Inequity in clinical research access for service users presenting comorbidity within alcohol treatment settings: findings from a focused ethnographic study.

BACKGROUND: While healthcare policy has fostered implementation strategies to improve inclusion and access of under-served groups to clinical care, systemic and structural elements still disproportionately prevent service users from accessing research opportunities embedded within clinical settings. This contributes to the widening of health inequalities, as the absence of representativeness prevents the applicability and effectiveness of evidence-based interventions in under-served clinical populations. The present study aims to identify the individual (micro), organisational (meso) and structural (macro) barriers to clinical research access in patients with comorbid alcohol use disorder and alcohol-related liver disease. METHODS: A focused ethnography approach was employed to explore the challenges experienced by patients in the access to and implementation of research processes within clinical settings. Data were collected through an iterative-inductive approach, using field notes and patient interview transcripts. The framework method was utilised for data analysis, and themes were identified at the micro, meso and macro levels. RESULTS: At the micro-level, alcohol-related barriers included encephalopathy and acute withdrawal symptoms. Alcohol-unrelated barriers also shaped the engagement of service users in research. At the meso-level, staff and resource pressures, as well as familiarity with clinical and research facilities were noted as influencing intervention delivery and study retention. At the wider, macro-level, circumstances including the 'cost of living crisis' and national industrial action within healthcare settings had an impact on research processes. The findings emphasise a 'domino effect' across all levels, demonstrating an interplay between individual, organisational and structural elements influencing access to clinical research. CONCLUSIONS: A combination of individual, organisational and structural barriers, exacerbated by the COVID-19 pandemic, and the socioeconomic landscape in which the study was conducted further contributed to the unequal access of under-served groups to clinical research participation. For patients with comorbid alcohol use disorder and alcohol-related liver disease, limited access to research further contributes towards a gap in effective evidence-based treatment, exacerbating health inequalities in this clinical population.

Dysregulated anti-oxidant signalling and compromised mitochondrial integrity negatively influence regulatory T cell function and viability in liver disease.

BACKGROUND: Dysregulated inflammatory responses and oxidative stress are key pathogenic drivers of chronic inflammatory diseases such as liver cirrhosis (LC). Regulatory T cells (Tregs) are essential to prevent excessive immune activation and maintain tissue homeostasis. While inflammatory cues are well known to modulate the function and stability of Tregs, the extent to which Tregs are influenced by oxidative stress has not been fully explored. METHODS: The phenotypic and functional properties of CD4+CD25+CD127lo/- Tregs isolated from patients with LC were compared to healthy controls (HC). Treg redox state was investigated by characterizing intracellular reactive oxygen species (ROS), NADPH oxidase-2 (Nox2) activity, mitochondrial function, morphology, and nuclear factor-erythroid 2-related factor (Nrf2) antioxidant signalling. The relevance of Nrf2 and its downstream target, Heme-oxygenase-1 (HO-1), in Treg function, stability, and survival, was further assessed using mouse models and CRISPR/Cas9-mediated HO-1 knock-out. FINDINGS: Circulating Tregs from LC patients displayed a reduced suppressive function, correlating with liver disease severity, associated with phenotypic abnormalities and increased apoptosis. Mechanistically, this was linked to a dysregulated Nrf2 signalling with resultant lower levels of HO-1, enhanced Nox2 activation, and impaired mitochondrial respiration and integrity. The functional deficit in LC Tregs could be partially recapitulated by culturing control Tregs in patient sera. INTERPRETATION: Our findings reveal that Tregs rely on functional redox homeostasis for their function, stability, and survival. Targeting Treg specific anti-oxidant pathways may have therapeutic potential to reverse the Treg impairment in conditions of oxidative damage such as advanced liver disease. FUNDING: This study was funded by the Wellcome Trust (211113/A/18/Z).

Mitochondrial respiratory chain activity is associated with severity, corticosteroid response and prognosis of alcoholic hepatitis.

