Hepatic encephalopathy as a complication of liver disease

Pattern Clustering of Symmetric Regional Cerebral Edema on Brain MRI in Patients with Hepatic Encephalopathy

Purpose

Metabolic abnormalities in hepatic encephalopathy (HE) cause brain edema or demyelinating disease, resulting in symmetric regional cerebral edema (SRCE) on MRI. This study aimed to investigate the usefulness of the clustering analysis of SRCE in predicting the development of brain failure.

Materials and Methods

MR findings and clinical data of 98 consecutive patients with HE were retrospectively analyzed. The correlation between the 12 regions of SRCE was calculated using the phi (Φ) coefficient, and the pattern was classified using hierarchical clustering using the φ2 distance measure and Ward's method. The classified patterns of SRCE were correlated with clinical parameters such as the model for end-stage liver disease (MELD) score and HE grade.

Results

Significant associations were found between 22 pairs of regions of interest, including the red nucleus and corpus callosum (Φ = 0.81, p < 0.001), crus cerebri and red nucleus (Φ = 0.72, p < 0.001), and red nucleus and dentate nucleus (Φ = 0.66, p < 0.001). After hierarchical clustering, 24 cases were classified into Group I, 35 into Group II, and 39 into Group III. Group III had a higher MELD score (p = 0.04) and HE grade (p = 0.002) than Group I.

Conclusion

Our study demonstrates that the SRCE patterns can be useful in predicting hepatic preservation and the occurrence of cerebral failure in HE.

Psychometric tests, critical flicker frequency, and inflammatory indicators in covert hepatic encephalopathy diagnosis

Background and Aim

Hepatic encephalopathy (HE) is a frequent complication of liver diseases. Systemic inflammation is key for HE pathogenesis. The main goal of the study was to investigate the role of psychometric tests, critical flicker frequency (CFF), and comparative evaluation of inflammatory indicators for the diagnosis of covert HE (CHE).

Materials and Methods

The study was a prospective, nonrandomized, case-control study with a total of 76 cirrhotic patients and 30 healthy volunteers. The West Haven criteria were used to determine the occurrence of CHE in cirrhotic patients. Psychometric tests were applied to healthy and cirrhotic groups. CFF, venous ammonia, serum endotoxin, IL-6, IL-18, tumor necrosis factor alpha (TNF-α) levels, and hemogram parameters were evaluated for cirrhotic patients.

Results

CFF values and psychometric tests were found to accurately discriminate CHE positives from CHE negatives (p<0.05). When the control group was excluded, the digit symbol test and the number connection A test failed, unlike CFF and other psychometric tests. Using CFF, a 45 Hz cutoff value had 74% specificity and 75% sensitivity. Basal albumin levels (p=0.063), lymphocyte-to-monocyte ratio (LMR) (p=0.086), and neutrophil-to-lymphocyte ratio (p 0.052) were significant, albeit slightly, among CHE groups. Basal albumin levels had 50% sensitivity and 71% specificity when 2.8 g/dL was used as a cutoff value to determine CHE.

Conclusion

Both psychometric tests and CFF can be useful in diagnosing CHE. Using cytokine and endotoxin levels seems to be inadequate to diagnose CHE. Using LMR and albumin levels instead of psychometric tests for diagnosing CHE can be promising.

Host-microbiome interactions: Gut-Liver axis and its connection with other organs

An understanding of connections between gut microbiome and liver has provided important insights into the pathophysiology of liver diseases. Since gut microbial dysbiosis increases gut permeability, the metabolites biosynthesized by them can reach the liver through portal circulation and affect hepatic immunity and inflammation. The immune cells activated by these metabolites can also reach liver through lymphatic circulation. Liver influences immunity and metabolism in multiple organs in the body, including gut. It releases bile acids and other metabolites into biliary tract from where they enter the systemic circulation. In this review, the bidirectional communication between the gut and the liver and the molecular cross talk between the host and the microbiome has been discussed. This review also provides details into the intricate level of communication and the role of microbiome in Gut-Liver-Brain, Gut-Liver-Kidney, Gut-Liver-Lung, and Gut-Liver-Heart axes. These observations indicate a complex network of interactions between host organs influenced by gut microbiome.

