Metabolic disorder and functional disturbance in the central executive network in minimal hepatic encephalopathy.

The aim of this paper is to investigate dynamical functional disturbance in central executive network in minimal hepatic encephalopathy and determine its association with metabolic disorder and cognitive impairment. Data of magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging were obtained from 27 cirrhotic patients without minimal hepatic encephalopathy, 20 minimal hepatic encephalopathy patients, and 24 healthy controls. Central executive network was identified utilizing seed-based correlation approach. Dynamic functional connectivity across central executive network was calculated using sliding-window approach. Functional states were estimated by K-means clustering. Right dorsolateral prefrontal cortex metabolite ratios (i.e. glutamate and glutamine complex/total creatine, myo-inositol / total creatine, and choline / total creatine) were determined. Neurocognitive performance was determined by psychometric hepatic encephalopathy scores. Minimal hepatic encephalopathy patients had decreased myo-inositol / total creatine and choline / total creatine and increased glutamate and glutamine complex / total creatine in right dorsolateral prefrontal cortex (all P ≤ 0.020); decreased static functional connectivity between bilateral dorsolateral prefrontal cortex and between right dorsolateral prefrontal cortex and lateral-inferior temporal cortex (P ≤ 0.001); increased frequency and mean dwell time in state-1 (P ≤ 0.001), which exhibited weakest functional connectivity. Central executive network dynamic functional indices were significantly correlated with right dorsolateral prefrontal cortex metabolic indices and psychometric hepatic encephalopathy scores. Right dorsolateral prefrontal cortex myo-inositol / total creatine and mean dwell time in state-1 yielded best potential for diagnosing minimal hepatic encephalopathy. Dynamic functional disturbance in central executive network may contribute to neurocognitive impairment and could be correlated with metabolic disorder.

A neural mass model for disturbance of alpha rhythm in the minimal hepatic encephalopathy.

One of the early markers of minimal hepatic encephalopathy (MHE) is the disruption of alpha rhythm observed in electroencephalogram (EEG) signals. However, the underlying mechanisms responsible for this occurrence remain poorly understood. To address this gap, we develop a novel biophysical model MHE-AWD-NCM, encompassing the communication dynamics between a cortical neuron population (CNP) and an astrocyte population (AP), aimed at investigating the relationship between alpha wave disturbance (AWD) and mechanistical principles, specifically concerning astrocyte-neuronal communication in the context of MHE. In addition, we introduce the concepts of peak power density and peak frequency within the alpha band as quantitative measures of AWD. Our model faithfully reproduces the characteristic EEG phenomenology during MHE and shows how impairments of communication between CNP and AP could promote AWD. The results suggest that the disruptions in feedback neurotransmission from AP to CNP, along with the inhibition of GABA uptake by AP from the extracellular space, contribute to the observed AWD. Moreover, we found that the variation of external excitatory stimuli on CNP may play a key role in AWD in MHE. Finally, the sensitivity analysis is also performed to assess the relative significance of above factors in influencing AWD. Our findings align with the physiological observations and provide a more comprehensive understanding of the complex interplay of astrocyte-neuronal communication that underlies the AWD observed in MHE, which potentially may help to explore the targeted therapeutic interventions for the early stage of hepatic encephalopathy.

Episodic overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt does not increase mortality in patients with cirrhosis.

