Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism.
Ontology highlight
ABSTRACT:
SUBMITTER: Diaz-Fontenla F
PROVIDER: S-EPMC5537191 | biostudies-other | 2017 Jul
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The syndrome we refer to as Hepatic Encephalopathy (HE) was first characterized by a team of Nobel Prize winning physiologists led by Pavlov and Nencki at the Imperial Institute of Experimental Medicine in Russia in the 1890's. This focused upon the key observation that performing a portocaval shunt, which bypassed nitrogen-rich blood away from the liver, induced elevated blood and brain ammonia concentrations in association with profound neurobehavioral changes. There exists however a spectrum of metabolic encephalopathies attributable to a variety (or even absence) of liver hepatocellular dysfunctions and it is this spectrum rather than a single disease entity that has come to be defined as HE. Differences in the underlying pathophysiology, treatment responses and outcomes can therefore be highly variable between acute and chronic HE. The term also fails to articulate quite how systemic the syndrome of HE can be and how it can be influenced by the gastrointestinal, renal, nervous, or immune systems without any change in background liver function. The pathogenesis of HE therefore encapsulates a complex network of interdependent organ systems which as yet remain poorly characterized. There is nonetheless a growing recognition that there is a complex but influential synergistic relationship between ammonia, inflammation (sterile and non-sterile) and oxidative stress in the pathogenesis HE which develops in an environment of functional immunoparesis in patients with liver dysfunction. Therapeutic strategies are thus moving further away from the traditional specialty of hepatology and more towards novel immune and inflammatory targets which will be discussed in this review.
| S-EPMC4442852 | biostudies-other
Project description:Treatment options for refractory hepatic encephalopathy (HE) are limited. Patients who fail medical management may harbor large portosystemic shunts (PSSs) which are possible therapeutic targets. This study aims to describe patient selection, effectiveness, and safety of percutaneous PSS embolization in those with medically refractory HE. A retrospective evaluation of consecutive adult patients with medically refractory HE referred for PSS embolization at a tertiary center was performed (2003-2015). Patient data collected included the type of HE, medications, Model for End-Stage Liver Disease (MELD) score, shunt type, embolization approach, and materials used. Outcomes of interest were immediate (7 days), intermediate (1-4 months), and longer-term (6-12 months) effectiveness and periprocedural safety. Effectiveness was determined based on changes in hospitalization frequency, HE medications, and symptoms. Twenty-five patients with large PSS were evaluated for shunt embolization. Five were excluded due to high MELD scores (n = 1), comorbid conditions (n = 1), or technical considerations (n = 3). Of 20 patients who underwent embolization, 13 had persistent and 7 had recurrent HE; 100% (20/20) achieved immediate improvement. Durable benefit was achieved in 100% (18/18) and 92% (11/12) at 1-4 and 6-12 months, respectively. The majority (67%; 8/12) were free from HE-related hospitalizations over 1 year; 10% developed procedural complications, and all resolved. Six developed new or worsening ascites. In conclusion, PSS embolization is a safe and effective treatment strategy that should be considered for select patients with medically refractory HE. Liver Transplantation 22 723-731 2016 AASLD.
| S-EPMC4917293 | biostudies-literature
Project description:Ammonia production is implicated in the pathogenesis of hepatic encephalopathy (HE), being intestinal glutaminase activity the main source for ammonia. Management of ammonia formation can be effective in HE treatment by lowering intestinal ammonia production. The use of glutaminase inhibitors represents one way to achieve this goal. In this work, we have performed a search for specific inhibitors that could decrease glutaminase activity by screening two different groups of compounds: i) a group integrated by a diverse, highly pure small molecule compounds derived from thiourea ranging from 200 to 800 Daltons; and ii) a group integrated by commonly use compounds in the treatment of HE. Results shown that THDP-17 (10 µM), a thiourea derivate product, could inhibit the intestinal glutaminase activity (57.4±6.7%). Inhibitory effect was tissue dependent, ranging from 40±5.5% to 80±7.8% in an uncompetitive manner, showing Vmax and Km values of 384.62 µmol min(-1), 13.62 mM with THDP-17 10 µM, respectively. This compound also decreased the glutaminase activity in Caco-2 cell cultures, showing a reduction of ammonia and glutamate production, compared to control cultures. Therefore, the THDP-17 compound could be a good candidate for HE management, by lowering ammonia production.
