An artificial intelligence-generated model predicts 90-day survival in alcohol-associated hepatitis: A global cohort study.

BACKGROUND AND AIMS: Alcohol-associated hepatitis (AH) poses significant short-term mortality. Existing prognostic models lack precision for 90-day mortality. Utilizing artificial intelligence in a global cohort, we sought to derive and validate an enhanced prognostic model. APPROACH AND RESULTS: The Global AlcHep initiative, a retrospective study across 23 centers in 12 countries, enrolled patients with AH per National Institute for Alcohol Abuse and Alcoholism criteria. Centers were partitioned into derivation (11 centers, 860 patients) and validation cohorts (12 centers, 859 patients). Focusing on 30 and 90-day postadmission mortality, 3 artificial intelligence algorithms (Random Forest, Gradient Boosting Machines, and eXtreme Gradient Boosting) informed an ensemble model, subsequently refined through Bayesian updating, integrating the derivation cohort's average 90-day mortality with each center's approximate mortality rate to produce posttest probabilities. The ALCoholic Hepatitis Artificial INtelligence Ensemble score integrated age, gender, cirrhosis, and 9 laboratory values, with center-specific mortality rates. Mortality was 18.7% (30 d) and 27.9% (90 d) in the derivation cohort versus 21.7% and 32.5% in the validation cohort. Validation cohort 30 and 90-day AUCs were 0.811 (0.779-0.844) and 0.799 (0.769-0.830), significantly surpassing legacy models like Maddrey's Discriminant Function, Model for End-Stage Liver Disease variations, age-serum bilirubin-international normalized ratio-serum Creatinine score, Glasgow, and modified Glasgow Scores ( p < 0.001). ALCoholic Hepatitis Artificial INtelligence Ensemble score also showcased superior calibration against MELD and its variants. Steroid use improved 30-day survival for those with an ALCoholic Hepatitis Artificial INtelligence Ensemble score > 0.20 in both derivation and validation cohorts. CONCLUSIONS: Harnessing artificial intelligence within a global consortium, we pioneered a scoring system excelling over traditional models for 30 and 90-day AH mortality predictions. Beneficial for clinical trials, steroid therapy, and transplant indications, it's accessible at: https://aihepatology.shinyapps.io/ALCHAIN/ .

Feeding behaviour, locomotion rhythms and blood biochemistry of the neotropical red-tail catfish (Phractocephalus hemioliopterus).

The study evaluated the feeding behaviour of Phractocephalus hemioliopterus through the animals' ability to adapt to the self-feeding system, their preferred feeding times and locomotor activity, as well as the blood biochemistry of juveniles fed in a light/dark cycle. The study was carried out through two experiments, the first of which contained two phases. In experiment 1 - phase I, 24 juveniles (35.28 ± 0.62 g) were distributed in eight 48 l tanks. The tanks were equipped with a self-feeding system and the experiment consisted of evaluating whether the animals were able to adapt to the self-feeding system, as well as evaluating the preferred feeding times and locomotor activity of these animals. A feeding challenge to the animals was introduced in phase II, based on the results of phase I. The results of the first phase evidenced a nocturnal feeding preference. Thus, the feeding challenge consisted of measuring whether the animal would feed during the day and how long it would take to adapt. When the animals consumed 100% of the amount of feed provided daily, phase II was ended. In experiment 2, 24 juveniles of P. hemioliopterus (182.00 ± 14.03 g) were distributed in eight 96 l tanks. This experiment consisted of two treatments with four repetitions, one with exclusive feeding during the middle of the light cycle and another with exclusive feeding in the middle of the dark cycle. At the end, blood samples were collected from the animals for blood biochemistry evaluations. In experiment 1 - phase I, the results showed that the fish adapted very well to the self-feeding system and had a strictly nocturnal feeding behaviour and locomotor rhythm. When they were submitted to the feeding challenge in phase II, the feed intake was stabilized from the 17th day onwards, proportionally to the nocturnal consumption observed in the first phase, thus demonstrating feeding plasticity. In experiment 2, the feeding times influenced the animals' biochemical parameters. Animals fed during the night had higher values of cholesterol and triglycerides than animals fed during the day. It is concluded that P. hemioliopterus has fast adaptability to a self-feeding system, with strictly nocturnal feeding and locomotor behaviours. However, it has feeding plasticity, adapting its behaviour according to food availability. Blood biochemical parameters are influenced by the light/dark feeding cycle.