BACKGROUND & AIMS: Overt hepatic encephalopathy (OHE) is a major complication of transjugular intrahepatic portosystemic shunt (TIPS) placement, given its high incidence and possibility of refractoriness to medical treatment. Nevertheless, the impact of post-TIPS OHE on mortality has not been investigated in a large population. METHODS: We designed a multicenter, non-inferiority, observational study to evaluate the mortality rate at 30 months in patients with and without OHE after TIPS. We analyzed a database of 614 patients who underwent TIPS in three Italian centers and estimated the cumulative incidence of OHE and mortality with competitive risk analyses, setting the non-inferiority limit at 0.12. RESULTS: During a median follow-up of 30 months (IQR 12-30), 293 patients developed at least one episode of OHE. Twenty-seven (9.2%) of them experienced recurrent/persistent OHE. Patients with OHE were older (64 [57-71] vs. 59 [50-67] years, p <0.001), had lower albumin (3.1 [2.8-3.5] vs. 3.25 [2.9-3.6] g/dl, p = 0.023), and had a higher prevalence of pre-TIPS OHE (15.4% vs. 9.0%, p = 0.023). Child-Pugh and MELD scores were similar. The 30-month difference in mortality between patients with and without post-TIPS OHE was 0.03 (95% CI -0.042 to 0.102). Multivariable analysis showed that age (subdistribution hazard ratio 1.04, 95% CI 1.02-1.05, p <0.001) and MELD score (subdistribution hazard ratio 1.09, 95% CI 1.05-1.13, p <0.001), but not post-TIPS OHE, were associated with a higher mortality rate. Similar results were obtained when patients undergoing TIPS for variceal re-bleeding prophylaxis (n = 356) or refractory ascites (n = 258) were analyzed separately. The proportion of patients with persistent OHE after TIPS was significantly higher in the group of patients who died. The robustness of these results was increased following propensity score matching. CONCLUSION: Episodic OHE after TIPS is not associated with mortality in patients undergoing TIPS, regardless of the indication. IMPACT AND IMPLICATIONS: Overt hepatic encephalopathy (OHE) is a common complication in patients with advanced liver disease and it is particularly frequent following transjugular intrahepatic portosystemic shunt (TIPS) placement. In patients with cirrhosis outside the setting of TIPS, the development of OHE negatively impacts survival, regardless of the severity of cirrhosis or the presence of acute-on-chronic liver failure. In this multicenter, non-inferiority, observational study we demonstrated that post-TIPS OHE does not increase the risk of mortality in patients undergoing TIPS, irrespective of the indication. This finding alleviates concerns regarding the weight of this complication after TIPS. Intensive research to improve patient selection and risk stratification remains crucial to enhance the quality of life of patients and caregivers and to avoid undermining the positive effects of TIPS on survival.

A new clinical and prognostic characterization of the patterns of decompensation of cirrhosis.

BACKGROUND & AIMS: The prognostic impact of acute decompensation (AD), i.e. the development of complications that require hospitalization, has recently been assessed. However, complications of cirrhosis do not necessarily require hospitalization and can develop progressively, as in the recently defined non-acute decompensation (NAD). Nevertheless, there is no data regarding the incidence and prognostic impact of NAD. The aim of the study was to evaluate the incidence and the prognostic impact of NAD and AD in outpatients with cirrhosis. METHODS: A total of 617 outpatients with cirrhosis from two Italian tertiary centers (Padua and Milan) were enrolled from January 2003 to June 2021 and followed prospectively until the end of the study, death or liver transplantation. The complications registered during follow-up were considered as AD if they required hospitalization, or NAD if managed at the outpatient clinic. RESULTS: During follow-up, 154 patients (25.0% of total patients) developed complications, 69 patients (44.8%) developed NAD and 85 (55.2%) developed AD, while 29 patients with NAD (42.0%) developed a further episode of AD during follow-up. Sixty-month survival was significantly higher in patients with no decompensation than in patients with NAD or AD. On multivariable analysis, AD (hazard ratio [HR] 21.07, p <0.001), NAD (HR 7.13, p <0.001), the etiological cure of cirrhosis (HR 0.38, p <0.001) and model for end-stage liver disease score (HR 1.12, p = 0.003) were found to be independent predictors of mortality. CONCLUSIONS: The first decompensation is non-acute in almost 50% of outpatients, though such events are still associated with decreased survival compared to no decompensation. Patients who develop NAD must be treated with extreme care and monitored closely to prevent the development of AD. IMPACT AND IMPLICATIONS: This multicenter study is the first to investigate the role of non-acute decompensation (NAD) in patients with cirrhosis. In fact, while the unfavorable impact of acute decompensation is well known, there is currently a dearth of evidence on NAD, despite it being a common occurrence in clinical practice. Our data show that almost half of decompensations in patients with cirrhosis can be considered NAD and that such events are associated with a higher risk of mortality than no decompensation. This study has important clinical implications because it highlights the need to carefully consider patients who develop NAD, in order to prevent further decompensation and reduce mortality.

Small Transjugular Intrahepatic Portosystemic Shunt Plus Variceal Embolization for Gastric Varices: A Multicenter Cohort Study.