BACKGROUND AND AIMS: Little is known about the extent of mitochondrial respiratory chain (MRC) activity dysfunction in patients with alcoholic hepatitis (AH). We aimed to assess the hepatic MRC activity in AH patients and its potential impact on the severity and prognosis of this life-threatening liver disease. METHODS: MRC complexes were measured in liver biopsies of 98 AH patients (non-severe, 17; severe, 81) and in 12 histologically normal livers (NL). Severity was assessed according to Maddrey's Index and MELD score. Corticosteroid response rate and cumulative mortality were also evaluated. RESULTS: The activity of the five MRC complexes was markedly decreased in the liver of AH patients compared with that of NL subjects, being significantly lower in patients with severe AH than in those with non-severe AH. There was a negative correlation between the activity of all MRC complexes and the severity of AH. Interestingly, only complex I and III activities showed a significant positive correlation with the corticosteroid response rate and a significant negative correlation with the mortality rate at all-time points studied. In a multivariate regression analysis, besides the MELD score and the corticosteroid response rate, complex I activity was significantly associated with 3-month mortality (OR = 6.03; p = 0.034) and complex III activity with 6-month mortality (OR = 4.70; p = 0.041) in AH patients. CONCLUSION: Our results indicate that MRC activity is markedly decreased in the liver of AH patients, and, particularly, the impairment of MRC complexes I and III activity appears to have a significant impact on the clinical outcomes of patients with AH.

Golden opportunity for intervention? Identifying vitamin D deficiency in patients with substance use disorders in hospital.

SETTING: Based at a busy city hospital, the alcohol care team is a drug and alcohol specialist service, taking referrals for a wide range of patients with substance use disorders (SUD). OBJECTIVES: Patients with SUD are at high risk of vitamin D deficiency; this relates to frequent fractures and proximal myopathy. The coronavirus pandemic brought vitamin D into focus. Local guidelines advise that patients at high risk of vitamin D deficiency are offered replacement. There were no local data on vitamin D deficiency prevalence or any mention of patients with SUD in local vitamin D guidelines. The main aim of this project was to offer vitamin D checks and replacement to all appropriate patients. RESULTS: We collected data on 207 patients, [pilot study (n=50) and two subsequent samples (n=95 and n=62)]. Our pilot study showed that no patients were offered vitamin D testing or replacement. We then offered vitamin D checks to 95 patients. Most had low vitamin D (30 patients were vitamin D deficient and 26 were vitamin D insufficient). We provided vitamin D replacement and follow-up advice. Quality improvement was demonstrated 6 months later. We collected data on a further 62 patients who were all on our current or recent caseload. Following exclusions, nearly half (48%) of patients had had a vitamin D check. Almost all of these (95%) had low vitamin D (60% being classified as deficient). CONCLUSIONS: Patients had not been offered vitamin D replacement despite often having multiple risk factors for vitamin D deficiency. Vitamin D checks (and subsequent replacement) rose in frequency since the outset of this project. Local guidelines should add SUD as a risk factor for vitamin D deficiency. Hospital admission provides a rich opportunity to offer this simple intervention to patients who are often poorly engaged with community services.

Diagnosis, presentation and initial severity of Autoimmune Hepatitis (AIH) in patients attending 28 hospitals in the UK.

BACKGROUND & AIMS: There is limited information regarding patients with AIH outside relatively few large centres. We describe here the presenting features of patients with AIH, collected as part of an audit involving 28 UK hospitals. METHODS: Patients (incident since 1/1/2007 or prevalent since 1/1/2000) were ≥18 years and either met 1999 International AIH Group (IAIHG) diagnostic criteria (n = 1164), or received immunosuppressive therapy for clinically diagnosed AIH (n = 103). RESULTS: Of 1267 patients (80% women, 91% Caucasian, age (median(range)) 55(8-86) years, 0.5% had acute viral hepatitis (CMV/EBV/HEV); 2% were taking Nitrofurantoin and 0.7% Khat. Twenty-one percent had clinical decompensation and/or a MELD score of >15. Time from first abnormal liver tests to diagnosis was ≥1 year in 19% and was longer in jaundiced vs non-jaundiced patients. HBV and HCV serology were undocumented in 4%, serum immunoglobulins in 31% and autoantibodies in 11%-27%. When documented, ≥1 antibody was present in 83%. LKM-1-positive and autoantibody-negative patients had more severe disease. Histological cirrhosis was reported in 23%, interface hepatitis 88%, predominant lymphocytes/plasma cells 75%, rosettes 19% and emperipolesis 0.4%. Only 65% of those meeting 1999 IAIHG criteria also met simplified IAIHG criteria. University Hospitals compared to District General Hospitals, were more likely to report histological features of AIH. CONCLUSIONS: This cohort from across the UK is older than other multicentre AIH cohorts. One-fifth had decompensation or MELD >15. Diagnosis was delayed in 19%, diagnostic testing was incomplete in one-third and rosettes and emperipolesis were infrequently reported.

