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.

Two Faces of Neutrophils in Liver Disease Development and Progression.

Neutrophils, the most abundant type of leukocyte in human blood, play a major role in host defense against invading pathogens and in sterile injury. Neutrophil infiltration is characteristic of inflammation because of its antimicrobial and cytotoxic activities. Neutrophils also actively participate in the resolution of inflammation and subsequent tissue repair by acting as a critical mediator between the inflammation and resolution phases of tissue damage. However, neutrophils that are consistently exposed to inflammatory conditions lose their self-resolving capabilities and maintain an inflammatory phenotype, further exacerbating tissue damage. The current review describes how neutrophils interact with tissue microenvironments and acquire disease-specific phenotypes under chronic inflammatory conditions. Here, we aim to provide a better understanding of neutrophil-mediated pathogenesis of various liver diseases.

Differences in autoimmune hepatitis based on inflammation localization.

Histopathology is essential for the diagnosis and evaluation of disease activity of autoimmune hepatitis (AIH). We aimed to elucidate the characteristics of AIH from the localization of inflammation. We re-evaluated a nationwide survey that was performed in Japan in 2018 of AIH patients diagnosed between 2014 and 2017. A total of 303 patients were enrolled, and the clinical and treatment characteristics were compared between the patients with predominantly portal inflammation (230 patients) or lobular inflammation (73 patients). AIH patients with lobular inflammation had a higher probability of being diagnosed with acute hepatitis than those with portal inflammation. Liver enzyme levels were higher in patients with lobular inflammation, whereas immunoglobulin G levels were higher in patients with portal inflammation. The prevalence of an alanine aminotransferase level < 30 U/L after 6 months of treatment was significantly higher in patients with lobular inflammation than in those with portal inflammation (81.7% vs. 67.3%, P = 0.046). The localization of inflammation may be useful for evaluating the onset of AIH.

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.

Chronic Hepatitis E is associated with cholangitis.

BACKGROUND AND AIMS: Sporadic hepatitis E is an emerging indigenous disease in Europe induced by genotype 3 of the virus. While the disease takes an acute self-limited course in immunocompetent individuals, under immunocompromised conditions chronic hepatitis E might develop. The histology of chronic hepatitis E has not been described in detail systematically. METHODS: Liver biopsies from 19 immunosuppressed patients with chronic hepatitis E were collected: 17 were organ transplant recipients, one had a CD4-deficiency and one had received steroid therapy because of ulcerative colitis. Biopsies were processed with standard stains. Evaluation of histologic activity and fibrosis was performed according to Ishak. Additionally, immunohistochemistry with antibodies directed against open reading frame 2 and 3 of the virus was performed and liver biopsies were tested for hepatitis E virus RNA. RESULTS: Biochemical data showed an increase in alanine transaminase, aspartate transaminase, gamma-glutamyl transferase and total bilirubin. Histopathology displayed typical features of chronic hepatitis with mild to moderate activity. The number of polymorphonuclear leucocytes was considerably increased and all patients had a florid cholangitis that presented as a destructive form in five of them. Hepatocytes and bile duct epithelia stained positive for hepatitis E virus by immunohistochemistry. CONCLUSIONS: Chronic hepatitis E in immunocompromised individuals runs a similar course as hepatitis B and C and shows similar histopathology. However, the presence of destructive cholangitis in some cases accompanied by an increased number of polymorphonuclear leucocytes is markedly different. Immunohistochemically the virus is present in bile duct epithelia, seemingly the cause for cholangitis.

Modeling the Chronification Tendency of Liver Infections as Evolutionary Advantage.

Here, we discuss how the tendency of a liver infection to chronify can be seen as an evolutionary advantage for infected individuals. For this purpose, we present a set of reaction-diffusion equations as a mathematical model of viral liver infections, which allows chronic and acute courses of the liver infection. We introduce a cumulative wealth function, and finally, we show that an immune response favoring the chronification is evolutionary advantageous at the same time.

Effects of dual plasma molecular adsorption system on liver function, electrolytes, inflammation, and immunity in patients with chronic severe hepatitis.

