Ariel Unser

Altered profile of human gut microbiome is associated with cirrhosis and its complications

BACKGROUND & AIMS The gut microbiome is altered in cirrhosis; however its evolution with disease progression is only partly understood. We aimed to study changes in the microbiome over cirrhosis severity, its stability over time and its longitudinal alterations with decompensation. METHODS Controls and age-matched cirrhotics (compensated/decompensated/hospitalized) were included. Their stool microbiota was quantified using multi-tagged pyrosequencing. The ratio of autochthonous to non-autochthonous taxa was calculated as the cirrhosis dysbiosis ratio (CDR); a low number indicating dysbiosis. Firstly, the microbiome was compared between controls and cirrhotic sub-groups. Secondly, for stability assessment, stool collected twice within 6months in compensated outpatients was analyzed. Thirdly, changes after decompensation were assessed using (a) longitudinal comparison in patients before/after hepatic encephalopathy development (HE), (b) longitudinal cohort of hospitalized infected cirrhotics MELD-matched to uninfected cirrhotics followed for 30days. RESULTS 244 subjects [219 cirrhotics (121 compensated outpatients, 54 decompensated outpatients, 44 inpatients) and 25 age-matched controls] were included. CDR was highest in controls (2.05) followed by compensated (0.89), decompensated (0.66), and inpatients (0.32, p<0.0001) and negatively correlated with endotoxin. Microbiota and CDR remained unchanged in stable outpatient cirrhotics (0.91 vs. 0.86, p=0.45). In patients studied before/after HE development, dysbiosis occurred post-HE (CDR: 1.2 to 0.42, p=0.03). In the longitudinal matched-cohort, microbiota were significantly different between infected/uninfected cirrhotics at baseline and a low CDR was associated with death and organ failures within 30days. CONCLUSIONS Progressive changes in the gut microbiome accompany cirrhosis and become more severe in the setting of decompensation. The cirrhosis dysbiosis ratio may be a useful quantitative index to describe microbiome alterations accompanying cirrhosis progression.

The Stroop smartphone application is a short and valid method to screen for minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) detection is difficult because of the unavailability of short screening tools. Therefore, MHE patients can remain undiagnosed and untreated. The aim of this study was to use a Stroop smartphone application (app) (EncephalApp_Stroop) to screen for MHE. The app and standard psychometric tests (SPTs; 2 of 4 abnormal is MHE, gold standard), psychometric hepatic encephalopathy score (PHES), and inhibitory control tests (ICTs) were administered to patients with cirrhosis (with or without previous overt hepatic encephalopathy; OHE) and age‐matched controls from two centers; a subset underwent retesting. A separate validation cohort was also recruited. Stroop has an “off” state with neutral stimuli and an “on” state with incongruent stimuli. Outcomes included time to complete five correct runs as well as number of trials needed in on (Ontime) and off (Offtime) states. Stroop results were compared between controls and patients with cirrhosis with or without OHE and those with or without MHE (using SPTs, ICTs, and PHES). Receiver operating characteristic analysis was performed to diagnose MHE in patients with cirrhosis with or without previous OHE. One hundred and twenty‐five patients with cirrhosis (43 previous OHE) and 134 controls were included in the original cohort. App times were correlated with Model for End‐Stage Liver Disease (Offtime: r = 0.57; Ontime: r = 0.61; P < 0.0001) and were worst in previous OHE patients, compared to the rest and controls. Stroop performance was also significantly impaired in those with MHE, compared to those without MHE, according to SPTs, ICTs, and PHES (all P < 0.0001). A cutoff of >274.9 seconds (Ontime plus Offtime) had an area under the curve of 0.89 in all patients and 0.84 in patients without previous OHE for MHE diagnosis using SPT as the gold standard. The validation cohort showed 78% sensitivity and 90% specificity with the >274.9‐seconds Ontime plus Offtime cutoff. App result patterns were similar between the centers. Test‐retest reliability in controls and those without previous OHE was good; a learning effect on Ontime in patients with cirrhosis without previous OHE was noted. Conclusion: The Stroop smartphone app is a short, valid, and reliable tool for screening of MHE. (Hepatology 2013;58:1122‐1132)

