Optimization of immunosuppression strategies for the establishment of chronic hepatitis E virus infection in rabbits.

Chronic hepatitis E mostly occurs in organ transplant recipients and can lead to rapid liver fibrosis and cirrhosis. Previous studies found that the development of chronic hepatitis E virus (HEV) infection is linked to the type of immunosuppressant used. Animal models are crucial for the study of pathogenesis of chronic hepatitis E. We previously established a stable chronic HEV infection rabbit model using cyclosporine A (CsA), a calcineurin inhibitor (CNI)-based immunosuppressant. However, the immunosuppression strategy and timing may be optimized, and how different types of immunosuppressants affect the establishment of chronic HEV infection in this model is still unknown. Here, we showed that chronic HEV infection can be established in 100% of rabbits when CsA treatment was started at HEV challenge or even 4 weeks after. Tacrolimus or prednisolone treatment alone also contributed to chronic HEV infection, resulting in 100% and 77.8% chronicity rates, respectively, while mycophenolate mofetil (MMF) only led to a 28.6% chronicity rate. Chronic HEV infection was accompanied with a persistent activation of innate immune response evidenced by transcriptome analysis. The suppressed adaptive immune response evidenced by low expression of genes related to cytotoxicity (like perforin and FasL) and low anti-HEV seroconversion rates may play important roles in causing chronic HEV infection. By analyzing HEV antigen concentrations with different infection outcomes, we also found that HEV antigen levels could indicate chronic HEV infection development. This study optimized the immunosuppression strategies for establishing chronic HEV infection in rabbits and highlighted the potential association between the development of chronic HEV infection and immunosuppressants.IMPORTANCEOrgan transplant recipients are at high risk of chronic hepatitis E and generally receive a CNI-based immunosuppression regimen containing CNI (tacrolimus or CsA), MMF, and/or corticosteroids. Previously, we established stable chronic HEV infection in a rabbit model by using CsA before HEV challenge. In this study, we further optimized the immunosuppression strategies for establishing chronic HEV infection in rabbits. Chronic HEV infection can also be established when CsA treatment was started at the same time or even 4 weeks after HEV challenge, clearly indicating the risk of progression to chronic infection under these circumstances and the necessity of HEV screening for both the recipient and the donor preoperatively. CsA, tacrolimus, or prednisolone instead of MMF significantly contributed to chronic HEV infection. HEV antigen in acute infection phase indicates the development of chronic infection. Our results have important implications for understanding the potential association between chronic HEV infection and immunosuppressants.

Pegylated interferon may be considered in chronic viral hepatitis E resistant to ribavirin in kidney transplant recipients.

BACKGROUND: Hepatitis E virus (HEV) may be resistant to immunosuppression reduction and ribavirin treatment in kidney transplant recipients because of mutant strains and severe side effects of ribavirin which conduct to dose reduction. Sofosbuvir efficacy is controversial. Peg-interferon 2 alpha (PEG-IFN) is currently contraindicated due to a high risk of acute humoral and cellular rejection. The present study assessed, for the first time, the effect of PEG-IFN in a kidney transplant recipient infected with HEV. CASE PRESENTATION: The patient had chronic active HEV that was resistant to immunosuppression reduction and optimal ribavirin treatment. He developed significant liver fibrosis. PEG-IFN was administered for 10 months, and it was well tolerated and did not induce rejection. A sustained virological response was obtained. CONCLUSIONS: We conclude that prolonged treatment with PEG-IFN in kidney transplant recipients infected with HEV could be considered as a salvage option.

Human microbiome is a diagnostic biomarker in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. Increasing evidence indicates a close relationship between HCC and the human microbiota. Herein, we reviewed the important potential of the human microbiota as a diagnostic biomarker of HCC. DATA SOURCES: Several innovative studies have investigated the characteristics of the gut and oral microbiomes in patients with HCC and proposed that the human microbiome has the potential to be a diagnostic biomarker of HCC. Literature from February 1999 to February 2019 was searched in the PubMed database using the keywords "microbiota" or "microbiome" or "microbe" and "liver cancer" or "hepatocellular carcinoma", and the results of clinical and experimental studies were analyzed. RESULTS: Specific changes occur in the human microbiome of patients with HCC. Moreover, the gut microbiome and oral microbiome can be used as non-invasive diagnostic biomarkers for HCC. Furthermore, they also have certain diagnostic potential for precancerous diseases of HCC. The diagnostic potential of the blood microbiota and ascites microbiota in HCC will be gradually discovered in the future. CONCLUSIONS: The human microbiome is valuable to the diagnosis of HCC and provides a novel strategy for targeted therapy of HCC. The human microbiome may be widely used in the diagnosis, treatment and prognosis for multiple system diseases or cancers in the future.

