Hepatic Encephalopathy: An Update on the Pathophysiology and Therapeutic Options

Alcoholism and Socioeconomic Status among Patients with Hepatic Encephalopathy in Association with Increased Mortality

Background

Hepatic encephalopathy (HE) is a complex neuropsychiatric disorder indicated by a deterioration in the functioning of hepatocytes. Impaired brain function is observed in advanced alcoholic liver disease particularly manifesting as HE. The pathophysiology of alcohol-related HE remains unclear. Accordingly, this study aimed to assess alcoholism and socioeconomic status of patients with liver disease compared with stages of HE.

Methods

This cross-sectional study was conducted on 62 alcoholic patients who have been consuming alcohol for more than 14 years. Patients were recruited based on the assessment of clinical symptoms and diagnosed according to the MELD and Child-Pugh scoring systems.

Findings

Descriptive statistics including demographic details and clinical features of patients were classified based on alcoholism and socioeconomic status. Patients belonging to the lower- and middle-income classes were more in number with a mean age of 46.66±10.21 and 47.14±6.36 years, respectively compared to upper-middle- and upper-income classes. The amount of alcohol intake was 116.59±45.60 in the middle class and 110.0±62.45 in the upper class.

Conclusion

Increased progression of HE leads to a rise in the mortality rate due to higher consumption of alcohol. HE is a severe complication in alcohol-related liver cirrhosis that contributes to impaired cognitive function in patients.

Hepatic encephalopathy - recent advances in treatment and diagnosis

INTRODUCTION

Hepatic encephalopathy (HE) is a peculiar kind of brain dysfunction typical of liver cirrhosis characterized by nonspecific neurological and psychiatric manifestations. HE ranges from minimal hepatic encephalopathy (MHE) to the most severe form characterized by alteration of consciousness or coma (overt HE, OHE). Once the diagnosis of OHE is made, every effort to identify and correct the precipitating cause is essential for the resolution of symptoms. Clinical studies that assessed the prevalence and incidence of any type of HE (MHE and OHE) in patients affected by cirrhosis were included in this review. No language, publication date, or publication status restrictions were imposed. The studies were identified by searching electronic databases (PubMed and SCOPUS).

AREAS COVERED

The most widely empirical pharmacological approach consists of non-absorbable antibiotics (rifaximin) and non-absorbable disaccharides (lactulose, lactitol per os and per enemas). Other agents (including branched-chain amino acids, probiotics, other antibiotics, or intravenous L-ornithine L-aspartate) are available, but the evidence supporting their efficacy remains under debate.

EXPERT OPINION

Gray areas and future needs remain the therapeutic approach to MHE and issues in the design of therapeutic studies for HE which have been extensively discussed in this review.

Ashwagandha-loaded nanocapsules improved the behavioral alterations, and blocked MAPK and induced Nrf2 signaling pathways in a hepatic encephalopathy rat model

Ashwagandha (ASH), a vital herb in Ayurvedic medicine, demonstrated potent preclinical hepato- and neuroprotective effects. However, its efficacy is limited due to low oral bioavailability. Accordingly, we encapsulated ASH extract in chitosan-alginate bipolymeric nanocapsules (ASH-BPNCs) to enhance its physical stability and therapeutic effectiveness in the gastrointestinal tract. ASH-BPNC was prepared by emulsification followed by sonication. The NCs showed small particle size (< 220 nm), zeta-potential of 25.2 mV, relatively high entrapment efficiency (79%), physical stability at acidic and neutral pH, and in vitro release profile that extended over 48 h. ASH-BPNC was then investigated in a thioacetamide-induced hepatic encephalopathy (HE) rat model. Compared with free ASH, ASH-BPNC improved survival, neurological score, general motor activity, and cognitive task-performance. ASH-BPNC restored ALT, AST and ammonia serum levels, and maintained hepatic and brain architecture. ASH-BPNC also restored GSH, MDA, and glutathione synthetase levels, and Nrf2 and MAPK signaling pathways in liver and brain tissues. Moreover, ASH-BPNC downregulated hepatic NF-κB immunohistochemical expression. Moreover, the in vivo biodistribution studies demonstrated that most of the administered ASH-BPNC is accumulated in the brain and hepatic tissues. In conclusion, chitosan-alginate BPNCs enhanced the hepatoprotective and neuroprotective effects of ASH, thus providing a promising therapeutic approach for HE.