Salivary microbiota reflects changes in gut microbiota in cirrhosis with hepatic encephalopathy

Altered gut microbiome is associated with systemic inflammation and cirrhosis decompensation. However, the correlation of the oral microbiome with inflammation in cirrhosis is unclear. Our aim was to evaluate the oral microbiome in cirrhosis and compare with stool microbiome. Outpatients with cirrhosis (with/without hepatic encephalopathy [HE]) and controls underwent stool/saliva microbiome analysis (for composition and function) and also systemic inflammatory evaluation. Ninety‐day liver‐related hospitalizations were recorded. Salivary inflammation was studied using T helper 1 cytokines/secretory immunoglobulin A (IgA), histatins and lysozyme in a subsequent group. A total of 102 patients with cirrhosis (43 previous HE) and 32 age‐matched controls were included. On principal component analysis (PCA), stool and saliva microbiome clustered far apart, showing differences between sites as a whole. In salivary microbiome, with previous HE, relative abundance of autochthonous families decreased whereas potentially pathogenic ones (Enterobacteriaceae, Enterococcaceae) increased in saliva. Endotoxin‐related predicted functions were significantly higher in cirrhotic saliva. In stool microbiome, relative autochthonous taxa abundance reduced in previous HE, along with increased Enterobacteriaceae and Enterococcaceae. Cirrhotic stool microbiota demonstrated a significantly higher correlation with systemic inflammation, compared to saliva microbiota, on correlation networks. Thirty‐eight patients were hospitalized within 90 days. Their salivary dysbiosis was significantly worse and predicted this outcome independent of cirrhosis severity. Salivary inflammation was studied in an additional 86 age‐matched subjects (43 controls/43 patients with cirrhosis); significantly higher interleukin (IL)−6/IL‐1β, secretory IgA, and lower lysozyme, and histatins 1 and 5 were found in patients with cirrhosis, compared to controls. Conclusions: Dysbiosis, represented by reduction in autochthonous bacteria, is present in both saliva and stool in patients with cirrhosis, compared to controls. Patients with cirrhosis have impaired salivary defenses and worse inflammation. Salivary dysbiosis was greater in patients with cirrhosis who developed 90‐day hospitalizations. These findings could represent a global mucosal‐immune interface change in cirrhosis. (Hepatology 2015;62:1260‐1271)

Covert Hepatic Encephalopathy Is Independently Associated With Poor Survival and Increased Risk of Hospitalization

OBJECTIVES:Despite the high prevalence of covert hepatic encephalopathy (CHE) in cirrhotics without previous overt HE (OHE), its independent impact on predicting clinically relevant outcomes is unclear. The aim of this study was to define the impact of CHE on time to OHE, hospitalization, and death/transplant in prospectively followed up patients without previous OHE.METHODS:Outpatient cirrhotics without OHE were enrolled and were administered a standard paper–pencil cognitive battery for CHE diagnosis. They were systematically followed up and time to first OHE development, hospitalization (liver-related/unrelated), and transplant/death were compared between CHE and no-CHE patients at baseline using Cox regression.RESULTS:A total of 170 cirrhotic patients (55 years, 58% men, 14 years of education, Model for End-Stage Liver Disease (MELD 9), 53% hepatitis C virus (HCV), 20% nonalcoholic etiology) were included, of whom 56% had CHE. The entire population was followed up for 13.0±14.6 months, during which time 30% developed their first OHE episode, 42% were hospitalized, and 19% had a composite death/transplant outcome. Age, gender, etiology, the MELD score, and CHE status were included in Cox regression models for time to first OHE episode, hospitalization, death, and composite death/transplant outcomes. On Cox regression, despite controlling for MELD, those with CHE had a higher risk of developing OHE (hazard ratio: 2.1, 95% confidence interval 1.01–4.5), hospitalization (hazard ratio: 2.5, 95% confidence interval 1.4–4.5), and death/transplant (hazard ratio: 3.4, 95% confidence interval 1.2–9.7) in the follow-up period.CONCLUSIONS:Covert HE is associated with worsened survival and increased risk of hospitalization and OHE development, despite controlling for the MELD score. Strategies to detect and treat CHE may improve these risks.

