPV, PDW and P-LCR gradually elevated in the RG (P<0.05), whilst coagulation factors, ALB, PLT and PA all gradually decreased (P<0.05). The value of area under the curve (AUC) of each coagulation index for early diagnosis of cirrhosis was >0.80, and the sensitivity was >80% (P<0.05).

CONCLUSION

Coagulation indexes, coagulation factors, platelet parameters and liver function all effectively reflect the level of liver injury; especially which, coagulation indexes are related to the severity of liver injury, and can provide evidence for the early diagnosis of cirrhosis patients, with clinical significance.

A Novel Non-Invasive Device for the Assessment of Central Venous Pressure in Hospital, Office and Home

Background

Venous congestion can be quantified by central venous pressure (CVP) and its monitoring is crucial to understand and follow the hemodynamic status of patients with cardio-respiratory diseases. The standard technique for CVP measurement is invasive, requiring the insertion of a catheter into a jugular vein, with potential complications. On the other hand, the current non-invasive methods, mainly based on ultrasounds, remain operator-dependent and are unsuitable for use in the home environment. In this paper, we will introduce a novel, non-invasive device for the hospital, office and home assessment of CVP.

Methods

After describing the measurement concept, we will report a preliminary experimental study enrolling 5 voluntary healthy subjects to evaluate the VenCoM measurements’ repeatability, and the system’s capability in measuring small elicited venous pressure variations (2 mmHg), as well as an induced venous hypertension within a pathological range (12÷20 mmHg).

Results

The experimental measurements showed a repeatability of ±1mmHg. The VenCoM device was able to reliably detect the elicited venous pressure variations and the simulated congestive status.

Discussion and Conclusion

The proposed non-invasive VenCoM device is able to provide a fast and repeatable CVP estimate, having a wide spectrum of potential clinical applications, including the monitoring of venous congestion in heart failure patients and in subjects with renal and hepatic dysfunction, as well as pulmonary hypertension (PH) that can be extended to pneumonia COVID-19 patients even after recovery. The device needs to be tested further on a large sample size of both healthy and pathological subjects, to systematically validate its reliability and impact in clinical setting.

Evaluation of the Relationship Between Pulmonary Artery Hypertension and Esophageal Varices Bleeding in Transplantation Candidates

Introduction: Esophageal varices bleeding (EVB) in liver cirrhosis is an important cause of mortality and morbidity. We aimed to study the relationship between systolic pulmonary artery pressure (sPAP) and EV grade and EVB.

Methods: A total of 229 patients, 183 male and 46 female, who were determined to have EV in the upper gastrointestinal tract endoscopy and who had a transthoracic echocardiogram (TTE) were included in this study.

Results: The frequency of pulmonary hypertension (PHT) and EVB was determined to be 16% and 45%, respectively, in our study, and 20% of those who had bleeding had PHT; 70.3% of the cases with PHT were determined to have grade III varices while this rate was lower at 52.9% in cirrhosis without PHT. A significant correlation was determined between Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh score, platelet, albumin, and sPAP in those without a history of bleeding (p<0.05).

Conclusion: An increase in the rate of grade III varices has been noted along with the prevalence of PHT in patients with portal hypertension. It has been determined that the increase in PAP is associated with an increase in the MELD score, which is closely associated with mortality and morbidity. Therefore, this positive relationship between the MELD score and PHT may lead to an increase in the frequency of advanced-stage EV.

Changes in Liver Mechanical Properties and Water Diffusivity During Normal Pregnancy Are Driven by Cellular Hypertrophy

During pregnancy, the body’s hyperestrogenic state alters hepatic metabolism and synthesis. While biochemical changes related to liver function during normal pregnancy are well understood, pregnancy-associated alterations in biophysical properties of the liver remain elusive. In this study, we investigated 26 ex vivo fresh liver specimens harvested from pregnant and non-pregnant rats by diffusion-weighted imaging (DWI) and magnetic resonance elastography (MRE) in a 0.5-Tesla compact magnetic resonance imaging (MRI) scanner. Water diffusivity and viscoelastic parameters were compared with histological data and blood markers. We found livers from pregnant rats to have (i) significantly enlarged hepatocytes (26 ± 15%, p < 0.001), (ii) increased liver stiffness (12 ± 15%, p = 0.012), (iii) decreased viscosity (−23 ± 14%, p < 0.001), and (iv) increased water diffusivity (12 ± 11%, p < 0.001). In conclusion, increased stiffness and reduced viscosity of the liver during pregnancy are mainly attributable to hepatocyte enlargement. Hypertrophy of liver cells imposes fewer restrictions on intracellular water mobility, resulting in a higher hepatic water diffusion coefficient. Collectively, MRE and DWI have the potential to inform on structural liver changes associated with pregnancy in a clinical context.

