Pro-inflammatory cytokines are raised in extrahepatic portal venous obstruction, with minimal hepatic encephalopathy

Prevalence of hepatic encephalopathy in patients with non-cirrhotic portal hypertension: A systematic review and meta-analysis

BACKGROUND

Hepatic encephalopathy, (HE) although commonly associated with cirrhosis, has also been reported in non-cirrhotic portal hypertension (NCPH). The importance of identifying and treating HE in NCPH lies in the fact that many patients may be wrongly diagnosed as having psychiatric or neurologic disorders. Hence, we aimed to systematically review the prevalence of HE in NCPH.

METHODS

A comprehensive search of three databases (Medline, Embase and Scopus) was conducted from inception to November 2022 for studies reporting on the prevalence of minimal HE (MHE) and overt HE (OHE) in patients with NCPH. Results were presented as pooled proportions with their 95% confidence intervals (CI).

RESULTS

Total 25 studies (n = 1487) were included after screening 551 records. The pooled prevalence of MHE in NPCH was 32.9% (95% CI: 26.7-39.0) without any difference between adult (32.9%, 95% CI: 23.5-42.3) and pediatric patients (32.6%, 95% CI: 26.1-39.1) (p = 0.941). There was no significant difference in the prevalence between patients with NCPH and compensated cirrhosis with odds ratio of 1.06 (95% CI: 0.77-1.44). The pooled event rate for prior history of OHE in NCPH was 1.2% (95% CI: 0.3-2.1).

CONCLUSION

Around one-third of the patients with NCPH have MHE, irrespective of age group. OHE is extremely rare in NCPH and is usually associated with a precipitating factor.

Novel Serum Biomarkers Associated With Pediatric Hepatic Encephalopathy: A Systematic Review

BACKGROUND

The pathophysiology of pediatric hepatic encephalopathy (HE) is not well understood. Various serum biomarkers associated with HE may provide insight into its pathology, but their use and interpretation in clinical practice for diagnosis and prognostication remain undetermined. We sought to investigate reported correlations of serum biomarkers with presence and degree of HE in children.

METHODS

We conducted a systematic review of studies examining novel serum biomarkers and cytokines in association with HE that included children on PubMed, Embase, Lilacs, and Scopus. We utilized Covidence for abstract and text review by 2 independent reviewers for each study.

RESULTS

We reviewed 2824 unique publications; 15 met criteria for inclusion. Categories of biomarkers reported were inflammatory cytokines, products of amino acid metabolism, trace elements and vitamins, and hepatic and neuro biomarkers. Of 19 individual biomarkers, only 5 were measured in more than 1 study. Elevations in interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were most commonly reported as associated with HE. Notably, we observed lower average IL-6 and TNF-alpha levels in pediatric-only studies compared to mixed age studies. Overall, high bias and poor applicability to our review question was observed. We encountered low numbers of studies with pediatric focus, and few conducted with low bias study designs.

CONCLUSION

Investigated biomarkers span a large range of categories and suggest potentially useful correlations with HE. Further well-designed prospective biomarker research is necessary to better elucidate the pathogenesis of HE in children and improve early detection and clinical care.

Evaluation of oxidative damage to biomolecules and inflammation in patients with urea cycle disorders