Identification of abnormal fucosylated-glycans recognized by LTL in saliva of HBV-induced chronic hepatitis, cirrhosis, and hepatocellular carcinoma.

The hepatitis B virus (HBV)-induced chronic liver diseases are serious health threats worldwide. There is evidence to display the alterations of salivary N-linked glycans related to the development of HBV-infected liver diseases. Here, we further investigated the alterations of fucosylated N/O-glycans recognized by LTL in saliva from 120 subjects (30 healthy volunteers (HV), 30 patients with hepatitis B (HB), 30 patients with hepatic cirrhosis (HC), and 30 patients with hepatocellular carcinoma (HCC)) using salivary microarrys and MALDI-TOF/TOF-MS. The results showed that the expression level of fucosylated glycans recognized by LTL was significantly increased in HCC compared with other subjects (P < 0.0001). Besides, the fucosylated glycoproteins were isolated from pooled saliva of HV, HB, HC, and HCC by LTL-magnetic particle conjugates. Then, N/O- glycans were released from the isolated glycoproteins with PNGase F and NaClO, and were identified by MALDI-TOF-MS, respectively. Totally, there were 21/20, 25/18, 29/19, and 28/24 N/O-glycan peaks that were identified and annotated with proposed structures in saliva of HV, HB, HC, and HCC. Among the total, there were 8 N-glycan peaks (e.g., m/z 1905.634, 2158.777 and 2905.036) and 15 O-glycan peaks (e.g., 1177.407, 1308.444 and 1322.444) that only presented in patients with HBV-induced liver diseases. One N-glycan peak (m/z 2205.766) was unique in HC, and 9 O-glycan peaks (e.g., m/z 1157.420, 1163.417 and 1193.402) were unique in HCC. This study could facilitate the discovery of biomarkers for HC and HCC based on precise alterations of fucosylated N/O-glycans in saliva.

Defining virus-specific CD8+ TCR repertoires for therapeutic regeneration of T cells against chronic hepatitis E.

BACKGROUND & AIMS: Immunosuppressed patients with chronic hepatitis E virus infection (cHEV), who are ineligible or have failed current treatment with off-label ribavirin, are a potential target population for T cell-based therapy. T cell responses are important for viral control. Herein, we aimed to identify human leukocyte antigen (HLA)-A2 restricted HEV-specific CD8+ T cell epitopes and T cell receptors (TCR) targeting these epitopes, as the basis for a redirected TCR treatment approach for patients with cHEV. METHODS: HEV genotype 3 overlapping peptide pools were used to screen HEV-specific CD8+ T cell immune responses in HLA-A2+ patients with acute HEV infection and healthy donors, by intracellular cytokine staining. CD8+ T cells targeting the identified epitopes were sorted for sequencing of the TCR repertoires by next generation sequencing. Messenger RNA encoding these TCRs were introduced into lymphocytes of healthy donors and patients with cHEV through TCR redirection. TCR-engineered lymphocytes were evaluated for Dextramer®-binding capacity, target sensitivity and cytotoxicity against peptide-loaded T2 cells. RESULTS: HEV-specific responses were observed across open reading frame (ORF)1 and ORF2 of the HEV genome in patients with acute resolving HEV infection. HLA-A2-restricted HEV-specific CD8+ T cell epitopes targeting the HEV RNA helicase and RNA-dependent RNA polymerase were selected for functional studies. Introduction of HEV-specific TCRs into lymphocytes of immunocompetent donors and patients with chronic hepatitis E enabled the lymphocytes to bind HEV Dextramers, secrete multiple cytokines and exert cytotoxicity in a target-specific manner. CONCLUSION: We identified TCRs that target HEV-specific CD8+ T cell epitopes, and characterized their immune properties, which may have clinical potential in future T cell-based therapy. LAY SUMMARY: Patients who are immunosuppressed are vulnerable to developing chronic liver disease following infection with hepatitis E virus (HEV). To-date, there is no approved therapy for chronic hepatitis E. Interferon-α and ribavirin are off-label treatment options, but their applications are limited by side effects. Thus, immunotherapy, more specifically T cell-based therapy, may be an alternative approach. We designed T cell receptor-engineered T cells that effectively conferred immune cells, taken from patients with chronic hepatitis E, with the ability to recognize virus-specific epitopes and mediate killing of target cells in vitro.

Clinical features and determinants of chronicity in hepatitis E virus infection.

