Hepatic encephalopathy: a review of its pathophysiology and treatment

Long-Term Effects of Rifaximin on Patients with Hepatic Encephalopathy: Its Possible Effects on the Improvement in the Blood Ammonia Concentration Levels, Hepatic Spare Ability and Refractory Ascites

Background and Objectives: To investigate the long-term efficacy of rifaximin (RFX) for hyperammonemia and efficacy for refractory ascites in patients with cirrhosis. Materials and Methods: We enrolled 112 patients with liver cirrhosis who were orally administered RFX in this study. Changes in the clinical data of patients were evaluated up to 36 months after RFX administration. The primary endpoint was a change in blood ammonia levels. Secondary endpoints included changes in clinical symptoms, Child−Pugh (CP) score, number of hospitalizations, degree of refractory ascites, adverse events, and the relationship between RFX administration and the renin-angiotensin-aldosterone system. Results: An improved rate of overt hepatic encephalopathy (HE) of 82.7% was observed 3 months after RFX administration, which significantly induced a progressive decrease in blood ammonia concentration and an improved CP score up to 36 months. No serious RFX treatment-related adverse events were observed. 36.5% in patients after RFX administration improved refractory ascites. After RFX administration, patients with satisfactory control of hepatic ascites without addition of diuretic had lower renin concentration than those with poor control (p < 0.01). At less than 41 pg/mL renin concentration, the control of refractory ascites was significantly satisfactory (p < 0.0001). Conclusions: RFX reduced blood ammonia concentration and improved hepatic spare ability and the quality of life of patients with long-term HE to up to 36 months. Our study revealed the effects of RFX against refractory ascites, suggesting that renin concentration may be a predictive marker for assessing ascites control.

A Double-Blind, Randomized Placebo-Controlled Trial of Probiotic Lactobacillus casei Shirota in Stable Cirrhotic Patients

Background: In cirrhosis, a pathological gut microbiome has been linked with immune dysfunction. A pilot study of probiotic Lactobacillus casei Shirota (LcS) in alcoholic cirrhosis demonstrated significant improvement in neutrophil function. This study aimed to evaluate the efficacy of LcS on neutrophil function and significant infection rates in patients with cirrhosis. Methods: 92 cirrhotic patients (Child-Pugh score ≤10) were randomized to receive LcS or placebo, three times daily for six months. Primary end-points were incidence of significant infection and neutrophil function. Secondary end-points were cytokine profile, endotoxin, bacterial DNA positivity, intestinal permeability and quality of life. Results: Rates of infection, decompensation or neutrophil function did not differ between placebo and probiotic groups. LcS significantly reduced plasma monocyte chemotactic protein-1 and, on subgroup analysis, plasma interleukin-1β (alcoholic cirrhosis), interleukin-17a and macrophage inflammatory protein-1β (non-alcoholic cirrhosis), compared with placebo. No significant differences in intestinal permeability, bacterial translocation or metabolomic profile were observed. Conclusion: LcS supplementation in patients with early cirrhosis is safe. Although no significant infections were observed in either group, LcS improved cytokine profile towards an anti-inflammatory phenotype, an effect which appears to be independent of bacterial translocation.

Preliminary experience with single fecal microbiota transplant for treatment of recurrent overt hepatic encephalopathy-A case series

Experimental studies demonstrated that fecal microbiota transplant (FMT) may reverse intestinal microbial dysbiosis. In this retrospective case series, we share our experience of treating recurrent overt hepatic encephalopathy (HE) with single FMT treatment. A total of 10 patients, age ranged from 25 to 65 years, were treated with single FMT through colonoscopy using fecal material received from rigorously screened patient-identified donors. There was sustained clinical response with single FMT treatment in 6 patients at post-treatment week 20. Arterial ammonia concentration decreased considerably (96 [87.25-117.75] vs. 74 [70-82]; p = 0.024) at post-treatment week 20. Moreover, there was statistically significant decrease in Child-Turcotte-Pugh (CTP) score (9.5 [9-10.75] vs. 8 [7-8]; p = 0.005) and model for end-stage liver disease (MELD) score (18 [16.25-19] vs. 15 [14-16]; p = 0.008). Four patients experienced six adverse-events. Overt HE and re-hospitalization were observed in 3 and 2 patients, respectively. One patient (who also experienced overt HE) died within 2 months of the index procedure.