Muscle Protein Signaling in C2C12 Cells Is Stimulated to Similar Degrees by Diverse Commercial Food Protein Sources and Experimental Soy Protein Hydrolysates.

Dietary protein stimulates muscle protein synthesis and is essential for muscle health. We developed a screening assay using C2C12 mouse muscle cells to assess the relative abilities of diverse commercial protein sources and experimental soy protein hydrolysates (ESH), after simulated gut digestion (SGD), to activate the mechanistic target of rapamycin complex I (mTORC1) muscle protein synthesis signaling pathway (p70S6K(Thr389) phosphorylation). Activation of mTORC1 was expressed as a percentage of a maximal insulin response. The bioactivities of proteins grouped by source including fish (81.3 ± 10.6%), soy (66.2 ± 4.7%), dairy (61.8 ± 4.3%), beef (53.7 ± 8.6%), egg (52.3 ± 10.6%), soy whey (43.4 ± 8.6%), and pea (31.4 ± 10.6%) were not significantly different from each other. Bioactivity for ESH ranged from 28.0 ± 7.5 to 98.2 ± 6.6%. The results indicate that both the protein source and processing conditions are key determinants for mTORC1 activation. Regression analyses demonstrated that neither leucine nor total branched-chain amino acid content of proteins is the sole predictor of mTORC1 activity and that additional factors are necessary.

Role of toll-like receptor 4 in mediating multiorgan dysfunction in mice with acetaminophen induced acute liver failure.

Strategies for the prevention of multiorgan dysfunction (MOD) in acetaminophen (APAP)-induced acute liver failure (ALF) are an unmet need. Our study tested the hypothesis that sterile inflammation induced by APAP in a mouse model would activate toll-like receptor 4 (TLR4) in the liver and extrahepatic organs and lead to the progression of ALF and MOD and that the administration of the novel TLR4 antagonist STM28 (a peptide formed of 17 amino-acids) would prevent liver injury and associated MOD. ALF and, subsequently, MOD were induced in TLR4-knockout (KO) mice (B6.B10ScN-Tlr4 (lpsdel) /JthJ) and wild-type (WT) mice (C57BL/6) with APAP (500 mg/kg). A second set of experiments was conducted to evaluate the effects of a pretreatment with a novel TLR4 antagonist, STM28, on APAP-induced MOD in CD1 mice. Animals were sacrificed at the coma stage, and plasma, peripheral blood cells, liver, kidneys, and brain were collected. Biochemistry values and cytokines were measured. Liver and kidneys were studied histologically and were stained for TLR4 and activated Kupffer cells, and the expression of nuclear factor kappa B-p65 was quantified with western blotting. Brain water was measured in the frontal cortex. After APAP administration, TLR4-KO (NFkBp65) mice were relatively protected from liver necrosis and end-organ dysfunction and had significantly better survival than WT controls (P < 0.01). STM28 attenuated liver injury and necrosis, reduced creatinine levels, and delayed the time to a coma significantly. The increases in cytokines in the plasma and liver, including TLR4 expression and the activation of Kupffer cells, after APAP administration were reduced significantly in the STM28-treated animals. The increased number of circulating myeloid cells was reduced significantly after STM28 treatment. In conclusion, these data provide evidence for an important role of the TLR4 antagonist in the prevention of the progression of APAP-induced ALF and MOD.

