Faecal microbiota transplantation for first or second Clostridioides difficile infection (EarlyFMT): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Clostridioides difficile infection is an urgent antibiotic-associated health threat with few treatment options. Microbiota restoration with faecal microbiota transplantation is an effective treatment option for patients with multiple recurring episodes of C difficile. We compared the efficacy and safety of faecal microbiota transplantation compared with placebo after vancomycin for first or second C difficile infection. METHODS: We did a randomised, double-blind, placebo-controlled trial (EarlyFMT) at a university hospital in Aarhus, Denmark. Eligible patients were aged 18 years or older with first or second C difficile infection (defined as ≥3 watery stools [Bristol stool chart score 6-7] per day and a positive C difficile PCR test). Patients were randomly assigned (1:1) to faecal microbiota transplantation or placebo administered on day 1 and between day 3 and 7, after they had received 125 mg oral vancomycin four times daily for 10 days. Randomisation was done by investigators using a computer-generated randomisation list provided by independent staff. Patients and investigators were masked to the treatment group. The primary endpoint was resolution of C difficile-associated diarrhoea (CDAD) 8 weeks after treatment. We followed up patients for 8 weeks or until recurrence. We planned to enrol 84 patients with a prespecified interim analysis after 42 patients. The primary outcome and safety outcomes were analysed in the intention-to-treat population, which included all randomly assigned patients. The trial is registered with ClinicalTrials.gov, NCT04885946. FINDINGS: Between June 21, 2021, and April 1, 2022, we consecutively screened 86 patients, of whom 42 were randomly assigned to faecal microbiota transplantation (n=21) or placebo (n=21). The trial was stopped after the interim analysis done on April 7, 2022 for ethical reasons because a significantly lower rate of resolution was identified in the placebo group compared with the faecal microbiota transplantation group (Haybittle-Peto boundary limit p<0·001). 19 (90%; 95% CI 70-99) of 21 patients in the faecal microbiota transplantation group and seven (33%, 95% CI 15-57) of 21 patients in the placebo group had resolution of CDAD at week 8 (p=0·0003). The absolute risk reduction was 57% (95% CI 33-81). Overall, 204 adverse events occurred, with one or more adverse events being reported in 20 of 21 patients in the faecal microbiota transplantation group and all 21 patients in the placebo group. Diarrhoea (n=23 in the faecal microbiota transplantation group; n=14 in the placebo group) and abdominal pain (n=14 in the faecal microbiota transplantation group; n=11 in the placebo group) were the most common adverse events. Three serious adverse events possibly related to study treatment occurred (n=1 in the faecal microbiota transplantation group; n=2 in the placebo group), but no deaths or colectomies during the 8-week follow-up. INTERPRETATION: In patients with first or second C difficile infection, first-line faecal microbiota transplantation is highly effective and superior to the standard of care vancomycin alone in achieving sustained resolution from C difficile. FUNDING: Innovation Fund Denmark.

Rifaximin-α reduces gut-derived inflammation and mucin degradation in cirrhosis and encephalopathy: RIFSYS randomised controlled trial.