Urea cycle disorders (UCD) are inborn errors of metabolism that occur due to a loss of function in enzymes and transporters involved in the urea cycle, causing an intoxication by hyperammonemia and accumulation of metabolites. Patients can develop hepatic encephalopathy (HE), severe neurological and motor disabilities, and often death. The mechanisms involved in the pathophysiology of UCD are many and complex, but there are strong indications that oxidative stress and inflammation are present, being responsible for at least part of the cellular damage that occurs in these diseases. The aim of this study was to evaluate oxidative and nitrosative damage and inflammation in UCD, to better understand the pathophysiology mechanisms of these diseases. We evaluated the nitrite and nitrate content, thiobarbituric acid-reactive substances (TBARS), carbonyl protein content and a panel of cytokines in plasma sample of 14 patients. The UCD patients group consisted of individuals affected with ornithine transcarbamylase deficiency (n = 8), carbamoyl phosphate synthetase deficiency (n = 2), argininosuccinate synthetase deficiency (n = 2); arginase 1 deficiency (n = 1) and argininosuccinate lyase deficiency (n = 1). Patients mean age at diagnosis was 5.25 ± 9.86 years-old and mean concentrations were compared with healthy individuals of matched age and gender. We found a significant reduction in nitrogen reactive species in patients when compared to controls. TBARS was increased in patients, indicating lipid peroxidation. To evaluate protein oxidative damage in UCD, the carbonyl content was measured, and the results also demonstrated an increase in this biomarker. Finally, we found that UCD patients have enhanced concentrations of cytokines, with pro-inflammatory interleukins IL-6, IL-8, interferon-γ and TNF-α, and anti-inflammatory IL-10 being increased when compared to the control group. In conclusion, our results demonstrate that oxidative stress and inflammation occurs in UCD and probably contribute to the severe brain damage present in patients.

Surgical management of extrahepatic portal vein obstruction in children: advantages of MesoRex shunt compared with distal splenorenal shunt

PURPOSE

To review surgical management of extrahepatic portal vein obstruction (EHPVO) at Red Cross War Memorial Children's Hospital and compare MesoRex shunt (MRS) with distal splenorenal shunt (DSRS).

METHODS

This is a single-centre retrospective review documenting pre- and post-operative data in 21 children. Twenty-two shunts were performed, 15 MRS and 7 DSRS, over an 18-year period. Patients were followed up for a mean of 11 years (range 2-18). Data analysis included demographics, albumin, prothrombin time (PT), partial thromboplastin time (PTT), International normalised ratio (INR), fibrinogen, total bilirubin, liver enzymes and platelets before the operation and 2 years after shunt surgery.

RESULTS

One MRS thrombosed immediately post-surgery and the child was salvaged with DSRS. Variceal bleeding was controlled in both groups. Significant improvements were seen amongst MRS cohort in serum albumin, PT, PTT, and platelets and there was a mild improvement in serum fibrinogen. The DSRS cohort showed only a significant improvement in the platelet count. Neonatal umbilic vein catheterization (UVC) was a major risk for Rex vein obliteration.

CONCLUSION

In EHPVO, MRS is superior to DSRS and improves liver synthetic function. DSRS does control variceal bleeding but should only be considered when MRS is not technically feasible or as a salvage procedure when MRS fails.

The shaping of gut immunity in cirrhosis

Cirrhosis is the common end-stage of chronic liver diseases of different etiology. The altered bile acids metabolism in the cirrhotic liver and the increase in the blood-brain barrier permeability, along with the progressive dysbiosis of intestinal microbiota, contribute to gut immunity changes, from compromised antimicrobial host defense to pro-inflammatory adaptive responses. In turn, these changes elicit a disruption in the epithelial and gut vascular barriers, promoting the increased access of potential pathogenic microbial antigens to portal circulation, further aggravating liver disease. After summarizing the key aspects of gut immunity during homeostasis, this review is intended to update the contribution of liver and brain metabolites in shaping the intestinal immune status and, in turn, to understand how the loss of homeostasis in the gut-associated lymphoid tissue, as present in cirrhosis, cooperates in the advanced chronic liver disease progression. Finally, several therapeutic approaches targeting the intestinal homeostasis in cirrhosis are discussed.