BACKGROUND: To investigate the effects of dual plasma molecular adsorption system (DPMAS) on the liver function, electrolytes, inflammation, and immunity in patients with chronic severe hepatitis (CSH). METHODS: Total of 162 patients with CSH treated in our hospital from March 2016 to December 2018 were enrolled and equally randomly divided into control group (n = 81) and observation group (n = 81). The patients in control group were treated with plasma exchange, while those in observation group were additionally treated with DPMAS based on the treatment in control group. The liver function, electrolytes, inflammation, and immunity were evaluated and compared between the two groups. RESULTS: After treatment, the liver function indexes in observation group were significantly favorable compared with those in control group, with the reduction in TBIL, DBIL, ALT, and rise of CHE levels (P < 0.05). The levels of K+ , Na+ , Cl- , and Ca2+ in both groups were significantly improved after treatment (P < 0.05), although there were no significant differences between the two groups (P > 0.05). The levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in both groups declined after treatment compared with those before treatment, and those levels in observation group were higher than that in control group (P < 0.05). After treatment, the levels of cluster of differentiation 3+ (CD3+ ), CD4+ , and CD4+ /CD8+ were higher in observation group than those in control group, with decreasing level of CD8+ (P < 0.05). CONCLUSION: Dual plasma molecular adsorption system can effectively improve the liver function, effectively correct the electrolyte disorders, reduce the inflammatory response, and adjust the immunity in patients with CSH.

Mucosal-Associated Invariant T Cells in Chronic Inflammatory Liver Disease.

The broadening field of microbiome research has led to a substantial reappraisal of the gut-liver axis and its role in chronic liver disease. The liver is a central immunologic organ that is continuously exposed to food and microbial-derived antigens from the gastrointestinal tract. Mucosal-associated invariant T (MAIT) cells are enriched in the human liver and can be activated by inflammatory cytokines and microbial antigens. In chronic inflammatory liver disease, MAIT cells are depleted suggesting an impaired MAIT cell-dependent protection against bacterial infections.

Systemic inflammation and immune cell phenotypes are associated with neuro-psychiatric symptoms in patients with chronic inflammatory liver diseases.

BACKGROUND & AIMS: Chronic inflammatory liver diseases are frequently associated with neuropsychiatric and cognitive dysfunctions. We hypothesized that symptomatic patients may show altered levels of soluble inflammatory mediators (SIMs) as well as changes in immune cell phenotypes. METHODS: A comprehensive immune-phenotyping including investigation of 50 SIMs as well as ex-vivo phenotypes of NK-cells, CD3+, CD4+, CD8+ and regulatory T cells in 40 patients with viral and autoimmune chronic liver diseases was performed. The patients' cognitive functions were assessed using an extensive battery of neuropsychological testing. RESULTS AND CONCLUSION: Overall, our data indicate that while SIMs are significantly up-regulated, NK- and T-cells are less-activated in patients with neuropsychiatric symptoms accompanying chronic inflammatory liver diseases compared to patients without these symptoms. Moreover, HCV patients showed a unique pattern of immune alterations as compared to patients with HBV, autoimmune hepatitis and primary biliary cirrhosis. These findings hint towards potential mechanisms explaining these symptoms in patients with chronic liver diseases.

Functional role of CCL5/RANTES for HCC progression during chronic liver disease.