BACKGROUND & AIMS: Rifaximin-α is efficacious for the prevention of recurrent hepatic encephalopathy (HE), but its mechanism of action remains unclear. We postulated that rifaximin-α reduces gut microbiota-derived endotoxemia and systemic inflammation, a known driver of HE. METHODS: In a placebo-controlled, double-blind, mechanistic study, 38 patients with cirrhosis and HE were randomised 1:1 to receive either rifaximin-α (550 mg BID) or placebo for 90 days. PRIMARY OUTCOME: 50% reduction in neutrophil oxidative burst (OB) at 30 days. SECONDARY OUTCOMES: changes in psychometric hepatic encephalopathy score (PHES) and neurocognitive functioning, shotgun metagenomic sequencing of saliva and faeces, plasma and faecal metabolic profiling, whole blood bacterial DNA quantification, neutrophil toll-like receptor (TLR)-2/4/9 expression and plasma/faecal cytokine analysis. RESULTS: Patients were well-matched: median MELD (11 rifaximin-α vs. 10 placebo). Rifaximin-α did not lead to a 50% reduction in spontaneous neutrophil OB at 30 days compared to baseline (p = 0.48). However, HE grade normalised (p = 0.014) and PHES improved (p = 0.009) after 30 days on rifaximin-α. Rifaximin-α reduced circulating neutrophil TLR-4 expression on day 30 (p = 0.021) and plasma tumour necrosis factor-α (TNF-α) (p <0.001). Rifaximin-α suppressed oralisation of the gut, reducing levels of mucin-degrading sialidase-rich species, Streptococcus spp, Veillonella atypica and parvula, Akkermansia and Hungatella. Rifaximin-α promoted a TNF-α- and interleukin-17E-enriched intestinal microenvironment, augmenting antibacterial responses to invading pathobionts and promoting gut barrier repair. Those on rifaximin-α were less likely to develop infection (odds ratio 0.21; 95% CI 0.05-0.96). CONCLUSION: Rifaximin-α led to resolution of overt and covert HE, reduced the likelihood of infection, reduced oralisation of the gut and attenuated systemic inflammation. Rifaximin-α plays a role in gut barrier repair, which could be the mechanism by which it ameliorates bacterial translocation and systemic endotoxemia in cirrhosis. CLINICAL TRIAL NUMBER: ClinicalTrials.gov NCT02019784. LAY SUMMARY: In this clinical trial, we examined the underlying mechanism of action of an antibiotic called rifaximin-α which has been shown to be an effective treatment for a complication of chronic liver disease which effects the brain (termed encephalopathy). We show that rifaximin-α suppresses gut bacteria that translocate from the mouth to the intestine and cause the intestinal wall to become leaky by breaking down the protective mucus barrier. This suppression resolves encephalopathy and reduces inflammation in the blood, preventing the development of infection.

Activation and Functional Priming of Blood Neutrophils in Non-Alcoholic Fatty Liver Disease Increases in Non-Alcoholic Steatohepatitis.

INTRODUCTION: In non-alcoholic fatty liver disease (NAFLD), neutrophils in liver infiltrates are activated, which may contribute to disease progression towards non-alcoholic steatohepatitis (NASH). However, the functional status of the blood neutrophils remains unknown and their role in the disease mechanisms is thus uncertain. We therefore characterized activation and function of blood neutrophils in patients with NAFLD in relation to clinical disease markers and the NAFLD plasma milieu. METHODS: We studied 20 patients with NAFLD, among these 6 patients with NASH, and 14 healthy persons. Neutrophil activation, interleukin (IL)-8 production and oxidative burst were measured by flow cytometry on participants´ neutrophils and on healthy neutrophils exposed in vitro to plasma from the study participants. RESULTS: Blood neutrophils from the NASH patients showed a doubling in their expression of the activation marker CD62L. Also, all NAFLD patients had 50-100% increased expression of CD11b. Functionally, NASH neutrophils had 30% elevated IL-8 production and more than doubled spontaneous oxidative burst. In all NAFLD patients, higher spontaneous oxidative burst was associated with worse liver function. Incubation of healthy neutrophils with NAFLD plasma paradoxically slightly reduced CD62L and CD11b expression, and NASH plasma also reduced the frequency of IL-8-producing neutrophils. CONCLUSION: In NAFLD, blood neutrophils are activated, and in NASH also functionally primed. This suggests a progressive neutrophil aggressiveness already present with liver fat infiltration. However, NAFLD plasma in vitro, if anything, had the opposite effect on the healthy neutrophils so the NAFLD-related neutrophil activation cannot be attributed to humoral factors and remains unexplained.

Early loss of T lymphocyte 4-1BB receptor expression is associated with higher short-term mortality in alcoholic hepatitis.