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

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

Prevention of acute kidney injury in a rodent model of cirrhosis following selective gut decontamination is associated with reduced renal TLR4 expression.

BACKGROUND & AIMS: Superimposed infection and/or inflammation precipitate renal failure in cirrhosis. This study aimed at testing the hypothesis that increased gut bacterial translocation in cirrhosis primes the kidney to the effect of superimposed inflammation by upregulating expression of Toll-like receptor 4 (TLR4), NFκB, and cytokines. A well-characterized bile-duct ligated (BDL) model of cirrhosis, which develops renal failure following superimposed inflammatory insult with lipopolysaccharide (LPS), was used and selective gut decontamination was performed using norfloxacin. METHODS: Sprague-Dawley rats were studied: Sham, Sham+LPS; BDL, BDL+LPS; an additional BDL and BDL+LPS groups were selectively decontaminated with norfloxacin. Plasma biochemistry, plasma renin activity (PRA) and cytokines and, protein expression of TLR4, NFκB, and cytokines were measured in the kidney homogenate. The kidneys were stained for TLR4, TLR2, and caspase-3. Endotoxemia was measured using neutrophil burst and Limulus amoebocyte lysate (LAL) assays. RESULTS: The groups treated with norfloxacin showed significant attenuation of the increase in plasma creatinine, plasma and renal TNF-α and renal tubular injury on histology. The increased renal protein expression of TLR4, NFκB, and caspase-3 in the untreated animals was significantly attenuated in the norfloxacin treated animals. PRA was reduced in the treated animals and severity of endotoxemia was also reduced. CONCLUSIONS: The results show for the first time that kidneys in cirrhosis show an increased expression of TLR4, NFκB, and the pro-inflammatory cytokine TNF-α, which makes them susceptible to a further inflammatory insult. This increased susceptibility to LPS can be prevented with selective decontamination, providing novel insights into the pathophysiology of renal failure in cirrhosis.

Evidence of neutrophil functional defect despite inflammation in stable cirrhosis.

BACKGROUND & AIMS: Deranged neutrophil function in alcoholic hepatitis has been shown to be transmissible to normal neutrophils by patient plasma. The aims of this study were (i) to evaluate whether patients with stable cirrhosis have a similar transmissible neutrophil defect and (ii) to explore the possible mechanisms. METHODS: Plasma samples from 108 stable cirrhotic patients (Child A or B: 58; Child C: 50) and matched controls were incubated with normal neutrophils. Neutrophil resting respiratory burst, phagocytosis, and toll-like receptors 2, 4, and 9 expressions as well as plasma endotoxin, bacterial DNA, and cytokines were measured. In a separate study, eight patients and five controls were studied using a novel 'skin-window' technique to evaluate neutrophil function in an area of induced sterile inflammation. RESULTS: Patient plasma induced neutrophil phagocytic dysfunction was greater in patients with more severe disease and was associated with increased expression of toll-like receptors 2 and 4. An increased resting respiratory burst was observed in a subset of patients, showing higher levels of inflammatory cytokines and more pronounced phagocytic impairment. No correlation was found with endotoxemia or bacterial DNA. In patients with compensated cirrhosis and apparently normal neutrophil function, the 'skin-window' study disclosed a severe phagocytic defect at the site of inflammation. Significantly higher levels of neutrophil elastase and IL-8 were found in the blister fluid. CONCLUSIONS: Stable cirrhosis is characterized by neutrophil phagocytic dysfunction which may be subtle and only revealed in inflamed peripheral tissues where excessive inflammatory mediators continue to be released.

Acute liver failure: a review.

Since publication of the first descriptions of acute liver failure (ALF) as a distinct clinical entity in the 1950's, the understanding of the pathophysiologic mechanisms involved and the management options have increased substantially. ALF still represents a major challenge for todays hepatologists, because it can rapidly lead to multiorgan failure and death that may be preventable with appropriate intervention. This article summarizes the basic patho-physiology underlying ALF, compares epidemiologic trends in the United States, the United Kingdom, and the Far East, and reviews prognostic markers and treatment options for ALF.