Inhibition of Autotaxin Ameliorates LPA-Mediated Neuroinflammation and Alleviates Neurological Dysfunction in Acute Hepatic Encephalopathy

Growing evidence suggests an essential role of neuroinflammation in behavioral abnormalities associated with hepatic encephalopathy (HE). Here, we report the involvement of autotaxin-lysophosphatidic acid (LPA) signaling in HE's pathogenesis. We demonstrate that the autotaxin (ATX) inhibitor PF-8380 attenuates neuroinflammation and improves neurological dysfunction in the mouse model of HE. In the thioacetamide (TAA)-induced model of HE, we found a twofold increase in the levels of ammonia in the brain and in plasma along with a significant change in HE-related behavioral parameters. Mice with HE show an increased brain weight, increased levels of tumor necrosis factor-α (TNF-α), IL-1β (interleukin-1β), interleukin-6 (IL-6), and LPA 18:0 in the cerebral cortex and hippocampus, and increased levels of LPA 18:0 in plasma. Treatment with the autotaxin inhibitor (ATXi) did not affect liver injury, as we observed no change in liver function markers including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBIL) and no change in ammonia levels in the brain and plasma. However, ATXi treatment significantly ameliorated the neuroinflammation, reduced the levels of LPA 18:0 in the cerebral cortex and hippocampus in the brain and plasma, and reduced brain edema and the levels of IL1β, IL-6, and TNF-α. The neurobehavioral symptoms for HE such as the cognitive and motor function deficit and overall clinical grading score were significantly improved in ATXi-treated mice. Mouse astrocytes and microglia stimulated with NH₄CL with or without ATXi showed significant attenuation of oxidative stress and the neuroinflammatory effect of NH4CL in ATXi-treated cells.

Sleep disturbances in newly diagnosed treatment-naïve patients with Wilson's disease

Introduction

Most neurodegenerative and chronic liver disorders are associated with sleep disturbances (SD). SD may be expected to occur in patients with Wilson’s disease (WD), an inherited disorder of copper metabolism that mostly affects the liver and brain; however, there is a lack of observations, particularly in treatment-naïve WD patients.

Methods

We evaluated SD in 19 newly diagnosed treatment-naïve WD patients. All patients completed the Beck Depression Inventory (BDI), the Athens Insomnia Scale (AIS) and the Epworth Sleepiness Scale (ESS), and underwent nightlong video polysomnography (vPSG). Results of vPSG in WD patients were compared with results from 19 sex- and age-matched healthy controls.

Results

Depressive symptoms were not reported by patients on routine examination although three patients were diagnosed with mild depression. No patients reported SD during routine examination; three patients had insomnia according to the AIS and all patients scored 0 on the ESS. Despite the lack of reporting of SD by patients, significant differences were observed between WD patients and controls following vPSG analysis: WD patients had shorter mean total sleeping time (366.2 vs. 451.7 min), a lower percentage of rapid-eye movement (15.4 vs. 20.6%), longer sleep latency (36.7 vs. 10.4 min) and lower sleep efficiency (76.2 vs. 93.8%) (all P ≤ 0.01). SD tended to be worse in patients with neurological WD compared with hepatic WD.

Conclusions

As SD may precede depression and severely affect quality of life, our findings suggest that patients with WD should be screened for SD with suitable methods.

Evidence-based approach to management of hepatic encephalopathy in adults

Hepatic encephalopathy (HE) is a reversible syndrome of impaired brain function and represents one of the many complications of portal hypertension and decompensated liver disease. Although ammonia is clearly implicated in the pathogenesis of HE, the pathogenesis of HE is multifactorial with numerous mechanisms that results in functional impairment of neuronal cells. The initial management of HE focuses on supportive care and stabilization which includes providing appropriate nutritional support. Thereafter, focus should be on identifying and treating the precipitating factors. There are many therapeutic agents available for the management of HE, most of which are directed towards lowering the gut nitrogen load and thus the serum ammonia level. This review aims to provide an update on the conventional and emerging treatment options for HE.

