Translating the potential of the urine steroid metabolome to stage NAFLD (TrUSt-NAFLD): study protocol for a multicentre, prospective validation study.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) affects approximately one in four individuals and its prevalence continues to rise. The advanced stages of NAFLD with significant liver fibrosis are associated with adverse morbidity and mortality outcomes. Currently, liver biopsy remains the 'gold-standard' approach to stage NAFLD severity. Although generally well tolerated, liver biopsies are associated with significant complications, are resource intensive, costly, and sample only a very small area of the liver as well as requiring day case admission to a secondary care setting. As a result, there is a significant unmet need to develop non-invasive biomarkers that can accurately stage NAFLD and limit the need for liver biopsy. The aim of this study is to validate the use of the urine steroid metabolome as a strategy to stage NAFLD severity and to compare its performance against other non-invasive NAFLD biomarkers. METHODS AND ANALYSIS: The TrUSt-NAFLD study is a multicentre prospective test validation study aiming to recruit 310 patients with biopsy-proven and staged NAFLD across eight centres within the UK. 150 appropriately matched control patients without liver disease will be recruited through the Oxford Biobank. Blood and urine samples, alongside clinical data, will be collected from all participants. Urine samples will be analysed by liquid chromatography-tandem mass spectroscopy to quantify a panel of predefined steroid metabolites. A machine learning-based classifier, for example, Generalized Matrix Relevance Learning Vector Quantization that was trained on retrospective samples, will be applied to the prospective steroid metabolite data to determine its ability to identify those patients with advanced, as opposed to mild-moderate, liver fibrosis as a consequence of NAFLD. ETHICS AND DISSEMINATION: Research ethical approval was granted by West Midlands, Black Country Research Ethics Committee (REC reference: 21/WM/0177). A substantial amendment (TrUSt-NAFLD-SA1) was approved on 26 November 2021. TRIAL REGISTRATION NUMBER: ISRCTN19370855.

Automated and reproducible cell identification in mass cytometry using neural networks.

The principal use of mass cytometry is to identify distinct cell types and changes in their composition, phenotype and function in different samples and conditions. Combining data from different studies has the potential to increase the power of these discoveries in diverse fields such as immunology, oncology and infection. However, current tools are lacking in scalable, reproducible and automated methods to integrate and study data sets from mass cytometry that often use heterogenous approaches to study similar samples. To address these limitations, we present two novel developments: (1) a pre-trained cell identification model named Immunopred that allows automated identification of immune cells without user-defined prior knowledge of expected cell types and (2) a fully automated cytometry meta-analysis pipeline built around Immunopred. We evaluated this pipeline on six COVID-19 study data sets comprising 270 unique samples and uncovered novel significant phenotypic changes in the wider immune landscape of COVID-19 that were not identified when each study was analyzed individually. Applied widely, our approach will support the discovery of novel findings in research areas where cytometry data sets are available for integration.

National study of NAFLD management identifies variation in delivery of care in the UK between 2019 to 2022.

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is associated with liver and cardiovascular morbidity and mortality. Recently published NAFLD Quality Standards include 11 key performance indicators (KPIs) of good clinical care. This national study, endorsed by British Association for the Study of the Liver (BASL) and British Society of Gastroenterology (BSG), aimed to benchmark NAFLD care in UK hospitals against these KPIs. Methods: This study included all new patients with NAFLD reviewed in the outpatient clinic in the months of March 2019 and March 2022. Participating UK hospitals self-registered for the study through BASL/BSG. KPI outcomes were compared using Fisher's exact or Chi-square tests. Results: Data from 776 patients with NAFLD attending 34 hospitals (England [25], Scotland [four], Wales [three], Northern Ireland [two]) were collected. A total of 85.3% of hospitals reported established local liver disease assessment pathways, yet only 27.9% of patients with suspected NAFLD had non-invasive fibrosis assessment documented at the point of referral to secondary care. In secondary care, 79.1% of patients had fibrosis assessment. Assessment of cardiometabolic risk factors including obesity, type 2 diabetes, hypertension, and smoking were conducted in 73.2%, 33.0%, 19.3%, and 54.9% of all patients, respectively. There was limited documentation of diet (35.7%) and exercise advice (55.1%). Excluding those on statins, only 9.1% of patients with NAFLD at increased cardiovascular risk (T2DM and/or QRISK-3 >10%) had documented discussion of statin treatment. Significant KPI improvements from 2019 to 2022 were evident in use of non-invasive fibrosis assessment before secondary care referral, statin recommendations, and diet and exercise recommendations. Conclusions: This national study identified substantial variation in NAFLD management in the UK with clear areas for improvement, particularly fibrosis risk assessment before secondary care referral and management of associated cardiometabolic risk factors. Impact and implications: This study identified significant variation in the management of NAFLD in the UK. Only 27.9% of patients with suspected NAFLD had non-invasive fibrosis assessment performed to identify those at greater risk of advanced liver disease before specialist referral. Greater emphasis is needed on the management of associated cardiometabolic risk factors in individuals with NAFLD. Hospitals with multidisciplinary NAFLD service provision had higher rates of fibrosis evaluation and assessment and management of cardiometabolic risk than hospitals without multidisciplinary services. Further work is needed to align guideline recommendations and real-world practice in NAFLD care.