Feeding and locomotor rhythm of the ornamental cichlid fish Amatitlania sp. in different social groups.

The aim of this study was to evaluate the feeding activity and the rhythm of daily locomotor activity of the convict cichlid (Amatitlania sp.) kept in different social groups under a self-feeding system. A total of 120 animals was distributed among six repetitions of four social groups, as follows: group 1 with one male and one female per tank; group 2 with three males and three females per tank; group 3 with six males per tank; and group 4 with six females per tank. Feeding activity (FA) and locomotor activity (LA) were evaluated using photoelectric presence-sensors connected to automatic feeders. The fish were fed a commercial extruded diet (46% crude protein and 3600 kcal kg-1 of digestible energy). Animal growth was evaluated for all groups. After 30 days of experimentation, the fish stabilized their demands by adjusting their consumption. Amatitlania sp. showed predominantly diurnal FA and LA. All groups showed a peak of activity when the light was turned on and when it was turned off. In summary, FA and LA of Amatitlania sp. are predominantly diurnal and independent of social group. Pairs and groups of males and females together consume less food in relation to groups of one sex or the other due to reproductive behaviour. On the other hand, groups of only males or females consume more food because they lack reproductive stimuli and thus prioritize growth. These results may support good feeding management practices for this ornamental cichlid. Studies relating feeding behaviour with different social groups are of great importance for determining effective feeding strategies for this species in captivity. Thus, such a study assists in a more efficient production of Amatitlania sp.

Rectal colonization by resistant bacteria increases the risk of infection by the colonizing strain in critically ill patients with cirrhosis.

BACKGROUND & AIMS: It remains unclear whether rectal colonization with multidrug-resistant organisms (MDROs) is prevalent and predisposes to infections by the same pathogens in patients with cirrhosis. METHODS: Two series of critically ill patients were evaluated. In the Barcelona cohort, 486 consecutive patients were prospectively evaluated, 129 with and 357 without cirrhosis (2015-2016). Rectal swabs were performed at admission and weekly thereafter (until intensive care unit [ICU] discharge) to detect MDRO colonization. Risk factors for colonization and infection by MDROs were evaluated. A retrospective cohort from Frankfurt (421 patients with cirrhosis; 2010-2018) was investigated to evaluate MDRO rectal colonization in another epidemiological scenario. RESULTS: In the Barcelona cohort, 159 patients were colonized by MDROs (32.7%), 102 (64.2%) at admission and 57 (35.8%) during follow-up. Patients with cirrhosis showed higher rates of rectal colonization at admission than those without cirrhosis (28.7% vs. 18.2%, p = 0.01) but similar colonization rates during ICU stay. Extended-spectrum beta-lactamase-Enterobacterales were the most frequent MDROs isolated in both groups. Colonization by MDROs independently increased the risk of infection by MDROs at admission and during follow-up. Risk of new infection by the colonizing strain was also significantly increased in patients with (hazard ratio [HR] 7.41) and without (HR 5.65) cirrhosis. Rectal colonization by MDROs was also highly prevalent in Frankfurt (n = 198; 47%; 131 at admission [66.2%] and 67 [33.8%] during follow-up), with vancomycin-resistant enterococci being the most frequent colonizing organism. Rectal colonization by MDROs was also associated with an increased risk of infection by MDROs in this cohort. Infections occurring in MDR carriers were mainly caused by the colonizing strain. CONCLUSION: Rectal colonization by MDROs is extremely frequent in critically ill patients with cirrhosis. Colonization increases the risk of infection by the colonizing resistant strain. LAY SUMMARY: Rectal colonization by multidrug-resistant organisms (MDROs) is a prevalent problem in patients with cirrhosis requiring critical care. The pattern of colonizing bacteria is heterogeneous with relevant differences between centers. Colonization by MDROs is associated with increased risk of infection by the colonizing bacteria in the short term. This finding suggests that colonization data could be used to guide empirical antibiotic therapy and de-escalation policies in patients with cirrhosis.

Identification of optimal therapeutic window for steroid use in severe alcohol-associated hepatitis: A worldwide study.

