PCSK9, apolipoprotein E and lipoviral particles in chronic hepatitis C genotype 3: evidence for genotype-specific regulation of lipoprotein metabolism.

BACKGROUND & AIMS: Hepatitis C virus (HCV) associates with lipoproteins to form "lipoviral particles" (LVPs) that can facilitate viral entry into hepatocytes. Initial attachment occurs via heparan sulphate proteoglycans and low-density lipoprotein receptor (LDLR); CD81 then mediates a post-attachment event. Proprotein convertase subtilisin kexin type 9 (PCSK9) enhances the degradation of the LDLR and modulates liver CD81 levels. We measured LVP and PCSK9 in patients chronically infected with HCV genotype (G)3. PCSK9 concentrations were also measured in HCV-G1 to indirectly examine the role of LDLR in LVP clearance. METHODS: HCV RNA, LVP (d<1.07g/ml) and non-LVP (d>1.07g/ml) fractions, were quantified in patients with HCV-G3 (n=39) by real time RT-PCR and LVP ratios (LVPr; LVP/(LVP+non-LVP)) were calculated. Insulin resistance (IR) was assessed using the homeostasis model assessment of IR (HOMA-IR). Plasma PCSK9 concentrations were measured by ELISA in HCV-G3 and HCV-G1 (n=51). RESULTS: In HCV-G3 LVP load correlated inversely with HDL-C (r=-0.421; p=0.008), and apoE (r=-0.428; p=0.013). The LVPr varied more than 35-fold (median 0.286; range 0.027 to 0.969); PCSK9 was the strongest negative predictor of LVPr (R(2)=16.2%; p=0.012). HOMA-IR was not associated with LVP load or LVPr. PCSK9 concentrations were significantly lower in HCV-G3 compared to HCV-G1 (p<0.001). PCSK9 did not correlate with LDL-C in HCV-G3 or G1. CONCLUSIONS: The inverse correlation of LVP with apoE in HCV-G3, compared to the reverse in HCV-G1 suggests HCV genotype-specific differences in apoE mediated viral entry. Lower PCSK9 and LDL concentrations imply upregulated LDLR activity in HCV-G3.

Omega-3 fatty acids and/or fluvastatin in hepatitis C prior non-responders to combination antiviral therapy - a pilot randomised clinical trial.

BACKGROUND & AIMS: Hepatitis C virus (HCV) utilises cholesterol and lipoprotein metabolism for replication and infectivity. Statins and omega-3 (n-3) polyunsaturated fatty acids (PUFA) have been shown to have antiviral properties in vitro. This open label pilot study evaluated the efficacy of fluvastatin (Lescol(®) 40-80 mg) and n-3 PUFA (Omacor(®) 1 g and 2-4 g) on HCV-RNA and lipoviral particles (LVP) in difficult to treat prior non-responders. METHODS: Patients (n = 60) were randomly allocated in a factorial design to: no active drug; low-dose n-3 PUFA; high-dose n-3 PUFA; fluvastatin; low-dose n-3 PUFA + fluvastatin; or high-dose n-3 PUFA + fluvastatin. 50/60 completed study drugs for 12 weeks and followed up to week 24. Comparison was made between fluvastatin (n = 24) vs no fluvastatin (n = 26) and n-3 PUFA high-dose (n = 17) vs low-dose (n = 17) vs none (n = 16). The primary outcomes were change in total HCV-RNA, LVP and ALT at week 12 compared with baseline. Secondary outcome was change in interferon-gamma-inducible protein-10 (IP10) as a measure of interferon activation. RESULTS: 35% had compensated cirrhosis and 45% were prior null responders. There was no significant change in total HCV RNA, LVP, non-LVP or LVP ratio in patients receiving fluvastatin or n-3 PUFAs. ALT was not significantly different in those treated with fluvastatin or n-3 PUFAs. 12 weeks of low-dose n-3 PUFA decreased median IP10 concentration by -39 pg/ml (-111, 7.0 pg/ml Q1-Q3). CONCLUSIONS: Fluvastatin and n-3 PUFAs have no effect on plasma HCV-RNA or LVP. The effect of low-dose n-3 PUFA on IP10 warrants further prospective evaluation as a supplemental therapy to enhance interferon sensitivity.