BACKGROUND & AIMS: The effect of transjugular intrahepatic portosystemic shunt (TIPS) plus variceal embolization for treating gastric varices (GVs) remains controversial. This nationwide multicenter cohort study aimed to evaluate whether adding variceal embolization to a small diameter (8-mm) TIPS could reduce the rebleeding incidence in patients with different types of GVs. METHODS: This retrospective cohort study involved 629 patients who underwent 8-mm TIPS for gastric varices at 7 medical centers. The primary endpoint was all-cause rebleeding, and the secondary endpoints included overt hepatic encephalopathy (OHE) and all-cause mortality. RESULTS: A total of 629 patients were included. Among them, 429 (68.2%) had gastroesophageal varices type 1 (GOV1), 145 (23.1%) had gastroesophageal varices type 2 (GOV2), and 55 (8.7%) had isolated gastric varices type 1 (IGV1). In the entire cohort, adjunctive embolization reduced rebleeding (6.2% vs 13.6%; P = .005) and OHE (31.0% vs 39.4%; P = .02) compared with TIPS alone. However, no significant differences were found in mortality (12.0% vs 9.7%; P = .42). In patients with GOV2 and IGV1, TIPS plus variceal embolization reduced both rebleeding (GOV2: 7.8% vs 25.1%; P = .01; IGV1: 5.6% vs 30.8%; P = .03) and OHE (GOV2: 31.8% vs 51.5%; P = .008; IGV1: 11.6% vs 38.5%; P = .04). However, in patients with GOV1, adjunctive embolization did not reduce rebleeding (5.9% vs 8.7%; P = .37) or OHE (33.1% vs 35.3%; P = .60). CONCLUSIONS: Compared with TIPS alone, 8-mm TIPS plus variceal embolization reduced rebleeding and OHE in patients with GOV2 and IGV1. These findings suggest that patients with GOV2 and IGV1, rather than GOV1, could benefit from embolization with TIPS.

Minimal hepatic encephalopathy is associated with a higher risk of overt hepatic encephalopathy and poorer survival.

BACKGROUND AND AIMS: Minimal hepatic encephalopathy (MHE) is a frequent complication in patients with liver cirrhosis. Its impact on predicting the development of overt hepatic encephalopathy (OHE) and survival has not been studied in large multicenter studies. METHODS: Data from patients recruited at eight centers across Europe and the United States were analyzed. MHE was detected using the psychometric hepatic encephalopathy score (PHES). A subset was also tested with the simplified animal naming test (S-ANT1). Patients were followed for OHE development and death/liver transplantation (LTx). RESULTS: A total of 1462 patients with a median model of end-stage liver disease of 11 were included (Child-Pugh (CP) stages: A 47%/B 41%/C 12%). Median follow-up time was 19 months, during which 336 (23%) patients developed an OHE episode and 464 (32%) reached the composite end point of death/LTx (369 deaths, 95 LTx). In multivariable analyses, MHE (defined by PHES) was associated with the development of OHE (subdistribution hazard ratio 1.74, p < 0.001) and poorer LTx-free survival (hazard ratio 1.53, p < 0.001) in the total cohort as well as in the subgroup of patients without a history of OHE. In subgroup analyses, MHE (defined by PHES) was associated with OHE development in patients with CP B, whereas there was no association in patients with CP A or C. In the subgroup of patients with available S-ANT1, MHE (defined by S-ANT1) was independently associated with OHE development. Combined testing (PHES+S-ANT1) was superior to single testing for predicting OHE and poorer LTx-free survival. CONCLUSIONS: This large multicenter study demonstrates that screening for MHE is a useful tool for predicting OHE and poorer survival.

Excessive intragastric alcohol administration exacerbates hepatic encephalopathy and provokes neuronal cell death in male rats with chronic liver disease.

Hepatic encephalopathy (HE) is defined as decline in neurological function during chronic liver disease (CLD). Alcohol is a major etiological factor in the pathogenesis of fibrosis/cirrhosis and has also been documented to directly impact the brain. However, the role of alcohol in the development of HE in CLD remains unclear. Here, we investigated the impact of excessive alcohol administration on neurological deterioration in rats with CLD. Starting day 7 post-BDL surgery, rats were administered alcohol twice daily (51% v/v ethanol, 3 g/kg, via gavage) for 4 weeks. Motor coordination was assessed weekly using rotarod and anxiety-like behavior was evaluated with open field and elevated plus maze at 5 weeks. Upon sacrifice, brains were collected for western blot and immunohistochemical analyses to investigate neuronal integrity and oxidative stress status. Alcohol worsened motor coordination performance and increased anxiety-like behavior in BDL rats. Impairments were associated with decreased neuronal markers of NeuN and SMI311, increased apoptotic markers of cleaved/pro-caspase-3 and Bax/Bcl2, increased necroptosis markers of pRIP3 and pMLKL, decreased total antioxidant capacity (TAC), and increased 4-hydroxynonenal (4-HNE)modified proteins in the cerebellum of BDL-alcohol rats when compared to respective controls. Immunofluorescence confirmed the colocalization of cleaved caspase-3 and pMLKL in the granular neurons of the cerebellum of BDL-alcohol rats. Excessive alcohol consumption exacerbates HE which leads to associated apoptotic and necroptotic neuronal loss in the cerebellum of BDL-alcohol rats. Additionally, higher levels of 4-HNE and decreased TAC in the cerebellum of BDL-alcohol rats suggest oxidative stress is the triggering factor of apoptotic and necroptotic neuronal loss/injury.