Cognitive Impairement in Non-Cirrhotic Portal Hypertension: Highlights on Physiopathology, Diagnosis and Management

Hepatic encephalopathy (HE) is one of the most frequent complications of cirrhosis. Several studies and case reports have shown that cognitive impairment may also be a tangible complication of portal hypertension secondary to chronic portal vein thrombosis and to porto-sinusoidal vascular disease (PSVD). In these conditions, representing the main causes of non-cirrhotic portal hypertension (NCPH) in the Western world, both overt and minimal/covert HE occurs in a non-neglectable proportion of patients, even lower than in cirrhosis, and it is mainly sustained by the presence of large porto-systemic shunt. In these patients, the liver function is usually preserved or only mildly altered, and the development of porto-systemic shunt is either spontaneous or iatrogenically frequent; HE is an example of type-B HE. To date, in the absence of strong evidence and large cooperative studies, for the diagnosis and the management of HE in NCPH, the same approach used for HE occurring in cirrhosis is applied. The aim of this paper is to provide an overview of type B hepatic encephalopathy, focusing on its pathophysiology, diagnostic tools and management in patients affected by porto-sinusoidal vascular disease and chronic portal vein thrombosis.

Meso-Rex bypass versus portosystemic shunt for the management of extrahepatic portal vein obstruction in children: systematic review and meta-analysis

PURPOSE

Extrahepatic portal vein obstruction (EHPVO) is a major cause of non-cirrhotic portal hypertension in children. Surgical procedures for EHPVO include portosystemic shunts (PSS) and meso-Rex bypass (MRB). We conducted a systematic review and meta-analysis to compare the effectiveness of MRB versus PSS in EHPVO patients.

METHODS

A systematic literature search was performed using four databases. Articles reporting EHPVO and comparing patients who received MRB and PSS were included in the analysis.

RESULTS

We retrieved 851 papers, of which five observational studies met the inclusion criteria. There was no difference in shunt complications, mortality, or gastrointestinal bleeding after surgery between MRB and PSS in the meta-analysis. MRB had increased shunt complications compared with PSS in the non-comparative studies. MRB had a potential advantage over PSS in long-term prognosis in one comparative study. Overall, the quality of the evidence was low.

CONCLUSIONS

Based on available data, our meta-analysis indicates that MRB does not increase shunt complications, mortality, or gastrointestinal bleeding after surgery. The present study did not reveal superiority for either MRB or PSS. The paucity of well conducted trials in this area justifies future multicenter studies and studies that examine long-term outcomes.

Polyherbal formulation Anoac‑H suppresses the expression of RANTES and VEGF for the management of bleeding hemorrhoids and fistula

Hemorrhoids and fistula are considered the most common anorectal conditions in the general population. These conditions affect the quality of a patient's life by causing pain and bleeding during defecation or even in the resting state. Lower grades of hemorrhoids may be controlled by traditional measures. However, surgery is an effective treatment option in recurrent-lower and higher-grade hemorrhoids. Surgical procedures are associated with various complications, including pain and delayed wound healing. Recurrence of hemorrhoids is also a major concern in the post-operative period. An anal fistula is the connection between the anus and the skin and causes severe pain, swelling, as well as blood and pus discharge. Fistula has serious social and economic consequences. Hence, it is important to understand the pathophysiology and molecular pathology of hemorrhoids and fistula, to identify the molecular targets and to develop pharmacological-interventions. In a previous study by our group, the polyherbal formulation Anoac-H was developed for the treatment of different stages of hemorrhoids and fistula, and it was demonstrated that Anoac-H is an effective formulation for treating hemorrhoids. However, the molecular mode of action of Anoac-H on hemorrhoids and fistula had remained elusive. In the present study, it was determined that this formulation reduces the migration of mesenchymal (fibroblasts) and immune (RAW 264.7) cells without affecting their viability. It was also observed that Anoac-H suppresses the expression of regulated upon activation, normal T cell expressed and presumably secreted (RANTES) and VEGF in fibroblasts and macrophages. Inflammation and elevated expression of RANTES and VEGF were observed in hemorrhoids and fistula. However, inflammation, as well as the expression of RANTES and VEGF, were significantly reduced in treated human hemorrhoid and fistula tissues as compared to untreated ones, confirming the in vitro results.

