Dynamic Elevation of Aromatic Amino Acids in Hepatitis C Virus-Induced Cirrhosis After a Standard Meal

INTRODUCTION

Perturbations in aromatic (AAAs) and branched-chain amino acids (BCAAs) are seen in decompensated liver disease. The aim of this study was to evaluate the dynamic, postprandial relationship between hepatitis C virus-induced liver disease and amino acid concentrations in patients with compensated liver disease.

METHODS

Patients infected with hepatitis C virus underwent a baseline liver biopsy to determine Ishak Fibrosis Score and evaluate the liver transcriptome. Patients ate a standard meal and underwent peripheral vein sampling at defined intervals. Quantitative analysis of amino acids was performed using liquid chromatography-tandem mass spectrometry.

RESULTS

At baseline, there was no difference in AAA and BCAA concentrations between patients with cirrhosis and non-cirrhotic patients. After a standard meal, AAAs, but not BCAAs, were elevated in patients with cirrhosis compared with non-cirrhotic patients at every time point. The HepQuant SHUNT fraction was significantly higher in patients with cirrhosis and positively correlated with AAA concentration at all time points, but not BCAA. Analysis of the hepatic transcriptome demonstrated greater downregulation of the AAA degradation pathways than the BCAA degradation pathways.

DISCUSSION

At baseline, cirrhotic patients with compensated liver disease have adequate reserve liver function to metabolize AAAs and BCAAs. When faced with a metabolic stressor, such as a standard meal, patients with cirrhosis are less able to metabolize the increased load of AAAs. This impairment correlates with portosystemic shunting. Further evaluation of AAA levels in compensated liver disease might further the understanding of the liver-muscle axis and the role it may play in the development of sarcopenia in liver disease.

Non-selective dampening of the host immune response after hepatitis C clearance and its association with circulating chemokine and endotoxin levels

BACKGROUND & AIMS

Direct-acting antiviral (DAA) therapy has revolutionized treatment for the hepatitis C virus (HCV). While DAA therapy is common, little is known about the intrahepatic immunological changes after sustained virologic response (SVR). We aim to describe transcriptional alterations of the gut microbiome and the liver after SVR.

METHODS

Twenty-two HCV patients were evaluated before and 9 months after 12 weeks of sofosbuvir/velpatasvir treatment. All achieved SVR. A liver biopsy, portal blood (direct portal vein cannulation), peripheral blood and stool samples were obtained. RNA-seq and immunofluorescent staining were performed on liver biopsies. RNA-seq and 16S rRNA metagenomics were performed on stool.

RESULTS

Differential expression within liver transcription showed 514 downregulated genes (FDR q < .05; foldchange > 2) enriched in inflammatory pathways; of note, GO:0060337, type 1 IFN signalling (p = 8e-23) and GO:0042742, defence response to bacterium (p = 8e-3). Interestingly, microbial products increased in the portal blood and liver after SVR. Due to the increase in microbial products, the gut microbiome was investigated. There was no dysbiosis by Shannon diversity index or Bacteroides/Firmicutes ratio. There was a differential increase in genes responsible for bacterial lipopolysaccharide production after SVR.

CONCLUSIONS

The decrease in the antiviral interferon pathway expression was expected after SVR; however, there was an unanticipated decrease in the transcription of genes involved in recognition and response to bacteria, which was associated with increased levels of microbial products. Finally, the alterations in the function of the gut microbiome are a promising avenue for further investigation of the gut-liver axis, especially in the context of the significant immunological changes noted after SVR.