Hepatitis E virus (HEV) has traditionally been associated with an acute, self-limiting hepatitis and is not known to have any chronic sequelae. HEV genotypes 1 and 2, which are human pathogens, have been associated with this self-limiting presentation, in both sporadic and epidemic settings. HEV genotype 3, which is zoonotically transmitted, is increasingly being reported as a cause of chronic infection in immunocompromised patients. These include patients with solid organ transplants, patients receiving chemotherapy for haematologic malignancies and patients infected with HIV. Chronic infection is associated with rapidly progressing liver disease and extrahepatic manifestations including neurologic disorders. We review the clinical manifestations of chronic HEV infection and discuss factors determining persistence and chronicity of HEV.

Evaluation of an antigen assay for diagnosing acute and chronic hepatitis E genotype 4 infection.

BACKGROUND AND AIM: Results obtained from different hepatitis E virus (HEV) tests are usually inconsistent. The detection of serum HEV antigen (Ag) has been suggested to be more sensitive for the diagnosis of genotypes 1 and 3 HEV. METHODS: We compared the diagnostic accuracies of serum HEV Ag and HEV RNA by using 202 serum samples from patients suspected acute viral hepatitis. RESULTS: The HEV Ag assay was 100% specific. The lower detected levels of viremia ranged from 102 to 103  copies/mL. The sensitivity of the HEV Ag test was 90.5%. One of the 42 cases was negative for anti-HEV IgM, but HEV Ag was still detectable. The detectable period of HEV Ag was in concordance with the detectable period of HEV RNA. Serum HEV Ag was persistently detected in two cases of chronic hepatitis E, confirmed by the persistent presence of HEV RNA despite being negative for anti-HEV IgM. HEV Ag demonstrated good consistency with positive HEV RNA (k = 0.938, P < 0.001). Receiver operating characteristic analysis of HEV Ag suggested a second cut-off value of >0.095 to predict HEV patients with 95.24% sensitivity and 98.75% specificity, and the area under the curve was 0.9887, which was higher than that of three commercial anti-HEV IgM ELISA tests. CONCLUSIONS: The presence of HEV Ag has good consistency with HEV RNA in both acute and chronic genotype 4 hepatitis E. HEV Ag is a more promising serum marker to identify active genotype 4 HEV infection than anti-HEV IgM and HEV RNA.

Hepatitis E virus in South America: The current scenario.

Hepatitis E virus (HEV) is one of the most frequent causes of acute viral hepatitis of enteric transmission worldwide. In South America the overall epidemiology has been little studied, and the burden of the disease remains largely unknown. A research of all scientific articles about HEV circulation in South America until November 2017 was carried out. Human seroprevalences of HEV varied according to the studied population: blood donors presented prevalence rates ranging from 1.8% to 9.8%, while reports from HIV-infected individuals, transplant recipients and patients on hemodialysis showed higher prevalence rates. Only 2 cases of chronic hepatitis in solid-organ transplant patients from Argentina and Brazil have been described. Detection of HEV in the swine population is widely prevalent in the region. Anti-HEV antibodies have also been recently documented in wild boars from Uruguay. Although scarce, studies focused on environmental and food HEV detection have shown viral presence in these kind of samples, highlighting possible transmission sources of HEV in the continent. HEV genotype 3 was the most frequently detected in the region, with HEV genotype 1 detected only in Venezuela and Uruguay. HEV is widely distributed throughout South America, producing sporadic cases of acute hepatitis, but as a possible agent of chronic hepatitis. Finding the virus in humans, animals, environmental samples and food, show that it can be transmitted through many sources, alerting local governments and health systems to improve diagnosis and for the implementation of preventive measures.

Chronic Infection With Camelid Hepatitis E Virus in a Liver Transplant Recipient Who Regularly Consumes Camel Meat and Milk.

There have been increasing reports of food-borne zoonotic transmission of hepatitis E virus (HEV) genotype 3, which causes chronic infections in immunosuppressed patients. We performed phylogenetic analyses of the HEV sequence (partial and full-length) from 1 patient from the Middle East who underwent liver transplantation, and compared it with other orthohepevirus A sequences. We found the patient to be infected by camelid HEV. This patient regularly consumed camel meat and milk, therefore camelid HEV, which is genotype 7, might infect human beings. Our finding links consumption of camel-derived food products to post-transplantation hepatitis E, which, if detected at early stages, can be cured with antiviral therapy and reduced administration of immunosuppressive agents.

A pilot study of salivary N-glycome in HBV-induced chronic hepatitis, cirrhosis, and hepatocellular carcinoma.

Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV), which can lead to chronic liver disease and put people at high risk of death from cirrhosis of the liver and liver cancer. However, little is known about the correlation of salivary N-linked glycans related to HBV-infected liver diseases. Here we investigated N-linked glycome in saliva from 200 subjects (50 healthy volunteers (HV), 40 HBV-infected patients (HB), 50 cirrhosis patients (HC), and 60 hepatocellular carcinoma patients (HCC) using MALDI-TOF/TOF-MS. Representative MS spectra of N-glycans with signal-to-noise ratios >6 were annotated using the GlycoWorkbench program. A total of 40, 47, 29, and 33 N-glycan peaks were identified and annotated from HV, HB, HC, and HCC groups, respectively. There were 15 N-glycan peaks (e.g., m/z 1647.587, 1688.613 and 2101.755) were present in all groups. Three N-glycan peaks (m/z 2596.925, 2756.962, and 2921.031) were unique in HV group, 2 N-glycan peaks (m/z 1898.676 and 1971.692) were unique in HB group, 5 N-glycan peaks (m/z 1954.677, 2507.914, 2580.930, 2637.952, and 3092.120) were unique in HC group, and 3 N-glycan peaks (m/z 2240.830, 2507.914, and 3931.338) were unique in HCC group. The proportion of fucosylated N-glycans was apparently increased in the HCC group (84.8%) than in any other group (73.1% ± 0.01), however, the proportion of sialylated N-glycans was decreased in HCC group (12.1%) than in any other group (17.23% ± 0.003). Our data provide pivotal information to distinguish between HBV-associated hepatitis, cirrhosis and HCC, and facilitate the discovery of biomarkers for HCC during its early stages based on precise alterations of N-linked glycans in saliva.

Evidence of hepatitis E virus transmission by renal graft.

Hepatitis E virus (HEV) can cause chronic infection among immunocompromised patients, especially solid organ transplant recipients, and can evolve to cirrhosis. Several modes of transmission are known. Here we describe the first two cases, to our knowledge, of HEV infection transmitted by a kidney graft from the same infected donor that led to chronic hepatitis. Consequently, systematic screening of donors by HEV serology and HEV RNA detection by polymerase chain reaction, particularly in endemic regions, should be considered.

Liver Biopsy in Chronic Liver Diseases: Is There a Favorable Benefit: Risk Balance?

Liver biopsy is still useful in selected clinical situations in which it is the only tool to obtain information necessary for the diagnosis, the prognosis, and the decision for treatment. Main examples are viral hepatitis with confounding co-morbidities, non alcoholic fatty liver disease, and autoimmune liver diseases.

FibroGENE: A gene-based model for staging liver fibrosis.

BACKGROUND & AIMS: The extent of liver fibrosis predicts long-term outcomes, and hence impacts management and therapy. We developed a non-invasive algorithm to stage fibrosis using non-parametric, machine learning methods designed for predictive modeling, and incorporated an invariant genetic marker of liver fibrosis risk. METHODS: Of 4277 patients with chronic liver disease, 1992 with chronic hepatitis C (derivation cohort) were analyzed to develop the model, and subsequently validated in an independent cohort of 1242 patients. The model was assessed in cohorts with chronic hepatitis B (CHB) (n=555) and non-alcoholic fatty liver disease (NAFLD) (n=488). Model performance was compared to FIB-4 and APRI, and also to the NAFLD fibrosis score (NFS) and Forns' index, in those with NAFLD. RESULTS: Significant fibrosis (⩾F2) was similar in the derivation (48.4%) and validation (47.4%) cohorts. The FibroGENE-DT yielded the area under the receiver operating characteristic curve (AUROCs) of 0.87, 0.85 and 0.804 for the prediction of fast fibrosis progression, cirrhosis and significant fibrosis risk, respectively, with comparable results in the validation cohort. The model performed well in NAFLD and CHB with AUROCs of 0.791, and 0.726, respectively. The negative predictive value to exclude cirrhosis was>0.96 in all three liver diseases. The AUROC of the FibroGENE-DT performed better than FIB-4, APRI, and NFS and Forns' index in most comparisons. CONCLUSION: A non-invasive decision tree model can predict liver fibrosis risk and aid decision making.

Multiparametric magnetic resonance imaging predicts clinical outcomes in patients with chronic liver disease.