Guidelines for the diagnosis and treatment of cholangiocarcinoma: an update.

The British Society of Gastroenterology guidelines on the management of cholangiocarcinoma were originally published in 2002. This is the first update since then and is based on a comprehensive review of the recent literature, including data from randomised controlled trials, systematic reviews, meta-analyses, cohort, prospective and retrospective studies.

Rising trends in cholangiocarcinoma: is the ICD classification system misleading us?

BACKGROUND & AIMS: Cholangiocarcinomas (CC) can be sub-divided into intrahepatic (IHCC) or extrahepatic (EHCC). Hilar or 'Klatskin' tumours are anatomically extrahepatic. Most international studies, also from the UK, report increasing IHCC and decreasing EHCC incidence. The second edition of the International Classification of Diseases for Oncology (ICD-O-2) assigned 'Klatskin' tumours a unique histology code (8162/3), but this was cross-referenced to the topography code for intrahepatic (IHBD) rather than extrahepatic bile duct tumours (EHBD). Under the third ICD-O edition, 'Klatskin' tumours are cross-referenced to either IHBD or EHBD. New editions of the ICD-O classification are adopted at different time points by different countries. We investigated the impact of changing ICD-O classifications and the potential misclassification of hilar/'Klatskin' tumours on bile duct tumour and CC incidence rates in England and Wales and the US. We also examined whether coding practices by cancer registries in England and Wales could be influencing these rates. METHODS: We analysed age-standardised incidence rates (ASIR) in England and Wales for IHBD and EHBD tumours between 1990 and 2008, then transferred all 'Klatskin' tumours from IHBD to EHBD and reanalysed rates from 1995, when ICD-O-2 was introduced in the UK. We also compared trends in IHBD, EHBD, and 'Klatskin' tumours in England and Wales with those in the USSEER (Surveillance, Epidemiology and End Results) database. Coding practice at Cancer registry level in England and Wales was investigated via a questionnaire completed by all national cancer registries. RESULTS: In England and Wales, 1990-2008, ASIR of IHBD cancers rose (0.43-1.84/100,000 population in males; 0.27-1.51 in females) but fell for EHBD (0.78-0.51/100,000 population in males; 0.62-0.39 in females). After transferring all 'Klatskin' tumours from IHBD to EHBD, there remained a marked increase in ASIR of IHBD cancers and a decrease in ASIR for EHBD, as only 1% of CC were reportedly 'Klatskin'. The US SEER data showed that ASIR for IHBD gradually rose from 0.59/100,000 population in 1990 to 0.91 in 2001, then sharply fell before plateauing at 0.60 by 2007. ASIR for EHBD remained relatively stable at around 0.80/100,000 population until 2001, then began increasing, to 0.97 by 2007. Annually, between 1995 and 2008, the vast majority of 'Klatskin' tumours in England and Wales were coded as IHBD. This was also the case in the SEER data until 2001, when the situation was reversed and subsequently most 'Klatskin' tumours were coded as EHBD. US trends coincide with a switch from ICD-O2 to ICD-O-3 in 2001. In the UK, the switch to ICD-O-3 only occurred in 2008. On questioning, cancer registries in England and Wales stated they would not code a CC described as 'hilar' with the designated 'Klatskin' histology code. If the tumour site is unspecified, most registries classify CC as intrahepatic. CONCLUSIONS: Changes in ICD-classification may be influencing observed changes in IHBD and EHBD incidence rates. Coding misclassification is likely to have been skewing CC registration to an intrahepatic site, thereby contributing to the previously reported rise in intrahepatic tumours.

Apolipoprotein-E and hepatitis C lipoviral particles in genotype 1 infection: evidence for an association with interferon sensitivity.