Pharmacokinetics/pharmacodynamics of L-ornithine phenylacetate in overt hepatic encephalopathy and the effect of plasma ammonia concentration reduction on clinical outcomes

Hepatic encephalopathy (HE) is a serious neurocognitive complication of liver dysfunction, often associated with elevated plasma ammonia. Ornithine phenylacetate (OP), a potent ammonia scavenger, is being evaluated for the treatment of acute/overt HE. The pharmacokinetics and pharmacodynamics of OP in patients with HE were characterized in this phase IIb study (NCT01966419). Adult patients hospitalized with an overt HE episode, cirrhosis, and plasma ammonia above the upper limit of normal (ULN) who failed to improve after 48 hours’ standard care were randomly assigned to continuous intravenous OP (10, 15, or 20 g/day, based on Child–Turcotte–Pugh score) or matching placebo for 5 days. Plasma levels of ornithine and phenylacetic acid (PAA) and plasma/urinary levels of phenylacetylglutamine (PAGN) (primary metabolite of PAA) were regularly assessed; plasma ammonia level was the primary pharmacodynamic variable. PAA demonstrated dose‐dependent pharmacokinetics; ornithine and PAGN levels increased with dose. PAGN urinary excretion represented ~50%–60% of administered PAA across all doses. Mean reduction in plasma ammonia with OP at 3 hours postinfusion was significantly greater versus placebo (p = 0.014); and time to achieve plasma ammonia less than or equal to the ULN was significantly reduced (p = 0.028). Achievement of clinical response based on HE stage was associated with a greater reduction in mean plasma ammonia level (p = 0.009). OP effects on plasma ammonia were consistent with its proposed mechanism of action as a primary ammonia scavenger, with a significant association between reduced plasma ammonia and improvement in HE stage. OP should be further evaluated as a promising treatment for hyperammonemia in patients with overt HE.

Ammonia and the Muscle: An Emerging Point of View on Hepatic Encephalopathy

In the last years the link between the presence of muscular alterations and hepatic encephalopathy (HE), both minimal and overt, has been deeply studied. The pathophysiological background supporting the relationship between muscle depletion, and HE is characterized by an imbalance between the capacity of muscle in ammonia metabolism and trafficking and the inability of the liver in removing ammonia through urea synthesis due to liver failure and/or the presence of porto-systemic shunts. This review will focus on the clinical burden, the physio pathological mechanisms understanding the liver muscle axis and principles of management of muscular alterations in cirrhosis.

Cerebrolysin Prevents Brain Injury in a Mouse Model of Liver Damage

Liver damage can lead to secondary organ damage by toxic substances and catabolic products accumulation which can increase the permeability of blood-brain barrier, leading to cognitive impairment. The only real treatment for end stage liver failure is grafting. With some, but not all, neurological symptoms subsiding after transplantation, the presence of brain damage can impair both the short and long-term outcome. We tested if Cerebrolysin can prevent brain injury in an experimental model of non-viral liver damage in mice. Behavior, abdominal ultrasound evaluation and immunohistochemistry were used to evaluate the animals. No ultrasound or behavior differences were found between the control and treated animals, with both groups displaying more anxiety and no short-term memory benefit compared to sham mice. Cerebrolysin treatment was able to maintain a normal level of cortical NeuN+ cells and induced an increase in the area occupied by BrdU+ cells. Surprisingly, no difference was observed when investigating Iba1+ cells. With neurological complications of end-stage liver disease impacting the rehabilitation of patients receiving liver grafts, a neuroprotective treatment of patients on the waiting lists might improve their rehabilitation outcome by ensuring a minimal cerebral damage.

Quality of life as a therapeutic objective in the management of hepatic encephalopathy and the potential role of rifaximin-α

OBJECTIVE

Quality of life (QoL) is impaired in patients with hepatic encephalopathy and rifaximin-α can improve QoL within 6 months. This study assessed the importance of QoL as a therapeutic objective in hepatic encephalopathy management; whether QoL is routinely assessed in hepatic encephalopathy patients in clinical practice and the role of rifaximin-α in this context.

METHODS

A survey was conducted of healthcare professionals (HCPs) from Europe and Australia involved in hepatic encephalopathy management. HCPs rated the importance of a range of therapeutic objectives on a 1-7 Likert scale (1 = not at all important; 7 = extremely important). HCPs were also required to provide three patient record forms (PRFs) based on their last three hepatic encephalopathy patients.

RESULTS

There were 218 HCP respondents, who provided 654 PRFs (patients treated with rifaximin-α, n = 347; patients not treated with rifaximin-α, n = 307). The mean Likert score was highest for the therapeutic objective 'improving a patient's QoL' (6.4), which was rated significantly more highly than all other therapeutic objectives, including 'reducing the patient's likelihood of hospital readmission' (6.1; P < 0.001) and 'preventing death of the patient' (6.1; P < 0.001). Despite this, only 28.3% of PRFs documented specific QoL data assessment. Patients receiving rifaximin-α were treated later in their disease course than those not receiving rifaximin-α.