BACKGROUND & AIMS: During liver inflammation, triggering fibrogenesis and carcinogenesis immune cells play a pivotal role. In the present study we investigated the role of CCL5 in human and in murine models of chronic liver inflammation leading to hepatocellular carcinoma (HCC) development. METHODS: CCL5 expression and its receptors were studied in well-defined patients with chronic liver disease (CLD) and in two murine inflammation based HCC models. The role of CCL5 in inflammation, fibrosis, tumor initiation and progression was analyzed in different cell populations of NEMOΔhepa/CCL5-/- animals and after bone marrow transplantation (BMT). For therapeutic intervention Evasin-4 was injected for 24h or 8weeks. RESULTS: In CLD patients, CCL5 and its receptor CCR5 are overexpressed - an observation confirmed in the Mdr2-/- and NEMOΔhepa model. CCL5 deletion in NEMOΔhepa mice diminished hepatocyte apoptosis, compensatory proliferation and fibrogenesis due to reduced immune cell infiltration. Especially, CD45+/Ly6G+ granulocytes, CD45+/CD11b+/Gr1.1+/F4/80+ pro-inflammatory monocytes, CD4+ and CD8+ T cells were decreased. One year old NEMOΔhepa/CCL5-/- mice displayed smaller and less malignant tumors, characterized by reduced proliferative capacity and less pronounced angiogenesis. We identified hematopoietic cells as the main source of CCL5, while CCL5 deficiency did not sensitise NEMOΔhepa hepatocytes towards TNFα induced apoptosis. Finally, therapeutic intervention with Evasin-4 over a period of 8weeks ameliorated liver disease progression. CONCLUSION: We identified an important role of CCL5 in human and functionally in mice with disease progression, especially HCC development. A novel approach to inhibit CCL5 in vivo thus appears encouraging for patients with CLD. LAY SUMMARY: Our present study identifies the essential role of the chemoattractive cytokine CCL5 for liver disease progression and especially hepatocellular carcinoma development in men and mice. Finally, the inhibition of CCL5 appears to be encouraging for therapy of human chronic liver disease.

Set7 facilitates hepatitis C virus replication via enzymatic activity-dependent attenuation of the IFN-related pathway.

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, usually resulting in persistent infection involving hepatic steatosis, cirrhosis, and hepatocellular carcinoma via escape of the host's immune response. Set7 is a lysine-specific methyltransferase that is involved in gene regulation and virus replication. However, the mechanism underlying the immune evasion between HCV and Set7 is not well understood. In this study, we observed that the expression of Set7 in Huh7.5.1 cells was upregulated by HCV infection, and high levels of Set7 expression were also found in the sera, PBMCs, and liver tissue of HCV patients relative to healthy individuals. Further investigation showed that Set7 enhanced HCV replication in an enzymatic activity-dependent manner. Moreover, our data showed that Set7 decreased the expression of virus-induced IFN and IFN-related effectors, such as dsRNA-activated protein kinase and 2',5'-oligoadenylate synthetase. Further investigation suggested that Set7 suppressed the endogenous IFN expression by reducing the nuclear translocation of IFN regulatory factor 3/7 and the p65 subunit of NF-κB and reduced IFN-induced dsRNA-activated protein kinase and 2',5'-oligoadenylate synthetase via attenuation of the phosphorylation of STAT1 and STAT2. Additionally, IFN receptors, including IFNAR1 and IFNAR2, which are located upstream of the JAK/STAT pathway, were reduced by Set7. Taken together, our results reveal that Set7 facilitates HCV replication through the attenuation of IFN signaling pathways and IFN-related effectors.

Chronic Hepatitis Due to Gluten Enteropathy - a Case Report.

BACKGROUND: Celiac disease is an immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals. CASE DESCRIPTION: A 45-year-old Caucasian woman presented with severe iron-deficient anemia and mild elevation of liver enzymes. Upper endoscopy was done in the context of evaluation of anemia, which revealed reduced duodenal folds and mosaic pattern of the mucosa, but also grade II esophageal varices and portal hypertensive gastropathy. Duodenal biopsy showed total villous atrophy, diffuse mainly lymphocytic infiltrate, presence of intra-epithelial lymphocytes. Serology test confirmed celiac disease by the typical pattern of high titer positive IgA and IgG antibodies to tissue transglutaminase. Liver biopsy was performed for staging and etiological evaluation, because laboratory screening ruled out common viral, metabolic and autoimmune liver disease. Liver morphology was consistent with chronic hepatitis without findings for extensive fibrosis. Our patient had poor dietary compliance, so we failed to established improvement of liver enzymes and resolution of anemia during follow-up. CONCLUSIONS: We would like to stress on the diverse clinical manifestations of celiac disease and the importance of serologic screening with antibodies to tissue transglutaminase in differential diagnosis of chronic liver disease.