Single-cell phenotypes of peripheral blood immune cells in early and late stages of non-alcoholic fatty liver disease.

BACKGROUND/AIMS: Immune and inflammatory cells respond to multiple pathological hits in the development of nonalcoholic steatohepatitis (NASH) and fibrosis. Relatively little is known about how their type and function change through the non-alcoholic fatty liver disease (NAFLD) spectrum. Here we used multi-dimensional mass cytometry and a tailored bioinformatic approach to study circulating immune cells sampled from healthy individuals and people with NAFLD. METHODS: Cytometry by time of flight using 36 metal-conjugated antibodies was applied to peripheral blood mononuclear cells (PBMCs) from biopsy-proven NASH fibrosis (late disease), steatosis (early disease), and healthy patients. Supervised and unsupervised analyses were used, findings confirmed, and mechanisms assessed using independent healthy and disease PBMC samples. RESULTS: Of 36 PBMC clusters, 21 changed between controls and disease samples. Significant differences were observed between diseases stages with changes in T cells and myeloid cells throughout disease and B cell changes in late stages. Semi-supervised gating and re-clustering showed that disease stages were associated with fewer monocytes with active signalling and more inactive NK cells; B and T cells bearing activation markers were reduced in late stages, while B cells bearing co-stimulatory molecules were increased. Functionally, disease states were associated with fewer activated mucosal-associated invariant T cells and reduced toll-like receptor-mediated cytokine production in late disease. CONCLUSION: A range of innate and adaptive immune changes begin early in NAFLD, and disease stages are associated with a functionally less active phenotype compared to controls. Further study of the immune response in NAFLD spectrum may give insight into mechanisms of disease with potential clinical application.

Association of gamma-glutamyltransferase levels with total mortality, liver-related and cardiovascular outcomes: A prospective cohort study in the UK Biobank.

Background: Gamma-glutamyltransferase (GGT) levels in the blood can be a sensitive marker of liver injury but the extent to which they give insight into risk across multiple outcomes in a clinically useful way remains uncertain. Methods: Using data from 293,667 UK Biobank participants, the relationship of GGT concentrations to self-reported alcohol intake and adiposity markers were investigated. We next investigated whether GGT predicted liver-related, cardiovascular (CV) or all-cause mortality, and potentially improved CV risk prediction. Findings: Higher alcohol intake and greater waist circumference (WC) were associated with higher GGT; the association was stronger for alcohol with evidence of a synergistic effect of WC. Higher GGT concentrations were associated with multiple outcomes. Compared to a GGT of 14.5 U/L (lowest decile), values of 48 U/L for women and 60 U/L for men (common upper limits of 'normal') had hazard ratios (HRs) for liver-related mortality of 1.83 (95% CI 1.60-2.11) and 3.25 (95% CI 2.38-4.42) respectively, for CV mortality of 1.21 (95% CI 1.14-1.28) and 1.43 (95% CI 1.27-1.60) and for all-cause mortality of 1.15 (95% CI 1.12-1.18) and 1.31 (95% CI 1.24-1.38). Adding GGT to a risk algorithm for CV mortality reclassified an additional 1.24% (95% CI 0.14-2.34) of participants across a binary 5% 10-year risk threshold. Interpretation: Our study suggests that a modest elevation in GGT levels should trigger a discussion with the individual to review diet and lifestyle including alcohol intake and consideration of formal liver disease and CV risk assessment if not previously done. Funding: British Heart Foundation Centre of Research Excellence Grant (grant number RE/18/6/34217), NHS Research Scotland (grant number SCAF/15/02), the Medical Research Council (grant number MC_UU_00022/2); and the Scottish Government Chief Scientist Office (grant number SPHSU17).