BACKGROUND & AIMS: Hepatitis C virus (HCV) interacts with apolipoproteins B (apoB) and E (apoE) to form infectious lipoviral particles (LVP). Response to peginterferon is influenced by interferon-stimulated genes (ISGs) and IL28B genotype. LDL cholesterol (LDL-C) also predicts interferon response, therefore we hypothesised that LVP may also be associated with interferon sensitivity. METHODS: LVP (HCV RNA density ≤1.07 g/ml) and 'non-LVP' (d >1.07 g/ml) were measured in 72 fasted HCV-G1 patients by iodixanol density gradient ultracentrifugation and the LVP ratio (LVP/LVP+non-LVP) was calculated. Fasting lipid profiles and apolipoproteins B and E were measured. Interferon-gamma-inducible protein 10 kDa (IP10), a marker of ISGs, was measured by ELISA. RESULTS: Complete early virological response (EVR) was associated with lower apoE (23.9±7.7 vs. 36.1±15.3 mg/L, p=0.013), higher LDL-C (p=0.039) and lower LVP ratios (p=0.022) compared to null responders. In multivariate linear regression analysis, apoE was independently associated with LVP (R(2) 19.5%, p=0.003) and LVP ratio (p=0.042), and negatively with LDL-C (p<0.001). IP10 was significantly associated with ApoB (p=0.001) and liver stiffness (p=0.032). IL28B rs12979860 CC was associated with complete EVR (p=0.044), low apoE (CC 28±11 vs. CT/TT 35±13 mg/L, p=0.048) and higher non-LVP (p=0.008). Logistic regression analysis indicated that patients with high LVP ratios were less likely to have EVR (odds ratio 0.01, p=0.018). CONCLUSIONS: In HCV-G1, interferon sensitivity is characterised by low LVP ratios and low apoE levels in addition to higher LDL-C and IL28B rs12979860 CC. Null-response is associated with increased LVP ratio. The association of apoE and LVP with peginterferon treatment response suggests that lipid modulation is a potential target to modify interferon sensitivity.

Insulin resistance and low-density apolipoprotein B-associated lipoviral particles in hepatitis C virus genotype 1 infection.

BACKGROUND: The density of hepatitis C virus (HCV) in plasma is heterogeneous but the factors which influence this are poorly understood. Evidence from animal models and cell culture suggest that low-density apolipoprotein B (apoB)-associated HCV lipoviral particles (LVP) are more infectious than high-density HCV. Objective To measure LVP in patients with chronic hepatitis C genotype 1 (CHC-G1) and examine metabolic determinants of LVP load. Patients 51 patients with CHC-G1 infection. METHODS: Fasting lipid profiles and homeostasis model assessment of insulin resistance (HOMA-IR) were determined in 51 patients with CHC-G1. LVP and non-LVP viral load were measured by real-time PCR of plasma at density <1.07 g/ml and >1.07 g/ml, respectively, following iodixanol density gradient ultracentrifugation. The LVP ratio was calculated using the formula: LVP/(LVP + non-LVP). RESULTS: The mean LVP ratio was 0.241 but varied 25-fold (from 0.029 to 0.74). Univariate analysis showed that the LVP ratio correlated with HOMA-IR (p=0.004) and the triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio (p = 0.004), but not with apoB. In multivariate analysis, HOMA-IR was the main determinant of LVP load (log10IU/ml) (R²=16.6%; p = 0.037) but the TG/HDL-C ratio was the strongest predictor of the LVP ratio (R² = 24.4%; p = 0.019). Higher LVP ratios were associated with non-response to antiviral therapy (p = 0.037) and with greater liver stiffness (p = 0.001). CONCLUSION: IR and associated dyslipidaemia are the major determinants of low-density apoB-associated LVP in fasting plasma. This provides a possible mechanism to explain why IR is associated with more rapidly progressive liver disease and poorer treatment outcomes.

Remodelling of extracellular matrix is a requirement for the hepatic progenitor cell response.

BACKGROUND AND METHODS: In advanced liver damage, hepatic regeneration can occur through proliferation of a resident hepatic progenitor cell (HPC) population. HPCs are located within a designated niche in close association with myofibroblasts and bone marrow (BM) derived macrophages. Extra-cellular matrix (ECM) laminin invariably surrounds HPCs, but the functional requirement of this matrix-cell association is untested in vivo. Using the collagen Iα1((r/r)) mouse (r/r), which produces mutated collagen I resistant to matrix metalloproteinase degradation and has an exaggerated fibrotic response to liver injury, we test the relationship between collagen degradation, laminin deposition, and the HPC response. RESULTS: Chronic fibrotic carbon tetrachloride (CCl4) injury can induce a florid HPC response associated with dense laminin deposition. In the recovery phase after chronic CCl4 injury, r/r mice have a markedly attenuated HPC response compared to wild-types, together with persistence of collagen I and failure to deposit ECM laminin. Similar results were found in r/r mice given the choline-deficient ethionine supplemented diet, another model of the HPC response. In cross-over sex-mismatched BM transplantation (BMT) experiments between r/r mice and wild-types, the blunted HPC response of r/r mice was not rescued by wild-type BMT and likewise not conferred on to wild-type recipients by r/r BMT, demonstrating that the attenuated HPC response in r/r mice is a property intrinsic to the liver. CONCLUSION: Failure of ECM remodelling after chronic fibrotic liver injury hinders the ability of the liver to activate HPCs. Laminin-progenitor cell interactions within the HPC niche are a critical for HPC mediated regeneration.