CONCLUSIONS

HCPs consider QoL improvement the main therapeutic objective in hepatic encephalopathy management, but most do not explicitly assess QoL. Earlier introduction of rifaximin-α may safeguard QoL improvement even when QoL monitoring is not possible.

Neurologic Imaging in a Patient with Cirrhosis and Altered Mental Status: To CT or Not to CT

Hepatic encephalopathy represents a continuum of neuropsychiatric symptoms among patients with end-stage liver disease. When a patient with cirrhosis presents with altered mental status (AMS), routine neurologic imaging is not typically recommended, due to low diagnostic yield. Guidance from the American Association for the Study of Liver Disease states that, on initial presentation, brain imaging is not required unless there are other signs of intracranial pathology, including focal neurologic deficits. We present a case of a 61-year-old female with cirrhosis presenting with AMS without focal deficits, in whom neurological imaging revealed a meningioma and subsequent resection led to symptom improvement.

Successful treatment of recurrent hepatic encephalopathy with revision of transjugular intrahepatic portasystemic shunt and embolisation of splenorenal shunt

We present a case of 64-year-old US veteran who developed recurrent hepatic encephalopathy (HE) following transjugular intrahepatic portasystemic shunt (TIPSS) procedure. The patient had a history of metabolic syndrome and cirrhosis due to non-alcoholic steatohepatitis. He had undergone sleeve gastrectomy 1 year earlier with preoperative TIPSS placement. He developed recurrent symptoms of HE despite optimising his medications, resulting in poor quality of life and multiple hospitalisations. A liver Doppler ultrasound and CT scan of the abdomen was obtained which showed a patent TIPSS and a prominent shunt between the splenic vein and left renal vein via the left gonadal vein. This was treated with reduction of TIPSS, by placement of a covered stent in an hourglass configuration within the existing TIPSS stent and simultaneous embolisation of the splenorenal shunt by interventional radiology. The patient had complete resolution of symptoms following the procedure without any recurrence of HE.

Prevalence of Hepatic Encephalopathy from a Commercial Medical Claims Database in the United States

INTRODUCTION

Hepatic encephalopathy (HE), a complication of cirrhosis, is associated with increased healthcare resource utilization and mortality, and impaired quality of life. Information on the prevalence of HE in the US general population is limited.

METHODS

Prevalence of HE was estimated by sequential stepwise data analysis of the Symphony Health anonymized patient-level data (APLD) claims database. First, patients ≥ 18 years with International Classification of Diseases ninth/tenth edition, clinical modification (ICD-9/10-CM), and codes for cirrhosis from 2018 medical and hospital claims were used to estimate prevalence of cirrhosis within the data set and number of patients with cirrhosis in the US general population. Second, patients diagnosed with cirrhosis in the APLD data set from 2015-2016 with an HE ICD-9/10-CM code within 1 year of cirrhosis diagnosis were used to deduce the prevalence of HE within the data set and estimate the number of patients with HE in the US general population. Last, US DiagnosticSource data on serum ammonia level laboratory results measured within ±2 days of a confirmed HE event were merged with the APLD HE data set, then applied to the US general population.

RESULTS

Medical and hospital claims data were available for 272,256 patients with cirrhosis in 2018. An estimated 536,856 US adults had a diagnosis of cirrhosis (prevalence of 0.21%) in 2018. This proportion applied to the estimated number of patients with cirrhosis in the United States resulted in a prevalence estimate of 201,858 cirrhosis patients with HE in 2018. When factoring in serum ammonia data, prevalence was conservatively estimated as approximately 196,000 cirrhosis patients with HE and serum ammonia levels > 21 μmol/L.

CONCLUSIONS

In this longitudinal cohort-based study, it was estimated that ≈202,000 patients had HE in the United States in 2018, representing a considerable burden to society and payers.

Low yield of head CT in cirrhotic patients presenting with hepatic encephalopathy

Goals and background

The utility of routine head CT (HCT) in hepatic encephalopathy (HE) evaluation is unclear. We investigated HCT yield in detecting acute intracranial abnormalities in cirrhotic patients presenting with HE.

Study

Retrospective review of cirrhotic patient encounters with HE between 2016 and 2018 at Beaumont Health, in Michigan was performed. A low-risk (LR) indication for HCT was defined as altered mental status (AMS), which included dizziness and generalised weakness. A high-risk (HR) indication was defined as trauma/fall, syncope, focal neurological deficits (FNDs) or headache. Descriptive statistics and univariate/multivariate analyses by logistic regression were performed using SPSS to identify HCT abnormality correlates.