Cognition-tracking-based strategies for diagnosis and treatment of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE), which shows mild cognitive impairment, is a subtle complication of cirrhosis that has been shown to affect daily functioning and quality of life. However, until 2014, relevant guidelines do not give much attention to the diagnosis and treatment of MHE, resulting in patients being ignored and denied the benefits of treatment. In this review, we summarize recent cognition-based research about (1) alteration of nerve cells, including astrocytes, microglial cells and neurons, in mild cognitive impairment in MHE; (2) comparison of methods in detecting cognitive impairment in MHE; and (3) comparison of methods for therapy of cognitive impairment in MHE. We hope to provide information about diagnosis and treatment of cognitive impairment in patients with MHE.

Hippocampal atrophy and functional connectivity disruption in cirrhotic patients with minimal hepatic encephalopathy

The hippocampus is a crucial pathological node for minimal hepatic encephalopathy (MHE) and it is associated with various cognitive impairments. Investigations on alterations involving hippocampal morphology and functional connectivity (FC) in MHE are limited. This study aimed to simultaneously evaluate hippocampal volume and FC alterations and their association with cognitive decline in MHE. Twenty-two cirrhotic patients with MHE, 31 cirrhotic patients without MHE (NHE), and 43 healthy controls underwent high-resolution T1-weighted imaging, resting-state functional magnetic resonance imaging, and cognition assessment based on Psychometric Hepatic Encephalopathy Score (PHES). The structural images were preprocessed using a voxel-based morphometry method, during which hippocampal volume was measured. The hippocampal connectivity network was identified using seed-based correlation analysis. Hippocampal volume and FC strength were compared across the three groups and correlated against the PHES results of the cirrhotic patients. Compared to the controls, MHE patients exhibited a significantly lower bilateral hippocampal volume. A slight decrease in hippocampal volume was obtained from NHE to MHE, but it did not reach statistically significance. In addition, the average FC strength of the bilateral hippocampal connectivity network was significantly lower in the MHE patients. In particular, the MHE patients showed a decrease in FC involving the left hippocampus to bilateral posterior cingulate gyrus and left angular gyrus. The MHE patients also showed FC reduction between the right hippocampus and bilateral medial frontal cortex. A progressive reduction in hippocampal FC from NHE to MHE was also observed. The bilateral hippocampal FC strength (but not hippocampal volume) was positively correlated with the PHES results of the cirrhotic patients. Our assessment of MHE patients revealed decreased hippocampal volume, which suggests regional atrophy, and reduced hippocampal connectivity with regions that are primarily involved in the default-mode network, thereby suggesting a functional disconnection syndrome. These alterations reveal the mechanisms underlying cognitive deterioration with disease progression.

Noncirrhotic Portal Hypertension: Current and Emerging Perspectives

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are prototype noncirrhotic causes of portal hypertension (PHT), characterized by normal hepatic venous pressure gradient, variceal bleeds, and moderate to massive splenomegaly with preserved liver synthetic functions. Infections, toxins, and immunologic, prothrombotic and genetic disorders are possible causes in IPH, whereas prothrombotic and local factors around the portal vein lead to EHPVO. Growth failure, portal biliopathy, and minimal hepatic encephalopathy are long-term concerns in EHPVO. Surgical shunts and transjugular intrahepatic portosystemic shunt resolve the complications secondary to PHT. Meso-Rex shunt is now the standard-of-care surgery in children with EHPVO.

Hepatic Encephalopathy in Children With Acute Liver Failure: Utility of Serum Neuromarkers

BACKGROUND

Pediatric acute liver failure (PALF) is a public heath burden, often requiring prolonged hospitalization and liver transplantation. Hepatic encephalopathy (HE) is a complication of PALF with limited diagnostic tools to predict outcomes. Serum neurological markers (neuron-specific enolase, S100β, and myelin basic protein) can be elevated in traumatic or ischemic brain injury. We hypothesized that these neuromarkers would be associated with the development of HE in PALF.