Urinary metabolic biomarkers of hepatocellular carcinoma in an Egyptian population: a validation study.

The advent of metabonomics has seen a proliferation of biofluid profiling studies of patients with hepatocellular carcinoma. The majority of these studies have been conducted in single indigenous populations making the widespread applicability of candidate metabolite biomarkers difficult. Presented here is a urinary proton nuclear magnetic resonance spectroscopy study of mainly hepatitis C virus infected Egyptian patients with hepatocellular carcinoma, which corroborates findings of a previous study from our group of mainly hepatitis B-infected Nigerian patients with hepatocellular carcinoma. Using multivariate statistical analysis, in the form of orthogonal signal-corrected partial least squared discriminant analysis, the sensitivity and specificity of the technique for distinguishing patients with tumors from healthy controls and patients with cirrhosis was 100%/94% and 81%/71%, respectively. Discriminatory metabolites included glycine, trimethylamine-N-oxide, hippurate, citrate, creatinine, creatine, and carnitine. This metabolic profile bears similarity to profiles identified in the Nigerian cohort of subjects indicative of tumor effects on physiology, energy production, and aberrant chromosomal methylation. This is the first study to identify similarly altered urine metabolic profiles of hepatocellular carcinoma in two etiologically and ethnically distinct populations, suggesting that altered metabolism as a result of tumorogenesis is independent of these two factors.

A comparison of single-voxel clinical in vivo hepatic 31P MR spectra acquired at 1.5 and 3.0 Tesla in health and diseased states.

With the increasing availability of human MR scanners at various field strengths, the optimal field strength for in vivo clinical MR studies of the liver has become a focus of attention. Comparison between results at 3.0 and 1.5 T is of particular clinical interest, especially for multicentre studies. For MRS studies, higher field strengths should be advantageous, because improved sensitivity and chemical shift dispersion are expected. We report a comparison between single-voxel hepatic proton-decoupled (31)P MRS performed at 1.5 and 3.0 T in the same subjects using similar methodologies. Twelve healthy volunteers and 15 patients with chronic liver disease were studied. Improved spectral resolution was achieved using proton decoupling, and there was an improvement (21%) in the signal-to-noise ratio (SNR) of the phosphomonoester (PME) resonance at 3.0 T relative to 1.5 T. There was no significant change in nuclear Overhauser effects for PME or phosphodiesters (PDEs) between the two field strengths. The T(1) value of PDE was significantly longer at 3 T, although there was no significant change in the T(1) value of PME. There was no significant difference in the mean PME/PDE ratios for either the control or patient groups at both 1.5 and 3.0 T, but there was a small positive mean difference in PME/PDE at 3.0 T on pairwise testing between field strengths (+ 0.05, p < 0.01). There were significant correlations between PME/PDE values at the two magnetic field strengths (r = 0.806, p < 0.001). The underlying broad resonance was reduced at 3.0 T relative to 1.5 T, related to line broadening of the phospholipid bilayer signal. In conclusion, there was an improvement in hepatic (31)P MR signal quality at 3.0 T relative to 1.5 T. Broadly similar hepatic (31)P MR parameters were obtained at 1.5 and 3.0 T. The modest difference noted in the PME/PDE ratio between field strengths for patients with chronic liver disease should inform multicentre study design involving these field strengths.