Role of interleukin-23 in monocyte-derived dendritic cells of HBV-related acute-on-chronic liver failure and its correlation with the severity of liver damage

BACKGROUND

The role of interleukin-23 (IL-23) in monocyte-derived dendritic cells (MoDCs) from hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients remains unclear. The aim of this study was to observe the correlation between the activation of the IL-23 signaling pathway and the prognosis of HBV-ACLF patients.

MATERIALS AND METHODS

The baseline levels of serum IL-6, IL-12, IL-17, IL-23, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) from immune tolerant (IT), chronic hepatitis B (CHB), HBV-ACLF patients and healthy individuals who served as healthy controls (HCs) were analyzed using the Luminex system, whereas serum IL-23 from HBV-ACLF patients was measured by ELISA before and after treatment. Purified monocytes were isolated from peripheral blood and were induced into MoDCs, IL-23, IL-23R, NF-κB and TRAF6 expression in MoDCs from 4 groups was analyzed using real-time PCR, and IL-23R and intracellular IL-23 were evaluated by flow cytometry.

RESULTS

Serum IL-6, IL-12, IL-17, IL-23 and TNF-α levels were upregulated in HBV-ACLF patients compared with IT patients, CHB patients and HCs (P<0.05 for all). Serum IL-23 was closely correlated with elevated serum IL-17 in HBV-ACLF patients (r=0.5935, P<0.0001). Moreover, IL-23 and IL-23R levels were significantly upregulated in MoDCs from patients with CHB or HBV-ACLF compared with HCs, and further upregulation of IL-23 and IL-23R was observed in HBV-ACLF patients compared to CHB patients (P<0.05 for all). IL-23 expression was markedly enhanced and was correlated with elevated NF-κB and TRAF6 in MoDCs from HBV-ACLF patients (P<0.05 for both). Linear correlation analysis demonstrated significant correlations between the expression of IL-23 and disease severity markers (MELD scoring system, international normalized ratio, prothrombin time and total bilirubin, r=0.6874, r=0.6475, r=0.6249, r=0.3771, respectively, P<0.05 for all) for individual HBV-ACLF patients, and IL-23 levels were significantly upregulated in non-survival HBV-ACLF patients compared with survival HBV-ACLF patients (P<0.05).

CONCLUSION

IL-23 in serum and MoDCs is significantly elevated in HBV-ACLF patients, TRAF6/NF-κB may play a role in IL-23 production by MoDCs in HBV-ACLF patients and high pre-treatment IL-23 levels in MoDCs are associated with mortality in HBV-ACLF patients.

Pathological role for exocytotic glutamate release from astrocytes in hepatic encephalopathy

Liver failure can lead to generalized hyperammonemia, which is thought to be the underlying cause of hepatic encephalopathy. This neuropsychiatric syndrome is accompanied by functional changes of astrocytes. These glial cells enter ammonia-induced self-amplifying cycle characterized by brain oedema, oxidative and osmotic stress that causes modification of proteins and RNA. Consequently, protein expression and function are affected, including that of glutamine synthetase and plasmalemmal glutamate transporters, leading to glutamate excitotoxicity; Ca²⁺-dependent exocytotic glutamate release from astrocytes contributes to this extracellular glutamate overload.

Management of hepatic encephalopathy by traditional chinese medicine

In spite of the impressive progress in the investigation of hepatic encephalopathy (HE), the complex mechanisms underlying the onset and deterioration of HE are still not fully understood. Currently, none of the existing theories provide conclusive explanations on the symptoms that link liver dysfunction to nervous system disorders and clinical manifestations. This paper summarized the diagnostic and therapeutic approaches used for HE in modern medicine and traditional Chinese medicine and provided future perspective in HE therapies from the viewpoint of holistic and personalized Chinese medicine.