OBJECTIVES: In alcoholic hepatitis (AH), dysfunctional T lymphocytes may contribute to the high mortality from infections. T lymphocyte activation is governed by the expression of co-stimulatory receptors such as 4-1BB balanced by inhibitory receptors such as Programmed Death receptor 1 (PD-1). 4-1BB expression is unaccounted for in AH, while PD-1 is elevated. We characterized expression of 4-1BB and PD-1 and the associated T lymphocyte functional status in AH and investigated whether these were associated with short-term mortality. METHODS: Thirty-five patients with AH (at diagnosis and days 7 and 90) were compared with healthy controls (HC). Spontaneous and in vitro stimulated receptor expression were quantified by flow cytometry, and plasma proteins by ELISA. RESULTS: At diagnosis, the patients showed increased stimulated 4-1BB responses of CD4+ T lymphocytes. Also, the frequencies of PD-1+ T lymphocytes both with and without co-expressed 4-1BB were increased. Further, interferon-gamma was predominantly produced in T lymphocytes co-expressing 4-1BB. A decrease in the frequency of spontaneous 4-1BB+ T lymphocytes and an increase in soluble 4-1BB during the first week after diagnosis were associated with higher mortality at day 90 in AH. PD-1 expression showed no systematic dynamics related to mortality. CONCLUSIONS: We found an increased stimulated 4-1BB response of T lymphocytes in AH and early loss of these lymphocytes was associated with a higher short-term mortality. This suggests a role of T lymphocyte 4-1BB expression in the progression of AH.

Diminished Non-Classical Monocytes in the Blood Associate with Disease Severity in Alcoholic Hepatitis.

OBJECTIVE: Alcoholic hepatitis (AH) holds a high mortality, and vast macrophage infiltration of the liver is involved in the progressive liver injury. No efficient medical treatment exists, and macrophages may be a future treatment target. Here, we examine associations between non-classical monocyte subsets and cell surface markers of migration with disease activity in patients with severe AH. METHODS: We analyzed samples from two cohorts of patients with AH. Cohort 1 included 15 AH patients, followed for 30 days, and 8 healthy controls (HCs). Cohort 2 included 23 AH patients, followed for 90 days, and 9 HCs. Peripheral blood mononuclear cells (PBMCs) from both cohorts were analyzed by flow cytometry. Liver biopsies from cohort 2 were analyzed by RNA sequencing. RESULTS: Circulating non-classical monocytes in all but absent in patients with AH compared to HC in both cohorts (both p<0.0001). The frequency of non-classical monocytes was significantly associated with Maddrey's discriminant function (mDF) (r=-0.79, p=0.0008, cohort 1), Child-Pugh score (CP) (r=-0.56, p=0.03, cohort 1), Model for End-Stage Liver Disease (MELD) (r=-0.54, p=0.02, cohort 2) and C-reactive protein (CRP) (r=-0.51, p=0.027, cohort 2). The surface expression of CD11b was increased on non-classical monocytes in patients with AH compared to HC (p<0.0001) (cohort 1). The mRNA expression of CD11b was increased in liver biopsies in patients with AH compared to HC (cohort 2) (p<0.0001). CONCLUSION: In this study, we describe an almost complete depletion of circulating non-classical monocytes in the blood in two independent cohorts of patients with AH, which may be associated with a possible harmful recruitment of these cells to the liver. These results contribute to a better understanding of the disease, which hopefully can lead to therapies that target the acute inflammatory response leading to severe AH.

Interferon lambda 4 genotype and pathway in alcoholic hepatitis.

OBJECTIVES: Single nucleotide polymorphisms within the interferon lambda 4 (IFNL4) gene influence liver inflammation and fibrosis in chronic liver disease. We investigated whether this is also the case during acute liver disease, alcoholic hepatitis. We, therefore, related variants within the IFNL4 gene to the clinical course of acute alcoholic hepatitis, and characterized the activation state of the IFN lambda system in these patients. METHODS: In this pilot study, 58 patients with alcoholic hepatitis were genotyped for the rs368234815IFNL4 single nucleotide polymorphism (deltaG, deltaG/TT: IFN lambda 4 positive, TT/TT: IFN lambda 4 negative). The genotypes were related to mortality, infection and inflammation and expression of the IFNL receptor 1 and IFN inducible genes were measured in liver and peripheral leukocytes. RESULTS: Amongst the alcoholic hepatitis patients who died, the IFN negative patients live longer after diagnosis, and also the IFN negative patients tended to have an overall short-term survival benefit compared to IFN lambda positive patients (p = .058). The IFN lambda 4 negative patients at diagnosis had fewer circulating monocytes and lower plasma soluble CD163. The patients with alcoholic hepatitis had reduced expression of the IFNL receptor 1in both liver and blood compared with healthy controls. In blood, the expression of IFN stimulated genes was lower than in healthy controls and most so in the patients, who died. CONCLUSIONS: The IFN lambda 4 pathway seems involved in the acute disease processes of alcoholic hepatitis and patients without IFN lambda expression seem to have a short-term survival benefit.