Non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. NAFLD is defined by excess fat in the liver and has a multidirectional relationship with metabolic syndrome. The prevalence of NAFLD has risen rapidly in recent years in line with the obesity epidemic and associated increases in type 2 diabetes, hypertension and hypercholesterolaemia. Patients with NAFLD are at risk of cardiovascular disease and cancer, and in a proportion of individuals, NAFLD is associated with liver damage. This article summarises the epidemiology of NAFLD, the clinical approach to risk-assessing patients and briefly outlines current and future management options.

Stat2 loss disrupts damage signalling and is protective in acute pancreatitis.

The severity of sterile inflammation, as seen in acute pancreatitis, is determined by damage-sensing receptors, signalling cascades and cytokine production. Stat2 is a type I interferon signalling mediator that also has interferon-independent roles in murine lipopolysaccharide-induced NF-κB-mediated sepsis. However, its role in sterile inflammation is unknown. We hypothesised that Stat2 determines the severity of non-infective inflammation in the pancreas. Wild type (WT) and Stat2-/- mice were injected i.p. with caerulein or l-arginine. Specific cytokine-blocking antibodies were used in some experiments. Pancreata and blood were harvested 1 and 24 h after the final dose of caerulein and up to 96 h post l-arginine. Whole-tissue phosphoproteomic changes were assessed using label-free mass spectrometry. Tissue-specific Stat2 effects were studied in WT/Stat2-/- bone marrow chimera and using Cre-lox recombination to delete Stat2 in pancreatic and duodenal homeobox 1 (Pdx1)-expressing cells. Stat2-/- mice were protected from caerulein- and l-arginine-induced pancreatitis. Protection was independent of type I interferon signalling. Stat2-/- mice had lower cytokine levels, including TNF-α and IL-10, and reduced NF-κB nuclear localisation in pancreatic tissue compared with WT. Inhibition of TNF-α improved (inhibition of IL-10 worsened) caerulein-induced pancreatitis in WT but not Stat2-/- mice. Phosphoproteomics showed downregulation of MAPK mediators but accumulation of Ser412-phosphorylated Tak1. Stat2 deletion in Pdx1-expressing acinar cells (Stat2flox/Pdx1-cre ) reduced pancreatic TNF-α expression, but not histological injury or serum amylase. WT/Stat2-/- bone marrow chimera mice were protected from pancreatitis irrespective of host or recipient genotype. Stat2 loss results in disrupted signalling in pancreatitis, upstream of NF-κB in non-acinar and/or bone marrow-derived cells. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Proteomic screening of plasma identifies potential noninvasive biomarkers associated with significant/advanced fibrosis in patients with nonalcoholic fatty liver disease.

Noninvasive biomarkers are clinically useful for evaluating liver fibrosis stage in patients with nonalcoholic fatty liver disease (NAFLD). The aim of the present study was to compare plasma proteins in patients with early nonalcoholic steatohepatitis (NASH) (F0-F1) versus NASH with significant/advanced fibrosis (F2-F4) to determine whether candidate proteins could be used as potential noninvasive biomarkers. Nineteen biopsy-proven NAFLD patients including ten early NASH patients and nine NASH patients with significant/advanced fibrosis were enrolled in the present study. High-resolution proteomics screening of plasma was performed with the SCIEX TripleTOF 5600 System. Proteins were quantified using two different software platforms, Progenesis Qi and Scaffold Q+, respectively. Progenesis Qi analysis resulted in the discovery of 277 proteins compared with 235 proteins in Scaffold Q+. Five consensus proteins (i.e. Complement component C7; α-2-macroglobulin; Complement component C8 γ chain; Fibulin-1; α-1-antichymotrypsin) were identified. Complement component C7 was three-fold higher in the NASH group with significant/advanced fibrosis (F2-F4) compared with the early NASH (F0-F1) group (q-value = 3.6E-6). Complement component C7 and Fibulin-1 are positively correlated with liver stiffness (P=0.000, P=0.002, respectively); whereas, Complement component C8 γ chain is negatively correlated (P=0.009). High levels of Complement C7 are associated with NASH with significant/advanced fibrosis and Complement C7 is a perfect classifier of patients included in this pilot study. Further studies will be needed in a larger validation cohort to confirm the utility of complement proteins as biomarkers or mechanistic determinants of NASH with significant/advanced fibrosis.