Validation of EncephalApp, Smartphone-Based Stroop Test, for the Diagnosis of Covert Hepatic Encephalopathy

BACKGROUND & AIMS Detection of covert hepatic encephalopathy (CHE) is difficult, but point-of-care testing could increase rates of diagnosis. We aimed to validate the ability of the smartphone app EncephalApp, a streamlined version of Stroop App, to detect CHE. We evaluated face validity, test-retest reliability, and external validity. METHODS Patients with cirrhosis (n = 167; 38% with overt HE [OHE]; mean age, 55 years; mean Model for End-Stage Liver Disease score, 12) and controls (n = 114) were each given a paper and pencil cognitive battery (standard) along with EncephalApp. EncephalApp has Off and On states; results measured were OffTime, OnTime, OffTime+OnTime, and number of runs required to complete 5 off and on runs. Thirty-six patients with cirrhosis underwent driving simulation tests, and EncephalApp results were correlated with results. Test-retest reliability was analyzed in a subgroup of patients. The test was performed before and after transjugular intrahepatic portosystemic shunt placement, and before and after correction for hyponatremia, to determine external validity. RESULTS All patients with cirrhosis performed worse on paper and pencil and EncephalApp tests than controls. Patients with cirrhosis and OHE performed worse than those without OHE. Age-dependent EncephalApp cutoffs (younger or older than 45 years) were set. An OffTime+OnTime value of >190 seconds identified all patients with CHE with an area under the receiver operator characteristic value of 0.91; the area under the receiver operator characteristic value was 0.88 for diagnosis of CHE in those without OHE. EncephalApp times correlated with crashes and illegal turns in driving simulation tests. Test-retest reliability was high (intraclass coefficient, 0.83) among 30 patients retested 1-3 months apart. OffTime+OnTime increased significantly (206 vs 255 seconds, P = .007) among 10 patients retested 33 ± 7 days after transjugular intrahepatic portosystemic shunt placement. OffTime+OnTime decreased significantly (242 vs 225 seconds, P = .03) in 7 patients tested before and after correction for hyponatremia (126 ± 3 to 132 ± 4 meq/L, P = .01) 10 ± 5 days apart. CONCLUSIONS A smartphone app called EncephalApp has good face validity, test-retest reliability, and external validity for the diagnosis of CHE.

Diagnosis of Minimal Hepatic Encephalopathy Using Stroop EncephalApp: A Multicenter US-Based, Norm-Based Study.

Objectives:Diagnosing minimal hepatic encephalopathy (MHE) is challenging, and point-of-care tests are needed. Stroop EncephalApp has been validated for MHE diagnosis in single-center studies. The objective of the study was to validate EncephalApp for MHE diagnosis in a multicenter study.Methods:Outpatient cirrhotics (with/without prior overt hepatic encephalopathy (OHE)) and controls from three sites (Virginia (VA), Ohio (OH), and Arkansas (AR)) underwent EncephalApp and two gold standards, psychometric hepatic encephalopathy score (PHES) and inhibitory control test (ICT). Age-/gender-/education-adjusted values for EncephalApp based on direct norms, and based on ICT and PHES, were defined. Patients were followed, and EncephalApp cutoff points were used to determine OHE prediction. These cutoff points were then used in a separate VA-based validation cohort.Results:A total of 437 cirrhotics (230 VA, 107 OH, 100 AR, 36% OHE, model for end-stage liver disease (MELD) score 11) and 308 controls (103 VA, 100 OH, 105 AR) were included. Using adjusted variables, MHE was present using EncephalApp based on norms in 51%, EncephalApp based on PHES in 37% (sensitivity 80%), and EncephalApp based on ICT in 54% of patients (sensitivity 70%). There was modest/good agreement between sites on EncephalApp MHE diagnosis using the three methods. OHE developed in 13% of patients, which was predicted by EncephalApp independent of the MELD score. In the validation cohort of 121 VA cirrhotics, EncephalApp directly and based on gold standards remained consistent for MHE diagnosis with >70% sensitivity.Conclusions:In this multicenter study, EncephalApp, using adjusted population norms or in the context of existing gold standard tests, had good sensitivity for MHE diagnosis and predictive capability for OHE development.