BACKGROUND & AIMS: Corticosteroids are the only effective therapy for severe alcohol-associated hepatitis (AH), defined by a model for end-stage liver disease (MELD) score >20. However, there are patients who may be too sick to benefit from therapy. Herein, we aimed to identify the range of MELD scores within which steroids are effective for AH. METHODS: We performed a retrospective, international multicenter cohort study across 4 continents, including 3,380 adults with a clinical and/or histological diagnosis of AH. The main outcome was mortality at 30 days. We used a discrete-time survival analysis model, and MELD cut-offs were established using the transform-the-endpoints method. RESULTS: In our cohort, median age was 49 (40-56) years, 76.5% were male, and 79% had underlying cirrhosis. Median MELD at admission was 24 (19-29). Survival was 88% (87-89) at 30 days, 77% (76-78) at 90 days, and 72% (72-74) at 180 days. A total of 1,225 patients received corticosteroids. In an adjusted-survival-model, corticosteroid use decreased 30-day mortality by 41% (hazard ratio [HR] 0.59; 0.47-0.74; p <0.001). Steroids only improved survival in patients with MELD scores between 21 (HR 0.61; 0.39-0.95; p = 0.027) and 51 (HR 0.72; 0.52-0.99; p = 0.041). The maximum effect of corticosteroid treatment (21-30% survival benefit) was observed with MELD scores between 25 (HR 0.58; 0.42-0.77; p <0.001) and 39 (HR 0.57; 0.41-0.79; p <0.001). No corticosteroid benefit was seen in patients with MELD >51. The type of corticosteroids used (prednisone, prednisolone, or methylprednisolone) was not associated with survival benefit (p = 0.247). CONCLUSION: Corticosteroids improve 30-day survival only among patients with severe AH, especially with MELD scores between 25 and 39. LAY SUMMARY: Alcohol-associated hepatitis is a condition where the liver is severely inflamed as a result of excess alcohol use. It is associated with high mortality and it is not clear whether the most commonly used treatments (corticosteroids) are effective, particularly in patients with very severe liver disease. In this worldwide study, the use of corticosteroids was associated with increased 30-day, but not 90- or 180-day, survival. The maximal benefit was observed in patients with an MELD score (a marker of severity of liver disease; higher scores signify worse disease) between 25-39. However, this benefit was lost in patients with the most severe liver disease (MELD score higher than 51).

Effects of Albumin Treatment on Systemic and Portal Hemodynamics and Systemic Inflammation in Patients With Decompensated Cirrhosis.

BACKGROUND & AIMS: We investigated the effect of albumin treatment (20% solution) on hypoalbuminemia, cardiocirculatory dysfunction, portal hypertension, and systemic inflammation in patients with decompensated cirrhosis with and without bacterial infections. METHODS: We performed a prospective study to assess the effects of long-term (12 weeks) treatment with low doses (1 g/kg body weight every 2 weeks) and high doses (1.5 g/kg every week) of albumin on serum albumin, plasma renin, cardiocirculatory function, portal pressure, and plasma levels of cytokines, collecting data from 18 patients without bacterial infections (the Pilot-PRECIOSA study). We also assessed the effect of short-term (1 week) treatment with antibiotics alone vs the combination of albumin plus antibiotics (1.5 g/kg on day 1 and 1 g/kg on day 3) on plasma levels of cytokines in biobanked samples from 78 patients with bacterial infections included in a randomized controlled trial (INFECIR-2 study). RESULTS: Circulatory dysfunction and systemic inflammation were extremely unstable in many patients included in the Pilot-PRECIOSA study; these patients had intense and reversible peaks in plasma levels of renin and interleukin 6. Long-term high-dose albumin, but not low-dose albumin, was associated with normalization of serum level of albumin, improved stability of the circulation and left ventricular function, and reduced plasma levels of cytokines (interleukin 6, granulocyte colony-stimulating factor, interleukin 1 receptor antagonist, and vascular endothelial growth factor) without significant changes in portal pressure. The immune-modulatory effects of albumin observed in the Pilot-PRECIOSA study were confirmed in the INFECIR-2 study. In this study, patients given albumin had significant reductions in plasma levels of cytokines. CONCLUSIONS: In an analysis of data from 2 trials (Pilot-PRECIOSA study and INFECIR-2 study), we found that albumin treatment reduced systemic inflammation and cardiocirculatory dysfunction in patients with decompensated cirrhosis. These effects might be responsible for the beneficial effects of albumin therapy on outcomes of patients with decompensated cirrhosis. ClinicalTrials.gov, Numbers: NCT00968695 and NCT03451292.