Non-alcoholic fatty liver disease and risk of incident acute myocardial infarction and stroke: findings from matched cohort study of 18 million European adults.

OBJECTIVE: To estimate the risk of acute myocardial infarction (AMI) or stroke in adults with non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH). DESIGN: Matched cohort study. SETTING: Population based, electronic primary healthcare databases before 31 December 2015 from four European countries: Italy (n=1 542 672), Netherlands (n=2 225 925), Spain (n=5 488 397), and UK (n=12 695 046). PARTICIPANTS: 120 795 adults with a recorded diagnosis of NAFLD or NASH and no other liver diseases, matched at time of NAFLD diagnosis (index date) by age, sex, practice site, and visit, recorded at six months before or after the date of diagnosis, with up to 100 patients without NAFLD or NASH in the same database. MAIN OUTCOME MEASURES: Primary outcome was incident fatal or non-fatal AMI and ischaemic or unspecified stroke. Hazard ratios were estimated using Cox models and pooled across databases by random effect meta-analyses. RESULTS: 120 795 patients with recorded NAFLD or NASH diagnoses were identified with mean follow-up 2.1-5.5 years. After adjustment for age and smoking the pooled hazard ratio for AMI was 1.17 (95% confidence interval 1.05 to 1.30; 1035 events in participants with NAFLD or NASH, 67 823 in matched controls). In a group with more complete data on risk factors (86 098 NAFLD and 4 664 988 matched controls), the hazard ratio for AMI after adjustment for systolic blood pressure, type 2 diabetes, total cholesterol level, statin use, and hypertension was 1.01 (0.91 to 1.12; 747 events in participants with NAFLD or NASH, 37 462 in matched controls). After adjustment for age and smoking status the pooled hazard ratio for stroke was 1.18 (1.11 to 1.24; 2187 events in participants with NAFLD or NASH, 134 001 in matched controls). In the group with more complete data on risk factors, the hazard ratio for stroke was 1.04 (0.99 to 1.09; 1666 events in participants with NAFLD, 83 882 in matched controls) after further adjustment for type 2 diabetes, systolic blood pressure, total cholesterol level, statin use, and hypertension. CONCLUSIONS: The diagnosis of NAFLD in current routine care of 17.7 million patient appears not to be associated with AMI or stroke risk after adjustment for established cardiovascular risk factors. Cardiovascular risk assessment in adults with a diagnosis of NAFLD is important but should be done in the same way as for the general population.

ADAM17-Mediated Reduction in CD14++CD16+ Monocytes ex vivo and Reduction in Intermediate Monocytes With Immune Paresis in Acute Pancreatitis and Acute Alcoholic Hepatitis.