METHODS

PALF study participants enrolled between May 2012 and December 2014 by 12 participating centers were the subjects of this analysis. Daily HE assessments were determined by study investigators. Neurological and inflammatory markers were measured using enzyme-linked immunosorbent assay and MILLIPLEX techniques, respectively. To model encephalopathy, these markers were log2 transformed and individually examined for association with HE using a generalized linear mixed model with a logit link and random intercept.

RESULTS

Eighty-two children had neurological and inflammatory marker levels and HE assessments recorded, with the majority having assessments for 3 days during their illness. An indeterminate diagnosis (29%) was most common and the median age was 2.9 years. Significant associations were observed for HE with S100β (odds ratio 1.16, 95% confidence interval [1.03-1.29], P = 0.04) and IL-6 (odds ratio 1.24 [1.11-1.38], P = 0.006).

CONCLUSIONS

Serum S100β and IL-6 are associated with HE in children with PALF. Measuring these markers may assist in assessing neurological injury in PALF, impacting clinical decisions.

Stroop Test Validation to Screen for Minimal Hepatic Encephalopathy in Pediatric Extrahepatic Portal Venous Obstruction

OBJECTIVES

Minimal hepatic encephalopathy (MHE) has been reported in children with extrahepatic portal vein obstruction (EHPVO). MHE assessment is restricted to research situations as neuropsychiatric tests are time-intensive. Computerized Stroop Test (CST) has been used in cirrhotic adults for MHE screening. The study aims to assess MHE frequency in young Indian children with EHPVO and validate CST for MHE screening in pediatric EHPVO.

METHODS

Thirty-seven children with EHPVO between 7 and 12 years of age and 37 age- and sex-matched controls were enrolled. Fasting plasma ammonia was measured. MHE was diagnosed by Revised Amsterdamse Kinder Intelligentie Test. The performance of a Tamil language version of CST in MHE screening was assessed.

RESULTS

MHE was diagnosed in 18.9% (7/37) of EHPVO (EHPVO-MHE). Plasma ammonia levels were higher in EHPVO-MHE compared to EHPVO without MHE (EHPVO-No-MHE) but abnormal plasma ammonia levels are unsuitable for MHE screening. CST was administered in 35 EHPVO and 37 controls. EHPVO-MHE, compared to EHPVO-No-MHE, had longer "on time," "off time," "(on+off) time," and "(on-off) time." For MHE diagnosis, specificity and sensitivity of "(on+off) time" were 100% and 89.6% for a cutoff of >180.4 seconds (area under receiver operating characteristic = 0.97).

CONCLUSIONS

In the absence of other risk factors for neurological insult or patent surgical shunts, MHE frequency in young Indian children with EHPVO, determined by Revised Amsterdamse Kinder Intelligentie Test, was lesser than in earlier studies. CST is suitable for MHE screening in clinical practice to select patients for neuropsychiatric evaluation.

Idiopathic portal hypertension and extrahepatic portal venous obstruction

BACKGROUND

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations.

AIM

The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO.

RESULTS

IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO.

CONCLUSION

This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

Evaluation of cognitivity, proinflammatory cytokines, and brain magnetic resonance imaging in minimal hepatic encephalopathy induced by cirrhosis and extrahepatic portal vein obstruction

BACKGROUND AND AIMS

Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE) and is characterized by deficits in neurocognitive performance without any clinical symptoms of HE. In the current study, we aim to evaluate and compare the neurocognitive, biochemical, and brain magnetic resonance (MR) imaging changes between patients with cirrhotic MHE and extrahepatic portal vein obstruction (EHPVO) MHE.

METHODS

Thirty-three cirrhotic and 14 EHPVO patients were diagnosed with MHE and were included in the analysis along with 24 normal healthy volunteers. All subjects underwent MR imaging including diffusion tensor imaging and proton MR spectroscopy (¹ H-MRS) followed by cognitive assessments, critical flicker frequency (CFF) measurements, quantification of blood ammonia, and serum proinflammatory cytokine levels.