Efficacy of Albumin Treatment for Patients with Cirrhosis and Infections Unrelated to Spontaneous Bacterial Peritonitis.

BACKGROUND & AIMS: We performed a randomized trial to determine whether albumin should be administered to patients with infections unrelated to spontaneous bacterial peritonitis (SBP). METHODS: We performed a multicenter, open-label trial in which 118 patients with cirrhosis, non-SBP infections, and additional risk factors for poor outcome were randomly assigned to receive antibiotics plus albumin (study group; n = 61) or antibiotics alone (control group; n = 57). The primary outcome was in-hospital mortality; secondary outcomes were effect of albumin on disease course. RESULTS: There were no significant differences at baseline between groups in results from standard laboratory tests, serum markers of inflammation, circulatory dysfunction, or liver severity scores. However, the combined prevalence of acute on chronic liver failure (ACLF) and kidney dysfunction was significantly higher in the study group (44.3% vs 24.6% in the control group; P = .02), indicating greater baseline overall severity. There was no significant difference in the primary outcome between groups (13.1% in the study group vs 10.5% in the control group; P = .66). Circulatory and renal functions improved in only the study group. A significantly higher proportion of patients in the study group had resolution of ACLF (82.3% vs 33.3% in the control group; P = .03). A significantly lower proportion of patients in the study group developed nosocomial infections (6.6% vs 24.6% in the control group; P = .007). CONCLUSIONS: In a randomized trial of patients with advanced cirrhosis and non-SBP infections, in-hospital mortality was similar between those who received albumin plus antibiotics vs those who received only antibiotics (controls). However, patients given albumin were sicker at baseline and, during the follow-up period, a higher proportion had ACLF resolution and a lower proportion had nosocomial infections. ClinicalTrials.gov no: NCT02034279.

Multidrug-resistant bacterial infections in patients with decompensated cirrhosis and with acute-on-chronic liver failure in Europe.

BACKGROUND & AIMS: Antibiotic resistance has been increasingly reported in patients with decompensated cirrhosis in single-center studies. Prospective investigations reporting broad epidemiological data are scarce. We aimed to analyze epidemiological changes in bacterial infections in patients with decompensated cirrhosis. METHODS: This was a prospective evaluation of 2 series of patients hospitalized with decompensated cirrhosis. The Canonic series included 1,146 patients from Northern, Southern and Western Europe in 2011. Data on epidemiology, clinical characteristics of bacterial infections, microbiology and empirical antibiotic schedules were assessed. A second series of 883 patients from Eastern, Southern and Western Europe was investigated between 2017-2018. RESULTS: A total of 455 patients developed 520 infections (39.7%) in the first series, with spontaneous bacterial peritonitis, urinary tract infections and pneumonia the most frequent infections. Nosocomial episodes predominated in this series. Nearly half of the infections were culture-positive, of which 29.2% were caused by multidrug-resistant organisms (MDROs). MDR strains were more frequently isolated in Northern and Western Europe. Extended-spectrum beta-lactamase-producing Enterobacteriaceae were the most frequent MDROs isolated in this series, although prevalence and type differed markedly among countries and centers. Antibiotic resistance was associated with poor prognosis and failure of antibiotic strategies, based on third-generation cephalosporins or quinolones. Nosocomial infection (odds ratio [OR] 2.74; p < 0.001), intensive care unit admission (OR 2.09; p = 0.02), and recent hospitalization (OR 1.93; p = 0.04) were identified as independent predictors of MDR infection. The prevalence of MDROs in the second series (392 infections/284 patients) was 23%; 38% in culture-positive infections. A mild increase in the rate of carbapenem-resistant Enterobacteriaceae was observed in this series. CONCLUSIONS: MDR bacterial infections constitute a prevalent, growing and complex healthcare problem in patients with decompensated cirrhosis and acute-on-chronic liver failure across Europe, negatively impacting on prognosis. Strategies aimed at preventing the spread of antibiotic resistance in cirrhosis should be urgently evaluated. LAY SUMMARY: Infections caused by bacteria resistant to the main antibiotic families are prevalent in patients with cirrhosis. This study demonstrates that this healthcare problem is increasing and extends through all European regions. Infections caused by these difficult to treat bacteria resolve less frequently and often cause the death of the patient. The type of resistant bacteria varies markedly among different hospitals.