No Effect in Alcoholic Hepatitis of Gut-Selective, Broad-Spectrum Antibiotics on Bacterial Translocation or Hepatic and Systemic Inflammation.

INTRODUCTION: In alcoholic hepatitis (AH), translocation of gut bacteria may drive hepatic macrophage activation and systemic inflammation. We investigated the effect of oral non-absorbable, broad-spectrum antibiotic treatment on bacterial translocation and liver and systemic inflammation in AH. METHODS: We consecutively recruited 31 patients with AH. Fourteen were given vancomycin 500 mg, gentamycin 40 mg, and meropenem 500 mg once daily for 7 days. Seventeen patients were a reference group receiving standard-of-care. Circulating markers of bacterial translocation and inflammation were measured at baseline, by day 7 and 90. Gut bacteriome profiling was performed before the intervention and at day 7. RESULTS: At study entry, blood lipopolysaccharide-binding protein was multifold higher than normal, remained unchanged at day 7, but decreased at day 90 (P < 0.001) with no difference between the study groups. The macrophage activation markers sCD163 and sCD206 showed the same pattern (P < 0.001, day 90), still without group differences. The systemic inflammation markers tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 showed similar dynamics without group differences. There was no difference in 90-day mortality (total of 6 deaths) between the groups. The remnant gut bacteriome was markedly diversified by the intervention with growth of bacterial species rare for human flora. DISCUSSION: In patients with AH, gut-targeted antibiotic treatment does not change markers of bacterial translocation and liver and systemic inflammation. This suggests that bacterial translocation is less important once the inflammatory process is established or that bacteriome reduction is less important than composition.

Low Interleukin-22 Binding Protein Is Associated With High Mortality in Alcoholic Hepatitis and Modulates Interleukin-22 Receptor Expression.

INTRODUCTION: In alcoholic hepatitis (AH), high interleukin (IL)-22 production is associated with disease improvement, purportedly through enhanced infection resistance and liver regeneration. IL-22 binding protein (BP) binds and antagonizes IL-22 bioactivity, but data on IL-22BP in liver disease suggest a complex interplay. Despite the scarcity of human data, IL-22 is in clinical trial as treatment of AH. We, therefore, in patients with AH, described the IL-22 system focusing on IL-22BP and associations with disease course, and mechanistically pursued the human associations in vitro. METHODS: We prospectively studied 41 consecutive patients with AH at diagnosis, days 7 and 90, and followed them for up to 1 year. We measured IL-22 pathway proteins in liver biopsies and blood and investigated IL-22BP effects on IL-22 in hepatocyte cultures. RESULTS: IL-22BP was produced in the gut and was identifiable in the patients with AH' livers. Plasma IL-22BP was only 50% of controls and the IL-22/IL-22BP ratio thus elevated. Consistently, IL-22-inducible genes were upregulated in AH livers at diagnosis. Low plasma IL-22BP was closely associated with high 1-year mortality. In vitro, IL-22 stimulation reduced IL-22 receptor (R) expression, but coincubation with IL-22BP sustained IL-22R expression. In the AH livers, IL-22R mRNA expression was similar to healthy livers, although IL-22R liver protein was higher at diagnosis. DISCUSSION: Plasma IL-22BP was associated with an adverse disease course, possibly because its low level reduces IL-22R expression so that IL-22 bioactivity was reduced. This suggests the IL-BP interplay to be central in AH pathogenesis, and in future treatment trials (see Visual abstract, Supplementary Digital Content 5, http://links.lww.com/CTG/A338).

Correction: Decreased monocyte shedding of the migration inhibitor soluble CD18 in alcoholic hepatitis.