The role of elastography in alcoholic liver disease: fibrosis staging and confounding factors, a review of the current literature

INTRODUCTION

Alcohol-related liver disease (ALD) was estimated to have a prevalence of 2% among the USA population. Since severe fibrosis in compensated patients is the main predictor of long-term survival, it is of utmost importance to early detect patients with severe fibrosis before decompensation occurs. Liver elastography has been used to stage liver fibrosis. However, there is a widespread lack in guidelines for the correct use of liver stiffness (LS) in ALD.

EVIDENCE ACQUISITION

A structured search was carried out on MEDLINE/PubMed database. From the original 225 research articles identified, only 12 studies met the inclusion criteria, with 10 studies being eventually included.

EVIDENCE SYNTHESIS

According to reported data, patients with aspartate aminotransferase (AST)>100 IU/L and 50 IU/L showed significantly higher values of LS if compared to patients with the same fibrosis stage. Also, excessive alcohol consumption greatly influences elastography, leading to false fibrosis staging. When LS values >5-6 kPa are detected, several aspects should be taken into account. First of all, the patient should be asked about the current alcohol consumption (i.e. active vs. abstinence, determination of abstinence period, and quantification of alcohol intake), and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. Secondly, clinicians should check liver transaminases level, and if AST are above 100 IU/L, they should be aware of a possible overestimation of fibrosis. However, whether transaminases-adapted cut-off values should be used for ad-hoc decisions in patients with no time or option to withdraw from alcohol consumption is still a matter of debate.

CONCLUSIONS

We hope that our review article may serve as a reference point in the prospect of futures guidelines.

Open-label Study with Nalmefene as Needed Use in Alcohol-Dependent Patients with Evidence of Elevated Liver Stiffness and/or Hepatic Steatosis

AIMS

This open-label study in patients with alcohol dependence and evidence of elevated liver stiffness and/or hepatic steatosis was designed to explore the efficacy of nalmefene (18 mg) in reducing alcohol consumption and its subsequent effects on a variety of clinically relevant liver parameters.

METHODS

Adult patients with a diagnosis of alcohol dependence and evidence of elevated liver stiffness and/or hepatic steatosis (liver stiffness >6 kPa or controlled attenuation parameter (CAP) >215 dB/m as measured by transient elastography) were recruited at two study sites in Germany. During the 12-week treatment period, patients were instructed to take nalmefene each day they perceived a risk of drinking alcohol.

RESULTS

All 45 enrolled patients took at least one dose of nalmefene and 39 completed the study. After 12 weeks of study treatment with nalmefene patients showed a reduction in alcohol consumption of -13.5 days/month heavy drinking days and -45.8 g/day total alcohol consumption. Most liver parameters showed modest changes at Week 12; there was a 13% decrease in liver stiffness and 10% reduction in CAP values. Results indicated non-significant negative associations between alcohol consumption and liver stiffness and/or CAP over this 12-week study. Nalmefene was generally well tolerated, and most adverse events were mild or moderate, the most frequent being dizziness.

CONCLUSIONS

Patients treated with nalmefene for 12 weeks had reductions in alcohol consumption by ~50% relative to baseline and showed trends to improvement in liver stiffness and CAP.

The Role of Vascular Injury and Congestion in the Pathogenesis of Cirrhosis: the Congestive Escalator and the Parenchymal Extinction Sequence

Purpose of Review

Current research into the pathogenesis of cirrhosis is largely dominated by investigations of hepatocellular injury and fibrogenesis, mostly in short-term experimental models. Cirrhosis in the human evolves for decades with histologic features that are very different from the models studied, dominated by hepatic vein obstruction and congestion. This is a clue that the mechanisms operating in the human are different from those in most animal models.

Recent Findings

This paper presents an updated “vascular hypothesis” with previously unpublished observations that provide a more complete understanding of the pathogenesis of chronic liver disease in the human: (1) a definition of parenchymal extinction emphasizing the importance of sinusoidal destruction, (2) analysis of the temporal evolution of parenchymal extinction lesions, (3) new data to quantify hepatic vein obstruction, (4) a “congestive escalator” hypothesis to explain how vascular obstruction occurs, beginning with sinusoidal endothelial cell injury, fluid translocation, and vascular compression by mechanics known as “compartment syndrome,” (5) a “nested cone model” of hepatic vein anatomy that predisposes to compartment syndrome in the human, and (6) a proposal for the mechanism of collagen formation in response to congestion (“congestive fibrosis”).

Summary

The guiding principle in this model is that flow has to be vented to keep pressure gradients within the physiological range. Vascular obstruction causes tissue congestion which induces further vascular obstruction that drives a congestive escalator leading to progressive parenchymal extinction. This model may be applicable to all types of cirrhosis found in the human.