Adverse Events and Acute Chronic Liver Failure in Patients With Cirrhosis Undergoing Endoscopic Retrograde Cholangiopancreatography: A Multicenter Matched-Cohort Study.

BACKGROUND: Data on the outcome of adverse events (AEs) and the risk of developing acute-on-chronic liver failure (ACLF) after ERCP in patients with cirrhosis are unknown. We examined the incidence and risk factors of post-ERCP AEs in patients with cirrhosis and the appearance of ACLF after ERCP. METHODS: In this multicenter, retrospective, matched-cohort study, we evaluated ERCPs performed from January 2002 to 2015. A group of patients with cirrhosis with non-ERCP interventions and one without interventions was also analyzed for the development of ACLF. RESULTS: A total of 441 ERCPs were analyzed; 158 in patients with cirrhosis (cases) and 283 in patients without cirrhosis (controls). The overall rate of AEs after all ERCPs was significantly higher in cases compared to controls (17% vs 9.5, p = 0.02). Cholangitis developed more in cases compared to controls (6.3% vs 1.8%; p = 0.01). In a subanalysis of those with sphincterotomy, the rate of bleeding was higher in those with cirrhosis (9.4% vs 3.4%; p = 0.03). Logistic regression identified cirrhosis (OR, 2.48; 95% CI, 1.36-4.53; p = 0.003) and sphincterotomy (OR, 2.66; 95% CI, 1.23-5.72; p = 0.01) as risk factors of AEs. A total of 18/158 (11.4%) cases developed ACLF after ERCP. ACLF occurred in 7/27 cases with post-ERCP AEs and in 11/131 without post-ERCP AEs (25.9% vs 8.3%; p = 0.01). A total of 3.2% (13/406) patients without interventions developed ACLF compared to 17.5% (102/580) who developed ACLF after non-ERCP interventions. Patients with decompensated cirrhosis at ERCP had a higher risk of developing ACLF (17% vs 6.8%; p = 0.04). Patients with a MELD score ≥ 15 were 3.1 times more likely (95% CI: 1.14-8.6; p = 0.027) to develop ACLF after ERCP. CONCLUSIONS: The rate of AEs after ERCP is higher in patients with cirrhosis compared to the non-cirrhotic population. The incidence of ACLF is higher in those with AEs after ERCP compared to those without AEs, especially cholangitis. The development of ACLF is common after ERCP and other invasive procedures. ACLF can be precipitated by numerous factors which include preceding events before the procedure, including manipulation of the bile duct, and AEs after an ERCP.

Coagulation Failure in Patients With Acute-on-Chronic Liver Failure and Decompensated Cirrhosis: Beyond the International Normalized Ratio.

Balanced hemostasis with hypocoagulable and hypercoagulable features may occur in acute-on-chronic liver failure (ACLF). The characteristics and prognostic impact of the coagulation profile in ACLF are unknown. Consecutive patients with ACLF (n = 36) and acute decompensation (AD; n = 24) were included. Blood samples for thromboelastometry (TE) were obtained at admission and 72 hours thereafter. The coagulation profile was evaluated in patients with and without ACLF and in those with and without systemic inflammatory response syndrome. The impact of the coagulation profile on transfusion requirements, bleeding events, and short-term survival was assessed. At admission, patients with ACLF showed more hypocoagulable characteristics compared to AD subjects, with prolonged time to initial fibrin formation and clot formation time and decreased maximum clot firmness and alpha-angle values. TE parameters worsened at 72 hours in ACLF but improved in patients with AD. Prevalence of a hypocoagulable profile (three or more TE parameters outside range) was significantly higher in patients with ACLF either at admission (61% versus 29% in AD; P = 0.03) or during follow-up. Hypocoagulability correlated with systemic inflammation and was associated with higher 28-day (45% versus 16%; P = 0.02) and 90-day (52% versus 19%; P = 0.01) mortality rates but not with transfusion requirements or bleeding. Prolonged time to initial fibrin formation (extrinsic TE assay >80 seconds) and Model for End-Stage Liver Disease score at baseline were independent predictors of 28-day mortality. Conclusion: Patients with ACLF frequently show hypocoagulable features with prolonged time to initial fibrin formation and clot formation time and reduced clot firmness; these alterations worsen after admission, correlate with systemic inflammation, and translate into higher short-term mortality; hypofibrinolysis could contribute to organ failure in ACLF.