Manganese accumulation in the CNS and associated pathologies

Manganese (Mn) is an essential metal for life. It is a key constituent of clue enzymes in the central nervous system, contributing to antioxidant defenses, energetic metabolism, ammonia detoxification, among other important functions. Until now, Mn transport mechanisms are partially understood; however, it is known that it shares some mechanisms of transport with iron. CNS is susceptible to Mn toxicity because it possesses mechanisms that allow Mn entry and favor its accumulation. Cases of occupational Mn exposure have been extensively reported in the literature; however, there are other ways of exposure, such as long-term parental nutrition and liver failure. Manganism and hepatic encephalopathy are the most common pathologies associated with the effects of Mn exposure. Both pathologies are associated with motor and psychiatric disturbances, related in turn to mechanisms of damage such as oxidative stress and neurotransmitters alterations, the dopaminergic system being one of the most affected. Although manganism and Parkinson's disease share some characteristics, they differ in many aspects that are discussed here. The mechanisms for Mn transport and its participation in manganism and hepatic encephalopathy are also considered in this review. It is necessary to find an effective therapeutic strategy to decrease Mn levels in exposed individuals and to treat Mn long term effects. In the case of patients with chronic liver failure it would be worthwhile to test a low-Mn diet in order to ameliorate symptoms of hepatic encephalopathy possibly related to Mn accumulation.

Correlation of the expression of toll-like receptors in monocyte-derived dendritic cells with prognosis of chronic severe hepatitis B

OBJECTIVE

This study aims to measure the expression of toll-like receptors (TLR) in monocyte-derived dendritic cells (MoDC) from chronic severe hepatitis B (CSHB), to assess the contribution of TLRs in CSHB.

METHODS

Peripheral blood was collected from 40 CSHB patients, 30 chronic hepatitis B (CHB) patients, and 30 healthy individuals who served as healthy controls (HCs). Purified monocytes were isolated by a combination of Histopaque-1.077 and CD14 Microbeads. MoDCs were induced with granulocyte macrophage colony-stimulating factor and interleukin-4 for 6 days from CD14(+) monocytes. The expression of TLRs in MoDC was measured using real-time PCR and flow cytometry.

RESULTS

The expressions of TLR-1, -2, -7 were significantly higher in MoDC of CSHB than that of HCs, of which the level of TLR-3 was decreased. Particularly in CSHB patients, the TLR-3 expression was further decreased compared to CHB patients. In non-survival CSHB patients, TLR-3 level was significantly decreased, while TLR-2 expression was dramatically increased. Linear correlation analysis demonstrated significant correlations between TLR-3 level and disease severity markers (total bilirubin, prothrombin activity, creatinine, white blood cell count, and maximum volume of ascitic fluid) in individual CSHB patients.

CONCLUSIONS

TLR-2 and TLR-3 may be involved in the pathogenesis of CSHB, and TLR-3 may influence the prognosis of CSHB.

Morphological changes of rat astrocytes induced by liver damage but not by manganese chloride exposure

Liver cirrhosis is a common cause of death around the world. One of its more severe complications is hepatic encephalopathy. As a consequence of liver impairment, manganese (Mn) and other substances accumulate in the brain. Astrocytic morphological changes have been found in postmortem brains of cirrhotic patients. In this study we used a model of cirrhosis induced by bile duct ligation and Mn accumulation by exposing rats to MnCl(2) (1 mg Mn/ml) in their drinking water. Four experimental groups were used: Sham, Sham plus Mn treatment, BDL (bile duct ligated) and BDL plus Mn treatment. Brain Mn was measured by atomic absorption spectrophotometry in cortex, striatum and globus pallidus. Altered and normal astrocytes were counted in the same brain areas. Brain Mn was highest in rats of the BDLMn group. An increased number of altered astrocytes was found only in BDL groups, Mn did not modify this effect. No changes were found in the total number of astrocytes. According to our results, biliary obstruction induced an increase in the number of altered astrocytes since early stages of cirrhosis and Mn did not affect this effect.

An overview of psychiatric issues in liver disease for the consultation-liaison psychiatrist

Liver disease is a common cause of morbidity and mortality in the United States and elsewhere. Arising from infectious, hereditary, or toxin-induced sources, the detection of liver disease often requires a high index of suspicion. Clinical presentations are highly variable and are often accompanied by neuropsychiatric symptoms. This fact, along with an increased incidence of liver disease among patients with primary psychiatric disorders and the presence of varied drug use, complicates the tasks of providing care to patients with liver disease. To assist the consultation-liaison psychiatrist, the authors present the first of a two-part series focused on psychiatric issues in liver disease.

Altered blood-brain barrier permeability in rats with prehepatic portal hypertension turns to normal when portal pressure is lowered

AIM

To study the blood-brain barrier integrity in prehepatic portal hypertensive rats induced by partial portal vein ligation,at 14 and 40 d after ligation when portal pressure is spontaneously normalized.