| S-EPMC4201470 | biostudies-literature
Project description:Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology, but its specific influence in liver is less understood. Here, we studied how CH influences the liver gene expression program in adulthood. Pregnant rats were given the antithyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as reductions in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, the feed efficiency increased in CH, and this was accompanied by significant catch-up growth. On PND80, significant reductions in body mass, tail length, and circulating IGF-I levels remained in CH rats. Conversely, the mRNA levels of known GH target genes were significantly upregulated. The serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in the expression of hepatic genes involved in lipid metabolism, including an increased transcription of PPAR? and a reduced expression of genes involved in fatty acid and cholesterol uptake, cellular sterol efflux, triglyceride assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to the onset of hypothyroidism in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters and to T3 replacement with an enhanced activation of malic enzyme. In summary, we provide in vivo evidence that neonatal hypothyroidism influences the hepatic transcriptional program and tissue sensitivity to hormone treatment in adulthood. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood.
| S-EPMC3354003 | biostudies-literature
Project description:The therapeutic effects of iron, zinc and magnesium trace elements, as well as rifaximin were investigated and compared in HE rats. In this study, HE rats were treated with either ferrous sulfate (HE-Fe, 30 mg/kg/day), zinc sulfate (HE-Zn, 30 mg/kg/day), magnesium sulfate (HE-Mg, 50 mg/kg/day) or rifaximin (HE-Rf, 50 mg/kg/day), which was mixed with water and administered orally for 61 days. The Morris water maze (MWM) and open-field tests were used to evaluate cognitive and locomotor function. The blood ammonia levels before and after administration of the glutamine challenge test, manganese concentration and glutamine synthetase (GS) activity were measured. Significantly longer MWM escape latencies, less locomotor activity, higher blood ammonia levels, higher brain manganese concentrations and higher GS activity were observed in HE rats. However, HE-Mg and HE-Rf rats had significantly shorter MWM escape latencies, increased locomotor activity, lower blood ammonia, lower brain manganese concentrations and lower GS activity. Partial improvements were observed in HE-Fe and HE-Zn rats. The results indicated that oral administration of magnesium can significantly improve the cognitive and locomotor functions in HE rats by reducing the brain manganese concentration and regulating GS activity.
| S-EPMC5431966 | biostudies-literature
Project description:Objective: Hepatic encephalopathy (HE) characterized by neuropsychiatric abnormalities is a major complication of cirrhosis with high mortality. However, the pathogenesis of HE has not been fully elucidated. This study aimed to determine endogenous hydrogen sulfide (H2S) in the blood of HE patients and investigate the role of H2S in an astrocytic model of HE. Methods: Patients with and without HE were recruited to determine plasma H2S levels and blood microbial 16S rRNA gene. Rat astrocytes were employed as a model of HE by treatment of NH4Cl. Exogenous H2S was preadded. Cell viability was measured by Cell Counting Kit-8 (CCK-8) assay, and cell death was evaluated by lactate dehydrogenase (LDH) release. Apoptosis was determined by Hoechst 33342/Propidium Iodide (PI) Double Staining and Western blot analysis of apoptosis-related protein expression. Intracellular reactive oxygen species (ROS) levels were assessed by flow cytometer. Expressions of Nrf2 and its downstream regulated genes were examined by immunofluorescence staining and Western blot, respectively. Nrf2 gene knockdown was performed by antisense shRNA of Nrf2 gene. Results: There was a significant decrease in H2S levels in cirrhotic patients with HE compared with without HE. Blood microbiota analyses revealed that certain strains associated with H2S production were negatively correlated with HE. In vitro, H2S markedly attenuated NH4Cl-induced cytotoxicity, oxidative stress, and apoptosis. This effect was mediated by Nrf2/ARE signaling, and knockdown of Nrf2 expression abolished the antagonistic effect of H2S on NH4Cl-induced neurotoxicity in astrocytes. Conclusion: Levels of H2S and bacteria associated with H2S production are decreased in HE, and H2S functions as the neuroprotector against NH4Cl-induced HE by activating Nrf2/ARE signaling of astrocytes.