A review of the use of transient elastography in the assessment of fibrosis and steatosis in the post-liver transplant patient

Liver biopsy is considered the gold standard method for diagnosing and staging liver disease, particularly in the post-liver transplant setting. Given the invasive nature of biopsy, alternate means for accurately assessing liver fibrosis and steatosis are preferred especially as the number of patients with fatty liver disease is increasing. Transient elastography has been validated as a useful tool for evaluation of liver fibrosis, as has controlled attenuation parameter index as a tool for assessing steatosis. It is a non-invasive, rapid, and highly reproducible approach to demonstrate the presence of fibrosis among non-transplant patients with chronic liver disease of various etiologies. However, it has not yet found wide acceptance in liver transplant recipients. There are few published studies evaluating the merits and applicability of transient elastography to assess allografts after liver transplantation. We review the published data on the use of transient elastography with concurrent controlled attenuation parameter in liver transplant recipients and recommend its greater use to follow allograft function over time.

Patients With Signs of Advanced Liver Disease and Clinically Significant Portal Hypertension Do Not Necessarily Have Cirrhosis

BACKGROUND & AIMS

Patients with hepatic venous pressure gradients (HVPGs) of 10 mm Hg or greater and chronic liver disease often are assumed to have cirrhosis. We investigated the association between HVPGs and cirrhosis, using histologic findings as the reference standard. We also assessed the prevalence and characteristics of patients with HVPGs of 10 mm Hg or greater without cirrhosis.

METHODS

We performed a retrospective analysis of 157 consecutive patients, 89 with suspected cirrhosis and hepatic hemodynamic data collected from 2015 through 2017. Biopsy specimens collected had 10 or more portal tracts from each patient and were analyzed for features of cirrhosis. Biopsy specimens with histologic features of cirrhosis were excluded and the remaining biopsy specimens were re-reviewed by an expert pathologist. The fibrosis area was calculated digitally by image analysis.

RESULTS

HVPG identified patients with cirrhosis with an area under the receiver operating characteristic curve of 0.879: 14 of 89 patients with HVPG of 10 mm Hg or greater (16%) had no histologic features of cirrhosis (METAVIR scores <4 and Ishak scores <6). The median HVPG was 11 mm Hg (range, 10-22 mm Hg). Based on METAVIR scores, 7 patients had fibrosis stage F3, 4 patients had fibrosis stage F2, and 3 patients had fibrosis stages F0 or F1. The mean area of fibrosis in livers was 16.2% ± 6.5%. All 14 patients had perisinusoidal fibrosis and 8 patients had hepatocyte ballooning. The most common diagnoses were nonalcoholic steatohepatitis (n = 5) and nodular regenerative hyperplasia (n = 4). An HVPG cut-off value of 12 mm Hg identified patients with cirrhosis with 92% specificity, misclassifying 5 patients with different etiologies of liver disease.

CONCLUSIONS

In a retrospective analysis of 89 consecutive patients with chronic liver disease and an HVPG of 10 mm Hg or greater, 16% were not found to have cirrhosis upon biopsy analysis. Most of these patients had nonalcoholic steatohepatitis or nodular regenerative hyperplasia. Perisinusoidal fibrosis and hepatocyte ballooning might increase sinusoidal pressure. An HVPG cut-off value of 12 mm Hg or greater identified patients with cirrhosis with 92% specificity.

Spleen stiffness to liver stiffness ratio significantly differs between ALD and HCV and predicts disease-specific complications

Background & Aims

Both liver stiffness (LS) and spleen stiffness (SS) are widely used to non-invasively assess liver fibrosis and portal hypertension, respectively. We aimed to identify the impact of disease etiology, namely the localization of inflammation (portal vs. lobular), on the SS/LS ratio.

Methods

In this multicenter study, LS and SS were prospectively assessed in 411 patients with alcohol-related liver disease (ALD) or hepatitis C virus (HCV) using FibroScan® (Echosens, Paris); changes in these parameters were also studied in response to treatment (alcohol withdrawal, HCV therapy). LS and spleen length (SL) were further analyzed in a retrospective cohort of 449 patients with long-term data on decompensation/death.