METHODS

Adult male Wistar rats were divided into four groups: Group I: Sham14d , sham operated; Group II: PH14d , portal vein stenosis; (both groups were used 14 d after surgery); Group III: Sham40d, Sham operated and Group IV: PH40d Portal vein stenosis (Groups II and IV used 40 d after surgery). Plasma ammonia,plasma and cerebrospinal fluid protein and liver enzymes concentrations were determined. Trypan and Evans blue dyes, systemically injected,were investigated in hippocampus to study blood-brain barrier integrity. Portal pressure was periodically recorded.

RESULTS

Forty days after stricture, portal pressure was normalized, plasma ammonia was moderately high, and both dyes were absent in central nervous system parenchyma. All other parameters were reestablished. When portal pressure was normalized and ammonia level was lowered, but not normal, the altered integrity of blood-brain barrier becomes reestablished.

CONCLUSION

The impairment of blood-brain barrier and subsequent normalization could be a mechanism involved in hepatic encephalopathy reversibility.Hemodynamic changes and ammonia could trigger blood-brain barrier alterations and its reestablishment.

Improvement of regional cerebral blood flow after oral intake of branched-chain amino acids in patients with cirrhosis

AIM: To evaluate the effect of oral intake of branched-chain amino acids (BCAA) on brain perfusion in patients with liver cirrhosis.

METHODS: Single photon emission computed tomography scans were performed in 43 patients with cirrhosis and in 15 age-matched healthy subjects. Twenty-nine out of forty-three patients were randomly treated with either BCAA granules or placebo, and single photon emission computed tomography was performed before and after the treatment. We measured the regional cerebral blood flow values using a three-dimensional stereotaxic region of interest template.

RESULTS: Cirrhotic patients had regions of significant hypoperfusion in the bilateral central (right P = 0.039, P<0.05; left P = 0.006 P<0.01), parietal (right P = 0.018, P<0.05; left P = 0.009, P<0.01), angular (right P = 0.039, P<0.05; left P = 0.008, P<0.01), and left pericallosal segments (P = 0.038 P<0.05) as compared with healthy subjects. A significant increase in cerebral perfusion was observed 70 min after the oral intake of BCAA in the angular (right P = 0.012, P<0.05; left P = 0.049, P<0.05), temporal (right P = 0.012, P<0.05; left P=0.038, P<0.05), pericallosal segments (right P = 0.025, P<0.05; left P = 0.049, P<0.05) and left precentral (P = 0.044, P<0.05), parietal (P = 0.040, P<0.05) and thalamus (P = 0.033, P<0.05). No significant change in perfusion was observed in the placebo group.

CONCLUSION: Administration of BCAA rapidly improves cerebral perfusion.

Chronic exposure to ammonia alters the modulation of phosphorylation of microtubule-associated protein 2 by metabotropic glutamate receptors 1 and 5 in cerebellar neurons in culture

Hyperammonemia impairs signal transduction associated to glutamate receptors and phosphorylation of some neuronal proteins including microtubule-associated protein 2 (MAP-2). The aim of this work was to analyze the effects of hyperammonemia on modulation of MAP-2 phosphorylation by metabotropic glutamate receptors (mGluRs) in rat cerebellar neurons in culture. Hyperammonemia increased basal phosphorylation of MAP-2 (180%). Activation of mGluRs 1 and 5 with (S)-3,5-dihydroxyphenylglycine (DHPG) increased MAP-2 phosphorylation (170%) in control neurons but not in neurons exposed to ammonia. Activation of mGluRs 2 and 3 with (2S,3S,4S)-CCG/(2S, 1'S,2'S)-2-(carboxycyclopropyl)glycine increased slightly (25%) MAP-2 phosphorylation in neurons exposed to ammonia or not. Activation of mGluR5 with (+/-)-trans-azetidine-2,4-dicarboxylic acid increased MAP-2 phosphorylation (24%) in control neurons but decreased it by 56% in neurons exposed to ammonia. Activation of mGluR1 using 2-methyl-6-(phenylethynyl)pyridine and DHPG increased MAP-2 phosphorylation 183% in control neurons but only 89% in neurons exposed to ammonia. In control neurons mGluR1 activation greatly increases phosphorylation of MAP-2, while activation of mGluRs 5, 2 or 3 increased it slightly. Taken together, hyperammonemia reduces the increase in MAP-2 phosphorylation induced by mGluR1activation. Moreover, in neurons exposed to ammonia activation of mGluR5 reduces MAP-2 phosphorylation. These effects reflect significant alterations in signal transduction associated to mGluR1 and mGluR5 in hyperammonemia that may contribute to altered glutamatergic neurotransmission and to the neurological alterations in hyperammonemia and hepatic encephalopathy.