Improved cognition after rifaximin treatment is associated with changes in intra- and inter-brain network functional connectivity.

BACKGROUND: Rifaximin is a non-reabsorbable antibiotic which acts at gut level, and improves cognition and inflammatory parameters in minimal hepatic encephalopathy (MHE) patients, but not all patients show the same level of response. This study aims to assess brain activity, both within and between brain networks, following rifaximin treatment, considering the differences between response groups as well. METHODS: Twenty-two healthy controls and 53 patients with cirrhosis (22 without and 31 with MHE, diagnosed by Psychometric Hepatic Encephalopathy Score, PHES) performed psychometric, attention and coordination tests, and blood inflammatory parameters were measured. Resting-state functional magnetic resonance imaging (fMRI) acquisitions were performed on controls and MHE patients. Eighteen MHE patients underwent a rifaximin treatment for 6 months, after which all measures were repeated. fMRI images were analysed and changes after treatment were assessed. RESULTS: After rifaximin treatment, 13 patients improved their PHES score (Responder patients) while 5 did not (Non-responder patients). No significant decrease in blood ammonia was observed after rifaximin treatment, but there was a decrease in plasma inflammatory cytokines in responder patients. A global effect of rifaximin was detected on the sensorimotor and fronto-parietal networks. Responder patients showed a relative increase of thalamic network connectivity in comparison to non-responder patients. Before treatment, responder and non-responder patients showed connectivity differences in basal ganglia network. The connection of the sensorimotor and thalamic networks between them and with other networks suffered changes after treatment. These connections between networks mostly decreased after treatment. All changes and differences showed a significant level of correlation with the performance of psychometric tests and the blood levels of inflammatory biomarkers. CONCLUSIONS: There was an improvement of the communication between executive, motor and attention-related brain areas, and their functional independence following rifaximin treatment. Patients who respond also show a less deteriorated connection involved in these functions before treatment. Results suggest that the improved inflammatory state of MHE patients, following rifaximin treatment would favour the observed changes in brain function and enhanced cognitive performance.

Systematic review of the role of calprotectin in cirrhosis.

BACKGROUND: Calprotectin is a calcium-binding-S100-protein synthetized mainly in neutrophils which has been demonstrated to be an accurate biomarker of the presence of these cells. Gut barrier dysfunction in patients with advanced chronic liver disease (ACLD), in addition to the lack of noninvasive tools for diagnosis and prognosis of cirrhosis decompensations, has raised interest in this biomarker. AIMS: Our aim is to summarize the current evidence regarding the role of calprotectin in terms of its diagnostic and prognostic utility in ACLD. METHODS: We performed a systematic search (PROSPERO registration no. CRD42023389069) of original articles published without any restrictions on the publication date until January 2023 providing information about calprotectin for the prognosis or diagnosis of ACLD and its decompensations in adult patients. RESULTS: A total 227 articles were identified, and 26 observational studies finally met the inclusion criteria. In 14 studies, calprotectin was measured in ascitic fluid, all of which reported higher calprotectin values in spontaneous bacterial peritonitis, while cut-off points for its diagnosis were proposed in nine studies. Three studies reported higher faecal calprotectin levels in patients with hepatic encephalopathy and portal hypertension. Four studies evaluated faecal calprotectin and one plasma calprotectin as biomarkers for gut barrier integrity and bacterial translocation. CONCLUSIONS: Calprotectin is emerging as a promising biomarker in ACLD, particularly for the management of bacterial infections and alcohol-related liver disease. Further research with better study designs should help to determine the feasibility of calprotectin measurement in routine clinical practice.

Long-term albumin improves the outcomes of patients with decompensated cirrhosis and diabetes mellitus: Post hoc analysis of the ANSWER trial.