Results

Both, SS and SL were significantly higher in HCV compared to ALD (42.0 vs. 32.6 kPa, p≪0.0001, 15.6 vs. 11.9 cm, p≪0.0001) despite a lower mean LS in HCV. Consequently, the SS to LS ratio and the SL to LS ratio were significantly higher in HCV (3.8 vs. 1.72 and 1.46 vs. 0.86, p≪0.0001) through all fibrosis stages. Notably, SL linearly increased with SS and the relation between SS and SL was identical in HCV and ALD. In contrast, livers were much larger in ALD at comparable LS. After treatment, LS significantly decreased in both diseases without significant changes to the SS/LS ratio. In the prognostic cohort, patients with ALD had higher LS values (30.5 vs. 21.3 kPa) and predominantly presented with jaundice (65.2%); liver failure was the major cause of death (p≪0.01). In contrast, in HCV, spleens were larger (17.6 vs. 12.1 cm) while variceal bleeding was the major cause of decompensation (73.2%) and death (p≪0.001).

Conclusion

Both SS/LS and SL/LS ratios are significantly higher in patients with portal HCV compared to lobular ALD. Thus, combined LS and SS or SL measurements provide additional information about disease etiology and disease-specific complications.

Lay summary

Herein, we show that patients with hepatitis C virus infection (HCV) have higher spleen stiffness and portal pressure than patients with alcohol-related liver disease (ALD), within the same fibrosis stage and matched to liver stiffness. Thus, the spleen stiffness to liver stiffness ratio is significantly higher in patients with HCV compared to ALD. Additionally, patients with HCV more commonly progress to portal hypertension-related complications (e.g. variceal bleeding), while patients with ALD more commonly progress to liver failure (e.g. jaundice). The spleen stiffness to liver stiffness ratio is a useful tool to confirm disease etiology and predict disease-specific complications.

•

SS/LS ratio is significantly higher in patients with portal HCV compared to lobular ALD.

•

Patients with HCV have higher SS and portal pressure than patients with ALD and the same LS.

•

Patients with HCV die earlier from portal hypertension-related complications.

•

Patients with ALD die earlier from liver failure.

•

Combined LS and SS measurements provide extra information about disease etiology and disease-specific complications.

Transient liver elastography in normal pregnancy - a longitudinal cohort study

Background and aim: Transient elastography can detect liver fibrosis by estimation of liver stiffness. Results may be falsely high when blood flow to the liver is increased, such as during late stages of pregnancy. The aim of the present study was to longitudinally evaluate transient elastography in healthy pregnant women. Methods: We recruited 24 healthy women with normal singleton pregnancies in a longitudinal cohort study. All women underwent transient elastography at gestational week 18-20, week 26-28 and week 36-38, as well as after a minimum of 8 weeks postpartum. Results: Mean age at baseline was 30.6 years ± 4.1, and mean BMI was 22.3 kg/m²±1.9. 14 women (58%) were nulliparous. The pregnancy outcomes were normal, with no cases of preeclampsia or gestational diabetes. Mean gestational length was 284 days ± 7. Mean liver stiffness increased from 3.8 kPa during the second trimester to 5.9 kPa during the third trimester (p = .002). At the third trimester, 2 women (8%) had an elastography measurement of >7.9 kPa. Postpartum, liver stiffness decreased to early second trimester levels (5.9 to 3.8 kPa, p = .002), and no woman had liver stiffness values above 7.9 kPa. Likewise, the mean Controlled Attenuation Parameter (CAP) increased from 186 dB/m in the second trimester to 215 dB/m in the third trimester (p = .01) and reversed postpartum (215 to 193 dB/m, p = .03). Conclusion: Liver stiffness and CAP increase reversibly during normal pregnancies, and slightly elevated levels in the third trimester can be considered a normal finding. Lay summary An ultrasound-based method called transient elastography can be used to measure fat content and estimate fibrosis in the liver. In this study, we examined healthy women three times during their pregnancy and once after labor to evaluate the effects of a normal pregnancy on a healthy liver. The ultrasound-estimation of fibrosis and fat content increased during pregnancy and reversed afterwards, without any other signs of disease in the liver.

Green Tea Catechins Effectively Altered Hepatic Fibrogenesis in Rats by Inhibiting ERK and Smad1/2 Phosphorylation

Polyphenols derived from green tea have been reported to have a wide range of profound functions. Tea catechins, including epicatechin, epigallocatechin (EGC), epicatechin-3- O-gallate (ECG), and epigallocatechin-3- O-gallate (EGCG), are considered as the major bioactive polyphenols in tea. The present study was designed to elucidate the potential antifibrogenic role of three abundant tea catechins (ECG, EGC, and EGCG) in a CCl₄-induced fibrotic rat and their underlying molecular mechanisms. Tea catechins, especially groups of ECG, EGC, and EGCG, effectively induced several beneficial alterations of liver injury markers, oxidative status, and liver histology. Furthermore, catechins ameliorated liver fibrosis, as evidenced by the reduced expression of desmin, α-smooth muscle actin, transforming growth factor β (TGF-β), and downstream ERK1/2 and Smad1/2 phosphorylation. The most significant inhibitory effect on those proteins was observed in ECG (300 mg/kg) and EGCG (300 mg/kg) groups. In addition, catechins conferred their protective role by downregulating the proinflammation cytokines TGF-β, tumor necrosis factor α, and interleukin 17. It is postulated that tea catechins, particularly ECG and EGCG, are potential therapeutic candidates in antifibrotic therapy.