Results

Five hundred twenty unique encounters were reviewed. Mean age was 63.4 (12.1) years, 162 (37.5%) had alcoholic cirrhosis and median Model for End-Stage Liver Disease (MELD)-score was 17 (13–23). LR indication was reported in 408 (78.5%) patients and FNDs reported in 24 (4.6%) patients. Only 13 (2.5%) patients were found to have an acute intracranial pathology (seven haemorrhagic stroke, two ischaemic stroke, four subdural haematoma). Aspirin use prior to presentation (aOR 4.6, 95% CI 1.1 to 19.2), and HR indication (aOR 7.3, 95% CI 2.3 to 23.8) were independent correlates of acute intracranial pathology on HCT. Age, sex, MELD-score, haemoglobin, platelet count, race and cirrhosis aetiology did not correlate with HCT abnormalities. Number needed to screen to identify one acute pathology was 14 in HR indications versus 82 for LR indications.

Conclusion

Routine HCTs in cirrhotic patients presenting with HE with AMS in the absence of history of trauma, headache, syncope, FNDs or aspirin use is of low diagnostic yield.

Real-World Experience of the One-Year Efficacy of Rifaximin Add-On to Lactulose Is Superior to Lactulose Alone in Patients with Cirrhosis Complicated with Recurrent Hepatic Encephalopathy in Taiwan

Background: Hepatic encephalopathy (HE), a neuropsychiatric complication of decompensated cirrhosis, is associated with high mortality and high risk of recurrence. Rifaximin add-on to lactulose for 3 to 6 months is recommended for the prevention of recurrent episodes of HE after the second episode. However, whether the combination for more than 6 months is superior to lactulose alone in the maintenance of HE remission is less evident. Therefore, the aim of this study is to evaluate the one-year efficacy of rifaximin add-on to lactulose for the maintenance of HE remission in Taiwan. Methods: We conducted a real-world single-center retrospective cohort study to compare the long-term efficacy of rifaximin add-on to lactulose (group R + L) versus lactulose alone (group L, control group). Furthermore, the treatment efficacy before and after rifaximin add-on to lactulose was also analyzed. The primary endpoint of our study was time to first HE recurrence (Conn score ≥ 2). All patients were followed up every three months until death, and censored at one year if still alive. Results and Conclusions: 12 patients were enrolled in group R + L. Another 31 patients were stratified into group L. Sex, comorbidity, ammonia level, and ascites grade were matched while age, HE grade, and model for end-stage liver disease (MELD) score were adjusted in the multivariable logistic regression model. Compared with group L, significant improvement in the maintenance of HE remission and decreased episodes and days of HE-related hospitalizations were demonstrated in group R + L. The serum ammonia levels were significantly lower at the 3rd and 6th month in group 1. Concerning changes before and after rifaximin add-on in group R + L, mini-mental status examination (MMSE), episodes of hospitalization, and variceal bleeding also improved at 6 and 12 months. Days of hospitalization, serum ammonia levels also improved at 6th month. Except for concern over price, no patients discontinued rifaximin due to adverse events or complications. The above results provide evidence for the one-year use of rifaximin add-on to lactulose in reducing HE recurrence and HE-related hospitalization for patients with decompensated cirrhosis.

Elevation of Autoantibodies to Cerebral Proteins in Hepatic Encephalopathy: Another Pathogenic Factor?

BACKGROUND

The pathophysiology of hepatic encephalopathy (HE) is incompletely understood. It remains elusive how the contributing factors of neuronal ammonia accumulation, cell swelling, and inflammation interact.

OBJECTIVE

The objective of this study was to find the correlation between neuronal autoantibody levels and the degree of HE as first indication of immune-mediated pathogenesis.

METHODS

We investigated serum autoantibody levels of representative brain proteins in patients with HE as well as in an experimental rat model with cirrhosis and HE after carbon tetrachloride exposure. They were examined in relation to presence of HE and the degree of neurological impairment evaluated by quantitative scores.

RESULTS

In HE, an increase in all of the examined antibodies was observed in serum. The grade of antibody elevation correlated to the degree of encephalopathy registered by quantitative evaluation of brain dysfunction.

CONCLUSION

The degree of HE parallels neuronal autoantibody elevation. In case a causal relationship could finally be established, it adds to the understanding of HE and may open a new perspective for treatment of this handicapping condition by immunosuppressive strategies.