Genetic factors in the pathogenesis of cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CC) is increasing in incidence, but its pathogenesis remains poorly understood. Chronic inflammation of the bile duct and cholestasis are major risk factors, but most cases in the West are sporadic. Genetic polymorphisms in biliary transporter proteins have been implicated in benign biliary disease and, in the case of progressive familial cholestasis, have been associated with childhood onset of CC. In the current study, five biologically plausible candidate genes were investigated: ABCB11 (BSEP), ABCB4 (MDR3), ABCC2 (MRP2), ATP8B1 (FIC1) and NR1H4 (FXR). METHODS: DNA was collected from 172 Caucasian individuals with confirmed CC. A control cohort of healthy Caucasians was formed. Seventy-three SNPs were selected using the HapMap database to capture genetic variation around the five candidate loci. Genotyping was undertaken with a competitive PCR-based system. Confirmation of Hardy-Weinberg equilibrium and Cochran-Armitage trend testing were performed using PLINK. Haplotype frequencies were compared using haplo.stats. RESULTS: All 73 SNPs were in Hardy-Weinberg equilibrium. Four SNPs in ABCB11 were associated with altered susceptibility to CC, including the V444A polymorphism, but these associations did not retain statistical significance after Bonferroni correction for multiple testing. Haplotype analysis of the genotyped SNPs in ATP8B1 identified significant differences in frequencies between cases and controls (global p value of 0.005). CONCLUSION: Haplotypes in ATP8B1 demonstrated a significant difference between CC and control groups. There was a trend towards significant association of V444A with CC. Given the biological plausibility of polymorphisms in ABCB11 and ATP8B1 as risk modifiers for CC, further study in a validation cohort is required.

Multi-excitation fluorescence spectroscopy for analysis of non-alcoholic fatty liver disease.

BACKGROUND AND OBJECTIVES: The increasing incidence of non-alcoholic fatty liver diseases (NAFLD) and the consequent progression to cirrhosis is expected to become a major cause of liver transplantation. This will exacerbate the organ donor shortage and mean that 'marginal' fatty liver grafts are more frequently used. Autofluorescence spectroscopy is a fast, objective, and non-destructive method to detect change in the endogenous fluorophores distribution and could prove to be a valuable tool for NAFLD diagnosis and transplant graft assessment. MATERIALS AND METHODS: A system was constructed consisting of a fibre probe with two laser diodes that provided excitation light at 375 and 405 nm, and an imaging spectrograph system. This was used to distinguish fluorescence spectra acquired from the harvested livers from mice with NAFLD of differing severity (healthy, mild steatotic and steatohepatitic). The fluorescence data were entered into a sparse multiclass probabilistic algorithm for disease classification. Histopathology, thiobarbituric acid reactive substances (TBARS) and alanine transaminase (ALT) assays were conducted in addition to the fluorescence measurements RESULTS: TBARS and ALT assays enabled differentiation of the steatohepatitic group from the mild steatosis and control groups (P ≤ 0.028) but failed to separate the mild steatotic group from the control group. The three groups were all clearly differentiated from each other using fluorescence spectroscopy, and classification accuracy was found to be 95%. CONCLUSION: Fluorescence spectroscopy appears to be a promising approach for the analysis of diseased liver tissue.

Differences in phosphatidylcholine and bile acids in bile from Egyptian and UK patients with and without cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CC) is a fatal malignancy, the incidence of which is increasing worldwide, with substantial regional variation. Current diagnostic techniques to distinguish benign from malignant biliary disease are unsatisfactory. Metabolic profiling of bile may help to differentiate benign from malignant disease. No previous studies have compared the metabolic profiles of bile from two geographically and racially distinct groups of CC patients. OBJECTIVES: This study aimed to compare metabolic profiles of bile, using in vitro proton magnetic resonance spectroscopy, from CC patients from Egypt and the UK, and from patients with CC and patients with non-malignant biliary disease. METHODS: A total of 29 bile samples, collected at cholangiography, were analysed using an 11.7-T system. Samples were from eight CC patients in either Egypt (n = 4) or the UK (n = 4) and 21 patients with benign biliary disease (choledocholithiasis [n = 8], sphincter of Oddi dysfunction [n = 8], primary sclerosing cholangitis [n = 5]). RESULTS: Bile phosphatidylcholine (PtC) was significantly reduced in CC patients. Egyptian CC patients had significantly lower biliary PtC levels compared with UK patients. Taurine- and glycine-conjugated bile acids (H-26 and H-25 protons, respectively) were significantly elevated in bile from patients with CC compared with bile from patients with benign diseases (P = 0.013 and P < 0.01, respectively). CONCLUSIONS: Biliary PtC levels potentially differentiate CC from benign biliary disease. Reduced biliary PtC in Egyptian compared with UK patients may reflect underlying carcinogenic mechanisms.