Impact of Food Intake on Liver Stiffness Determined by 2-D Shear Wave Elastography: Prospective Interventional Study in 100 Healthy Patients

The aim was to evaluate the influence of food intake on liver stiffness measurement (LSM), performed with 2-D shear wave elastography (Logiq E9, GE Medical Systems, Wauwatosa, WI, USA). One hundred healthy volunteers were prospectively enrolled. Mean age was 25.8 (19-55) y, and mean body mass index was 22.43 (17.3-30.8) kg/m². Patients fasted for at least 3 h and subsequently ingested a liquid meal of 800 kcal. Liver stiffness and portal vein velocity were measured before and after food intake. Food intake resulted in significantly higher LSM values compared with baseline LSM (5.74 ± 0.94 kPa vs. 4.80 ± 0.94 kPa, p < 0.001). On multiple linear regression analysis, body mass index was significantly positively correlated with the LSM increase after food intake (p = 0.01). No correlation between the increase in LSM and the increase in post-prandial portal vein velocity was observed (r = 0.09). In summary, food intake has a significant influence on LSM. There is an 11% risk of misclassifying non-fasting, healthy patients as having significant fibrosis.

Non-invasive diagnosis and biomarkers in alcohol-related liver disease

Even though alcohol-related liver disease (ALD) is a major cause of severe liver disease worldwide, most patients with ALD are diagnosed at the decompensation stage. Liver biopsy is still considered the gold standard for establishing a definite diagnosis and assessing the fibrosis stage of ALD, but it is an invasive procedure, associated with significant morbidity. During the last decade, non-invasive tests have been developed to estimate the severity of liver fibrosis and steatosis. Measurement of liver stiffness by transient elastography has become the most commonly used non-invasive parameter to evaluate fibrosis. In ALD, transient elastography has been demonstrated to have an excellent performance to detect advanced fibrosis and cirrhosis. However, aspartate aminotransferase levels must be considered when interpreting liver stiffness cut-offs. Non-invasive biological tests have also been evaluated to assess liver fibrosis in ALD. The commercially available Enhanced Liver Fibrosis test and FibroTest have comparable performance for the diagnosis of advanced fibrosis in ALD, with studies suggesting that they are better than other biological tests (i.e. FIB-4 and APRI). Although ultrasound is still accepted as an initial screen for fatty liver diagnosis, new methods have recently been developed to detect steatosis. Magnetic resonance spectroscopy and magnetic resonance imaging techniques are highly accurate and reproducible, with superior sensitivities and specificities for detecting histological steatosis than ultrasound. However, low availability and high cost limit the use of magnetic resonance techniques in routine clinical practice. More recently, controlled attenuation parameter was developed as a novel tool to non-invasively assess liver steatosis; performed in combination with transient elastography, it was suggested to be superior to regular ultrasound for detecting steatosis and was shown to have acceptable diagnostic accuracy. New serum biomarkers are under investigation to non-invasively diagnose more severe forms of ALD and to predict prognosis of patients.

Liver stiffness reversibly increases during pregnancy and independently predicts preeclampsia

AIM

To study liver stiffness (LS) during pregnancy and its association with complications during pregnancy.

METHODS

In this observational, diagnostic study, 537 pregnant women were prospectively enrolled at the Department of Obstetrics and Gynecology, University hospital Heidelberg and Salem Medical Center. LS was measured using the Fibroscan device (Echosens, Paris) in all women and in 41 cases 24 h after delivery. Clinical and morphological data were recorded and abdominal ultrasound and standard laboratory tests were performed. No complications were observed in 475 women (controls) while preeclampsia and intrahepatic cholestasis of pregnancy (ICP) developed in 22 and 40 women, respectively.

RESULTS

In controls, LS increased significantly from initially 4.5 ± 1.2 kPa in the second trimester to 6.0 ± 2.3 kPa (P < 0.001) in the third trimester. In the third trimester, 41% of women had a LS higher than 6 kPa. Elevated LS in controls was significantly correlated with alkaline phosphatase, leukocytes, gestational age and an increase in body weight and body mass index (BMI). In women with pregnancy complications, LS was significantly higher as compared to controls (P < 0.0001). Moreover, in multivariate analysis, LS was an independent predictor for preeclampsia with an odds ratio of 2.05 (1.27-3.31) and a cut-off value of 7.6 kPa. In contrast, ICP could not be predicted by LS. Finally, LS rapidly decreased in all women within 24 h after delivery from 7.2 ± 3.3 kPa down to 4.9 ± 2.2 kPa (P < 0.001).