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Decreased monocyte shedding of the migration inhibitor soluble CD18 in alcoholic hepatitis.

OBJECTIVES: During alcoholic hepatitis (AH) monocytes traverse the vascular boundaries and massively invade the liver. In principle, tissue extravasation can be limited through shedding of CD18 integrins from leukocytes, including monocytes. The soluble (s) product sCD18 conceals adhesion receptors on the endothelium, which reduces monocyte extravasation. In AH, monocytes are dysfunctional, but whether this involves their self-generated anti-migration is unknown. Our aim was, therefore, to investigate monocyte CD18 dynamics in AH. METHODS: We studied 50 AH patients and 20 healthy controls. We measured monocyte expression and conformational activation of CD18, plasma (P)-sCD18, stimulated in vitro CD18 shedding and P-sCD18 in a short-term chronic-binge mouse model. RESULTS: AH-derived monocytes had a 30-60% higher expression of active CD18 receptors (p < 0.01), but the sCD18 concentration per monocyte was reduced in vivo by 30% and in vitro by 120% (p < 0.01). Ethanol reduced the in vitro shedding of CD18 in the patients only. TNFα increased sCD18 concentration per monocyte, but less so in the patients (p < 0.04). P-sCD18 per monocyte was inversely related to disease severity. In early alcoholic liver disease, P-sCD18 was decreased in the mouse model. CONCLUSIONS: The monocyte CD18 integrins are highly activated in AH and the single monocyte shedding of CD18 was decreased favoring tissue extravasation. Alcohol in itself and altered monocyte responsiveness to TNFα may explain this lowered shedding. TRANSLATIONAL IMPACT: The contribution of this mechanism to the excessive monocyte liver infiltration in AH should be further explored as it may serve as a potential therapeutic target to limit liver inflammation.

In vitro efficacy of pro- and anticoagulant strategies in compensated and acutely ill patients with cirrhosis.

BACKGROUND & AIMS: A simultaneous decline in pro- and anticoagulant drivers in patients with liver diseases results in a "rebalanced" haemostatic system, even in acutely ill patients. Nevertheless, both bleeding and thrombotic events are common. Here, we explored efficacy of pro- and antihaemostatic strategies in compensated and acutely ill cirrhotics which may be unpredictable given the profound haemostatic changes. METHODS: We tested the effects in vitro of the addition of clinically relevant doses of commonly used pro- and antihaemostatic strategies in plasma from healthy individuals (n = 30) and patients with compensated (n = 18) and acutely decompensated cirrhosis (n = 18), and acute-on-chronic liver failure (n = 10). We used thrombin generation tests and fibrin clot permeability assays to assess potency of various approaches. RESULTS: Fresh frozen plasma and recombinant factor VIIa modestly increased thrombin generation (10%-20%). Prothrombin complex concentrate increased thrombin generation two-fold in controls and 2-4-fold in patients. Clot permeability decreased after addition of fibrinogen concentrate by 51% in controls and by 50%-60% in patients. Low molecular weight heparin decreased thrombin generation by 18% in controls and by 23%-54% in patients. Similarly, dabigatran decreased thrombin generation by 33% in controls and by 47%-100% in patients. In contrast, rivaroxaban decreased thrombin generation by 55% in controls, but only by 11%-38% in patients. CONCLUSIONS: These in vitro data suggest little prohaemostatic effect of fresh frozen plasma and recombinant factor VIIa in acutely ill cirrhotics, whereas prothrombin complex concentrate and fibrinogen concentrate clearly improved haemostasis. Furthermore, our data suggest the requirement for dose adjustments of commonly used anticoagulants in these patients.

Balanced haemostasis with both hypo- and hyper-coagulable features in critically ill patients with acute-on-chronic-liver failure.