Impaired immune responses and increased susceptibility to infection characterize acute inflammatory conditions such as pancreatitis and alcoholic hepatitis and are major causes of morbidity and mortality. However, the mechanisms that drive this apparent immune paresis remain poorly understood. Monocytes mediate host responses to damage and pathogens in health and disease, and three subsets of monocytes have been defined based on CD14 and CD16 expression. We sought to determine the changes in monocyte subsets in acute pancreatitis (AP) and acute alcoholic hepatitis (AAH), together with functional consequences and mechanisms that underlie this change. Peripheral blood mononuclear cells (PBMCs) from patients with AP or AAH were compared with healthy controls. Monocyte subsets were defined by HLA-DR, CD14, and CD16 expression. Changes in surface and intracellular protein expression and phosphorylation were determined by flow cytometry. Phenotype and function were assessed following stimulation with lipopolysaccharide (LPS) or other agonists in the presence of specific inhibitors of TNFα and a disintegrin and metalloproteinase 17 (ADAM17). Patients with AP and AAH had reduced CD14++CD16+ intermediate monocytes compared to controls. Reduction of intermediate monocytes was recapitulated ex vivo by stimulating healthy control PBMCs with Toll-like receptor (TLR) agonists LPS, flagellin or polyinosilic:polycytidylic acid (poly I:C). Stimulation caused shedding of CD14 and CD16, which could be reversed using the ADAM17 inhibitor, TMI005 but not direct inhibitors of TNFα, a known ADAM17-target. Culturing PBMCs from healthy controls resulted in expansion of intermediate monocytes, which did not occur when LPS was in the culture medium. Cultured intermediate monocytes showed reduced expression of CX3CR1, CCR2, TLR4, and TLR5. We found reduced migratory responses, intracellular signaling and pro-inflammatory cytokine production, and increased expression of IL-10. Stimulation with TLR agonists results in ADAM17-mediated shedding of phenotypic markers from CD16+ monocytes, leading to apparent "loss" of intermediate monocytes. Reduction in CD14++CD16- monocytes and increased CD14++CD16+ is associated with altered responses in functional assays ex vivo. Patients with AP and AAH had reduced proportions of CD14++CD16+ monocytes and reduced phosphorylation of NFκB and IL-6 production in response to bacterial LPS. Together, these processes may contribute to the susceptibility to infection observed in AP and AAH.

Risks and clinical predictors of cirrhosis and hepatocellular carcinoma diagnoses in adults with diagnosed NAFLD: real-world study of 18 million patients in four European cohorts.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a common condition that progresses in some patients to steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma (HCC). Here we used healthcare records of 18 million adults to estimate risk of acquiring advanced liver disease diagnoses in patients with NAFLD or NASH compared to individually matched controls. METHODS: Data were extracted from four European primary care databases representing the UK, Netherlands, Italy and Spain. Patients with a recorded diagnosis of NAFLD or NASH (NAFLD/NASH) were followed up for incident cirrhosis and HCC diagnoses. Each coded NAFLD/NASH patient was matched to up to 100 "non-NAFLD" patients by practice site, gender, age ± 5 years and visit recorded within ± 6 months. Hazard ratios (HR) were estimated using Cox models adjusted for age and smoking status and pooled across databases by random effects meta-analyses. RESULTS: Out of 18,782,281 adults, we identified 136,703 patients with coded NAFLD/NASH. Coded NAFLD/NASH patients were more likely to have diabetes, hypertension and obesity than matched controls. HR for cirrhosis in patients compared to controls was 4.73 (95% CI 2.43-9.19) and for HCC, 3.51 (95% CI 1.72-7.16). HR for either outcome was higher in patients with NASH and those with high-risk Fib-4 scores. The strongest independent predictor of a diagnosis of HCC or cirrhosis was baseline diagnosis of diabetes. CONCLUSIONS: Real-world population data show that recorded diagnosis of NAFLD/NASH increases risk of life-threatening liver outcomes. Diabetes is an independent predictor of advanced liver disease diagnosis, emphasising the need to identify specific groups of patients at highest risk.

Non-invasive markers of liver fibrosis in fatty liver disease are unreliable in people of South Asian descent.