Type-2 diabetes mellitus is a frequent comorbidity of cirrhosis independently associated with cirrhosis-related complications and mortality. This post hoc analysis of the ANSWER trial database assessed the effects of long-term human albumin (HA) administration on top of the standard medical treatment (SMT) on the clinical outcomes of a subgroup of 85 outpatients with liver cirrhosis, uncomplicated ascites and insulin-treated diabetes mellitus type 2 (ITDM). Compared to patients in the SMT arm, the SMT + HA group showed a better overall survival (86% vs. 57%, p = .016) and lower incidence rates of paracenteses, overt hepatic encephalopathy, bacterial infections, renal dysfunction and electrolyte disorders. Hospital admissions did not differ between the two arms, but the number of days spent in hospital was lower in the SMT + HA group. In conclusion, in a subgroup of ITDM outpatients with decompensated cirrhosis and ascites, long-term HA administration was associated with better survival and a lower incidence of cirrhosis-related complications.

Predictors of clinical trajectories of patients with acutely decompensated cirrhosis. An external validation of the PREDICT study.

BACKGROUND AND AIMS: The PREDICT study recently showed that acutely decompensated (AD) patients with cirrhosis can present three different clinical phenotypes in the 90 days after admission: (1) pre-ACLF, developing acute-on-chronic liver failure (ACLF); (2) unstable decompensated cirrhosis (UDC), being re-admitted for AD without ACLF and (3) stable decompensated cirrhosis (SDC), not presenting readmission or ACLF. This study aimed to externally validate the existence of these three distinct trajectories and to identify predictors for the occurrence of each trajectory. METHODS: Baseline data, 3-month ACLF and readmission incidence and 1-year survival were analysed in a prospective cohort of patients admitted for AD. A multinomial multivariable model was used to evaluate the association between baseline features and clinical trajectories. RESULTS: Of the 311 patients enrolled, 55% met the criteria for SDC, 18% for UDC and 27% for pre-ACLF, presenting a significantly different 1-year mortality: pre-ACLF 65%, UDC 46%, SDC 21% (p < .001). The presence of hepatic encephalopathy (HE) was associated with UDC (p = .043), while the absence of ascites to SDC (p = .017). Among laboratory parameters, an increase in MELD-Na (p = .001) and C-reactive protein (p = .009) and a decrease in haemoglobin (p = .004) and albumin (p = .008) levels were associated with pre-ACLF. CONCLUSION: The present study confirms that AD patients have three different clinical trajectories with different mortality rates. Besides the severity of cirrhosis, the association with C-reactive protein supports the predominant role of systemic inflammation in ACLF pathophysiology. Finally, HE is associated with the UDC phenotype highlighting the need for better management of this complication after discharge.

Elucidating hippocampal proteome dynamics in moderate hepatic encephalopathy rats: insights from high-resolution mass spectrometry.

Hepatic encephalopathy (HE) is a debilitating neurological disorder associated with liver failure and characterized by impaired brain function. Decade-long studies have led to significant advances in our understanding of HE; however, effective therapeutic management of HE is lacking, and HE continues to be a significant cause of morbidity and mortality in patients, underscoring the need for continued research into its pathophysiology and treatment. Accordingly, the present study provides a comprehensive overview aimed at elucidating the molecular underpinnings of HE and identifying potential therapeutic targets. A moderate-grade HE model was induced in rats using thioacetamide, which simulates the liver damage observed in patients, and its impact on cognitive function, neuronal arborization, and cellular morphology was also evaluated. We employed label-free LC-MS/MS proteomics to quantitatively profile hippocampal proteins to explore the molecular mechanism of HE pathogenesis; 2175 proteins were identified, 47 of which exhibited significant alterations in moderate-grade HE. The expression of several significantly upregulated proteins, such as FAK1, CD9 and Tspan2, was further validated at the transcript and protein levels, confirming the mass spectrometry results. These proteins have not been previously reported in HE. Utilizing Metascape, a tool for gene annotation and analysis, we further studied the biological pathways integral to brain function, including gliogenesis, the role of erythrocytes in maintaining blood-brain barrier integrity, the modulation of chemical synaptic transmission, astrocyte differentiation, the regulation of organ growth, the response to cAMP, myelination, and synaptic function, which were disrupted during HE. The STRING database further elucidated the protein‒protein interaction patterns among the differentially expressed proteins. This study provides novel insights into the molecular mechanisms driving HE and paves the way for identifying novel therapeutic targets for improved disease management.

Preventive and therapeutic effects of rifaximin on hepatic encephalopathy with differential application dosages and strategies: a network meta-analysis.

