Type I Interferon Elevates Co-Regulatory Receptor Expression on CMV- and EBV-Specific CD8 T Cells in Chronic Hepatitis C

The novel immune landscape of immune-checkpoint blockade in EBV-associated malignancies

The Epstein-Barr virus (EBV) is a ubiquitous gamma-herpesvirus and a class 1 carcinogen that is closely associated with a series of malignant lymphomas and epithelial cell carcinomas. Although these EBV-related cancers may exhibit different features in clinical symptoms and anatomical sites, they all have a characteristic immune-suppressed tumor immune microenvironment (TIME) that is tightly correlated with an abundance of tumor-infiltrating lymphocytes (TILs) that primarily result from the EBV infection. Overwhelming evidence indicates that an upregulation of immune-checkpoint molecules is a powerful strategy employed by the EBV to escape immune surveillance. While previous studies have mainly focused on the therapeutic effects of PD-1 and CTLA-4 blockades in treating EBV-associated tumors, several novel inhibitory receptors (e.g., CD47, LAG-3, TIM-3, VISTA, and DDR1) have recently been identified as potential targets for treating EBV-associated malignancies (EBVaMs). This review retrospectively summarizes the biological mechanisms used for immune checkpoint evasion in EBV-associated tumors. Its purpose is to update our current knowledge concerning the underlying mechanisms by which an immune checkpoint blockade triggers host antitumor immunity against EBVaMs. Additionally, this review may help investigators to more fully understand the correlation between EBV infection and tumor development and subsequently develop novel therapeutic strategies.

Imprinted immune abnormalities in liver transplant patients cured of hepatitis C with antiviral drugs

Chronic HCV infection induces interferon and dysregulates immune responses through inflammation and chronic antigenic stimulation. Antiviral drugs can cure HCV, providing a unique opportunity to examine the immunological restoration that does and does not occur when a chronic viral infection is eradicated. We quantified blood cytokines levels and used mass cytometry to immunophenotype peripheral blood mononuclear cells before and after HCV cure in 2 groups of patients and controls. At baseline, serum interferon α and soluble CD163 (a macrophage product) were elevated in both liver transplant and nonliver transplant patients compared to controls; the frequencies of several peripheral blood mononuclear cell populations differed from controls; and programmed death protein 1-positivity was increased in nearly all T cell subsets. Many abnormalities persisted after HCV cure, including elevated programmed death protein 1 expression on CD4 naïve and central memory T cells, elevated soluble CD163, and expansion of the plasmablast/plasma cell compartment. Several myeloid-lineage subsets, including Ag-presenting dendritic cells, remained dysregulated. In mechanistic studies, interferon α treatment increased programmed death protein 1 on human T cells and increased T cell receptor signaling. The data identify immunological abnormalities that persist after curative HCV treatment. Before cure, high levels of interferon α may stimulate programmed death protein 1 expression on human T cells, causing persistent functional changes.

Lasting differential gene expression of circulating CD8 T cells in chronic HCV infection with cirrhosis identifies a role for Hedgehog signaling in cellular hyperfunction

Background

The impact of chronic hepatic infection on antigen non-specific immune cells in circulation remains poorly understood. We reported lasting global hyperfunction of peripheral CD8 T cells in HCV-infected individuals with cirrhosis. Whether gene expression patterns in bulk CD8 T cells are associated with the severity of liver fibrosis in HCV infection is not known.

Methods

RNA sequencing of blood CD8 T cells from treatment naïve, HCV-infected individuals with minimal (Metavir F0-1 ≤ 7.0 kPa) or advanced fibrosis or cirrhosis (F4 ≥ 12.5 kPa), before and after direct-acting antiviral therapy, was performed. CD8 T cell function was assessed by flow cytometry.