OBJECTIVE: Liver biopsy is the most accurate method for determining stage and grade of injury in non-alcoholic fatty liver disease (NAFLD). Given risks and limitations of biopsy, non-invasive tests such as NAFLD fibrosis score, aspartate transaminase (AST) to platelet ratio index, Fib-4, AST/alanine transaminase ratio and BARD are used. Prevalence and severity of NAFLD and metabolic syndrome vary by ethnicity, yet tests have been developed in largely white populations. We tested our hypothesis that non-invasive tests that include metabolic parameters are less accurate in South Asian compared with white patients. DESIGN: Retrospective cross-sectional. SETTING: Specialist liver centre. PATIENTS: Patients with histologically confirmed NAFLD. INTERVENTIONS: Scores calculated using clinical data taken within 1 week and compared with histology (Kleiner). MAIN OUTCOME MEASURES: Diagnostic test characteristics. RESULTS: 175 patients were identified. South Asians (n=90) were younger, had lower body mass index and lower proportion of obesity compared with white patients (n=79), with comparable rates of diabetes and liver injury. Tests are less sensitive at detecting advanced fibrosis in South Asian compared with white patients. Relative risk of correct diagnosis in white patients compared with South Asians is 1.86 (95% CI 1.4 to 2.6). In binary logistic regression models, ethnicity and platelet count predicted accuracy. Transient elastography was equally and highly accurate in both ethnicities. CONCLUSIONS: Blood test-based non-invasive scores are less accurate in South Asian patients, irrespective of metabolic parameters. Ethnicity should be considered when devising risk-stratification algorithms for NAFLD.

Periodontitis is associated with significant hepatic fibrosis in patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) has a bidirectional association with metabolic syndrome. It affects up to 30% of the general population, 70% of individuals with diabetes and 90% with obesity. The main histological hallmark of progressive NAFLD is fibrosis. There is a bidirectional epidemiological link between periodontitis and metabolic syndrome. NAFLD, periodontitis and diabetes share common risk factors, are characterised by inflammation and associated with changes in commensal bacteria. Therefore we tested the hypothesis that periodontitis is associated with NAFLD and with significant fibrosis in two study groups. METHODS: We analyzed data from a population-based survey and a patient-based study. NHANES III participants with abdominal ultrasound and sociodemographic, clinical, and oral examination data were extracted and appropriate weighting applied. In a separate patient-based study, consenting patients with biopsy-proved NAFLD (or with liver indices too mild to justify biopsy) underwent dental examination. Basic Periodontal Examination score was recorded. RESULTS: In NHANES, periodontitis was significantly associated with steatosis in 8172 adults even after adjusting for sociodemographic factors. However, associations were fully explained after accounting for features of metabolic syndrome. In the patient-based study, periodontitis was significantly more common in patients with biopsy-proven NASH and any fibrosis (F0-F4) than without NASH (p = 0.009). Periodontitis was more common in patients with NASH and significant fibrosis (F2-4) than mild or no fibrosis (F0-1, p = 0.04). CONCLUSIONS: Complementary evidence from an epidemiological survey and a clinical study show that NAFLD is associated with periodontitis and that the association is stronger with significant liver fibrosis.

Care standards for non-alcoholic fatty liver disease in the United Kingdom 2016: a cross-sectional survey.

OBJECTIVE: Guidelines for the assessment of non-alcoholic fatty liver disease (NAFLD) have been published in 2016 by National Institute for Health and Care Excellence and European Associations for the study of the Liver-European Association for the study of Diabetes-European Association for the study of Obesity. Prior to publication of these guidelines, we performed a cross-sectional survey of gastroenterologists and hepatologists regarding NAFLD diagnosis and management. DESIGN: An online survey was circulated to members of British Association for the Study of the Liver and British Society of Gastroenterology between February 2016 and May 2016. RESULTS: 175 gastroenterologists/hepatologists responded, 116 completing the survey, representing 84 UK centres. 22% had local NAFLD guidelines. 45% received >300 referrals per year from primary care for investigation of abnormal liver function tests (LFTs). Clinical assessment tended to be performed in secondary rather than primary care including body mass index (82% vs 26%) and non-invasive liver screen (86% vs 32%) and ultrasound (81% vs 37%). Widely used tools for non-invasive fibrosis risk stratification were aspartate transaminase (AST)/alanine transaminase (ALT) ratio (53%), Fibroscan (50%) and NAFLD fibrosis score (41%). 78% considered liver biopsy in selected cases. 50% recommended 10% weight loss target as first-line treatment. Delivery of lifestyle interventions was mostly handed back to primary care (56%). A minority have direct access to community weight management services (22%). Follow-up was favoured by F3/4 fibrosis (72.9%), and high-risk non-invasive fibrosis tests (51%). Discharge was favoured by simple steatosis at biopsy (30%), and low-risk non-invasive scores (25%). CONCLUSIONS: The survey highlights areas for improvement of service provision for NAFLD assessment including improved recognition of non-alcoholic steatohepatitis in people with type 2 diabetes, streamlining abnormal LFT referral pathways, defining non-invasive liver fibrosis assessment tools, use of liver biopsy, managing metabolic syndrome features and improved access to lifestyle interventions.