RESULTS

We observed abnormal neurocognitive functions and CFF measurements in both cirrhotic MHE and EHPVO MHE patients as compared with controls. Significantly increased blood ammonia, serum proinflammatory cytokines (IL-6, TNF-α) level, mean diffusivity in multiple brain sites, ¹ H-MRS derived glutamate/glutamine (Glx)/creatine (Cr), and significantly decreased ¹ H-MRS derived myo-inositol/Cr were observed in both cirrhotic MHE and EHPVO MHE compared with those of controls. Choline/Cr level was significantly decreased in cirrhotic MHE as compared with controls and EHPVO MHE.

CONCLUSIONS

Cirrhotic MHE showed more severe changes on mean diffusivity in multiple brain sites and inflammation as compared with EHPVO MHE. This study confirms that there are significant difference in neurocognitive, biochemical, and MR profile between cirrhotic MHE and EHPVO MHE, which may help to understand the pathophysiologies of these two types of MHE and may contribute to improve their clinical managements.

Brain magnetic resonance in hepatic encephalopathy

The term hepatic encephalopathy (HE) covers a wide spectrum of neuropsychiatric abnormalities caused by portal-systemic shunting. The diagnosis requires demonstration of liver dysfunction or portal-systemic shunts and exclusion of other neurologic disorders. Most patients with this condition have liver dysfunction caused by cirrhosis, but it also occurs in patients with acute liver failure and less commonly, in patients with portal-systemic shunts that are not associated with hepatocellular disease. Various magnetic resonance (MR) techniques have improved our knowledge about the pathophysiology of HE. Proton MR spectroscopy and T1-weighted imaging can detect and quantify accumulations of brain products that are normally metabolized or eliminated such as glutamine and manganese. Other MR techniques such as T2-weighted and diffusion-weighted imaging can identify white matter abnormalities resulting from disturbances in cell volume homeostasis secondary to brain hyperammonemia. Partial or complete recovery of these abnormalities has been observed with normalization of liver function or after successful liver transplantation. MR studies have undoubtedly improved our understanding of the mechanisms involved in the pathogenesis of HE, and some findings can be considered biomarkers for monitoring the effects of therapeutic measures focused on correcting this condition.

Non-cirrhotic portal hypertension

Non-cirrhotic portal hypertension (NCPH) encompasses a wide range of disorders, primarily vascular in origin, presenting with portal hypertension (PHT), but with preserved liver synthetic functions and near normal hepatic venous pressure gradient (HVPG). Non-cirrhotic portal fibrosis/Idiopathic PHT (NCPF/IPH) and extrahepatic portal venous obstruction (EHPVO) are two prototype disorders in the category. Etiopathogenesis in both of them centers on infections and prothrombotic states. Presentation and management strategies focus on repeated well tolerated episodes of variceal bleed and moderate to massive splenomegaly and other features of PHT. While the long-term prognosis is generally good in NCPF, portal biliopathy and parenchymal extinction after prolonged PHT makes outcome somewhat less favorable in EHPVO. While hepatic schistosomiasis, congenital hepatic fibrosis and nodular regenerative hyperplasia have their distinctive features, they often present with NCPH.

Non-cirrhotic portal hypertension - diagnosis and management

NCPH is a heterogeneous group of liver disorders of vascular origin, leading to PHT with near normal HVPG. NCPF/IPH is a disorder of young adults or middle aged women, whereas EHPVO is a disorder of childhood. Early age acute or recurrent infections in an individual with thrombotic predisposition constitute the likely pathogenesis. Both disorders present with clinically significant PHT with preserved liver functions. Diagnosis is easy and can often be made clinically with support from imaging modalities. Management centers on control and prophylaxis of variceal bleeding. In EHPVO, there are additional concerns of growth faltering, portal biliopathy, MHE and parenchymal dysfunction. Surgical shunts are indicated in patients with failure of endotherapy, bleeding from sites not amenable to endotherapy, symptomatic hypersplenism or symptomatic biliopathy. Persistent growth failure, symptomatic and recurrent hepatic encephalopathy, impaired quality of life or massive splenomegaly that interferes with daily activities are other surgical indications. Rex-shunt or MLPVB is the recommended shunt for EHPVO, but needs proper pre-operative radiological assessment and surgical expertise. Both disorders have otherwise a fairly good prognosis, but need regular and careful surveillance. Hepatic schistosomiasis, CHF and NRH have similar presentation and comparable prognosis.