BACKGROUND: Cirrhotic patients have complex haemostatic abnormalities. Current evidence suggests stable cirrhotic (SC) patients have a "re-balanced" haemostatic state. However, limited data exists in acute decompensated (AD) or acute on chronic liver failure (ACLF) patients. METHODS: We utilised thrombin generation analysis, fibrinolysis assessment, and evaluation of haemostatic parameters to assess haemostasis in liver disease of progressive severity. RESULTS: The study cohorts were comprised of: SC, n=8; AD n=44; ACLF, n=17; and Healthy Control (HC), n=35. There was a progressive increase across the cohorts in INR (p=0.0001), Factor VIII (p=0.0001) and VWF levels (p=0.0001) and a correspondingly decrease in anti-thrombin (p=0.0001), ADAMTS-13 (p=0.01) and fibrinogen levels (p=0.0001). In the presence of thrombomodulin, thrombin generation was equivalent or significantly higher in all the cohorts compared to HC (p=0.0001). Compared to AD, ACLF had a lower ETP (p=0.002) and thrombin peak (p=0.0001). There was no significant difference across the cohorts in clot lysis time (p=0.07), although compared to HC, AD had a significantly shorter lysis time (p=0.001). CONCLUSIONS: Our cohorts, despite significant differences in haemostatic parameters, displayed intact thrombin generation but progressive hypo-functional clot stability and potentially but not universal hyper-functional haemostasis.

The soluble mannose receptor (sMR) is elevated in alcoholic liver disease and associated with disease severity, portal hypertension, and mortality in cirrhosis patients.

BACKGROUND AND AIMS: Hepatic macrophages (Kupffer cells) are involved in the immunopathology of alcoholic liver disease (ALD). The mannose receptor (MR, CD206), expressed primarily by macrophages, mediates endocytosis, antigen presentation and T-cell activation. A soluble form, sMR, has recently been identified in humans. We aimed to study plasma sMR levels and its correlation with disease severity and survival in ALD patients. METHODS: We included 50 patients with alcoholic hepatitis (AH), 68 alcoholic cirrhosis (AC) patients (Child-Pugh A (23), B (24), C (21)), and 21 healthy controls (HC). Liver status was described by the Glasgow Alcoholic Hepatitis Score (GAHS), Child-Pugh (CP) and MELD-scores, and in AC patients the hepatic venous pressure gradient (HVPG) was measured by liver vein catheterisation. We used Kaplan-Meier statistics for short-term survival (84-days) in AH patients and long-term (4 years) in AC patients. We measured plasma sMR by ELISA. RESULTS: Median sMR concentrations were significantly elevated in AH 1.32(IQR:0.69) and AC 0.46(0.5) compared to HC 0.2(0.06) mg/L; p<0.001 and increased in a stepwise manner with the CP-score (p<0.001). In AC sMR predicted portal hypertension (HVPG ≥10 mmHg) with an area under the Receiver Operator Characteristics curve of 0.86 and a high sMR cut-off (>0.43 mg/l) was associated with increased mortality (p = 0.005). CONCLUSION: The soluble mannose receptor is elevated in alcoholic liver disease, especially in patients with AH. Its blood level predicts portal hypertension and long-term mortality in AC patients.

The damage-associated molecular pattern HMGB1 is elevated in human alcoholic hepatitis, but does not seem to be a primary driver of inflammation.

The role of sterile inflammation caused by release of damage-associated molecular patterns (DAMP) remains unclear in human alcoholic hepatitis (AH). The DAMP, high mobility group box-1 protein (HMGB1) is released by tissue damage and inflammation. We aimed to investigate whether HMGB1 is a primary inflammatory driver in AH by determining HMGB1 serum levels and effects on inflammatory cells from AH patients. We measured serum HMGB1 in 34 AH patients and 10 healthy controls using ELISA. Toll-like receptor 4 (TLR4) and CD14 expressions were assessed by flow cytometry on HMGB1-stimulated peripheral blood mononuclear cells (PBMC) and ELISA was used to measure TNF-α and IL-1ß in the supernatants. We observed 5-fold higher serum levels of HMGB1 in AH patients at the day of diagnosis and day 30, but no associations to clinical outcome. HMGB1 stimulation increased the expression of TLR4 on CD14+-monocytes compared with unstimulated cells in the AH patients. The TNF-α and IL-1ß production in response to HMGB1 was diminished in AH patients. In conclusion, AH patients have increased levels of HMGB1 in their blood. This combined with an increased TLR4 expression, but an unaffected cytokine response to HMGB1 suggest that HMGB1 is not the primary driver of inflammation in AH.