Association between Liver Cirrhosis and Diabetes Mellitus: A Review on Hepatic Outcomes

BACKGROUND

Liver cirrhosis (LC) is largely associated with diabetes mellitus (DM). More than 80% of patients with LC manifest glucose intolerance and about 30% have type 2 DM. A particular and yet unrecognized entity is hepatogenous diabetes (HD), defined as impaired glucose regulation caused by altered liver function following LC. Numerous studies have shown that DM could negatively influence liver-related outcomes.

AIM

We aimed to investigate whether patients with LC and DM are at higher risk for hepatic encephalopathy (HE), variceal hemorrhage (VH), infections and hepatocellular carcinoma (HCC). The impact of DM on liver transplant (LT) outcomes was also addressed.

METHODS

Literature search was performed in PubMed, Ovid, and Elsevier databases. Population-based observational studies reporting liver outcomes in patients with LC were included.

RESULTS

Diabetics are at higher risk for HE, including post-transjugular intrahepatic portosystemic shunt HE. DM also increases the risk of VH and contributes to elevated portal pressure and variceal re-bleeding, while uncontrolled DM is associated with increased risk of bacterial infections. DM also increases the risk of HCC and contributes to adverse LT outcomes.

CONCLUSIONS

Patients with DM and LC may benefit from close follow-up in order to reduce readmissions and mortality. Due to the heterogeneity of available research, prospective multicenter clinical trials are needed to further validate these findings.

Role of Oxidative Stress in Hepatic and Extrahepatic Dysfunctions during Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a pathology that contains a broad liver dysfunctions spectrum. These alterations span from noninflammatory isolated steatosis until nonalcoholic steatohepatitis (NASH), a more aggressive form of the disease characterized by steatosis, inflammatory status, and varying liver degrees fibrosis. NAFLD is the most prevalent chronic liver disease worldwide. The causes of NAFLD are diverse and include genetic and environmental factors. The presence of NASH is strongly associated with cirrhosis development and hepatocellular carcinoma, two conditions that require liver transplantation. The liver alterations during NAFLD are well described. Interestingly, this pathological condition also affects other critical tissues and organs, such as skeletal muscle and even the cardiovascular, renal, and nervous systems. Oxidative stress (OS) is a harmful state present in several chronic diseases, such as NAFLD. The purpose of this review is to describe hepatic and extrahepatic dysfunctions in NAFLD. We will also review the influence of OS on the physiopathological events that affect the critical function of the liver and peripheral tissues.

Synergistic effect of aminoguanidine and l-carnosine against thioacetamide-induced hepatic encephalopathy in rats: behavioral, biochemical, and ultrastructural evidence

Hepatic encephalopathy depicts the cluster of neurological alterations that occur during acute or chronic hepatic injury. Hyperammonemia, inflammatory injury, and oxidative stress are the main predisposing factors for the direct and indirect changes in cerebral metabolism causing encephalopathy. The aim of this study was to evaluate the possible synergistic effect between aminoguanidine (AG; 100 mg/kg, p.o.) and l-carnosine (CAR; 200 mg/kg, p.o.) on hepatic encephalopathy that was induced by thioacetamide (TAA; 100 mg/kg, i.p.) administered three times weekly for six weeks. Behavioral changes, biochemical parameters, histopathological analysis, and immunohistochemical and ultrastructural studies were conducted 24 h after the last treatment. Combining AG with CAR improved TAA-induced locomotor impairment and motor incoordination evidenced by reduced locomotor activity and decline in motor skill performance, as well as ameliorated cognitive deficits. Moreover, both drugs restored the levels of serum hepatic enzymes and serum and brain levels of ammonia. In addition, the combination significantly modulated hepatic and brain oxidative stress biomarkers, inflammatory cytokines, and cleaved caspase-3 expression. Furthermore, they succeeded in activating nuclear erythroid 2-related factor 2 (Nrf2) expression and heme oxygenase-1 (HO-1) activity and ameliorating markers of hepatic encephalopathy, including hepatic necrosis and brain astrocyte swelling. This study shows that combining AG with CAR exerted a new intervention for hepatic and brain damage in hepatic encephalopathy due to their complementary antioxidant, anti-inflammatory effects and hypoammonemic effects via Nrf2/HO-1 activation and NO inhibition.