Impaired Gut-Liver-Brain Axis in Patients with Cirrhosis

Cirrhosis is associated with brain dysfunction known as hepatic encephalopathy (HE). The mechanisms behind HE are unclear although hyperammonemia and systemic inflammation through gut dysbiosis have been proposed. We aimed to define the individual contribution of specific gut bacterial taxa towards astrocytic and neuronal changes in brain function using multi-modal MRI in patients with cirrhosis. 187 subjects (40 controls, 147 cirrhotic; 87 with HE) underwent systemic inflammatory assessment, cognitive testing, stool microbiota analysis and brain MRI analysis. MR spectroscopy (MRS) changes of increased Glutamate/glutamine, reduced myo-inositol and choline are hyperammonemia-associated astrocytic changes, while diffusion tensor imaging (DTI) demonstrates changes in neuronal integrity and edema. Linkages between cognition, MRI parameters and gut microbiota were compared between groups. We found that HE patients had a significantly worse cognitive performance, systemic inflammation, dysbiosis and hyperammonemia compared to controls and cirrhotics without HE. Specific microbial families (autochthonous taxa negatively and Enterobacteriaceae positively) correlated with MR spectroscopy and hyperammonemia-associated astrocytic changes. On the other hand Porphyromonadaceae, were only correlated with neuronal changes on DTI without linkages with ammonia. We conclude that specific gut microbial taxa are related to neuronal and astrocytic consequences of cirrhosis-associated brain dysfunction.

Correction of hyponatraemia improves cognition, quality of life, and brain oedema in cirrhosis

BACKGROUND & AIMS Hyponatraemia in cirrhosis is associated with impaired cognition and poor health-related quality of life (HRQOL). However, the benefit of hyponatraemia correction is unclear. The aim of this study was to evaluate the effect of tolvaptan on serum sodium (Na), cognition, HRQOL, companion burden, and brain MRI (volumetrics, spectroscopy, and diffusion tensor imaging) in cirrhotics with hyponatraemia. METHODS Cirrhotics with Na <130 mEq/L were included for a four-week trial. At screening, patients underwent cognitive and HRQOL testing, serum/urine chemistries and companion burden assessment. Patients then underwent fluid restriction and diuretic withdrawal for two weeks after which cognitive tests were repeated. If Na was still <130 mEq/L, brain magnetic resonance imaging (MRI) was performed and tolvaptan was initiated for 14 days with frequent clinical/laboratory monitoring. After 14 days of tolvaptan, all tests were repeated. Comparisons were made between screen, pre-and post-drug periods Na, urine/serum laboratories, cognition, HRQOL and companion burden. RESULTS 24 cirrhotics were enrolled; seven normalized Na without tolvaptan with improvement in cognition. The remaining 17 received tolvaptan of which 14 completed the study over 13 ± 2 days (age 58 ± 6 years, MELD 17, 55% HCV, median 26 mg/day of tolvaptan). Serum Na and urine free water clearance increased with tolvaptan without changes in mental status or liver function. Cognitive function, HRQOL and companion burden only improved in these 14 patients after tolvaptan, along with reduced total brain and white matter volume, increase in choline on magnetic resonance spectroscopy, and reduced cytotoxic oedema. CONCLUSIONS Short-term tolvaptan therapy is well tolerated in cirrhosis. Hyponatraemia correction is associated with cognitive, HRQOL, brain MRI and companion burden improvement.