Effect of different treatments and alcohol addiction on gut microbiota in minimal hepatic encephalopathy patients

Minimal hepatic encephalopathy (MHE) is caused by dysbiosis of gut microbiota, particularly the ammonia-producing bacteria. Given the efficacy of certain treatments on MHE and the connection between alcoholism and MHE, a thorough understanding of how these strategies affect the gut microbiota in patients (alcoholic or non-alcoholic) will facilitate the assessment of their efficacy in the reshaping of gut microbiota. In the present study, a metagenomics approach was adopted to reveal alterations in gut microbiota of 14 MHE patients following treatment with rifaximin alone or rifaximin plus probiotics. Patients were grouped into the alcoholic and non-alcoholic groups to examine differences in terms of their response to treatment. Treatment reduced the overall microbiota diversity and decreased the abundance of certain ammonia-producing bacteria, such as Clostridium, with the treatment of rifaximin plus probiotics presenting a more apparent effect. Non-alcoholic MHE patients responded better to the treatment, as they presented greater reduction in microbiota diversity and a more consistent decline in certain ammonia-producing bacteria genera (such as Clostridium and Streptococcus) belonging to the Firmicutes phylum. In conclusion, treatment with rifaximin alone and rifaximin plus probiotics exhibited a different effect in different MHE patients, decreasing the overall gut microbiota diversity to various extents and reshaping microbiota in different ways. Furthermore, non-alcoholic MHE patients responded better to treatment in microbiota alterations.

Probiotics for people with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure or portosystemic shunt or both. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning, and represent a significant burden on healthcare resources. Probiotics are live micro-organisms, which when administered in adequate amounts, may confer a health benefit on the host.

OBJECTIVES

To determine the beneficial and harmful effects of probiotics in any dosage, compared with placebo or no intervention, or with any other treatment for people with any grade of acute or chronic hepatic encephalopathy. This review did not consider the primary prophylaxis of hepatic encephalopathy.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, conference proceedings, reference lists of included trials, and the World Health Organization International Clinical Trials Registry Platform until June 2016.

SELECTION CRITERIA

We included randomised clinical trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in people with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We conducted random-effects model meta-analysis due to obvious heterogeneity of participants and interventions. We defined a P value of 0.05 or less as significant. We expressed dichotomous outcomes as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 21 trials with 1420 participants, of these, 14 were new trials. Fourteen trials compared a probiotic with placebo or no treatment, and seven trials compared a probiotic with lactulose. The trials used a variety of probiotics; the most commonly used group of probiotic was VSL#3, a proprietary name for a group of eight probiotics. Duration of administration ranged from 10 days to 180 days. Eight trials declared their funding source, of which six were independently funded and two were industry funded. The remaining 13 trials did not disclose their funding source. We classified 19 of the 21 trials at high risk of bias.We found no effect on all-cause mortality when probiotics were compared with placebo or no treatment (7 trials; 404 participants; RR 0.58, 95% CI 0.23 to 1.44; low-quality evidence). No-recovery (as measured by incomplete resolution of symptoms) was lower for participants treated with probiotic (10 trials; 574 participants; RR 0.67, 95% CI 0.56 to 0.79; moderate-quality evidence). Adverse events were lower for participants treated with probiotic than with no intervention when considering the development of overt hepatic encephalopathy (10 trials; 585 participants; RR 0.29, 95% CI 0.16 to 0.51; low-quality evidence), but effects on hospitalisation and change of/or withdrawal from treatment were uncertain (hospitalisation: 3 trials, 163 participants; RR 0.67, 95% CI 0.11 to 4.00; very low-quality evidence; change of/or withdrawal from treatment: 9 trials, 551 participants; RR 0.70, 95% CI 0.46 to 1.07; very low-quality evidence). Probiotics may slightly improve quality of life compared with no intervention (3 trials; 115 participants; results not meta-analysed; low-quality evidence). Plasma ammonia concentration was lower for participants treated with probiotic (10 trials; 705 participants; MD -8.29 μmol/L, 95% CI -13.17 to -3.41; low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.When probiotics were compared with lactulose, the effects on all-cause mortality were uncertain (2 trials; 200 participants; RR 5.00, 95% CI 0.25 to 102.00; very low-quality evidence); lack of recovery (7 trials; 430 participants; RR 1.01, 95% CI 0.85 to 1.21; very low-quality evidence); adverse events considering the development of overt hepatic encephalopathy (6 trials; 420 participants; RR 1.17, 95% CI 0.63 to 2.17; very low-quality evidence); hospitalisation (1 trial; 80 participants; RR 0.33, 95% CI 0.04 to 3.07; very low-quality evidence); intolerance leading to discontinuation (3 trials; 220 participants; RR 0.35, 95% CI 0.08 to 1.43; very low-quality evidence); change of/or withdrawal from treatment (7 trials; 490 participants; RR 1.27, 95% CI 0.88 to 1.82; very low-quality evidence); quality of life (results not meta-analysed; 1 trial; 69 participants); and plasma ammonia concentration overall (6 trials; 325 participants; MD -2.93 μmol/L, 95% CI -9.36 to 3.50; very low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.