Systemic Oxidative Stress Markers in Cirrhotic Patients with Hepatic Encephalopathy: Possible Connections with Systemic Ammoniemia

Background and objectives: Oxidative stress shows evidence of dysregulation in cirrhotic patients with hepatic encephalopathy (HE), although there are still controversies regarding the connections between oxidative stress and ammonia in these patients. The aim of this study was to evaluate the oxidative stress implication in overt HE pathogenesis of cirrhotic patients. Materials and Methods: We performed a prospective case-control study, which included 40 patients divided into two groups: group A consisted of 20 cirrhotic patients with HE and increased systemic ammoniemia, and group B consisted of 20 cirrhotic patients with HE and normal systemic ammoniemia. The control group consisted of 21 healthy subjects matched by age and sex. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) levels (lipid peroxidation marker), and ammoniemia were evaluated. Results: We found a significant decrease in SOD and GPx activity and also a significant increase of MDA levels in cirrhotic patients with HE as compared to the healthy age-matched control group (1.35 ± 0.08 vs. 0.90 ± 0.08 U/mL, p = 0.002; 0.093 ± 0.06 vs. 0.006 ± 0.008 U/mL, p = 0.001; and 35.94 ± 1.37 vs. 68.90 ± 5.68 nmols/mL, p = 0.0001, respectively). Additionally, we found significant correlations between the main oxidative stress markers and the levels of systemic ammonia (r = 0.452, p = 0.005). Patients from group A had a significant increase of MDA as compared with those from group B (76.93 ± 5.48 vs. 50.06 ± 5.60 nmols/mL, p = 0.019). Also, there was a compensatory increase in the activity of both antioxidant enzymes (SOD and GPx) in patients with increased systemic ammoniemia (group A), as compared to HE patients from group B. Conclusions: Our results demonstrated a significant decrease in antioxidants enzymes activities (SOD and GPx), as well as a significant increase in MDA concentrations, adding new data regarding the influence of oxidative stress in HE pathogenesis in cirrhotic patients.

Dietary approach and gut microbiota modulation for chronic hepatic encephalopathy in cirrhosis

Hepatic encephalopathy (HE) is a common and serious neuropsychiatric complication of cirrhosis, acute liver failure, and porto-systemic shunting. HE largely contributes to the morbidity of patients with liver disease, severely affecting the quality of life of both patients and their relatives and being associated with poor prognosis. Its presentation is largely variable, manifesting with a broad spectrum of cognitive abnormalities ranging from subtle cognitive impairment to coma. The pathogenesis of HE is complex and has historically been linked with hyperammonemia. However, in the last years, it has become evident that the interplay of multiple actors, such as intestinal dysbiosis, gut hyperpermeability, and neuroinflammation, is of crucial importance in its genesis. Therefore, HE can be considered a result of a dysregulated gut-liver-brain axis function, where cognitive impairment can be reversed or prevented by the beneficial effects induced by “gut-centric” therapies, such as non-absorbable disaccharides, non-absorbable antibiotics, probiotics, prebiotics, and fecal microbiota transplantation. In this context dietary modifications, by modulating the intestinal milieu, can also provide significant benefit to cirrhotic patients with HE. This review will provide a comprehensive insight into the mechanisms responsible for gut-liver-brain axis dysregulation leading to HE in cirrhosis. Furthermore, it will explore the currently available therapies and the most promising future treatments for the management of patients with HE, with a special focus on the dietary approach.

Long-term management of hepatic encephalopathy with lactulose and/or rifaximin: a review of the evidence

A consolidated overview of evidence for the effectiveness and safety/tolerability of hepatic encephalopathy (HE) treatment over the long term is currently lacking. We identified and assessed published evidence for the long-term (≥6 months) pharmacological management of HE with lactulose and/or rifaximin. A literature search was conducted in PubMed (cutoff date 05 March 2018) using the search terms 'hepatic encephalopathy+rifaximin' and 'hepatic encephalopathy+lactulose'. All articles containing primary clinical data were manually assessed to identify studies in which long-term (≥6 months) effectiveness and/or safety/tolerability end points were reported for lactulose and/or rifaximin. Long-term effectiveness outcomes were reported in eight articles for treatment with lactulose alone and 19 articles for treatment with rifaximin, alone or in combination with lactulose. Long-term safety/tolerability outcomes were reported in six articles for treatment with lactulose alone and nine articles for treatment with rifaximin, alone or in combination with lactulose. These studies showed that lactulose is effective for the prevention of overt HE recurrence over the long term and that the addition of rifaximin to lactulose significantly reduces the risk of overt HE recurrence and HE-related hospitalization, compared with lactulose therapy alone, without compromising tolerability. Current evidence therefore supports recommendations for the use of lactulose therapy for the prevention of overt HE recurrence over the long term, and for the additional benefit of adding rifaximin to lactulose therapy. Addition of rifaximin to standard lactulose therapy may result in substantial reductions in healthcare resource utilization over the long term, by reducing overt HE recurrence and associated rehospitalization.