Immunotherapy in hepatocellular carcinoma: Primed to make a difference?

Advanced hepatocellular carcinoma (HCC) carries a dismal prognosis and the current treatment is limited to sorafenib, an agent with modest benefit. Preclinical data have indicated that several immunologic mechanisms are at play to promote HCC development and growth while impairing effective antitumor immune surveillance. Several novel approaches geared toward manipulating the immune response to HCC have suggested a therapeutic benefit in early-stage clinical trials, indicating a real potential to augment tumor-specific immunity and improve outcomes in patients with this disease. In the current study, the authors reviewed the barriers to an effective immune response against HCC and contemporary clinical investigations that may be "primed" to alter the natural history of HCC.

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.

Novel inflammatory biomarkers of portal pressure in compensated cirrhosis patients.

UNLABELLED: The rationale for screening inflammatory serum biomarkers of the hepatic vein pressure gradient (HVPG) is based on the fact that portal hypertension is pathogenically related to liver injury and fibrosis, and that in turn these are associated with the activation of inflammatory pathways. This was a nested cohort study in the setting of a randomized, clinical trial to assess the development of gastroesophageal varices (GEV) (N Engl J Med 2005;353:2254). Patients had cirrhosis and portal hypertension but did not have GEV. A total of 90 patients who had baseline day-1 sera available were enrolled in the present study. The objective of this study was to determine whether inflammatory biomarkers in conjunction with clinical parameters could be used to develop a predictive paradigm for HVPG. The correlations between HVPG and interleukin (IL)-1ß (P=0.0052); IL-1R-α (P=0.0085); Fas-R (P=0.0354), and serum VCAM-1 (P=0.0007) were highly significant. By using multivariate logistic regression analysis and selected parameters (transforming growth factor beta [TGFß]; heat shock protein [HSP]-70; at-risk alcohol use; and Child class B) we could exclude HVPG ≥ 12 mmHg with 86% accuracy (95% confidence interval [CI]: 67.78 to 96.16%) and the sensitivity was 87.01% (95% CI: 69.68 to 96.34%). Therefore, the composite test could identify 86% of compensated cirrhosis patients with HVPG below 12 mmHg and prevent unnecessary esophagogastroduodenoscopy with its associated morbidity and costs in these patients. Our diagnostic test was not efficient in predicting HVPG ≥ 12 mmHg. CONCLUSION: A blood test for HVPG could be performed in cirrhosis patients to prevent unnecessary esophagogastroduodenoscopy.

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.

Transitioning from Idiopathic to Explainable Autoimmune Hepatitis.

Autoimmune hepatitis lacks an identifiable cause, and its diagnosis requires the exclusion of etiologically defined diseases that resemble it. Insights into its pathogenesis are moving autoimmune hepatitis from an idiopathic to explainable disease, and the goal of this review is to describe the insights that are hastening this transition. Two types of autoimmune hepatitis are justified by serological markers, but they also have distinctive genetic associations (DRB1 and DQB1 genes) and autoantigens. DRB1 alleles are the principal susceptibility factors in white adults, and a six amino acid sequence encoded in the antigen-binding groove of class II molecules of the major histocompatibility complex can influence the selection of autoantigens. Polymorphisms, including variants of SH2B3 and CARD10 genes, may affect immune reactivity and disease severity. The cytochrome mono-oxygenase, CYP2D6, is the autoantigen associated with type 2 autoimmune hepatitis, and it shares homologies with multiple viruses that might promote self-intolerance by molecular mimicry. Chemokines, especially CXCL9 and CXCL10, orchestrate the migration of effector cells to sites of injury and are associated with disease severity. Cells of the innate and adaptive immune responses promote tissue damage, and possible deficiencies in the number and function of regulatory T cells may facilitate the injurious process. Receptor-mediated apoptosis is the principal mechanism of hepatocyte loss, and cell-mediated and antibody-dependent mechanisms of cytotoxicity also contribute. Insights that explain autoimmune hepatitis will allow triggering exogenous antigens to be characterized, risk management to be improved, prognostic indices to be refined, and site-specific therapeutic interventions to emerge.