AUTHORS' CONCLUSIONS

The majority of included trials suffered from a high risk of systematic error ('bias') and a high risk of random error ('play of chance'). Accordingly, we consider the evidence to be of low quality. Compared with placebo or no intervention, probiotics probably improve recovery and may lead to improvements in the development of overt hepatic encephalopathy, quality of life, and plasma ammonia concentrations, but probiotics may lead to little or no difference in mortality. Whether probiotics are better than lactulose for hepatic encephalopathy is uncertain because the quality of the available evidence is very low. High-quality randomised clinical trials with standardised outcome collection and data reporting are needed to further clarify the true efficacy of probiotics.

Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy

Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents.

Large-scale survey of gut microbiota associated with MHE Via 16S rRNA-based pyrosequencing

OBJECTIVES

Elucidating the minimal hepatic encephalopathy (MHE)-associated gut microbiome may help in predicting and lowering the high risk for MHE in patients with cirrhosis.

METHODS

Twenty-six MHE patients were recruited and screened from among those with liver cirrhosis without overt hepatic encephalopathy as defined by abnormality seen on two test modalities: number connection test part A and the digit symbol test. Using 26 MHE-matched normal relatives and 25 cirrhotic patients without MHE as controls, by means of 16S ribosomal RNA (rRNA)-based pyrosequencing, we examined and analyzed 241,622 bacterial 16S rDNA gene sequences from feces of 77 subjects.

RESULTS

Using multiple comparative analyses, our results found the continuous overrepresentation of two bacterial families, Streptococcaceae and Veillonellaceae, in cirrhotic patients with and without MHE, compared with normal individuals. In addition, we also discovered an MHE-unique interplay pattern of gut microbiota largely influenced by the members of those two families. Following these findings, we further revealed that gut urease-containing bacteria Streptococcus salivarius was absent in the normal group but was present in cirrhotic patients with and without MHE. The abundance of S. salivarius was significantly higher in cirrhotic patients with MHE than in those without (P=0.030), and the change in the amount of this bacteria was positively correlated with ammonia accumulation (R=0.58, P=0.003) in cirrhotic patients with MHE but not in those without.

CONCLUSIONS

Gut microbiota dysbiosis may be associated with the presence of MHE in cirrhotic patients, in particular with ammonia-increasing phenotype in MHE. Gut ammonia-increasing bacteria S. salivarius might be expected to be a potential biomarker of ammonia-lowering therapies in cirrhotic patients with MHE.