BACKGROUND: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that affects the prognosis of patients with liver disease and is considered an independent risk factor for hospitalization and death. Rifaximin has been approved for HE treatment. This review will analyze the effect of rifaximin on different stages of HE with differential application dosages and strategies by traditional and network meta-analyses. METHODS: We performed a systematic search of PubMed, EmBase, and Cochrane Library databases up to February 26, 2023, to identify randomized controlled trials (RCTs) about rifaximin for the prevention and treatment of HE. The outcomes included incidence of HE and HE progression, HE reversal, mortality, and adverse effects. RESULTS: A total of 21 studies were included. In the primary prevention of HE, rifaximin significantly reduced the incidence of HE (OR: 0.66; 95% CI: 0.45, 0.96; p = 0.032). In secondary prevention, rifaximin significantly reduced the risk of recurrence in patients who were in remission (OR: 0.38; 95% CI: 0.28, 0.52; p < 0.001). In the treatment of minimal HE, rifaximin significantly reduced the breakthrough of MHE to OHE (OR: 0.17; 95% CI: 0.04,0.63; p = 0.008). Rifaximin also significantly improved the clinical symptoms of MHE and OHE patients (OR: 3.76; 95% CI: 2.69, 5.25; p < 0.001). However, rifaximin did not reduce mortality at any stage in HE patients (OR: 0.79; 95% CI: 0.58, 1.08; p = 0.133). Additionally, rifaximin did not increase the risk of adverse effects (OR: 0.96; 95% CI: 0.74, 1.24; p = 0.749). In the network meta-analysis, the 400 mg T.I.D. intervention had a relative advantage for HE risks in primary and secondary prevention. In the treatment of MHE, 600 mg b.i.d. was superior in preventing the breakthrough from MHE to OHE. CONCLUSION: Rifaximin prevented HE risks and progression and improved clinical symptoms in patients with MHE but did not reduce mortality. For primary and secondary prevention, 400 mg t.i.d. could be considered. 600 mg b.i.d. could be considered in patients with MHE.

Possible pathogenetic role of ammonia in liver cirrhosis without hyperammonemia of venous blood: The so-called latency period of abnormal ammonia metabolism.

Ammonia plays a crucial role in the pathogenesis of hepatic encephalopathy. Ammonia is also involved in many other pathological conditions seen in cirrhosis, such as sarcopenia, liver fibrosis, hepatocellular injury, immune dysfunction, and hyperammonemia. Furthermore, the ammonia level of the veins is a useful prognostic factor for cirrhosis. In cirrhosis without hyperammonemia of the vein, however, covert hepatic encephalopathy has been reported. This discrepancy is because of the anatomical features of ammonia metabolism. There are two systems in the body for detoxifying ammonia: one is the urea cycle in the liver, and the other is the glutamine synthesis pathway in skeletal muscle and other tissues. The blood processed in the liver's urea cycle is then transported via arteries to various organs. Further processing occurs in the brain and skeletal muscle's glutamine synthesis pathway before entering the veins. When the urea cycle function decreases in cirrhosis, the ammonia levels in the artery increase. In response, the glutamine synthesis pathway compensates by increasing the capacity to process ammonia. Therefore, the ammonia concentration in the veins downstream of skeletal muscles does not increase immediately. However, the brain and skeletal muscles, which receive arterial blood, might be exposed to high ammonia concentrations. In addition, branched-chain amino acids in venous blood decrease. This period is the transition phase from early- to late-phase cirrhosis, and understanding the pathophysiology during this stage is extremely important for preventing the progression of cirrhosis.

Nutritional management for acute liver failure.

Acute liver failure (ALF) induces increased energy expenditure and disrupts the metabolism of essential nutrients. Hepatic encephalopathy is a complication of ALF with a poor prognosis and mainly involves the metabolic disturbance of amino acids in its pathogenesis. In this review, we discuss the nutritional management for ALF in consideration of the pathophysiology of ALF with respect to the impairment of hepatocyte function. It is known that enteral nutrition is recommended for patients with ALF, while parenteral nutrition is recommended for patients who cannot tolerate enteral nutrition. As ALF leads to a hypermetabolic state, the energy intake is recommended to cover 1.3 times the resting energy expenditure. Because of the high risk of hypoglycemia associated with disturbances in glucose metabolism, substantial glucose intake is recommended. Along with the deterioration of glucose metabolism, protein metabolism is also disrupted. As patients with ALF have increased systemic protein catabolism together with decreased protein synthesis, appropriate amounts of amino acids or protein under monitoring serum ammonia levels are recommended. In conclusion, nutritional management based on the understanding of nutritional pathophysiology is a pivotal therapeutic approach for patients with ALF. The approach should be individualized in the acute phase, the recovery phase, and the pretransplant phase.