Small intestinal bacterial overgrowth in cirrhosis: systematic review and meta-analysis

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) was detected in cirrhosis in many studies. The aim is to perform a systematic review and meta-analysis on the prevalence of SIBO in cirrhosis and on the relationship of SIBO with features of cirrhosis.

METHODS

PUBMED search (until 14 January 2018) was performed. Specific search terms were: '(cirrhosis) AND (SIBO OR bacterial overgrowth)'. Studies not relating to cirrhosis or SIBO, animal studies, and non-original articles were excluded. A meta-analysis of all studies was performed using a random-effects model.

RESULTS

117 references were identified by the PUBMED search. 3 references were added after handsearching the reference lists of all the articles. 99 references were excluded. 21 studies (included in total 1264 cirrhotics and 306 controls) remained for qualitative analysis and quantitative synthesis. Prevalence of SIBO for cirrhosis was 40.8% (95% CI 34.8-47.1), while the prevalence of SIBO for controls was 10.7% (95% CI 5.7-19.0). OR 6.83 (95% CI 4.16-11.21; p < 0.001). Prevalence of SIBO for decompensated cirrhosis was higher than prevalence of SIBO for compensated cirrhosis (50.5% vs. 31.2%; p < 0.001). SIBO in cirrhosis was associated with ascites (p < 0.001), minimal hepatic encephalopathy (p = 0.001), bacterial translocation (p = 0.026), spontaneous bacterial peritonitis (p = 0.008), prolonged orocecal transit time (p < 0.001), and was not associated with hypocoagulation. Further studies are required to clarify the relationship of SIBO with hyperbilirubinemia, hypoalbuminemia, overt hepatic encephalopathy in past, esophageal varices and systemic inflammation.

CONCLUSION

Small intestinal bacterial overgrowth is more often detected in cirrhosis than in healthy persons and is associated with some features of cirrhosis.

Aloin Inhibits Müller Cells Swelling in a Rat Model of Thioacetamide-Induced Hepatic Retinopathy

Swelling of retinal Müller cells is implicated in retinal edema and neuronal degeneration. Müller cell swelling is observed in patients with liver failure and is referred to as hepatic retinopathy. In the present study, we evaluated the effects of aloin, an anthraquinone-C-glycoside present in various Aloe species, on Müller cell dysfunction in a rat model of thioacetamide (TAA)-induced hepatic retinopathy. Experimental hepatic retinopathy was induced by three injections of TAA (200 mg/kg/day, intraperitoneal injection) for 3 days in rats. After the last injection of TAA, aloin (50 and 100 mg/kg) was orally gavaged for 5 days. The effects of aloin on the liver injury, serum ammonia levels, Müller cell swelling, glial fibrillary acidic protein (GFAP) expression, and gene expression of Kir4.1 and aquaporin-4 were examined. TAA-injected rats exhibited liver failure and hyperammonemia. In the TAA-injected rats, Müller cell bodies were highly enlarged, and GFAP, an indicator of retinal stress, was highly expressed in the retinas, indicating a predominant Müller cell gliosis. However, administration of aloin suppressed liver injury as well as Müller cell swelling through the normalization of Kir4.1 and aquaporin-4 channels, which play a key role in potassium and water transport in Müller cells. These results indicate that aloin may be helpful to protect retinal injury associated with liver failure.

[Prevention and treatment of hepatic encephalopathy]

Hepatic encephalopathy is a common neuropsychiatric complication of serious liver diseases and serves as a marker for worsening of their course and increasing the risk of death. The principal pathogenesis factors of hepatic encephalopathy is the excessive formation of ammonia and its accumulation by astrocytes. A key role in the prevention and treatment of hepatic encephalopathy is played by drugs that prevent hyperammonemia and promote the removal of ammonia from the body, namely lactulose, rifaximin and L-ornithine-L-aspartate. L-ornithine-L-aspartate has proven clinical effectiveness in the treatment of hepatic encephalopathy, prevents the transformation of minimal hepatic encephalopathy into overt forms, increases the tolerability of psychotropic drugs used in the treatment of alcohol dependence, and improves cognitive functions.