Sympathetic nervous activation, mitochondrial dysfunction and outcome in acutely decompensated cirrhosis: the metabolomic prognostic models (CLIF-C MET).

BACKGROUND AND AIMS: Current prognostic scores of patients with acutely decompensated cirrhosis (AD), particularly those with acute-on-chronic liver failure (ACLF), underestimate the risk of mortality. This is probably because systemic inflammation (SI), the major driver of AD/ACLF, is not reflected in the scores. SI induces metabolic changes, which impair delivery of the necessary energy for the immune reaction. This investigation aimed to identify metabolites associated with short-term (28-day) death and to design metabolomic prognostic models. METHODS: Two prospective multicentre large cohorts from Europe for investigating ACLF and development of ACLF, CANONIC (discovery, n=831) and PREDICT (validation, n=851), were explored by untargeted serum metabolomics to identify and validate metabolites which could allow improved prognostic modelling. RESULTS: Three prognostic metabolites strongly associated with death were selected to build the models. 4-Hydroxy-3-methoxyphenylglycol sulfate is a norepinephrine derivative, which may be derived from the brainstem response to SI. Additionally, galacturonic acid and hexanoylcarnitine are associated with mitochondrial dysfunction. Model 1 included only these three prognostic metabolites and age. Model 2 was built around 4-hydroxy-3-methoxyphenylglycol sulfate, hexanoylcarnitine, bilirubin, international normalised ratio (INR) and age. In the discovery cohort, both models were more accurate in predicting death within 7, 14 and 28 days after admission compared with MELDNa score (C-index: 0.9267, 0.9002 and 0.8424, and 0.9369, 0.9206 and 0.8529, with model 1 and model 2, respectively). Similar results were found in the validation cohort (C-index: 0.940, 0.834 and 0.791, and 0.947, 0.857 and 0.810, with model 1 and model 2, respectively). Also, in ACLF, model 1 and model 2 outperformed MELDNa 7, 14 and 28 days after admission for prediction of mortality. CONCLUSIONS: Models including metabolites (CLIF-C MET) reflecting SI, mitochondrial dysfunction and sympathetic system activation are better predictors of short-term mortality than scores based only on organ dysfunction (eg, MELDNa), especially in patients with ACLF.

Blood metabolomics uncovers inflammation-associated mitochondrial dysfunction as a potential mechanism underlying ACLF.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF), which develops in patients with cirrhosis, is characterized by intense systemic inflammation and organ failure(s). Because systemic inflammation is energetically expensive, its metabolic costs may result in organ dysfunction/failure. Therefore, we aimed to analyze the blood metabolome in patients with cirrhosis, with and without ACLF. METHODS: We performed untargeted metabolomics using liquid chromatography coupled to high-resolution mass spectrometry in serum from 650 patients with AD (acute decompensation of cirrhosis, without ACLF), 181 with ACLF, 43 with compensated cirrhosis, and 29 healthy individuals. RESULTS: Of the 137 annotated metabolites identified, 100 were increased in patients with ACLF of any grade, relative to those with AD, and 38 comprised a distinctive blood metabolite fingerprint for ACLF. Among patients with ACLF, the intensity of the fingerprint increased across ACLF grades, and was similar in patients with kidney failure and in those without, indicating that the fingerprint reflected not only decreased kidney excretion but also altered cell metabolism. The higher the ACLF-associated fingerprint intensity, the higher the plasma levels of inflammatory markers, tumor necrosis factor α, soluble CD206, and soluble CD163. ACLF was characterized by intense proteolysis and lipolysis; amino acid catabolism; extra-mitochondrial glucose metabolism through glycolysis, pentose phosphate, and D-glucuronate pathways; depressed mitochondrial ATP-producing fatty acid ß-oxidation; and extra-mitochondrial amino acid metabolism giving rise to metabotoxins. CONCLUSIONS: In ACLF, intense systemic inflammation is associated with blood metabolite accumulation and profound alterations in major metabolic pathways, in particular inhibition of mitochondrial energy production, which may contribute to the development of organ failures. LAY SUMMARY: Acute-on-chronic liver failure (ACLF), which develops in patients with cirrhosis, is characterized by intense systemic inflammation and organ failure(s). Because systemic inflammation is energetically expensive, its metabolic costs may result in organ dysfunction/failure. We identified a 38-metabolite blood fingerprint specific for ACLF that revealed mitochondrial dysfunction in peripheral organs. This may contribute to organ failures.

Validation of the Baveno VI criteria to identify low risk cirrhotic patients not requiring endoscopic surveillance for varices.