Gut Microbiota Alterations can predict Hospitalizations in Cirrhosis Independent of Diabetes Mellitus

Diabetes (DM) is prevalent in cirrhosis and may modulate the risk of hospitalization through gut dysbiosis. We aimed to define the role of gut microbiota on 90-day hospitalizations and of concomitant DM on microbiota. Cirrhotic outpatients with/without DM underwent stool and sigmoid mucosal microbial analysis and were followed for 90 days. Microbial composition was compared between those with/without DM, and those who were hospitalized/not. Regression/ROC analyses for hospitalizations were performed using clinical and microbial features. 278 cirrhotics [39% hepatic encephalopathy (HE), 31%DM] underwent stool while 72 underwent mucosal analyses. Ultimately, 94 were hospitalized and they had higher MELD, proton pump inhibitor (PPI) use and HE without difference in DM. Stool/mucosal microbiota were significantly altered in those who were hospitalized (UNIFRAC p< = 1.0e-02). Specifically, lower stool Bacteroidaceae, Clostridiales XIV, Lachnospiraceae, Ruminococcacae and higher Enterococcaceae and Enterobacteriaceae were seen in hospitalized patients. Concomitant DM impacted microbiota UNIFRAC (stool, p = 0.003, mucosa,p = 0.04) with higher stool Bacteroidaceae and lower Ruminococcaeae. Stool Bacteroidaceaeae and Clostridiales XIV predicted 90-day hospitalizations independent of clinical predictors (MELD, HE, PPI). Stool and colonic mucosal microbiome are altered in cirrhotics who get hospitalized with independent prediction using stool Bacteroidaceae and Clostridiales XIV. Concomitant DM distinctly impacts gut microbiota without affecting hospitalizations.

Cognitive Reserve Is a Determinant of Health-related Quality of Life in Patients With Cirrhosis, Independent of Covert Hepatic Encephalopathy and Model for End-Stage Liver Disease Score

BACKGROUND & AIMS Covert hepatic encephalopathy (CHE) is associated with cognitive dysfunction, which affects daily function and health-related quality of life (HRQOL) in patients with cirrhosis. The effects of CHE and liver disease are determined by cognitive reserve—the ability of the brain to cope with increasing damage while continuing to function—and are assessed by composite intelligence quotient (IQ) scores. We examined cognitive reserve as a determinant of HRQOL in patients with cirrhosis. METHODS We performed a prospective study of 118 outpatients with cirrhosis without overt HE (age, 56 y). We studied cognition using the standard paper-pencil battery; patients with below-normal results for more than 2 tests were considered to have CHE. We also assessed HRQOL (using the sickness impact profile [SIP]), psychosocial and physical scores (a high score indicates reduced HRQOL), model for end-stage liver disease (MELD) scores, and cognitive reserve (using the Barona Index, a validated IQ analysis, based on age, race, education, residence area, and occupation). Cognitive reserve was divided into average and high groups (<109 or >109), and MELD and SIP scores were compared. We performed regression analyses, using total SIP score and psychosocial and physical dimensions as outcomes, with cognitive reserve, CHE, and MELD score as predictors. RESULTS Study participants had average MELD scores of 9, and 14 years of education; 81% were white, 63% were urban residents, their mean IQ was 108 ± 8, and 54% had average cognitive reserve (the remaining 46% had high reserves). CHE was diagnosed in 49% of patients. Cognitive reserve was lower in patients with CHE (109) than without (105; P = .02). Cognitive reserve correlated with total SIP and psychosocial score (both r = -0.4; P < .001) and physical score (r = -0.3; P = .01), but not MELD score (P = .8). Patients with high cognitive reserve had a better HRQOL, despite similar MELD scores. In regression analyses, cognitive reserve was a significant predictor of total SIP (P < .001), psychosocial (P < .001), and physical scores (P < .03), independent of CHE, MELD, or psychiatric disorders. CONCLUSIONS A higher cognitive reserve is associated with a better HRQOL in patients with cirrhosis, despite similar disease severity and prevalence. This indicates that patients with good cognitive reserve are better able to withstand the demands of cirrhosis progression and CHE, leading to a better HRQOL. Patients with lower cognitive reserve may need more dedicated and earlier measures to improve HRQOL. Cognitive reserve should be considered when interpreting HRQOL and cognitive tests to evaluate patients with cirrhosis.