Characterization of urinary biomarkers of hepatocellular carcinoma using magnetic resonance spectroscopy in a Nigerian population.

Hepatocellular carcinoma (HCC) is the commonest primary hepatic malignancy worldwide. Current serum diagnostic biomarkers, such as alpha-fetoprotein, are expensive and insensitive in early tumor diagnosis. Urinary biomarkers differentiating HCC from chronic liver disease would be practical and widely applicable. Using an 11.7T nuclear magnetic resonance system, urine was analyzed from three well-matched subject groups, collected at Jos University Teaching Hospital (JUTH), Nigeria. Multivariate factor analyses were performed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). All patients were of Nigerian descent: 18 hepatitis B surface antigen (HBsAg)-positive patients with HCC, 10 HBsAg positive patients with cirrhosis, and 15 HBsAg negative healthy Nigerian controls. HCC patients were distinguished from healthy controls, and from the cirrhosis cohort, with sensitivity/specificity of 100%/93% and 89.5%/88.9%, respectively. Metabolites that most strongly contributed to the multivariate models were creatinine, carnitine, creatine and acetone. Urinary (1)H MRS with multivariate statistical analysis was able to differentiate patients with HCC from normal subjects and patients with cirrhosis. Creatinine, carnitine, creatine and acetone were identified as the most influential metabolites. These findings have identified candidate urinary HCC biomarkers which have potential to be developed as simple urinary screening tests for the clinic.

Hepatic lipid profiling in chronic hepatitis C: an in vitro and in vivo proton magnetic resonance spectroscopy study.

BACKGROUND & AIMS: Hepatic steatosis is an important factor in pathogenesis, progression and response to treatment in hepatitis C. We aimed to investigate differences in hepatic lipid composition in liver biopsies from patients with chronic hepatitis C using proton magnetic resonance spectroscopy ((1)H MRS) and to translate these findings to the in vivo clinical setting. METHODS: Two cohorts of patients with histologically defined chronic hepatitis C were studied. High-resolution MR spectra were obtained from 47 liver biopsy samples. These data were used to derive biologically relevant prior knowledge for the assignment and interpretation of lower-resolution in vivo hepatic MRS data acquired at 1.5T from a second cohort of 59 patients. MRS data were obtained both in vitro and in vivo from a subset of 11 patients. RESULTS: Multivariate factor analysis demonstrated characteristic MR spectral differences by fibrosis stage and genotype. Total lipid increased with fibrosis stage (r=0.43, p=0.003) and was higher in genotype 3 compared to genotype 1 (p=0.03), while lipid polyunsaturation decreased with increasing fibrosis stage (r=-0.55, p<0.0005) and, independently, with increasing steatosis. Non-invasive assessment using in vivo hepatic (1)H MRS corroborated in vitro findings, but the signal-to-noise ratio was insufficient for reliable assessment of lipid polyunsaturation in vivo. CONCLUSIONS: Hepatic lipid composition was analysed using MRS in patients with chronic hepatitis C in vitro and in vivo, demonstrating significant differences in indices by disease severity. High-resolution data informed the analysis and interpretation of in vivo spectra, but further improvements in spectral quality in vivo are required.