Inflammatory and Immune Responses to Surgery and Their Clinical Impact.

OBJECTIVE: The aim of this study was to describe current understanding of the local and systemic immune responses to surgery and their impact on clinical outcomes, predictive biomarkers, and potential treatment strategies. BACKGROUND: Patients undergoing major surgery are at risk of life-threatening inflammatory complications that include infection, the systemic inflammatory response syndrome (SIRS), or sepsis. Although improvements in surgical technique and peri-operative care have resulted in reduction in the rates of these complications, they remain high, especially in patients undergoing complex abdominal procedures. There are currently no drugs licensed specifically for the treatment of sepsis nor is it possible to identify those at highest risk, which would allow pre-emptive therapy that may improve outcomes. CONCLUSIONS: Local immune responses to surgery lead to systemic pro-inflammatory and immunosuppressive phases that are temporally related and proportionate in magnitude. Improved understanding of these mechanisms has implications for clinical study design and has led to the emergence of novel biomarkers such as Toll-like receptor expression. These can be used to stratify patient care pathways to maximize the benefit from current therapies or to select the right target at the right phase of illness for future drug development.

Systemic Inflammatory Response Syndrome After Major Abdominal Surgery Predicted by Early Upregulation of TLR4 and TLR5.

OBJECTIVES: To study innate immune pathways in patients undergoing hepatopancreaticobiliary surgery to understand mechanisms leading to enhanced inflammatory responses and identifying biomarkers of adverse clinical consequences. BACKGROUND: Patients undergoing major abdominal surgery are at risk of life-threatening systemic inflammatory response syndrome (SIRS) and sepsis. Early identification of at-risk patients would allow tailored postoperative care and improve survival. METHODS: Two separate cohorts of patients undergoing major hepatopancreaticobiliary surgery were studied (combined n = 69). Bloods were taken preoperatively, on day 1 and day 2 postoperatively. Peripheral blood mononuclear cells and serum were separated and immune phenotype and function assessed ex vivo. RESULTS: Early innate immune dysfunction was evident in 12 patients who subsequently developed SIRS (postoperative day 6) compared with 27 who did not, when no clinical evidence of SIRS was apparent (preoperatively or days 1 and 2). Serum interleukin (IL)-6 concentration and monocyte Toll-like receptor (TLR)/NF-κB/IL-6 functional pathways were significantly upregulated and overactive in patients who developed SIRS (P < 0.0001). Interferon α-mediated STAT1 phosphorylation was higher preoperatively in patients who developed SIRS. Increased TLR4 and TLR5 gene expression in whole blood was demonstrated in a separate validation cohort of 30 patients undergoing similar surgery. Expression of TLR4/5 on monocytes, particularly intermediate CD14CD16 monocytes, on day 1 or 2 predicted SIRS with accuracy 0.89 to 1.0 (areas under receiver operator curves). CONCLUSIONS: These data demonstrate the mechanism for IL-6 overproduction in patients who develop postoperative SIRS and identify markers that predict patients at risk of SIRS 5 days before the onset of clinical signs.

Immunosuppression in acutely decompensated cirrhosis is mediated by prostaglandin E2.