A Day-4 Lille Model Predicts Response to Corticosteroids and Mortality in Severe Alcoholic Hepatitis.

OBJECTIVES: Prednisolone therapy increases the risk of infections in patients with severe alcoholic hepatitis (SAH). We evaluated whether the use of the Lille Model at day 4 (LM4) is useful to predict response to prednisolone compared with the classic day 7 (LM7) in order to limit a futile exposure to corticosteroids. METHODS: We performed a retrospective analysis of a large multinational cohort of patients with SAH with Maddrey's discriminant function (DF) ≥32. Response to corticosteroids was assessed with LM4 and LM7, according to the validated cutoff value (CUV>0.45). Receiver operating characteristics (ROC) curves were constructed to determine the optimal CUV for LM4 and to compare accuracy between LM4, LM7, MELD (Model for End-Stage Liver Disease), and ABIC (age, bilirubin, international normalized ratio, and creatinine). Logistic regression models were constructed to predict 28- and 90-day mortality. Cox regression analysis was performed to assess long-term survival. RESULTS: A total of 163 (62.7%) out of 260 patients received corticosteroids. The median DF for the patients treated with corticosteroids was 64.1 (47.9-81.3). Overall 90-day mortality was 35.9%. The median LM4 and LM7 for the patients who received treatment was 0.39 (0.19-0.83) and 0.36 (0.13-0.77). LM4 was a strong independent predictor of 28-day mortality (OR 25.4, (95% confidence interval (CI) 5.1-126.8), P<0.001). By using LM4 with a CUV>0.45, 28- and 90-day survival was significantly higher for responders (90% and 76%) than non-responders (66% and 40%), P<0.001. Importantly, the area under the ROC curve for predicting mortality for LM4 was similar than the classic LM7 (0.77 vs. 0.75, respectively: P=0.558). CONCLUSIONS: LM4 is as accurate as LM7 in predicting response to corticosteroids, as well as 28- and 90-day mortality. Assessing the efficacy of prednisolone at an earlier time point can avoid a more prolonged futile use of this therapy.

Clinical course and short-term mortality of cirrhotic patients with infections other than spontaneous bacterial peritonitis.

BACKGROUND & AIMS: Clinical course and risk factors of death in non-spontaneous bacterial peritonitis (SBP) infections are poorly known. We assessed the prevalence of acute kidney injury (AKI) and type-1 hepatorenal syndrome (HRS), hospital, 30-day and 90-day mortality and risk factors of death in 441 decompensated patients. METHODS: Analysis of 615 non-SBP infections (161 urinary infections (UTI), 95 cellulitis, 92 suspected infections, 92 bacteraemias, 84 pneumonias, 21 bronchitis, 18 cholangitis, 15 spontaneous empyema, 13 secondary peritonitis, 24 other). RESULTS: Ninety-six percent of infections solved. AKI and type-1 HRS were developed in 37% and 9% of infections respectively. Overall hospital, 30-day and 90-day mortality rates were 11%, 12% and 18% respectively. Clinical course and mortality differed markedly across infections. Endocarditis, osteoarticular infections, pneumonia, spontaneous bacteraemia, cholangitis, secondary peritonitis and UTI showed higher rates of AKI. Prevalence of type-1 HRS was not significantly different among infections. Endocarditis, secondary peritonitis, pneumonia and bacteraemia showed lower rates of renal impairment resolution and higher hospital mortality associated with AKI (42% vs 12%, P<.0001) or type-1 HRS (71% vs 27%, P=.003) than the rest of infections. Age (HR: 1.04), serum sodium (HR: 0.91), serum bilirubin (HR: 1.06), INR (HR: 1.91), hepatic encephalopathy (HR: 2.44), ascites (HR: 3.06) and multidrug-resistant isolation (HR: 2.27) at infection diagnosis were independent predictors of death during hospitalization. CONCLUSIONS: Non-SBP infections constitute a heterogeneous group regarding clinical course and prognosis. Endocarditis, secondary peritonitis, pneumonia and bacteraemia show worse prognosis. The combination of data of liver and renal dysfunction and of the type of infection allows the identification of patients with poor prognosis.