Impact of pan-caspase inhibition in animal models of established steatosis and non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease is a progressive condition comprising steatosis, steatohepatitis, and cirrhosis. Caspase activation mediates apoptosis and the inflammatory response. Studies demonstrate increased apoptotic activity in NASH although its pathophysiological importance is uncertain. We sought to determine the effects of irreversible pan-caspase inhibition in murine models of established steatosis (high fat diet, HFD) and steatohepatitis (methionine-choline deficient diet, MCD). METHODS: In one study arm, male C3H/HeN mice were fed HFD; in the other, Db/Db mice were fed MCD. Once disease was established, animals were randomised to receive caspase inhibitor (VX-166), TPGS/PEG vehicle or no additional therapy until the end of the study. Biochemical and histological indices were examined to determine NASH activity and tissue oxidative stress. Apoptotic activity and cell turnover were assessed immunohistochemically by staining for caspase-cleaved CK-18 and PCNA. RESULTS: MCD and HFD significantly increased apoptosis, which was reduced by VX-166 treatment. VX-166 did not reduce steatosis but reduced histological inflammation, serum ALT levels, and oxidative stress, particularly in the MCD model. TPGS/PEG vehicle also exhibited some anti-inflammatory activity. CONCLUSIONS: In both models, VX-166 inhibited apoptosis and reduced histological inflammatory infiltrate although there was a more modest impact on other indices of liver injury. In addition, TPGS/PEG vehicle also exhibited some anti-inflammatory activity, likely through the antioxidant effects of vitamin E and changes in gut flora/mucosal interactions. These data suggest that caspase inhibition may represent a valid therapeutic approach; however, further studies to assess the long-term value of more selective caspase inhibition are merited.

Metabolic profiling of bile in cholangiocarcinoma using in vitro magnetic resonance spectroscopy.

OBJECTIVES: Cholangiocarcinoma (CCA) has a poor prognosis and its aetiology is inadequately understood. Magnetic resonance spectroscopy (MRS) of bile may provide insights into the pathogenesis of CCA and help identify novel diagnostic biomarkers. The aim of this study was to compare the chemical composition of bile from patients with CCA with that of bile from patients with benign biliary disease. METHODS: Magnetic resonance spectra were acquired from the bile of five CCA patients and compared with MRS of control bile from patients with benign biliary disease (seven with gallstones, eight with sphincter of Oddi dysfunction [SOD], five with primary sclerosing cholangitis [PSC]). Metabolic profiles were compared using both univariate and multivariate pattern-recognition analysis. RESULTS: Univariate analysis showed that levels of glycine-conjugated bile acids were significantly increased in patients with CCA, compared with the benign disease groups (P= 0.002). 7 beta primary bile acids were significantly increased (P= 0.030) and biliary phosphatidylcholine (PtC) levels were reduced (P= 0.010) in bile from patients with CCA compared with bile from gallstone patients. These compounds were also of primary importance in the multivariate analysis: the cohorts were differentiated by partial least squares discriminant analysis (PLS-DA). CONCLUSIONS: These preliminary data suggest that altered bile acid and PtC metabolism play an important role in CCA aetiopathogenesis and that specific metabolites may have potential as future biomarkers.

Phenotyping murine models of non-alcoholic fatty liver disease through metabolic profiling of intact liver tissue.

NAFLD (non-alcoholic fatty liver disease) is a common cause of chronic liver disease associated with the metabolic syndrome. Effective techniques are needed to investigate the potential of animal models of NAFLD. The present study aimed to characterize murine models of NAFLD by metabolic profiling of intact liver tissue. Mice of three strains (BALB/c, C3H and the novel mutant, Gena/263) were fed a control or high-fat diet. Biometric, biochemical and histological analysis demonstrated a spectrum of NAFLD from normal liver to steatohepatitis. Metabolic profiling of intact liver tissue, using (1)H MAS (proton magic angle spinning) MRS (magnetic resonance spectroscopy), showed an increase in the total lipid-to-water ratio, a decrease in polyunsaturation indices and a decrease in total choline with increasing disease severity. Principal components analysis and partial least-squares discriminant analysis showed separation of each model from its control and of each model from the total dataset. Class membership from the whole dataset was predicted with 100% accuracy in six out of eight models. Those models with steatosis discriminated from those with steatohepatitis with 100% accuracy. The separation of histologically defined steatohepatitis from simple steatosis is clinically important. Indices derived from (1)H MAS MRS studies may inform subsequent in vivo MRS studies at lower field strengths.

Expansion of hepatitis C-specific CD4+CD25+ regulatory T cells after viral clearance: a mechanism to limit collateral damage?