Results

In CD8 T cells from pre-DAA patients with advanced compared to minimal fibrosis, Gene Ontology analysis and Gene Set Enrichment Analysis identified differential gene expression related to cellular function and metabolism, including upregulated Hedgehog (Hh) signaling, IFN-α, -γ, TGF-β response genes, apoptosis, apical surface pathways, phospholipase signaling, phosphatidyl-choline/inositol activity, and second-messenger-mediated signaling. In contrast, genes in pathways associated with nuclear processes, RNA transport, cytoskeletal dynamics, cMyc/E2F regulation, oxidative phosphorylation, and mTOR signaling, were reduced. Hh signaling pathway was the top featured gene set upregulated in cirrhotics, wherein hallmark genes GLI1 and PTCH1 ranked highly. Inhibition of Smo-dependent Hh signaling ablated the expression of IFN-γ and perforin in stimulated CD8 T cells from chronic HCV-infected patients with advanced compared to minimal fibrosis. CD8 T cell gene expression profiles post-DAA remained clustered with pre-DAA profiles and disparately between advanced and minimal fibrosis, suggesting a persistent perturbation of gene expression long after viral clearance.

Conclusions

This analysis of bulk CD8 T cell gene expression in chronic HCV infection suggests considerable reprogramming of the CD8 T cell pool in the cirrhotic state. Increased Hh signaling in cirrhosis may contribute to generalized CD8 T cell hyperfunction observed in chronic HCV infection. Understanding the lasting nature of immune cell dysfunction may help mitigate remaining clinical challenges after HCV clearance and more generally, improve long term outcomes for individuals with severe liver disease.

Immunological scars after cure of hepatitis C virus infection: Long-HepC?

Hepatitis C virus (HCV) infection provides a unique opportunity to study the effects of spontaneous or treatment-induced viral elimination on the human immune system. Twenty to 50% of patients with acute HCV infection spontaneously clear the virus, which is related to the quality of the individual's immune response, while the chronic infection is associated with an altered and impaired immune response. Direct-acting antiviral agents are now available that provide sustained viral elimination in more than 95% of patients with chronic HCV infection. Viral elimination leads to a decrease in disease sequelae such as cirrhosis and hepatocellular carcinoma, and extrahepatic manifestations also improve. However, some patients may still experience long-term complications, and viral elimination does not protect against HCV reinfection. This review addresses the question of whether the altered and impaired immune response caused by HCV normalizes after viral elimination and if this may affect the long-term clinical course after HCV cure.

Distinct Immune Imprints of Post-Liver Transplantation Hepatitis C Persist Despite Viral Clearance

Recurrence or de novo infection of hepatitis C virus (HCV) after liver transplantation (LT) has been associated with progressive graft hepatitis that can be improved by treatment with novel direct-acting antivirals. Cases of rejection episodes have been described during and after HCV treatment. The evolution of innate and adaptive immune response during and after cure of HCV LT is unknown. We studied 74 protein biomarkers in the plasma of LT patients receiving antiviral therapy. In addition, deep immune phenotyping of both the myeloid and lymphoid immune cell subsets in peripheral blood mononuclear cells was performed. We found that LT patients with active HCV infection displayed distinct alterations of inflammatory protein biomarkers, such as C-X-Cmotif chemokine 10 (CXCL10), caspase 8, C-C motif chemokine 20 (CCL20), CCL19, interferon γ, CUB domain-containing protein 1 (CDCP1), interleukin (IL)-18R1, CXCL11, CCL3, IL8, IL12B, tumor necrosis factor-beta, CXCL6, osteoprotegerin, IL10, fms-related tyrosine kinase 3 ligand, hepatocyte growth factor, urokinase-type plasminogen activator, neurotrophin-3, CCL4, IL6, tumornecrosis factor receptor superfamily member 9, programmed death ligand 1, IL18, and monocyte chemotactic protein 1, and enrichment of peripheral immune cell subsets unlike patients without HCV infection who received transplants. Interestingly, patients who cleared HCV after LT did not normalize the altered inflammatory milieu nor did the peripheral immune cell subsets normalize to what would be seen in the absence of HCV recurrence. Overall, these data indicate that HCV-specific imprints on inflammatory analytes and immune cell subsets after LT are not completely normalized by therapy-induced HCV elimination. This is in line with the clinical observation that cure of HCV after LT did not trigger rejection episodes in many patients.