Freezing the Dynamic Gap for Selectivity: Motion-Based Design of Inhibitors of the Shikimate Kinase Enzyme.

Shikimate kinase (SK), the fifth enzyme of the aromatic amino acid biosynthesis, is a recognized target for antibiotic drug discovery. The potential of the distinct dynamic apolar gap, which isolates the natural substrate from the solvent environment for catalysis, and the motion of Mycobacterium tuberculosis and Helicobacter pylori SK enzymes, which was observed by molecular dynamics simulations, was explored for inhibition selectivity. The results of the biochemical and computational studies reveal that the incorporation of bulky groups at position C5 of 5-aminoshikimic acid and the natural substrate enhances the selectivity for the H. pylori enzyme due to key motion differences in the shikimic acid binding domain (mainly helix α5). These studies show that the less-exploited motion-based design approach not only is an alternative strategy for the development of competitive inhibitors, but could also be a way to achieve selectivity against a particular enzyme among its homologues.

Study of the Phosphoryl-Transfer Mechanism of Shikimate Kinase by NMR Spectroscopy.

The phosphoryl-transfer mechanism of shikimate kinase from Mycobacterium tuberculosis and Helicobacter pylori, which is an attractive target for antibiotic drug discovery, has been studied by 1D (1)H and (31)P NMR spectroscopy. Metaphosphoric acid proved to be a good mimetic of the metaphosphate intermediate and facilitated the ready and rapid evaluation by NMR spectroscopic analysis of a dissociative mechanism. The required closed form of the active site for catalysis was achieved by the use of ADP (product) or two synthetic ADP analogues (AMPNP, AMPCP). Molecular dynamics simulation studies reported here also revealed that the essential arginine (Arg116/Arg117 in H. pylori and M. tuberculosis, respectively), which activates the γ-phosphate group of ATP for catalysis and triggers the release of the product for turnover, would also be involved in the stabilisation of the metaphosphate intermediate during catalysis. We believe that the studies reported here will be helpful for future structure-based design of inhibitors of this attractive target. The approach is also expected be useful for studies on the possible dissociative mechanism of other kinase enzymes.

Alcoholic hepatitis: How far are we and where are we going?

 The burden of alcoholic liver disease continues to be a major public health problem worldwide. The spectrum of disease ranges from fatty liver to cirrhosis and hepatocellular carcinoma. Alcoholic hepatitis (AH) is a type of acute-on-chronic liver failure and the most severe form of alcoholic liver disease. Severe AH carries a poor short-term prognosis and its management is still challenging, with scarce advances in the last decades. Corticosteroids are still the first line of therapy in severe cases. Unfortunately, many patients do not respond and novel targeted therapies are urgently needed. Liver transplantation has shown extraordinary results in non-responders to corticosteroids however; its applicability is very low. This review summarizes the epidemiology, natural history, risk factors and pathogenesis of alcoholic liver disease with special focus on the latest advances in prognostic stratification and therapy of patients with alcoholic hepatitis.

Relative adrenal insufficiency in decompensated cirrhosis: Relationship to short-term risk of severe sepsis, hepatorenal syndrome, and death.