Clinical science workshop: targeting the gut-liver-brain axis.

A clinical science workshop was held at the ISHEN meeting in London on Friday 11th September 2014 with the aim of thrashing out how we might translate what we know about the central role of the gut-liver-brain axis into targets which we can use in the treatment of hepatic encephalopathy (HE). This review summarises the integral role that inter-organ ammonia metabolism plays in the pathogenesis of HE with specific discussion of the roles that the small and large intestine, liver, brain, kidney and muscle assume in ammonia and glutamine metabolism. Most recently, the salivary and gut microbiome have been shown to underpin the pathophysiological changes which culminate in HE and patients with advanced cirrhosis present with enteric dysbiosis with small bowel bacterial overgrowth and translocation of bacteria and their products across a leaky gut epithelial barrier. Resident macrophages within the liver are able to sense bacterial degradation products initiating a pro-inflammatory response within the hepatic parenchyma and release of cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-8 into the systemic circulation. The endotoxemia and systemic inflammatory response that are generated predispose both to the development of infection as well as the manifestation of covert and overt HE. Co-morbidities such as diabetes and insulin resistance, which commonly accompany cirrhosis, may promote slow gut transit, promote bacterial overgrowth and increase glutaminase activity and may need to be acknowledged in HE risk stratification assessments and therapeutic regimens. Therapies are discussed which target ammonia production, utilisation or excretion at an individual organ level, or which reduce systemic inflammation and endotoxemia which are known to exacerbate the cerebral effects of ammonia in HE. The ideal therapeutic strategy would be to use an agent that can reduce hyperammonemia and reduce systemic inflammation or perhaps to adopt a combination of therapies that can address both.

Circulating mannan-binding lectin, M-, L-, H-ficolin and collectin-liver-1 levels in patients with acute liver failure.

BACKGROUND & AIMS: The complement system is activated in liver diseases including acute liver failure (ALF); however, the role of the lectin pathway of complement has scarcely been investigated in ALF. The pathway is initiated by soluble pattern recognition molecules: mannan-binding lectin (MBL), M-, L-, and H-ficolin and collectin-liver-1 (CL-L1), which are predominantly synthesized in the liver. We aimed to study lectin levels in ALF patients and associations with clinical outcome. METHODS: Serum samples from 75 patients enrolled by the US ALF Study Group were collected on days 1 and 3. We included 75 healthy blood donors and 20 cirrhosis patients as controls. Analyses were performed using sandwich-type immunoassays (ELISA, TRIFMA). RESULTS: At day 1, the MBL level in ALF patients was 40% lower compared with healthy controls {[median (interquartile range) 0.72 µg/ml(0.91) vs. 1.15 (1.92)(P = 0.02]}, and increased significantly by day 3 [0.83 µg/ml(0.94)(P = 0.01)]. The M-ficolin level was 60% lower [0.54 µg/ml(0.50) vs. 1.48(1.01)(P < 0.0001)]. The CL-L1 level at day 1 was slightly higher compared with healthy controls [3.20 µg/ml(2.37) vs. 2.64(0.72)(P = 0.11)]; this was significant at day 3 [3.35(1.84)(P = 0.006)]. H- and L-ficolin levels were similar to healthy controls. Spontaneous ALF survivors had higher levels of MBL at day 1 [0.96 µg/ml(1.15) vs. 0.60(0.60)(P = 0.02)] and lower levels of L-ficolin by day 3 compared with patients who died or were transplanted [1.61 µg/ml(1.19) vs. 2.17(2.19)(P = 0.02)]. CONCLUSION: We observed significant dynamics in lectin levels in ALF patients, which may suggest they play a role in ALF pathogenesis. High MBL and low L-ficolin levels are associated with survival.

Cytotoxic T lymphocytes and natural killer cells display impaired cytotoxic functions and reduced activation in patients with alcoholic hepatitis.