On the impact of hepatitis C virus and heterologous immunity on alloimmune responses following liver transplantation

Virus-induced heterologous immunity is considered a barrier to transplantation tolerance. Yet, hepatitis C (HCV)-infected liver transplant (LT) patients occasionally achieve operational tolerance. We investigated the mechanisms through which HCV infection modulates donor-specific T cell responses following LT and the influence of HCV eradication. We generated T cell lines from HCV-infected LT and non-LT patients before and after HCV eradication and quantified alloreactive responses using cell lines expressing single-HLA class-I antigens in the presence/absence of PD-1/CTLA-4 blockade. HCV-specific CD8+ T cells cross-reacted with allogeneic class-I HLA molecules. HCV-positive LT recipients exhibited a higher proportion of CD8+ T cells coexpressing inhibitory receptors (PD-1/CTLA4) than HCV-negative LT, and their expression correlated with CXCL10 plasma levels. This resulted in decreased antidonor and third-party proliferative responses, which were significantly reversed by HCV eradication. PD-1/CTLA-4 blockade increased the proportion of HCV-specific CD8+ T cells reacting against donor only before viral clearance. In conclusion, HCV infection results in the generation of HCV-specific CD8+ T cells capable of reacting against allogeneic HLA molecules. Following LT, this results in a PD-1/CTLA4-dependent decrease in alloimmune responses. Our findings challenge the notion that heterologous immunity is necessarily detrimental in LT and provide an explanation for the association between HCV eradication and immune-mediated allograft damage.

Chronic genotype 1 hepatitis C along with cirrhosis drives a persistent imprint in virus-specific CD8+ T cells after direct-acting antiviral therapies

Chronic hepatitis C virus (HCV) infection impairs HCV CD8⁺ T-cell responses, while it could influence immune responses towards unrelated viruses/vaccines (e.g. cytomegalovirus, CMV, and influenza, Flu). The aim of our study was to delineate whether restoration of these virus-specific CD8⁺ T cells occurs after direct-acting antiviral (DAA) therapies and particularly in patients with cirrhosis. We performed longitudinal analysis (baseline, week 4, follow-up [FU] 12 and FU48) of virus-specific CD8⁺ T cells by multicolour flow cytometry in HCV-cirrhotic patients undergoing DAA therapy (n = 26) after in vitro expansion with immunodominant HCV, CMV and Flu epitopes restricted by HLA-A*02. HCV noncirrhotic patients (n = 9) and healthy individuals (n = 10) served as controls. We found that the proliferative capacity of HCV-specific CD8⁺ T cells increased from baseline up to FU48 in a significant proportion of cirrhotic and noncirrhotic patients. Nevertheless, these cells remained poor cytokine producers in both patient groups, regardless of the down-regulation of inhibitory co-regulatory receptors in HCV-cirrhotic patients at FU48. Likewise, high expression levels of these exhaustion markers were detected in CMV-/Flu-specific CD8⁺ T cells in HCV-cirrhotic patients at all time points, albeit without affecting their proliferative capacity or cytokine production. We conclude that DAA therapies induce restoration of the proliferative capacity of HCV-specific CD8⁺ T cells. However, these cells remain phenotypically and functionally impaired. Contrarily, the 'exhausted' phenotype in CMV-/Flu-specific CD8⁺ T cells in HCV-cirrhotic patients did not associate with their functions. Larger studier with longer follow-up may elucidate whether this complex interplay influences the outcome of cirrhotic patients.

Reversal of Immunity After Clearance of Chronic HCV Infection-All Reset?