CONCLUSION

During pregnancy, LS significantly and reversibly increases in the final trimester of pregnant women without complications. In women with preeclampsia, LS is significantly elevated and an independent non-invasive predictor.

Pharmacological decrease of liver stiffness is pressure-related and predicts long-term clinical outcome

Liver stiffness (LS) as measured by transient elastography is increasingly used to noninvasively assess liver fibrosis. However, LS is efficiently modulated by confounders like arterial and portal pressure (PP). We here study the effect of acute hemodynamic changes on LS (measured by µFibroscan) in a rodent model of cirrhosis in response to pharmacological modulation of PP by losartan, nitric oxide donors, and propranolol. Additionally, changes of LS and the hepatic venous pressure gradient (HVPG) under propranolol therapy were assessed with regard to clinical outcomes in a human cohort of n = 38 cirrhotic patients. In the animal model, cirrhosis induction resulted in a significant increase of LS and PP. After losartan or NO application, a LS decrease of 25% was strongly correlated with a concomitant decrease of mean arterial pressure (MAP) and PP. In contrast, acute propranolol administration decreased heart rate but not MAP resulting in stable LS. In the human cohort, most patients ( n = 25, 66%) showed a LS decrease after propranolol treatment initiation which significantly correlated to HVPG ( r = 0.518, P < 0.01) but was not accompanied by statistically significant changes in transaminases or model of end-stage liver disease (MELD). On multivariate analysis, patients with decreasing LS on propranolol had a decreased risk for experiencing a transplantation or death than patients with increasing LS irrespective of HVPG. In conclusion, LS changes after pharmacological interventions are influenced by hemodynamic effects on arterial and portal pressure. In humans, a LS decrease may be predictive of improved outcome irrespective of MELD scores and may serve as an additional follow-up tool in the future. NEW & NOTEWORTHY Liver stiffness (LS) is efficiently modulated by changes in portal venous and systemic pressures in an animal model of liver cirrhosis irrespective of baseline LS and portal pressure values. In humans, most patients show a decrease in LS after propranolol treatment initiation without statistically significant changes in transaminases or model of end-stage liver disease (MELD) scores. A decrease in LS may be associated with improved outcome and thus another valuable tool in the follow-up of patients after propranolol treatment initiation.

Alcoholic liver disease

Alcoholic liver disease (ALD) is the most prevalent type of chronic liver disease worldwide. ALD can progress from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which is characterized by hepatic inflammation. Chronic ASH can eventually lead to fibrosis and cirrhosis and in some cases hepatocellular cancer (HCC). In addition, severe ASH (with or without cirrhosis) can lead to alcoholic hepatitis, which is an acute clinical presentation of ALD that is associated with liver failure and high mortality. Most individuals consuming >40 g of alcohol per day develop AFL; however, only a subset of individuals will develop more advanced disease. Genetic, epigenetic and non-genetic factors might explain the considerable interindividual variation in ALD phenotype. The pathogenesis of ALD includes hepatic steatosis, oxidative stress, acetaldehyde-mediated toxicity and cytokine and chemokine-induced inflammation. Diagnosis of ALD involves assessing patients for alcohol use disorder and signs of advanced liver disease. The degree of AFL and liver fibrosis can be determined by ultrasonography, transient elastography, MRI, measurement of serum biomarkers and liver biopsy histology. Alcohol abstinence achieved by psychosomatic intervention is the best treatment for all stages of ALD. In the case of advanced disease such as cirrhosis or HCC, liver transplantation may be required. Thus, new therapies are urgently needed.

Increase in liver stiffness after transjugular intrahepatic portosystemic shunt is associated with inflammation and predicts mortality

Transjugular intrahepatic portosystemic shunt (TIPS) efficiently treats complications of portal hypertension. Liver and spleen stiffness might predict clinically significant portal hypertension. This prospective study investigated liver stiffness in patients receiving TIPS regardless of indication. Of 83 included patients, 16 underwent transient elastography immediately before and 30 minutes after TIPS (acute group), while 67 received shear wave elastography of liver and spleen 1 day before and 7 days after TIPS (chronic group) and were followed further. In blood samples obtained before TIPS from cubital, portal, and hepatic veins, levels of several interleukins (IL1b, IL6, IL8, IL10, IL18) and interferon-gamma were analyzed. In 27 patients (5 acute, 22 chronic), it resulted in an increase in liver stiffness of >10%. In 56 patients, liver stiffness decreased or remained unchanged (<10%). Importantly, spleen stiffness measured by shear wave elastography decreased in all patients (chronic group). None of the clinical or laboratory parameters differed between patients with increase in liver stiffness and those without. Of note, patients with increased liver stiffness showed higher overall and/or hepatic venous levels of proinflammatory cytokines at TIPS and higher incidence of organ failure and worse survival after TIPS. C-reactive protein values and increase of >10% in liver stiffness after TIPS were the only independent predictors of mortality in these patients.