The restoration of hippocampal nerve de-myelination by methylcobalamin relates with the enzymatic regulation of homocysteine level in a rat model of moderate grade hepatic encephalopathy.

This article describes how methylcobalamin (MeCbl) restores nerve myelination in a moderate- grade hepatic encephalopathy (MoHE) model of ammonia neurotoxicity. The comparative profiles of myelin basic protein (MBP), homocysteine (Hcy) and methionine synthase (MS: a MeCbl- dependent enzyme) activity versus nerve myelination status were studied in the hippocampus of the control, the MoHE (developed by administering 100 mg/kg bw thioacetamide i.p. for 10 days) and the MoHE rats treated with MeCbl (500 µg/kg BW i.p.) for 7 days. Compared to those of control rats, the hippocampal CA1 and CA3 regions of the MoHE rats showed significantly lower myelinated areas and MBP immunostaining. This coincided with the deranged myelin layering in TEM images, decreased MBP protein and its transcript levels in hippocampus of MoHE rats. However, all these parameters recovered to normal levels after MeCbl treatment. MeCbl is a cofactor of MS that catalyzes the conversion of Hcy to methionine as a feeder step of methylation reactions. We observed significantly increased serum and hippocampal Hcy levels in MoHE rats, however, these levels were restored to control values with a concordant activation of MS due to MeCbl treatment. A significant recovery in neurobehavioral impairments in the MoHE rats due to MeCbl treatment was also observed. These findings suggest that MoHE pathogenesis is associated with deranged nerve myelination in the hippocampus and that MeCbl treatment is able to restore it mainly by activating MS, a MeCbl-dependent Hcy-metabolizing enzyme.

Disparity Among African Americans in Transjugular Intrahepatic Portosystemic Shunt Procedure: A National Inpatient Sample Analysis from 2015 to 2020.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is a procedure used to alleviate patients with chronic liver cirrhosis and portal hypertension. Racial disparities were present in TIPS where numerous studies suggested African American patients experience higher in-hospital mortality rates. However, the incidence of post-TIPS surgical complications, such as HE, has yet to be examined among African Americans. Therefore, this study aimed to provide a comprehensive examination of the disparities in TIPS procedures among African American patients. METHODS: The study compared African American and Caucasian patients who underwent TIPS procedures in the National Inpatient Sample (NIS) database from the last quarter of 2015-2020 after ICD-10 change. Preoperative variables, including demographics, comorbidities, primary payer status, and hospital characteristics, were examined and multivariable analysis was used to assess outcomes correcting preoperative variables with p < 0.1. RESULTS: Compared to Caucasians, African Americans had higher in-hospital mortality (16.18 vs 8.22%, aOR 1.781, p < 0.01), hepatic encephalopathy (33.09 vs 27.44%, aOR 1.300, p = 0.05), and acute kidney injury (45.59 vs 29.60%, aOR 2.019, p < 0.01). Using the generalized linear model, African Americans have longer length of stay (11.04 ± 0.77 days vs 8.54 ± 0.16 days, p < 0.01). CONCLUSION: Despite a higher prevalence of cirrhosis, African Americans continue to have marked underrepresentation in TIPS procedures in recent years. Their underrepresentation, in conjunction with higher mortality, morbidity, and increased comorbidity conditions, could imply disparity in accessing care. This finding underscores the necessity for improved access to diagnostic and therapeutic services for African Americans with liver cirrhosis.

A Prospective Multimodal Education Intervention for Providers Does Not Increase Hepatic Encephalopathy Treatment Rates.

BACKGROUND: Over 50% of hospitalizations from hepatic encephalopathy (HE) are preventable, but patients often do not receive medical treatment. AIMS: To use a multimodal education intervention (MMEI) to increase HE treatment rates and to evaluate (1) trends in HE treatment, (2) predictors of receiving treatment, and (3) the impact of treatment on hospitalization outcomes. METHODS: Prospective single-center cohort study of patients hospitalized with HE from April 1, 2020-September 30, 2022. The first 15 months were a control ("pre-MMEI"), the subsequent 15 months (MMEI) included three phases: (1) prior authorization resources, (2) electronic order set, and (3) in-person provider education. Treatment included receiving any drug (lactulose or rifaximin), or combination therapy. Treatment rates pre- vs. post-MMEI were compared using logistic regression. RESULTS: 471 patients were included. There were lower odds of receiving any drug post-MMEI (p = 0.03). There was no difference in receiving combination therapy pre- or post-MMEI (p = 0.32). Predictors of receiving any drug included alcohol-related or cryptogenic cirrhosis (p's < 0.001), and the presence of ascites (p = 0.005) and/or portal hypertension (p = 0.003). The only significant predictor of not receiving any drug treatment was having autoimmune cirrhosis (p < 0.001). Patients seen by internal medicine (p = 0.01) or who were intoxicated (p = 0.02) were less likely to receive rifaximin. Any treatment was associated with higher 30-day liver disease-specific readmission (p < 0.001). CONCLUSION: This MMEI did not increase HE treatment rates, suggesting that alternative strategies are needed to identify and address barriers to treatment.