Brain edema in acute liver failure: role of neurosteroids

Brain edema is a major neurological complication of acute liver failure (ALF) and swelling of astrocytes (cytotoxic brain edema) is the most prominent neuropathological abnormality in this condition. Elevated brain ammonia level has been strongly implicated as an important factor in the mechanism of astrocyte swelling/brain edema in ALF. Recent studies, however, have suggested the possibility of a vasogenic component in the mechanism in ALF. We therefore examined the effect of ammonia on blood-brain barrier (BBB) integrity in an in vitro co-culture model of the BBB (consisting of primary cultures of rat brain endothelial cells and astrocytes). We found a minor degree of endothelial permeability to dextran fluorescein (16.2%) when the co-culture BBB model was exposed to a pathophysiological concentration of ammonia (5mM). By contrast, lipopolysaccharide (LPS), a molecule well-known to disrupt the BBB, resulted in an 87% increase in permeability. Since increased neurosteroid biosynthesis has been reported to occur in brain in ALF, and since neurosteroids are known to protect against BBB breakdown, we examined whether neurosteroids exerted any protective effect on the slight permeability of the BBB after exposure to ammonia. We found that a nanomolar concentration (10nM) of the neurosteroids allopregnanolone (THP) and tetrahydrodeoxycorticosterone (THDOC) significantly reduced the ammonia-induced increase in BBB permeability (69.13 and 58.64%, respectively). On the other hand, we found a marked disruption of the BBB when the co-culture model was exposed to the hepatotoxin azoxymethane (218.4%), but not with other liver toxins commonly used as models of ALF (thioacetamide and galactosamine, showed a 29.3 and 30.67% increase in permeability, respectively). Additionally, THP and THDOC reduced the effect of TAA and galactosamine on BBB permeability, while no BBB protective effect was observed following treatment with azoxymethane. These findings suggest that ammonia does not cause a significant BBB disruption, and that the BBB is intact in the TAA or galactosamine-induced animal models of ALF, likely due to the protective effect of neurosteroids that are synthesized in brain in the setting of ALF. However, caution should be exercised when using azoxymethane as an experimental model of ALF as it caused a severe breakdown of the BBB, and neurosteriods failed to protect against this breakdown.

Probiotics for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure and/or portosystemic shunt. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning and represent a significant burden on health care resources. Probiotics are live microorganisms, which when administered in adequate amounts may confer a health benefit on the host.

OBJECTIVES

To quantify the beneficial and harmful effects of any probiotic in any dosage, compared with placebo or no intervention, or with any other treatment for patients with any grade of acute or chronic hepatic encephalopathy as assessed from randomised trials.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, conference proceedings, reference lists of included trials and the WHO international clinical trials registry until April 2011 registry platform to identify new and ongoing trials.

SELECTION CRITERIA

We included randomised trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in patients with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed the risk of bias of the included trials and extracted data on relevant outcomes, with differences resolved by consensus. We conducted random-effects model meta-analysis due to obvious heterogeneity of patients and interventions. A P value of 0.05 or less was defined as significant. Dichotomous outcomes are expressed as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials of which 550 participants were randomised. Four of the seven trials compared a probiotic with placebo or no treatment in 245 participants, another trial compared a probiotic with lactulose in 40 participants , and the remaining two trials compared a probiotic with both placebo and lactulose in 265 participants. Each trial used different types of probiotics. Duration of administration of the experimental intervention varied from 10 days to 180 days. Two trials were industry funded, and five were unclear about origin of funding. All trials had high risk of bias. When probiotics were compared with no treatment, there was no significant difference in all-cause mortality (2 trials, 105 participants; 1/57 (2%) versus 1/48 (2%): RR 0.72; 95% CI 0.08 to 6.60), lack of recovery (4 trials, 206 participants; 54/107 (50%) versus 68/99 (69%): RR 0.72; 95% CI 0.49 to 1.05), adverse events (3 trials, 145 participants; 2/77 (3%) versus 6/68 (9%): RR 0.34; 95% CI 0.08 to 1.42), quality of life (1 trial, 20 participants contributed to the physical quality of life measurement, 20 participants contributed to the mental quality of life: MD Physical 0.00; 95% CI -5.47 to 5.47; MD Mental 4.00; 95% CI -1.82 to 9.82), or change of/or withdrawal from treatment (3 trials, 175 participants; 11/92 (12%) versus 7/83 (8%): RR 1.28; 95% CI 0.52 to 3.19). No trial reported sepsis or duration of hospital stay as an outcome. Plasma ammonia concentration was significantly lower for participants treated with probiotic at one month (3 trials, 226 participants: MD -2.99 μmol/L; 95% CI -5.70 to -0.29) but not at two months (3 trials, 181 participants: MD -1.82 μmol/L; 95% CI -14.04 to 10.41). Plasma ammonia decreased the most in the participants treated with probiotic at three months (1 trial, 73 participants: MD -6.79 μmol/L; 95% CI -10.39 to -3.19). When probiotics were compared with lactulose no trial reported all-cause mortality, quality of life, duration of hospital stay, or septicaemia. There were no significant differences in lack of recovery (3 trials, 173 participants; 47/87 (54%) versus 44/86 (51%): RR 1.05; 95% CI 0.75 to 1.47), adverse events (2 trials, 111 participants; 3/56 (5%) versus 6/55 (11%): RR 0.57; 95% CI 0.06 to 5.74), change of/or withdrawal from treatment at one month (3 trials, 190 participants; 8/95 (8%) versus 7/95 (7%): RR 1.10; 95% CI 0.40 to 3.03), plasma ammonia concentration (2 trials, 93 participants: MD -6.61 μmol/L; 95% CI -30.05 to 16.84), or change in plasma ammonia concentration (1 trial, 77 participants: MD 1.16 μmol/L; 95% CI -1.96 to 4.28).