CONCLUSION

This study demonstrates that the presence of systemic inflammation predisposes patients to develop increased liver stiffness after TIPS, a predictor of organ failure and death. (NCT03072615) (Hepatology 2018;67:1472-1484).

Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.

PPARγ Antagonizes Hypoxia-Induced Activation of Hepatic Stellate Cell through Cross Mediating PI3K/AKT and cGMP/PKG Signaling

Background and Aims

Accumulating evidence reveals that PPARγ plays a unique role in the regulation of hepatic fibrosis and hepatic stellate cells (HSCs) activation. This study was aimed at investigating the role of PPARγ in hypoxia-induced hepatic fibrogenesis and its possible mechanism.

Methods

Rats used for CCl4-induced hepatic fibrosis model were exposed to hypoxia for 8 hours each day. Rats exposed to hypoxia were treated with or without the PPARγ agonist rosiglitazone. Liver sections were stained with HE and Sirius red staining 8 weeks later. HSCs were exposed to hypoxic environment in the presence or absence of rosiglitazone, and expression of PPARγ and two fibrosis markers, α-SMA and desmin, were measured using western blot and immunofluorescence staining. Next, levels of PPARγ, α-SMA, and desmin as well as PKG and cGMP activity were detected using PI3K/AKT and a cGMP activator or inhibitor.

Results

Hypoxia promoted the induction and progress of hepatic fibrosis and HSCs activation. Meanwhile, rosiglitazone significantly antagonized the effects induced by hypoxia. Signaling by sGC/cGMP/PKG promoted the inhibitory effect of PPARγ on hypoxia-induced activation of HSCs. Moreover, PI3K/AKT signaling or PDE5 blocked the above response of PPARγ.

Conclusion

sGC/cGMP/PKG and PI3K/AKT signals act on PPARγ synergistically to attenuate hypoxia-induced HSC activation.

Evolution of nodule stiffness might predict response to local ablative therapy: A series of patients with hepatocellular carcinoma

BACKGROUND

Early information on treatment response of HCC to local ablative therapy is crucial. Elastography as a non-invasive method has recently been shown to play a potential role in distinguishing between benign and malignant liver lesions. Elastography of hepatocellular carcinoma (HCC) in early response to local ablative therapy has not been studied to date.

METHODS

We prospectively included a cohort of 14 patients with diagnosis of HCC who were treated with local ablative therapy (transarterial chemoembolization, TACE and/or radiofrequency ablation, RFA). We used 2D shear-wave elastography (RT 2D-SWE) to examine stiffness of HCC lesion before and 3, 30 and 90 days after local ablative therapy. Contrast-enhanced imaging after 90 days was performed to evaluate treatment response. Primary endpoint was stiffness of HCC in response to local ablative therapy. Secondary end point was tumor recurrence.

RESULTS

Stiffness of HCC nodules and liver showed no significant difference prior to local ablative therapy. As early as three days after treatment, stiffness of responding HCC was significantly higher compared to non-responding. Higher stiffness before treatment was significantly associated with tumor recurrence.

CONCLUSION

Nodule stiffness in general and RT 2D-SWE in particular could provide a useful tool for early prediction of HCC response to local ablative therapy.

Rapid change of liver stiffness after variceal ligation and TIPS implantation

Liver stiffness (LS) as measured by transient elastography is widely used to screen for liver fibrosis. However, LS also increases in response to pressure changes like congestion but no data on portal pressure are available. We study here the effect of rapid portal pressure changes on LS. Therefore, LS was assessed directly prior and after ligation of esophageal varices ( n = 11) as well as transjugular intrahepatic portosystemic shunt (TIPS) implantation in patients with established cirrhosis ( n = 14). Additionally, we retrospectively analyzed changes in LS and variceal size in patients with sequential gastroscopic monitoring and LS measurements ( n = 14). To study LS and portal pressure in healthy livers, LS (µFibroscan; Echosens, Paris, France) and invasive pressures (Powerlab, AD Instruments, New Zealand) were assessed in male Wistar rats after ligation of single liver lobes. Ligation of esophageal varices caused an immediate and significant increase of LS from 40.3 ± 19.0 to 56.1 ± 21.5 kPa. Likewise, LS decreased significantly from 53.1 ± 16.6 to 43.8 ± 17.3 kPa after TIPS placement, which correlated significantly with portal pressure ( r = 0.558). In the retrospective cohort, the significant LS decrease from 54.9 ± 23.5 to 47.9 ± 23.8 kPa over a mean observation interval of 4.3 ± 3 mo was significantly correlated with a concomitant increase of variceal size ( r = -0.605). In the animal model, LS and portal pressure increased significantly after single lobe ligation without changes of arterial or central venous pressure. In conclusion, rapid changes of portal pressure are a strong modulator of LS in healthy and cirrhotic organs. In patients with stable cirrhosis according to the model for end-stage liver disease (MELD), a decrease of LS may be indicative for enlarging varices. NEW & NOTEWORTHY Liver stiffness (LS) immediately increases after variceal ligation while it decreases after transjugular intrahepatic portosystemic shunt (TIPS) implantation due to portal pressure changes. LS and portal pressure rapidly increase after single lobe ligation in Wistar rats without changes of arterial or central venous pressure. Collateral formation may be one cause for a transient decrease in LS in the absence of other confounders. Such pressure changes should be considered when interpreting LS in clinical practice.