Liver disease is one of the leading causes of death worldwide. Patients with cirrhosis display an increased predisposition to and mortality from infection due to multimodal defects in the innate immune system; however, the causative mechanism has remained elusive. We present evidence that the cyclooxygenase (COX)-derived eicosanoid prostaglandin E2 (PGE2) drives cirrhosis-associated immunosuppression. We observed elevated circulating concentrations (more than seven times as high as in healthy volunteers) of PGE2 in patients with acute decompensation of cirrhosis. Plasma from these and patients with end-stage liver disease (ESLD) suppressed macrophage proinflammatory cytokine secretion and bacterial killing in vitro in a PGE2-dependent manner via the prostanoid type E receptor-2 (EP2), effects not seen with plasma from patients with stable cirrhosis (Child-Pugh score grade A). Albumin, which reduces PGE2 bioavailability, was decreased in the serum of patients with acute decompensation or ESLD (<30 mg/dl) and appears to have a role in modulating PGE2-mediated immune dysfunction. In vivo administration of human albumin solution to these patients significantly improved the plasma-induced impairment of macrophage proinflammatory cytokine production in vitro. Two mouse models of liver injury (bile duct ligation and carbon tetrachloride) also exhibited elevated PGE2, reduced circulating albumin concentrations and EP2-mediated immunosuppression. Treatment with COX inhibitors or albumin restored immune competence and survival following infection with group B Streptococcus. Taken together, human albumin solution infusions may be used to reduce circulating PGE2 levels, attenuating immune suppression and reducing the risk of infection in patients with acutely decompensated cirrhosis or ESLD.

A cross sectional study of colonic diverticulosis in the London Bangladeshi population.

BACKGROUND: Diverticular disease is the most common morphological abnormality of the colon and the fifth most important gastrointestinal disease in terms of cost in the Western world. Tower Hamlets is the poorest borough in London containing a large Bangladeshi community. We observed that emergency admissions with complications of colonic diverticulosis were minimal in the Bangladeshi community. The objective was to compare the background prevalence of colonic diverticulosis in Bangladeshis with other ethnicities in patients undergoing colonoscopy at a single centre in Tower Hamlets. METHODS: Four thousand four hundred and fifty-four consecutive colonoscopy reports over a 2-year period were retrospectively analysed. Patients under 40 years of age and repeat colonoscopies were excluded, leaving 3151 patients (mean age: 63 years; 48% male). Demographics including ethnicity and medical background were retrieved from the electronic patient record system and findings correlated with the prevalence of other 'Western' diseases in the cohort. RESULTS: Six hundred and thirty out of 3151 (20%) colonoscopies were performed on Bangladeshis. The prevalence of colonic diverticulosis was significantly lower in Bangladeshis (17/630: 2.7%) than Caucasians (673/1869: 36%), Indians/Pakistanis (16/161: 9.9%), Oriental (15/44: 34%) and Black (90/369: 24.4%) patient groups (χ(2) p < 0.0001 for all comparisons). The prevalence of classical sigmoid diverticulosis in the Bangladeshi cohort was only 1.0%, despite significantly more Bangladeshi patients undergoing colonoscopy for abdominal pain (p < 0.0001, χ(2)) and diarrhoea (p < 0.0034, χ(2)). There was also a significantly greater incidence of type 2 diabetes mellitus and ischaemic heart disease (p < 0.0001, χ(2)) in Bangladeshi patients. CONCLUSIONS: There is a negligible prevalence of colonic diverticulosis in the Bangladeshi population of London who undergo colonoscopy. This is in spite of a high incidence of type 2 diabetes and ischaemic heart disease. The effect of diet and genetics on the prevalence of colonic diverticulosis in Bangladeshis is not known and merits further investigation.

Pharmacology and therapeutic potential of interferons.

Interferon (IFN) is widely recognised to be an integral part of the innate immune response to viral infection. Since its initial discovery in 1957 by Isaacs and Lindenmann, various IFN sub-types have been identified and there are now three distinct classes recognised-Type I (IFN-α and IFN-ß), Type II (IFN-γ) and Type III (IFN-λ), distinguished by their differing receptors. As well as displaying profound antiviral activity in vivo, IFN has anti-proliferative, cytotoxic and anti-tumoural roles. In an attempt to harness their immunomodulatory potential, investigators and clinicians have investigated the use of IFNs for the treatment of human diseases with considerable success. For example, IFN-α preparations are now a critical component in the treatment of chronic Hepatitis C infection and IFN-ß therapy is now the first line treatment for relapsing remitting multiple sclerosis. However, IFN therapy is also associated with significant morbidity and in some patients is poorly tolerated. In this review, we explore the scientific basis for IFN therapy and outline its therapeutic scope. We describe the commonly encountered side effects and attempt to explain the less well recognised pulmonary complications including emerging evidence of life threatening and irreversible pulmonary vascular pathology. Finally, we look to the future of interferon drug treatment, examining the potential for emerging therapies.