Chronic viral infections cause deterioration of our immune system. However, since persistent infections rarely can be eliminated, the reinvigoration capacity of an exhausted immune system has remained largely elusive. Chronic hepatitis C virus (HCV) infection can since some years be effectively cured with novel direct acting antiviral agents. Thus, it is now possible to study reversal of immunity in patients that are cured from a long-lasting chronic infection. We here highlight recent developments in the analysis of various immune cell populations during and after clearance of HCV infection. Surprisingly, whereas reinvigoration of certain immune traits clearly can be seen, many features of immune exhaustion persist over time after viral elimination. Thus, a long-term chronic insult might result in irreversible damage to our immune system. This will be important to consider in therapeutic vaccination efforts against chronic infection and in the development of immunotherapy based strategies against cancer.

Elimination of hepatitis C virus has limited impact on the functional and mitochondrial impairment of HCV-specific CD8+ T cell responses

BACKGROUND & AIMS

Hepatitis C virus (HCV)-specific CD8+ T cells are functionally impaired in chronic hepatitis C. Even though HCV can now be rapidly and sustainably cleared from chronically infected patients, the repercussions of HCV clearance on virus-specific CD8+ T cells remain elusive. Here, we aimed to investigate if HCV clearance by direct-acting antivirals (DAAs) could restore the functionality of exhausted HCV-specific CD8+ T cell responses.

METHODS

HCV-specific CD8+ T cells in peripheral blood were obtained from 40 patients with chronic HCV infection, during and 6 months following IFN-free DAA therapy. These cells were analyzed for comprehensive phenotypes, proliferation, cytokine production, mitochondrial fitness and response to immune-checkpoint blockade.

RESULTS

We show that, unlike activation markers that decreased, surface expression of multiple co-regulatory receptors on exhausted HCV-specific CD8+ T cells remained unaltered after clearance of HCV. Likewise, cytokine production by HCV-specific CD8+ T cells remained impaired following HCV clearance. The proliferative capacity of HCV multimer-specific CD8+ T cells was not restored in the majority of patients. Enhanced in vitro proliferative expansion of HCV-specific CD8+ T cells during HCV clearance was more likely in women, patients with low liver stiffness and low alanine aminotransferase levels in our cohort. Interestingly, HCV-specific CD8+ T cells that did not proliferate following HCV clearance could preferentially re-invigorate their proliferative capacity upon in vitro immune-checkpoint inhibition. Moreover, altered mitochondrial dysfunction exhibited by exhausted HCV-specific CD8+ T cells could not be normalized after HCV clearance.

CONCLUSION

Taken together, our data implies that exhausted HCV-specific CD8+ T cells remain functionally and metabolically impaired at multiple levels following HCV clearance in most patients with chronic hepatitis C. Our results might have implications in cases of re-infection with HCV and for HCV vaccine development.

LAY SUMMARY

Direct-acting antiviral therapy results in cure of hepatitis C virus (HCV) in almost all treated patients. However, the impacts of HCV cure on immune responses remain controversial. Whether immune responses to HCV recover is important in cases of re-exposure, or for the resolution of extrahepatic manifestations. The main finding of our study was that HCV-specific T cells remain functionally impaired despite HCV clearance. This finding could explain the fact that HCV cure does not lead to protective immunity and that re-infections have frequently been observed.

Direct-Acting Antiviral Treatment of HCV Infection Does Not Resolve the Dysfunction of Circulating CD8+ T-Cells in Advanced Liver Disease