Pathological alterations in liver injury following congestive heart failure induced by volume overload in rats

Heart failure has emerged as a disease with significant public health implications. Following progression of heart failure, heart and liver dysfunction are frequently combined in hospitalized patients leading to increased morbidity and mortality. Here, we investigated the underlying pathological alterations in liver injury following heart failure. Heart failure was induced using a modified infrarenal aortocaval fistula (ACF) in male Wistar rats. Sham operated and ACF rats were compared for their morphometric and hemodynamic data, for histopathological and ultrastructural changes in the liver as well as differences in the expression of apoptotic factors. ACF-induced heart failure is associated with light microscopic signs of apparent congestion of blood vessels, increased apoptosis and breakdown of hepatocytes and inflammatory cell inifltration were observed. The glycogen content depletion associated with the increased hepatic fibrosis, lipid globule formation was observed in ACF rats. Moreover, cytoplasmic organelles are no longer distinguishable in many ACF hepatocytes with degenerated fragmented rough endoplasmic reticulum, shrunken mitochondria and heavy cytoplasm vacuolization. ACF is associated with the upregulation of the hepatic TUNEL-positive cells and proapoptotic factor Bax protein concomitant with the mitochondrial leakage of cytochrome C into the cell cytoplasm and the transfer of activated caspase 3 from the cytoplasm into the nucleus indicating intrinsic apoptotic events. Taken together, the results demonstrate that ACF-induced congestive heart failure causes liver injury which results in hepatocellular apoptotic cell death mediated by the intrinsic pathway of mitochondrial cytochrome C leakage and subsequent transfer of activated caspase 3 into to the nucleus to initiate overt DNA fragmentation and cell death.

Caspase-cleaved keratin-18 fragments increase during alcohol withdrawal and predict liver-related death in patients with alcoholic liver disease

Noninvasive assessment of disease activity in patients with nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) is still unsettled, but essential for the evaluation of disease progression. We here studied the association of total (M65) and caspase-cleaved (M30) serum keratin-18 fragments (n = 204) with histological parameters (n = 106) in heavy drinkers primarily admitted for alcohol withdrawal before and after alcohol detoxification. An age-, sex-, and fibrosis-stage matched NAFLD cohort (n = 30) was used for comparison. The prognostic value of M30 and M65 levels were assessed in an additional prospectively followed-up cohort of 230 patients with alcoholic cirrhosis (AC) using competing risk analyses. Among the histological parameters, both M30/65 correlated significantly and better than any other serum marker with apoptosis and liver damage, such as ballooning (r = 0.65; P < 0.001), followed by lobular inflammation (0.48; P < 0.001), steatosis (0.46; P < 0.001), but less with fibrosis (0.24; P < 0.001). Area under the receiver operating characteristics curves to detect ballooning, steatosis, or steatohepatitis (SH) were slightly better for M30 (P < 0.005). Optimal M30 cut-off values for mild and severe ballooning were 330 and 420 U/L, and 290 and 330 U/L for SH grades 1 and 2. No significant differences of M30/65 were found between the matched NAFLD and ALD cohort. In contrast to aspartate-amino-transferase and M65, M30 levels increased significantly from 391 to 518 U/L during alcohol detoxification. Moreover, levels of M30 and M65 predicted non-hepatocellular carcinoma liver-related mortality in patients with AC during a mean observation interval of 67.2 months.

CONCLUSION

Our data suggest M30 as highly specific marker of liver apoptosis both in ALD and NAFLD. In addition, hepatocellular apoptosis, as determined by M30 levels, occurs during alcohol withdrawal, and survival data point toward a novel underestimated role of apoptosis in patients with ALD. (Hepatology 2017;66:96-107).