UNLABELLED: The prevalence of relative adrenal insufficiency (RAI) in critically ill cirrhosis patients with severe sepsis is over 60% and associated features include poor liver function, renal failure, refractory shock, and high mortality. RAI may also develop in noncritically ill cirrhosis patients but its relationship to the clinical course has not yet been assessed. The current study was performed in 143 noncritically ill cirrhosis patients admitted for acute decompensation. Within 24 hours after hospitalization adrenal function, plasma renin activity, plasma noradrenaline and vasopressin concentration, and serum levels of nitric oxide, interleukin-6 and tumor necrosis factor alpha were determined. RAI was defined as a serum total cortisol increase <9 µg/dL after 250 µg of intravenous corticotropin from basal values <35 µg/dL. Patients were followed for 3 months. RAI was detected in 26% of patients (n = 37). At baseline, patients with RAI presented with lower mean arterial pressure (76 ± 12 versus 83 ± 14 mmHg, P = 0.009) and serum sodium (131 ± 7 versus 135 ± 5 mEq/L, P = 0.007) and higher blood urea nitrogen (32 ± 24 versus 24 ± 15 mg/dl, P = 0.06), plasma renin activity (7.1 ± 9.9 versus 3.4 ± 5.6 ng/mL*h, P = 0.03), and noradrenaline concentration (544 ± 334 versus 402 ± 316 pg/mL, P = 0.02). During follow-up, patients with RAI exhibited a higher probability of infection (41% versus 21%, P = 0.008), severe sepsis (27% versus 9%, P = 0.003), type-1 hepatorenal syndrome (HRS) (16% versus 3%, P = 0.002), and death (22% versus 7%, P = 0.01). CONCLUSION: RAI is frequent in noncritically ill patients with acute decompensation of cirrhosis. As compared with those with normal adrenal function, patients with RAI have greater impairment of circulatory and renal function, higher probability of severe sepsis and type-1 HRS, and higher short-term mortality.

Mycobacterium tuberculosis shikimate kinase inhibitors: design and simulation studies of the catalytic turnover.

Shikimate kinase (SK) is an essential enzyme in several pathogenic bacteria and does not have any counterpart in human cells, thus making it an attractive target for the development of new antibiotics. The key interactions of the substrate and product binding and the enzyme movements that are essential for catalytic turnover of the Mycobacterium tuberculosis shikimate kinase enzyme (Mt-SK) have been investigated by structural and computational studies. Based on these studies several substrate analogs were designed and assayed. The crystal structure of Mt-SK in complex with ADP and one of the most potent inhibitors has been solved at 2.15 Å. These studies reveal that the fixation of the diaxial conformation of the C4 and C5 hydroxyl groups recognized by the enzyme or the replacement of the C3 hydroxyl group in the natural substrate by an amino group is a promising strategy for inhibition because it causes a dramatic reduction of the flexibility of the LID and shikimic acid binding domains. Molecular dynamics simulation studies showed that the product is expelled from the active site by three arginines (Arg117, Arg136, and Arg58). This finding represents a previously unknown key role of these conserved residues. These studies highlight the key role of the shikimic acid binding domain in the catalysis and provide guidance for future inhibitor designs.

Urinary neutrophil gelatinase-associated lipocalin as biomarker in the differential diagnosis of impairment of kidney function in cirrhosis.

BACKGROUND & AIMS: Impairment of kidney function is common in cirrhosis but differential diagnosis remains a challenge. We aimed at assessing the usefulness of neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of tubular damage, in the differential diagnosis of impairment of kidney function in cirrhosis. METHODS: Two-hundred and forty-one patients with cirrhosis, 72 without ascites, 85 with ascites, and 84 with impaired kidney function, were studied. Urinary levels of NGAL were measured by ELISA. RESULTS: Patients with impaired kidney function had higher urinary NGAL levels compared to patients with and without ascites. Patients with urinary tract infection (n=25) had higher uNGAL values than non-infected patients. Patients with acute tubular necrosis (ATN) had uNGAL levels markedly higher (417µg/g creatinine (239-2242) median and IQ range) compared to those of patients with pre-renal azotemia due to volume depletion 30 (20-59), chronic kidney disease (CKD) 82 (34-152), and hepatorenal syndrome (HRS) 76 (43-263) µg/g creatinine (p<0.001 for all). Among HRS patients, the highest values were found in HRS-associated with infections, followed by classical (non-associated with active infections) type-1 and type-2 HRS (391 (72-523), 147 (83-263), and 43 (31-74) µg/g creatinine, respectively; p<0.001). Differences in uNGAL levels between classical type 1 HRS and ATN on the one hand and classical type 1 HRS and CKD and pre-renal azotemia on the other were statistically significant (p<0.05). CONCLUSIONS: uNGAL levels may be useful in the differential diagnosis of impairment of kidney function in cirrhosis. Urinary tract infections should be ruled out because they may increase uNGAL excretion.