AUTHORS' CONCLUSIONS

The trials we located suffered from a high risk of systematic errors ('bias') and high risk of random errors ('play of chance'). While probiotics appear to reduce plasma ammonia concentration when compared with placebo or no intervention, we are unable to conclude that probiotics are efficacious in altering clinically relevant outcomes. Demonstration of unequivocal efficacy is needed before probiotics can be endorsed as effective therapy for hepatic encephalopathy. Further randomised clinical trials are needed.

Innate immune dysfunction in acute and chronic liver disease

Liver cirrhosis is a common disease causing great public-health concern because of the frequent complications requiring hospital care. Acute liver failure is also prone to several complications but is rare. One of the main complications for both acute and chronic liver diseases is infection, which regularly causes decompensation of cirrhosis, possibly leading to organ failure and death. This review focuses on innate immune function in cirrhosis, acute-on-chronic liver failure and acute liver failure. The known defects of Kupffer cells, neutrophils and monocytes are discussed, together with the pathophysiological importance of gut permeability, portal hypertension and intrinsic cellular defects, and the role of endotoxin, albumin, lipoproteins and toll-like receptors. Based on these different pathomechanisms, the available information on therapeutic strategies is presented. Antibiotic and probiotic treatment, nutritional support, artificial liver support, and experimental strategies such as inhibition of toll-like receptors and use of albumin and colony-stimulating factors are highlighted.

Effect of probiotic treatment on deranged neutrophil function and cytokine responses in patients with compensated alcoholic cirrhosis

BACKGROUND/AIM

Endotoxaemia contributes to neutrophil dysfunction, infection risk and mortality in patients with alcoholic cirrhosis. As probiotics may decrease Gram-negative gut organisms, we hypothesised that probiotic treatment would restore neutrophil function.

METHODS

In an open-label study, patients with alcoholic cirrhosis (n=12) received Lactobacillus casei Shirota (6.5 x 10(9)) 3 times daily for 4 weeks. Data were compared to healthy controls (n=13) and cirrhotic patients (n=8) who did not receive probiotics. Neutrophil oxidative burst, phagocytosis, toll-like-receptor (TLR) expression, plasma cytokines and ex vivo endotoxin-stimulated cytokine production were measured.

RESULTS

Baseline neutrophil phagocytic capacity in patients was significantly lower compared to healthy controls (73% versus 98%, p<0.05), but normalised at the end of the study (n=10, 100%, p<0.05). No improvement was seen in disease controls. Soluble TNF-receptor (sTNFR)-1 and-2 and interleukin (IL)10 were significantly elevated in patients' plasma but did not change during the study. Ex vivo endotoxin-stimulated levels of sTNFR1, sTNFR2 and IL10 were significantly lower at the end of the study (p<0.05). TLR2, 4 and 9 were overexpressed in patients. TLR4 expression normalised by the end of the study.

CONCLUSIONS

Our data provide a proof-of-concept that probiotics restore neutrophil phagocytic capacity in cirrhosis, possibly by changing IL10 secretion and TLR4 expression, warranting larger randomised controlled and mechanistic studies.

Medical comorbidity and alcohol dependence

Alcohol dependence (AD) and, more generally, alcohol use disorders (AUDs) predispose individuals to adverse consequences that extend beyond the expected damage from alcohol-direct toxicity. Research has shown that the relationship of alcohol use to health outcomes is complex, as is the etiology of AD, and that the individual and social costs of alcohol-related problems are increasing. We review advances in alcohol science that explore the role of alcohol consumption and patterns of drinking in a range of medically comorbid conditions. Although new knowledge can assist in the development of appropriate medical management strategies, AUDs account for an important percentage of the global burden of disease and require approaches that are not uniquely focused on the identification and treatment of AD.