| S-EPMC7642620 | biostudies-literature
Project description:BackgroundSarcopenia and myosteatosis have been associated to a poor prognosis of cirrhosis and to a higher incidence of hepatic encephalopathy (HE). The prognostic implications of visceral and subcutaneous adiposity are less known.AimTo evaluate the modifications of visceral and subcutaneous adipose tissue after TIPS and to investigate their relationships with the modification of muscle mass and with the incidence of post-TIPS HE.Patients and methods35 cirrhotic patients submitted to TIPS were retrospectively studied. The modification of skeletal muscle index (SMI), muscle attenuation (myosteatosis), subcutaneous adipose tissue index (SATI), visceral adipose tissue index (VATI), assessed by CT-scan and plasma ammonia were evaluated before and after a mean follow-up of 19 ± 15 months after TIPS. The number of episodes of overt HE was also recorded.ResultsDuring the follow-up, the mean SMI and muscle attenuation increased significantly; SATI significantly increased while VATI significantly decreased, although not uniformly in all patients. By comparing the patients with or without improvement in their nutritional status after TIPS, MELD remained stable while the number of episodes of overt HE was significantly lower in the patients with improved SMI and in the patients with improved SATI. Finally, inverse correlation was observed between the variation of ammonia and SATI (r = -.40; P < .05).ConclusionIn addition to muscle mass, adipose tissue is modified after TIPS. The improvement of subcutaneous adipose tissue as well as of sarcopenia and myosteatosis is associated to the amelioration of cognitive impairment independently of liver function. The correlation between adipose tissue and ammonia modification may suggest an active role of the adipose tissue in the inter-organ ammonia trafficking.
| S-EPMC9293456 | biostudies-literature
Project description:Background and purposeIn acute hepatic encephalopathy, MR imaging abnormalities have been described in the PVWM, thalami, and corticospinal tracts. We sought to determine characteristic regions of involvement on FLAIR and DWI, to evaluate their reversibility, and to correlate MR imaging extent with clinical severity.Materials and methodsTwenty patients who presented clinically with acute hepatic encephalopathy and MR imaging <21 days after symptom onset were reviewed retrospectively. Two neuroradiologists recorded involved regions on FLAIR and DWI in each, measured ADC values in affected regions and NAWM, and scored the MR imaging severity/extent. The initial severity (West Haven grade), follow-up clinical severity (degree of improvement), and maximal PAL within ±8 days of MR imaging were recorded and correlated with the MR imaging severity.ResultsOn FLAIR and DWI respectively, there were abnormalities in the thalami (85%, 70%), PLIC (75%, 80%), PVWM (80%, 85%), and DBS (70%, 35%) and diffuse cortical involvement (30%, 25%). There were relatively strong significant (P < .005) correlations of FLAIR (r = 0.680, P = .001) and DWI severity (r = 0.690, P = .001) with PAL, and of PAL with the clinical outcome (r = 0.691, P = .001). Both FLAIR (r = 0.592, P = .006) and DWI (r = 0.487, P = .029) severity correlated moderately with the clinical outcome but were not significant at the P < .005 level after Bonferroni correction.ConclusionsPatients with acute hepatic encephalopathy may exhibit characteristic regions of involvement on FLAIR with DWI findings that can be reversible. The MR imaging extent on FLAIR and DWI strongly correlates with the maximal PAL, and PAL correlates well with the clinical outcome. Diffuse cortical involvement has a higher potential for neurologic sequelae but can be reversible.
| S-EPMC7966093 | biostudies-literature
Project description:Minimal hepatic encephalopathy (MHE) adversely affects the clinical outcomes of patients with liver cirrhosis. This prospective study aimed to evaluate the utility of the Stroop test in the diagnosis of MHE and prediction of overt hepatic encephalopathy (OHE) in Japanese patients with cirrhosis. We enrolled 152 patients who underwent the Stroop test between November 2018 and February 2020. MHE was diagnosed using a combination of neuropsychological tests as the gold standard. The enrolled patients were followed up prospectively until the occurrence of OHE or August 2020. The optimal cutoff value of the Stroop test measurements was determined by receiver operating characteristic (ROC) curve analysis, and its predictive ability was assessed using the area under the ROC curve (AUC). Among the 139 eligible patients, 50 (36%) were diagnosed with MHE. The OffTime+OnTime cutoff value of 218.3 seconds had the best discriminative ability for MHE diagnosis, with an AUC of 0.77, a sensitivity of 74%, and a specificity of 75%. During a median follow-up of 10.8 months, 6 (4%) patients developed OHE. The OffTime+OnTime cutoff value of 305.6 seconds had the highest predictive ability for OHE, with an AUC of 0.79, a sensitivity of 67%, and a specificity of 92%. This value predicted OHE occurrence independent of liver functional reserve and prior OHE (hazard ratio, 19.8; P = 0.003). These two cutoff values remained statistically significant even when patients with prior OHE were excluded from the analysis. Conclusion: The Stroop test was useful for diagnosing patients with MHE and predicting OHE in Japanese patients with cirrhosis.
| S-EPMC8435282 | biostudies-literature
Project description: Not available
| S-EPMC8257181 | biostudies-literature