Extracellular vesicles from hyperammonemic rats induce neuroinflammation in hippocampus and impair cognition in control rats.

Patients with liver cirrhosis show hyperammonemia and peripheral inflammation and may show hepatic encephalopathy with cognitive impairment, reproduced by rats with chronic hyperammonemia. Peripheral inflammation induces neuroinflammation in hippocampus of hyperammonemic rats, altering neurotransmission and leading to cognitive impairment. Extracellular vesicles (EVs) may transmit pathological effects from the periphery to the brain. We hypothesized that EVs from peripheral blood would contribute to cognitive alterations in hyperammonemic rats. The aims were to assess whether EVs from plasma of hyperammonemic rats (HA-EVs) induce cognitive impairment and to identify the underlying mechanisms. Injection of HA-EVs impaired learning and memory, induced microglia and astrocytes activation and increased TNFα and IL-1ß. Ex vivo incubation of hippocampal slices from control rats with HA-EVs reproduced these alterations. HA-EVs increased membrane expression of TNFR1, reduced membrane expression of TGFßR2 and Smad7 and IκBα levels and increased IκBα phosphorylation. This led to increased activation of NF-κB and IL-1ß production, altering membrane expression of NR2B, GluA1 and GluA2 subunits, which would be responsible for cognitive impairment. All these effects of HA-EVs were prevented by blocking TNFα, indicating that they were mediated by enhanced activation of TNFR1 by TNFα. We show that these mechanisms are very different from those leading to motor incoordination, which is due to altered GABAergic neurotransmission in cerebellum. This demonstrates that peripheral EVs play a key role in the transmission of peripheral alterations to the brain in hyperammonemia and hepatic encephalopathy, inducing neuroinflammation and altering neurotransmission in hippocampus, which in turn is responsible for the cognitive deficits.

Increased levels and activation of the IL-17 receptor in microglia contribute to enhanced neuroinflammation in cerebellum of hyperammonemic rats.

BACKGROUND: Patients with liver cirrhosis may show minimal hepatic encephalopathy (MHE) with mild cognitive impairment and motor incoordination. Rats with chronic hyperammonemia reproduce these alterations. Motor incoordination in hyperammonemic rats is due to increased GABAergic neurotransmission in cerebellum, induced by neuroinflammation, which enhances TNFα-TNFR1-S1PR2-CCL2-BDNF-TrkB pathway activation. The initial events by which hyperammonemia triggers activation of this pathway remain unclear. MHE in cirrhotic patients is triggered by a shift in inflammation with increased IL-17. The aims of this work were: (1) assess if hyperammonemia increases IL-17 content and membrane expression of its receptor in cerebellum of hyperammonemic rats; (2) identify the cell types in which IL-17 receptor is expressed and IL-17 increases in hyperammonemia; (3) assess if blocking IL-17 signaling with anti-IL-17 ex-vivo reverses activation of glia and of the TNFα-TNFR1-S1PR2-CCL2-BDNF-TrkB pathway. RESULTS: IL-17 levels and membrane expression of the IL-17 receptor are increased in cerebellum of rats with hyperammonemia and MHE, leading to increased activation of IL-17 receptor in microglia, which triggers activation of STAT3 and NF-kB, increasing IL-17 and TNFα levels, respectively. TNFα released from microglia activates TNFR1 in Purkinje neurons, leading to activation of NF-kB and increased IL-17 and TNFα also in these cells. Enhanced TNFR1 activation also enhances activation of the TNFR1-S1PR2-CCL2-BDNF-TrkB pathway which mediates microglia and astrocytes activation. CONCLUSIONS: All these steps are triggered by enhanced activation of IL-17 receptor in microglia and are prevented by ex-vivo treatment with anti-IL-17. IL-17 and IL-17 receptor in microglia would be therapeutic targets to treat neurological impairment in patients with MHE.