Adding another spectral dimension to1H magnetic resonance spectroscopy of hepatic encephalopathy

PURPOSE

To evaluate a localized two-dimensional correlated magnetic resonance spectroscopic (L-COSY) technique in patients with hepatic encephalopathy (HE) and healthy subjects, and to correlate the cerebral metabolite changes with neuropsychological (NP) test scores.

MATERIALS AND METHODS

Eighteen minimal hepatic encephalopathy (MHE) patients and 21 healthy controls have been investigated. A GE 1.5-T magnetic resonance (MR) scanner was used in combination with a body MR coil for transmission and a 3-inch surface coil for reception. A 27-mL voxel was localized by three slice-selective radio frequency (RF) pulses (90 degrees-180 degrees-90 degrees) in the anterior cingulate region. The total duration of each two-dimensional L-COSY spectrum was approximately 25 minutes. The NP battery included a total of 15 tests, which were grouped into six domains.

RESULTS

MR spectroscopic results showed a statistically significant decrease in myo-inositol (mI) and choline (Ch) and an increase in glutamate/glutamine (Glx) in patients when compared to healthy controls. There was also an increase in taurine (Tau) in patients. The NP results indicated a significant correlation between motor function assessed by NP tests and mI ratios recorded using two-dimensional L-COSY.

CONCLUSION

The study demonstrated the feasibility of evaluating the two-dimensional L-COSY sequence in a clinical environment. The results showed additional cerebral metabolites that can be measured with the technique in comparison to one-dimensional study.

Regulating effect of Chinese herbal medicine on the peritoneal lymphatic stomata in enhancing ascites absorption of experimental hepatofibrotic mice

AIM

To observe the regulatory effect of Chinese herbal medicine on peritoneal lymphatic stomata and its significance in treating ascites in liver fibrosis model mice.

METHODS

Two Chinese herbal composite prescriptions were used separately to treat the carbon tetrachloride-induced mouse model of liver fibrosis. The histo-pathologic changes of the liver sections (HE and VG stainings) were observed. The peritoneal lymphatic stomata was detected by scanning electron microscopy and computer image processing. The changes of urinary volume and sodium ion concentration were measured.

RESULTS

In the model group, lots of fibrous tissue formed in liver and extended into the hepatic lobules to separate them incompletely. In the treated and prevention groups, the histo-pathologic changes of liver was rather milder, only showed much less fibrous tissue proliferation in the hepatic lobules. The peritoneal lymphatic stomata enlarged with increased density in the experimental groups (diameter: PA, 3.07 +/- 0.69 microm; PB, 2.82 +/- 0.37 microm; TA, 3.25 +/- 0.82 microm and TB, 2.82 +/- 0.56 microm; density: PA, 7.11 +/- 1.90 stomata.1000 microm(-2); PB, 8.76 +/- 1.45 stomata.1000 microm(-2); TA, 6.55 +/- 1.44 stomata.1000 microm(-2)and TB, 8.76+/-1.79 stomata.1000 microm(-2)), as compared with the model group (diameter: 2.00+/-0.52 microm density: 4.45+/-1.05 stomata.1000 microm(-2)). After treatment, the urinary volume and sodium ion excretion increased in the experimental groups (PA, 231.28+/-41.09 mmol.L(-1); PB, 171.69 +/- 27.48 mmol.L(-1) and TA, 231.44 +/- 34.12 mmol.L(-1)), which were significantly different with those in the model group (129.33 +/- 36.75 mmol.L(-1)).

CONCLUSION

Chinese herbal medicine has marked effects in alleviating liver fibrosis, regulating peritoneal lymphatic stomata, improving the drainage of ascites from peritoneal cavity and causing increase of urinary volume and sodium ion excretion to reduce the water and sodium retention, and thus have favorable therapeutic effect in treating ascites.