BACKGROUND & AIMS: The Baveno VI guidelines propose that cirrhotic patients with a liver stiffness measurement (LSM) <20kPa and a platelet count >150,000/µl can avoid screening endoscopy as their combination is highly specific for excluding clinically significant varices. The aim of the study was to validate these criteria. METHODS: Transient elastography data was collected from two institutions from 2006-2015. Inclusion criteria were a LSM ⩾10kPa and an upper gastrointestinal endoscopy within 12months, with a diagnosis of compensated chronic liver disease. Exclusion criteria were porto-mesenteric-splenic vein thrombosis and non-cirrhotic portal hypertension. Varices were graded as low risk (grade <2) or high risk (grade ⩾2). RESULTS: The study included 310 patients (169 (55%) hepatitis C, and 275 (89%) Child-Pugh A). Varices were present in 23% cases, with 5% prevalence of high risk varices. Overall 102/310 (33%) met the Baveno VI criteria. Within this group 11% had varices and 2% had high risk varices, representing 2/15 (13%) of all high risk varices. The Baveno VI criteria gave a sensitivity 0.87, specificity 0.34, positive predictive value 0.06, negative predictive value 0.98, positive likelihood ratio 1.31 and negative likelihood ratio 0.39. The AUROC for LSM and platelet count combined was 0.746. CONCLUSIONS: The Baveno VI criteria performed well correctly identifying 98% of patients who could safely avoid endoscopy. LAY SUMMARY: This study examines the effectives of a recent set of guidelines published by the Baveno VI conference, which states that patients with chronic liver disease and a low liver stiffness (<20kPa) and high platelet count (>150) are at low risk of having varices and do not need a screening endoscopy. Varices are a complication of cirrhosis, confer a risk of serious bleeding, and can be diagnosed and treated by endoscopy. Our study reviewed the clinical records of patients who have had liver stiffness scans and endoscopy over a 9-year period at two hospitals. The results show that only about 2% of patients who meet the Baveno VI criteria will be miss-classified as not having varices.

Increased renal expression and urinary excretion of TLR4 in acute kidney injury associated with cirrhosis.

BACKGROUND: Patients with cirrhosis frequently develop renal dysfunction, a proportion of who do not fulfill criteria for hepatorenal syndrome (HRS). We hypothesized that the kidneys in these patients would exhibit histological and biomarker evidence of kidney injury. We looked specifically for TLR expression as they may mediate kidney injury. METHODS: Sixty seven subjects (6); alcoholic cirrhosis: compensated (9), acute deterioration of alcoholic cirrhosis (52)] were included. Renal dysfunction was defined as a creatinine of >133 µmol/L and/or according to the AKI network criteria. Urinary biomarkers, KIM-1, πGST, αGST and a novel biomarker, urinary TLR4 were measured. Renal biopsies were also available from eight other alcoholic cirrhosis patients (three non-HRS renal dysfunction; five HRS) that were stained for TLR4 and caspase-3. RESULTS: Fourteen patients developed renal dysfunction, amongst these three had type 2 HRS. KIM-1, πGST and αGST were higher in patients with acute deterioration of cirrhosis compared with patients with compensated cirrhosis, but did not differ between those with and without renal dysfunction. Urinary TLR4 was significantly higher in patients with renal dysfunction associated with infection/inflammation. Kidney biopsies from non-HRS renal dysfunction patients showed tubular damage with evidence of increased tubular expression of TLR4, and caspase-3. Minor changes were observed in HRS patients. CONCLUSIONS: The data provide proof of concept that renal dysfunction in patients with cirrhosis with superimposed inflammation is associated with significant tubular injury and apoptosis and with increased renal expression and urinary excretion of the TLR4, suggesting a potential role of TLR4 as mediator of renal injury.

Guidance document: risk assessment of patients with cirrhosis prior to elective non-hepatic surgery.

As a result of the increasing incidence of cirrhosis in the UK, more patients with chronic liver disease are being considered for elective non-hepatic surgery. A historical reluctance to offer surgery to such patients stems from general perceptions of poor postoperative outcomes. While this is true for those with decompensated cirrhosis, selected patients with compensated early-stage cirrhosis can have good outcomes after careful risk assessment. Well-recognised risks include those of general anaesthesia, bleeding, infections, impaired wound healing, acute kidney injury and cardiovascular compromise. Intra-abdominal or cardiothoracic surgery are particularly high-risk interventions. Clinical assessment supplemented by blood tests, imaging, liver stiffness measurement, endoscopy and assessment of portal pressure (derived from the hepatic venous pressure gradient) can facilitate risk stratification. Traditional prognostic scoring systems including the Child-Turcotte-Pugh and Model for End-stage Liver Disease are helpful but may overestimate surgical risk. Specific prognostic scores like Mayo Risk Score, VOCAL-Penn and ADOPT-LC can add precision to risk assessment. Measures to mitigate risk include careful management of varices, nutritional optimisation and where possible addressing any ongoing aetiological drivers such as alcohol consumption. The role of portal decompression such as transjugular intrahepatic portosystemic shunting can be considered in selected high-risk patients, but further prospective study of this approach is required. It is of paramount importance that patients are discussed in a multidisciplinary forum, and that patients are carefully counselled about potential risks and benefits.

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-1ß (alcoholic cirrhosis), interleukin-17a and macrophage inflammatory protein-1ß (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.