Chronic hepatitis C virus (HCV) infection disrupts immune functions, including that of cytotoxic CD8⁺ T-cells which are important mediators of immune response. While HCV cure aims to eliminate long term sequelae of infection, whether direct-acting antiviral (DAA) treatment results in immune reconstitution remains unclear. We and others have reported generalized CD8⁺ T-cell dysfunction in chronic HCV infection and our research suggests that the degree of liver damage is a factor in this process. Our recent research indicates that liver fibrosis is not readily reversed after DAA-mediated clearance of chronic HCV infection. We therefore examined the function of circulating CD8⁺ T-cell subsets in chronic HCV infection in the context of liver fibrosis severity, determined by ultrasound elastography and Metavir F-score system. We observed progressive shifts in CD8⁺ T-cell subset distribution in HCV-infected individuals with advanced liver fibrosis (F4) compared to minimal fibrosis (F0-1) or uninfected controls, and this remained unchanged after viral cure. Impaired CD8⁺ T-cell function was observed as a reduced proportion of CD107⁺ and perforin⁺ late effector memory cells in HCV⁺(F4) and HCV⁺(F0-1) individuals, respectively. In HCV⁺(F4) individuals, nearly all CD8⁺ T-cell subsets had an elevated proportion of perforin⁺ cells while naïve cells had increased proportions of IFN-γ⁺ and CD107⁺ cells. These exaggerated CD8⁺ T-cell activities were not resolved when evaluated 24 weeks after completion of DAA therapy and HCV clearance. This was further supported by sustained, high levels of cell proliferation and cytolytic activity. Furthermore, DAA therapy had no effect on elevated concentrations of systemic inflammatory cytokines and decreased levels of inhibitory TGF-β in the plasma of HCV⁺(F4) individuals, suggesting HCV infection and advanced liver disease result in a long-lasting immune activating microenvironment. These data demonstrate that in chronic HCV infection, liver fibrosis severity is associated with generalized hyperfunctional CD8⁺ T-cells, particularly with perforin production and cytotoxicity, and this persists after viral clearance. Whether DAA therapy will eliminate other related long-term sequelae in HCV⁺(F4) individuals remains an important research question.

HCC Immune Surveillance and Antiviral Therapy of Hepatitis C Virus Infection

OBJECTIVE

HCV clearance by current antiviral therapies improves clinical outcomes but falls short in eliminating the risk for hepatocellular carcinoma (HCC) emergence. As the HCC immune surveillance establishment is vital for the control of neoplastic development and growth, we investigated its correlation with on-/post-treatment HCC emergence, and further analyzed the influence of viral eradication on this setup in patients with HCV-related liver cirrhosis.

DESIGN

PBMC isolated at baseline and longitudinally during therapy were analyzed for tumor-associated antigen (TAA)-specific CD8+ T cell responses against glypican-3 overlapping peptides in vitro using high-definition flow cytometry. Multianalyte profiling of fifty soluble inflammatory mediators (SIM) in the plasma was also performed using Luminex-based multiplex technology.

RESULTS

Cirrhosis patients were characterized by an altered profile of distinct SIMs at baseline. At this time point, immune-surveilling T cells targeting specific HCC-associated antigens were readily detectable in HCV-free cirrhosis patients whilst being rather weak in such patients who further developed HCC upon virus eradication. Therapy-induced cure of HCV infection analogously reduced the strength of the prevailing HCC immune surveillance machinery, particularly by CD8+ T cells in cirrhosis patients. These results were further validated by T cell reactivities to six immuno-dominant HCC-associated HLA-A2-restricted epi-topes. Further, we demonstrated that this phenomenon was likely orchestrated by alterations in SIMs - with evidence of IL-12 being a major culprit.

CONCLUSION

Given the relationship between the baseline HCC-specific immune surveilling T cell responses and therapy-associated HCC emergence, and the impact of HCV clearance on its strength and magnitude, we recommend a continued HCC screening in cirrhotic HCV patients despite HCV resolution.

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.

Viral dominance patterns in chronic hepatitis delta determine early response to interferon alpha therapy