A Simple, Rapid, and Effective Heparinase Protocol to Enable Nucleic Acid Study from Frozen Heparinized Plasma

Cell-free RNAs (cfRNAs) are promising analytes as non-invasive biomarkers and have even greater potential if tied in with metabolomics. Plasma is an optimal source for cfRNAs but is often derived from a variety of anticoagulants. Plasma obtained in heparin is suitable for metabolomics but is difficult to utilize for qPCR-based downstream analysis. In the present study, we aimed to develop a simple, time-efficient, and cost-effective heparinase protocol, followed by library preparation and sequencing of human plasma cfRNAs drawn and stored in heparin at -80 °C for several years. Blood was collected in CPT™ sodium heparin tubes from patients with chronic HCV infection (NCT02400216) at the National Institutes of Health (NIH) Clinical Center. Plasma cfRNAs were treated with heparinase I and used for library preparation and next-generation sequencing (NGS). Heparinase treatment maintained RNA integrity and allowed for successful library preparation for all the study subjects even with 7 ng of cfRNAs as starting material. The classification report derived from Pavian R package v1.2.0 showed no artificial reads. The abundance of chordate over microbial reads suggests no addition of experimental error through heparinase I treatment. We report a novel and practical approach to heparinase treatment for human plasma collected and frozen in sodium heparin for several years. This is an effective demonstration of utilizing heparin plasma for NGS and downstream transcriptomic research, which could then be integrated with metabolomics from the same samples, maximizing efficiency and minimizing blood draws.

Longitudinal multi-omics analyses of the gut-liver axis reveals metabolic dysregulation in hepatitis C infection and cirrhosis

The gut and liver are connected via the portal vein, and this relationship, which includes the gut microbiome, is described as the gut-liver axis. Hepatitis C virus (HCV) can infect the liver and cause fibrosis with chronic infection. HCV has been associated with an altered gut microbiome; however, how these changes impact metabolism across the gut-liver axis and how this varies with disease severity and time is unclear. Here we used multi-omics analysis of portal and peripheral blood, faeces and liver tissue to characterize the gut-liver axis of patients with HCV across a fibrosis severity gradient before (n = 29) and 6 months after (n = 23) sustained virologic response, that is, no detection of the virus. Fatty acids were the major metabolites perturbed across the liver, portal vein and gut microbiome in HCV, especially in patients with cirrhosis. Decreased fatty acid degradation by hepatic peroxisomes and mitochondria was coupled with increased free fatty acid (FFA) influx to the liver via the portal vein. Metatranscriptomics indicated that Anaerostipes hadrus-mediated fatty acid synthesis influences portal FFAs. Both microbial fatty acid synthesis and portal FFAs were associated with enhanced hepatic fibrosis. Bacteroides vulgatus-mediated intestinal glycan breakdown was linked to portal glycan products, which in turn correlated with enhanced portal inflammation in HCV. Paired comparison of patient samples at both timepoints showed that hepatic metabolism, especially in peroxisomes, is persistently dysregulated in cirrhosis independently of the virus. Sustained virologic response was associated with a potential beneficial role for Methanobrevibacter smithii, which correlated with liver disease severity markers. These results develop our understanding of the gut-liver axis in HCV and non-HCV liver disease aetiologies and provide a foundation for future therapies.

HepQuant SHUNT Detects Portal Hypertension in Early Stages of Clinically Compensated Chronic Liver Disease

Physicians use portal pressure measurements in clinical practice and research but the methods are invasive, can cause complications, and are resource intensive.^1-3 Herein we describe preliminary findings of the minimally invasive HepQuant-SHUNT test in the diagnosis of portal hypertension in precirrhotic and compensated cirrhotic patients.

APECED-Associated Hepatitis: Clinical, Biochemical, Histological and Treatment Data From a Large, Predominantly American Cohort

BACKGROUND AND AIMS

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), caused by autoimmune regulator (AIRE) mutations, manifests with chronic mucocutaneous candidiasis (CMC) and multisystem autoimmunity, most often hypoparathyroidism (HP) and adrenal insufficiency (AI). European cohorts previously reported a ~10% prevalence of APECED-associated hepatitis (APAH) with presentations ranging from asymptomatic laboratory derangements to fatal fulminant hepatic failure. Herein, we characterized APAH in a large APECED cohort from the Americas.