The dynamics and role of cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, and NKT cells in the life-threatening inflammatory disease alcoholic hepatitis is largely unknown. These cells directly kill infected and damaged cells through, e.g., degranulation and interferon-γ (IFNγ) production, but cause tissue damage if overactivated. They also assist tissue repair via IL-22 production. We, therefore, aimed to investigate the frequency, functionality, and activation state of such cells in alcoholic hepatitis. We analyzed blood samples from 24 severe alcoholic hepatitis patients followed for 30 days after diagnosis. Ten healthy abstinent volunteers and 10 stable abstinent alcoholic cirrhosis patients were controls. Using flow cytometry we assessed cell frequencies, NK cell degranulation capacity following K562 cell stimulation, activation by natural killer group 2 D (NKG2D) expression, and IL-22 and IFNγ production. In alcoholic hepatitis we found a decreased frequency of CTLs compared with healthy controls (P < 0.001) and a similar trend for NK cells (P = 0.089). The NK cell degranulation capacity was reduced by 25% compared with healthy controls (P = 0.02) and by 50% compared with cirrhosis patients (P = 0.04). Accordingly, the NKG2D receptor expression was markedly decreased on NK cells, CTLs, and NKT cells (P < 0.05, all). The frequencies of IL-22-producing CTLs and NK cells were doubled compared with healthy controls (P < 0.05, all) but not different from cirrhosis patients. This exploratory study for the first time showed impaired cellular cytotoxicity and activation in alcoholic hepatitis. This is unlikely to cause hepatocyte death but may contribute toward the severe immune incompetence. The results warrant detailed and mechanistic studies.

Blood culture-positive infections in patients with alcoholic hepatitis.

Acute alcoholic hepatitis (AH) is a life-threatening disease and its course is often determined by infections. However, the pattern of pathogens has not been studied. We examined the microbiological pathogens that caused blood-borne infection in patients with AH. We included 32 AH patients without infection at inclusion. Patients were followed for 1 month and their infection status was recorded based on clinical records, radiologic exams and cultures of different secreta. Nine patients (28%) developed blood culture-positive infections. The agents were of heterogeneous aetiology and came from various sites of infection. Candida species accounted for three of these infections (33%). Five patients (16%) died, two of which had positive blood cultures. A high fraction was invasively infected by a heterogeneous spectrum of microbes including yeasts and commensal bacteria. This may reflect the severe immune impairment of AH and suggests thorough infection screening and an immediate broad-spectrum antibiotic approach if infection is suspected.

Hepatic macrophage activation and the LPS pathway in patients with alcoholic hepatitis: a prospective cohort study.

OBJECTIVES: Inflammatory activation of resident hepatic macrophages (Kupffer cells) by portal-derived lipopolysaccharide (LPS) has a primary role in animal models of alcoholic liver disease, but it has not been systematically or longitudinally studied in human alcoholic hepatitis (AH). METHODS: We followed 50 patients with AH for 30 days. 26 patients with stable alcoholic cirrhosis and 20 healthy individuals were controls. We measured the plasma (P) concentrations of soluble CD163 (sCD163; a specific marker of inflammatory macrophage activation) and the expression of CD163 in liver tissue by immunohistochemistry and stereology of liver biopsies. We also measured the key components of the LPS pathway, P-LPS, sCD14, and LPS-binding protein (LBP), by enzyme-linked immunosorbent assay (ELISA). The 84-day mortality was registered. RESULTS: At study entry, the sCD163 concentration was 10-fold higher than in the healthy controls and 30% higher than in the stable cirrhotics (P<0.002), and it correlated with the Glasgow Alcoholic Hepatitis, Model for End-stage Liver Disease, and Child-Pugh scores (r>0.35, P<0.02, all). The liver biopsies confirmed markedly increased CD163 staining (P<0.01). P-LPS, P-CD14, and P-LBP were increased to the same degree as sCD163. During the follow-up, the sCD163 and LPS pathway components all decreased by ∼25% (P<0.05) but remained higher than in both control groups. sCD163 was an independent predictor of the 84-day mortality. CONCLUSIONS: The hepatic inflammation of human AH involves marked activation of hepatic macrophages, likely via the LPS pathway. Hepatic macrophages may thus present a target for biological therapy of AH.