Correlation between interleukin-6 and ammonia in patients with overt hepatic encephalopathy due to cirrhosis

OBJECTIVE

Previous studies have shown that elevated serum levels of interleukin-6 (IL-6) correlate with the severity of overt hepatic encephalopathy (OHE) in cirrhotic patients. However, the correlation between serum IL-6 levels and plasma ammonia levels in these patients remains unclear. Therefore, the present study investigated this correlation between both variables in cirrhotic patients with OHE.

METHODS

Fifty-five cirrhotic patients with various grades of OHE, 29 cirrhotic patients without OHE, and 30 healthy controls were recruited. Concentrations of plasma ammonia and serum IL-6 were simultaneously measured.

RESULTS

In cirrhotic patients with OHE, the severity of OHE, represented by the West Haven criteria, correlated with serum IL-6 levels (r=0.43, P<0.05) and plasma ammonia levels (r=0.59, P<0.05). IL-6 and ammonia were found to be significant independent predictors of OHE severity (P<0.05 for both variables). Furthermore, the severity of liver cirrhosis, determined by Child-Pugh scores, correlated with serum IL-6 levels (r=0.45, P<0.05) and plasma ammonia levels (r=0.68, P<0.05) in these patients. Moreover, there was a significant positive correlation between serum IL-6 levels and plasma ammonia levels (r=0.58, P<0.05) in cirrhotic patients with OHE, but not in patients without OHE (r=0.42, P>0.05) or healthy controls (r=0.27, P>0.05). The correlation between IL-6 and ammonia was independent of infectious precipitating factors.

CONCLUSIONS

The results of the present study suggest that IL-6 might be involved in the mechanism by which ammonia contributes to the pathogenesis of OHE. There is also evidence of a potential synergistic interaction between proinflammatory cytokines and ammonia in the pathogenesis of OHE.

Pathogenesis of hepatic encephalopathy

Hepatic encephalopathy can be a serious complication of acute liver failure and chronic liver diseases, predominantly liver cirrhosis. Hyperammonemia plays the most important role in the pathogenesis of hepatic encephalopathy. The brain-blood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, GABA-ergic or benzodiazepine pathway abnormalities, manganese neurotoxicity, brain energetic disturbances, and brain blood flow abnormalities are considered to be involved in the development of hepatic encephalopathy. The influence of small intestine bacterial overgrowth (SIBO) on the induction of minimal hepatic encephalopathy is recently emphasized. The aim of this paper is to present the current views on the pathogenesis of hepatic encephalopathy.

Relationship between interleukin-6 and ammonia in patients with minimal hepatic encephalopathy due to liver cirrhosis

AIM

  Previous studies have shown significantly elevated levels of interleukin (IL)-6 in cirrhotic patients with minimal hepatic encephalopathy (MHE), but the relationship between circulating levels of IL-6 and ammonia is unclear. The aim of this study is to investigate the relationship between both variables in cirrhotic patients with MHE.

METHODS

  Psychometric tests including number connection test part A (NCT-A) and digit symbol test (DST) were performed to diagnose MHE in 85 cirrhotic patients. Simultaneously, circulating levels of IL-6 and ammonia were measured.