APPROACH AND RESULTS

Forty-five consecutive patients with APECED were evaluated (2013-2015) at the National Institutes of Health (NIH; NCT01386437). Hepatology consultation assessed hepatic and autoimmune biomarkers and liver ultrasound in all patients. Liver biopsies evaluated autoimmune features and fibrosis. The 16S ribosomal RNA (rRNA) sequencing was performed in 35 patients' stools (12 with and 23 without APAH). Among 43 evaluable patients, 18 (42%) had APAH; in 33.3% of those with APAH, APAH occurred before developing classic APECED diagnostic criteria. At APAH diagnosis, the median age was 7.8 years, and patients manifested with aminotransferase elevation and/or hyperbilirubinemia. All patients with APAH were in clinical remission during their NIH evaluation while receiving immunomodulatory treatment. We found no difference in age, sex, or prevalence of CMC, AI, or HP between patients with or without APAH. Autoantibody positivity against aromatic L-amino acid decarboxylase, cytochrome P450 family 1 subfamily A member 2, histidine decarboxylase (HDC), bactericidal/permeability-increasing fold-containing B1, tryptophan hydroxlase, and 21-hydroxylase (21-OH), and the homozygous c.967_979del13 AIRE mutation were associated with APAH development. Classical serological biomarkers of autoimmune hepatitis (AIH) were only sporadically positive. AIH-like lymphoplasmacytic inflammation with mild fibrosis was the predominant histological feature. Stool microbiome analysis found Slackia and Acidaminococcus in greater abundance in patients with APAH.

CONCLUSIONS

APAH is more common than previously described, may present early before classic APECED manifestations, and most often manifests with milder, treatment-responsive disease. Several APECED-associated autoantibodies, but not standard AIH-associated biomarkers, correlate with APAH.

Exploring the Link Between Platelet Numbers and Vascular Homeostasis Across Early and Late Stages of Fibrosis in Hepatitis C

BACKGROUND

Thrombocytopenia is a hallmark of advanced liver disease. Platelets, growth factors (GFs), and vascular integrity are closely linked factors in disease pathogenesis, and their relationship, particularly in early disease stages, is not entirely understood. The aim was to compare circulating platelets, growth factors, and vascular injury markers (VIMs) in hepatitis C-infected (HCV) patients with early fibrosis and cirrhosis.

METHODS

Retrospective evaluation of serum GFs and VIMs by ELISA were evaluated from twenty-six HCV patients. Analytes from an earlier time-point were correlated with MELD at a later time-point.

RESULTS

Platelets and GFs decreased, and VIMs increased with fibrosis. Platelets correlated positively with PDGF-AA, PDGF-BB, TGFB1, EGF, and P-selectin, and negatively with ICAM-3 and VCAM-1. P-selectin showed no correlations with VIMs but positively correlated with PDGF-AA, PDGF-BB, TGFB1, and EGF. Soluble VCAM-1 and ICAM-3 were linked to increasing fibrosis, liver enzymes, and synthetic dysfunction. Higher VCAM-1 and ICAM-3 and lower P-selectin at an earlier time-point were linked to higher MELD score at a later time-point.

CONCLUSION

In chronic HCV, progressive decline in platelets and growth factors with fibrosis and their associations suggest that platelets are an important source of circulating GFs and influence GF decline with fibrosis. Enhanced markers of vascular injury in patients with early fibrosis suggest an earlier onset of endothelial dysfunction preceding cirrhosis. Associations of VIMs with platelets suggest a critical link between platelets and vascular homeostasis. Circulating markers of vascular injury may not only have prognostic importance but emphasize the role of vascular dysfunction in liver disease pathogenesis (NCT00001971).

Bacterial Translocation and Host Immune Activation in Chronic Hepatitis C Infection

Hepatitis C virus (HCV) infects 71 million individuals, and barriers to treatment remain. Bacterial translocation is a complication of chronic HCV infection, and this study evaluated circulating microbial components including lipopolysaccharide, peptidoglycan, and β-D-glucan in addition to their pattern recognition receptors and degree of hepatic macrophage uptake. The findings suggest that regulation of serum peptidoglycan and β-D-glucan differs from that of lipopolysaccharide. Additionally, macrophage activation in the liver may be better reflected by the degree of macrophage uptake than by circulating levels of microbial markers. These findings allow for a greater understanding of bacterial translocation and host immune activation during HCV infection.