BACKGROUND & AIMS: Multiparametric magnetic resonance (MR) imaging has been demonstrated to quantify hepatic fibrosis, iron, and steatosis. The aim of this study was to determine if MR can be used to predict negative clinical outcomes in liver disease patients. METHODS: Patients with chronic liver disease (n=112) were recruited for MR imaging and data on the development of liver related clinical events were collected by medical records review. The median follow-up was 27months. MR data were analysed blinded for the Liver Inflammation and Fibrosis score (LIF; <1, 1-1.99, 2-2.99, and ⩾3 representing normal, mild, moderate, and severe liver disease, respectively), T2∗ for liver iron content and proportion of liver fat. Baseline liver biopsy was performed in 102 patients. RESULTS: Liver disease aetiologies included non-alcoholic fatty liver disease (35%) and chronic viral hepatitis (30%). Histologically, fibrosis was mild in 54 (48%), moderate in 17 (15%), and severe in 31 (28%) patients. Overall mortality was 5%. Ten patients (11%) developed at least one liver related clinical event. The negative predictive value of LIF<2 was 100%. Two patients with LIF 2-2.99 and eight with LIF⩾3 had a clinical event. Patients with LIF⩾3 had a higher cumulative risk for developing clinical events, compared to those with LIF<1 (p=0.02) and LIF 1-1.99 (p=0.03). Cox regression analysis including all 3 variables (fat, iron, LIF) resulted in an enhanced LIF predictive value. CONCLUSIONS: Non-invasive standardised multiparametric MR technology may be used to predict clinical outcomes in patients with chronic liver disease.

Immunology of hepatitis B virus and hepatitis C virus infection.

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.

Calcineurin inhibitors stimulate and mycophenolic acid inhibits replication of hepatitis E virus.

BACKGROUND & AIMS: Many recipients of organ transplants develop chronic hepatitis, due to infection with the hepatitis E virus (HEV). Although chronic HEV infection is generally associated with immunosuppressive therapies, little is known about how different immunosuppressants affect HEV infection. METHODS: A subgenomic HEV replication model, in which expression of a luciferase reporter gene is measured, and a full-length infection model were used. We studied the effects of different immunosuppressants, including steroids, calcineurin inhibitors (tacrolimus [FK506] and cyclosporin A), and mycophenolic acid (MPA, an inhibitor of inosine monophosphate dehydrogenase) on HEV replication in human hepatoma cell line Huh7. Expression of cyclophilins A and B (the targets of cyclosporin A) were knocked down using small hairpin RNAs. RESULTS: Steroids had no significant effect on HEV replication. Cyclosporin A promoted replication of HEV in the subgenomic and infectious models. Knockdown of cyclophilin A and B increased levels of HEV genomic RNA by 4.0- ± 0.6-fold and 7.2- ± 1.9-fold, respectively (n = 6; P < .05). A high dose of FK506 promoted infection of liver cells with HEV. In contrast, MPA inhibited HEV replication. Incubation of cells with guanosine blocked the antiviral activity of MPA, indicating that the antiviral effects of this drug involve nucleotide depletion. The combination of MPA and ribavirin had a greater ability to inhibit HEV replication than MPA or ribavirin alone. CONCLUSIONS: Cyclophilins A and B inhibit replication of HEV; this might explain the ability of cyclosporin A to promote HEV infection. On the other hand, the immunosuppressant MPA inhibits HEV replication. These findings should be considered when physicians select immunosuppressive therapies for recipients of organ transplants who are infected with HEV.

A mutation in the hepatitis E virus RNA polymerase promotes its replication and associates with ribavirin treatment failure in organ transplant recipients.

We analyzed blood samples collected from 15 patients with chronic hepatitis E who were recipients of solid-organ transplants. All patients cleared the hepatitis E virus (HEV) except for 2 (nonresponders); 1 patient died. A G1634R mutation in viral polymerase was detected in the HEV RNA of the nonresponders; this mutation did not provide the virus with resistance to ribavirin in vitro. However, the mutant form of a subgenomic replicon of genotype 3 HEV replicated more efficiently in vitro than HEV without this mutation, and the same was true for infectious virus, including in competition assays. Similar results were obtained for genotype 1 HEV. The G1634R mutation therefore appears to increase the replicative capacity of HEV in the human liver and hence reduce the efficacy of ribavirin.

Anti-tumour necrosis factor treatment of severe psoriasis complicated by Epstein-Barr Virus hepatitis and subsequently by chronic hepatitis.

A case is described of severe acute hepatitis in 47-year-old woman with chronic psoriasis and psoriatic arthritis treated with infliximab. Although clinical, serological and laboratory results were compatible with acute EBV hepatitis, it was difficult to differentiate between EBV infection and other non-infectious causes of hepatitis. The patient gradually developed chronic hepatitis with liver steatosis and efficient treatment with adalimumab had to be stopped. This case presents an uncommon complication that may arise from the use of biologic therapy and calls for caution in long-term management of psoriatic patients with internal comorbidities.