RESULTS

  Thirty-two (37.6%) cirrhotic patients were diagnosed with MHE. IL-6 and ammonia were the independent predictors of the presence of MHE (P < 0.05 for both variables). Circulating levels of IL-6 and ammonia correlated with the severity of MHE represented by results of NCT-A (r = 0.56, P < 0.05 and r = 0.39, P < 0.05, respectively) and DST (r = -0.48, P < 0.05 and r = -0.47, P < 0.05, respectively). Moreover, there was a significant correlation between circulating levels of IL-6 and those of ammonia in patients with MHE (r = 0.61, P < 0.05), and a positive additive interaction was found between IL-6 and ammonia on the presence of MHE, with a significant synergy index of 1.51 (95% confidence interval = 1.12-3.46).

CONCLUSION

  The present study demonstrates a significant correlation and a positive additive interaction between IL-6 and ammonia in cirrhotic patients with MHE, suggesting that IL-6 may have a potential synergistic relationship with ammonia in the induction of MHE.

Advantages of the meso-Rex bypass compared with portosystemic shunts in the management of extrahepatic portal vein obstruction in children

BACKGROUND

Consequences of extrahepatic portal vein obstruction (EHPVO) include variceal bleeding and hypersplenism due to portal hypertension, as well as metabolic abnormalities secondary to impaired portal venous circulation. The purpose of this study was to compare the effectiveness of meso-Rex bypass and portosystemic shunt (PSS) for reversing these symptoms in children with EHPVO.

STUDY DESIGN

All children with idiopathic EHPVO evaluated for potential meso-Rex bypass at a single institution between 1997 and 2010 were reviewed. Portosystemic shunt was performed in patients with refractory portal hypertension when meso-Rex bypass was not technically feasible. Outcomes of meso-Rex bypass and PSS were compared, including resolution of portal hypertensive bleeding and hypersplenism, as well as changes in liver synthetic function, ammonia levels, and somatic growth.

RESULTS

Sixty-five children with EHPVO underwent successful meso-Rex bypass, while 16 required PSS. Nearly all patients experienced complete relief of variceal bleeding after meso-Rex (96%) bypass and PSS (100%). The improvements in platelet count (+82.1 ± 60.0 vs +32.4 ± 56.3 thousand/μL; p=0.004), internal normalized ratio (-0.22 ± 0.27 vs 0.01 ± 0.14; p=0.022), and serum ammonia level (-26.8 ± 36.8 vs +19.4 ± 33.1 μM/L; p=0.002) were greater after meso-Rex bypass than PSS. Among patients with below average (standard deviation z-score<0) preoperative weight for age, the improvement in weight-for-age z-score was greater after meso-Rex bypass (+0.84 ± 0.98) than PSS (+0.17 ± 0.79, p=0.044). Median duration of follow-up was 4.45 years after meso-Rex bypass and 1.8 years after PSS.

CONCLUSIONS

Both meso-Rex bypass and PSS effectively relieve symptoms of portal hypertensive bleeding in children with EHPVO, although the meso-Rex better relieves hypersplenism. By restoring normal portal venous circulation, the meso-Rex bypass has additional metabolic benefits.

Focal cortical damage parallels cognitive impairment in minimal hepatic encephalopathy

Little attention has been paid to cortical integrity in patients with minimal hepatic encephalopathy (MHE), although cognitive functions affected in early stages of liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 3T magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood ammonia levels accounted for the loss of cortical integrity in different stages of liver disease. Finally, we assessed group differences in volume of different subcortical regions and their potential relationships with CFF scores/blood ammonia levels. Results showed a focal thinning of the superior temporal cortex and precuneus in MHE patients when compared with NMHE and controls. Relationships between blood ammonia levels and cortical thickness of the calcarine sulcus accounted for impaired visual judgment in patients with MHE when compared to NMHE. Regression analyses between cortical thickness and CFF predicted differences between controls and the two groups of HE patients, but failed to discriminate between patients with NMHE and MHE. Taking together, these findings provide the first report of cortical thinning in MHE patients, and they yield novel insights into the neurobiological basis of cognitive impairment associated with early stages of liver diseases.