BACKGROUND: Data from rodent models suggest that a subpopulation of CD4+ T cells, characterized by the constitutive expression of CD25, play a key role in regulating many immune responses. Human CD4+CD25+ T cells also appear to possess a regulatory function, but their role in infections is not fully defined. OBJECTIVES: We sought to explore the possibility of a role for CD4+CD25+ T cells in controlling immunity to hepatitis C virus (HCV). We hypothesized that CD4+CD25+ T cells might account for the paucity of immune responses measurable in chronically viremic patients by suppressing the immune responses to HCV antigens. METHODS: We compared the responses of PBMCs to 3 different recombinant HCV antigens before and after depletion of CD25+ cells in 15 chronically viremic patients, 14 nonviremic HCV antibody-positive subjects, and 14 healthy control subjects. We also tested the ability of CD4+CD25+ T cells purified from HLA-matched viremic or nonviremic blood to suppress the responses of HCV epitope-specific T-cell clones. RESULTS: To our surprise, depletion of peripheral blood CD25+ cells led to a pronounced increase in proliferation of and IFN-gamma production by PBMCs only in nonviremic patients. Furthermore, the CD4+CD25+ T cells purified from HLA-matched nonviremic blood (in contrast to CD4+CD25+ T cells isolated from chronically viremic blood) inhibited the responses of HCV epitope-specific T-cell clones. CONCLUSION: HCV-specific CD4+CD25+ regulatory T cells appear to accompany successful viral clearance.

Polymorphisms in Natural Killer Cell Receptor Protein 2D (NKG2D) as a Risk Factor for Cholangiocarcinoma.

BACKGROUND AND AIMS: Understanding of the significant genetic risk factors for Cholangiocarcinoma (CC) remains limited. Polymorphisms in the natural killer cell receptor G2D (NKG2D) gene have been shown to increase risk of CC transformation in patients with Primary Sclerosing Cholangitis (PSC). We present a validation study of NKG2D polymorphisms in CC patients without PSC. METHODS: Seven common Single Nucleotide Polymorphisms (SNPs) of the NKG2D gene were genotyped in 164 non-PSC related CC subjects and 257 controls with HaploView. The two SNPs that were positively identified in the previous Scandinavian study, rs11053781 and rs2617167, were included. RESULTS: The seven genotyped SNPs were not associated with risk of CC. Furthermore, haplotype analysis revealed that there was no evidence to suggest that any haplotype differs in frequency between cases and controls (P > 0.1). CONCLUSION: The common genetic variation in NKG2D does not correlate significantly with sporadic CC risk. This is in contrast to the previous positive findings in the Scandinavian study with PSC-patients. The failure to reproduce the association may reflect an important difference between the pathogenesis of sporadic CC and that of PSC-related CC. Given that genetic susceptibility is likely to be multifaceted and complex, further validation studies that include both sporadic and PSC-related CC are required.

NICE guidelines and a treatment algorithm for the management of chronic hepatitis B: a review of 12 years experience in west London.

BACKGROUND: Treatment strategies in chronic hepatitis B (CHB) are evolving as more potent oral antivirals become available. However, drug resistance remains a major challenge and policy guidelines on management are limited by the evidence base. This study aims to review the implications of the National Institute for Health and Clinical Excellence (NICE) guidelines in a cohort of unselected CHB patients in the United Kingdom and to evolve a management algorithm for their treatment. METHODS: In total, 783 unselected hepatitis B surface antigen-positive patients, were assessed of whom 212 (27%) underwent liver biopsy. Age, alanine aminotransferase, hepatitis B virus DNA and necroinflammatory score were analysed to determine their value as predictors of fibrosis. Patients with biopsy evidence of fibrosis were offered treatment and followed longitudinally. Six-month on-treatment virologic response was evaluated to determine the validity of this strategy in predicting the early emergence of resistance. RESULTS: Age, gender and necroinflammatory score were predictors of fibrosis in CHB patients, whereas age > 40 years was a predictor of cirrhosis in both hepatitis B e antigen (HBeAg)-positive (P < 0.03) and HBeAg-negative patients (P < 0.003). A total of 81% of HBeAg-positive and 65% of HBeAg-negative CHB patients who required adefovir add-on therapy were identifiable after 6 months of lamivudine monotherapy, by continuing HBV DNA positivity (P < 0.002 and P < 0.0001, respectively). CONCLUSIONS: Advanced liver disease was present in patients falling outside current treatment guidelines, highlighting the importance of liver histology in identifying fibrosis and the need for antiviral therapy. While 6 month on-treatment virologic response as a trigger for instituting add-on therapy may be an improvement on the current recommendations, such a strategy should be integrated into any new treatment algorithm, likely to consist of entecavir and tenofovir.