Chronic hepatitis D is caused by coinfection of hepatitis B and hepatitis D virus. While HDV is the dominant virus over HBV in the majority of cases, mechanisms and consequences of viral dominance are largely unknown. We aimed to investigate associations between viral dominance patterns and patients' characteristics and inflammatory features; 109 HDV-infected patients treated with PEG-IFNa-2α within the international multicentre, prospective HIDIT-2 trial were studied. Patients were classified as D- or B-dominant if the viral load of one virus exceeded that of the other virus by more than 1log₁₀ . Otherwise, no viral dominance (ND) was described. We used Luminex-based multiplex technology to study 50 soluble immune mediators (SIM) in pretreatment samples of 105 HDV RNA-positive patients. Dominance of HDV was evident in the majority (75%) of cases. While only 7% displayed B-dominance, 17% showed nondominance. D-dominance was associated with downregulation of 4 interleukins (IL-2ra, IL-13, IL-16 and IL-18) and 5 chemokines/cytokines (CTACK (CCL27), MCP-1 (CCL2), M-CSF, TRAIL and ICAM-1) while no analyte was increased. In addition, D-dominance could be linked to a delayed HDV RNA response to pegylated interferon as patients with B-dominance or nondominance showed higher early HDV RNA responses (61% at week 12) than D-dominant patients (11%; P < .001). In conclusion, this study revealed unexpected effects of viral dominance on clinical and immunological features in chronic hepatitis delta patients. Individualizing PEG-IFNa-2α treatment duration should consider viral dominance. Overall, our findings suggest an activated but exhausted IFN system in D-dominant patients.

The 7th Canadian Symposium on Hepatitis C Virus: “Toward Elimination of HCV: How to Get There”

Hepatitis C virus (HCV) affects more than 268,000 people in Canada. Both the Canadian Institutes of Health Research and the Public Health Agency of Canada recognize the significant impact of HCV-related liver diseases and supported the establishment of a national hepatitis C research network, the Canadian Network on Hepatitis C (CanHepC). Interferon-free direct-acting antiviral regimens lead to more than 95% cure rates in almost all patients with well-tolerated short-course therapy. However, the goal of eliminating HCV in Canada cannot be fully realized until we overcome the financial, geographical, cultural, and social barriers that affect the entire continuum of care from diagnosis and linkage to care through treatment and prevention of new and reinfections. Current practices face difficulties in reversing HCV-induced immunological defects, expanding treatment to neglected communities, combating reinfections and co-infections, and expediting and simplifying the processes of diagnosis and treatment. As part of its knowledge translation mandate, CanHepC has organized the annual Canadian symposium on hepatitis C since 2012. The theme of this year’s symposium, “Toward Elimination of HCV: How to Get There?” focused on identifying the requirements of our therapeutic strategies and health policies for the elimination of HCV in Canada.

Epstein-Barr virus- and cytomegalovirus-specific immune response in patients with brain cancer

Background

Patients with brain tumor or pancreatic cancer exhibit the poorest prognosis, while immune fitness and cellular immune exhaustion impacts their survival immensely. This work identifies differences in the immune reactivity to the common human pathogens cytomegalovirus (CMV) and Epstein–Barr virus (EBV) between patients with brain tumor in comparison to those with pancreatic cancer and healthy individuals.

Methods

We characterized the humoral and cellular immune responses of patients with brain tumor or pancreatic cancer to cytomegalovirus structural protein pp65 (CMV-pp65) as well as Epstein–Barr nuclear antigen-1 (EBNA-1) by whole-blood assay and ELISA.

Results

Anti-CMV-pp65 plasma immunoglobulin gamma (IgG) titers were significantly lower in patients with brain tumor compared to healthy donors and patients with pancreatic cancer. Among the responding patients with GBM, those with a weak anti-CMV IgG response also had a decreased median overall survival (p = 0.017, 667 vs 419 days) while patients with brain tumor showed a generally suppressed anti-CMV immune-reactivity. Patients with brain tumor exhibited a significantly lower interferon gamma (IFNγ) response to EBNA-1 and CMV-pp65 compared to patients with pancreatic cancer or healthy donors. This antigen-specific response was further amplified in patients with brain tumor upon conditioning of whole blood with IL-2/IL-15/IL-21. Exclusively in this setting, among the responding patients with GBM, those exhibiting a EBV-specific cellular immune response above the median also displayed an increased median overall survival pattern compared to weak responders (753 vs 370 days, p < 0.001).

Conclusions

This report provides (i) a fast and easy assay using common viral antigens and cytokine stimulation to screen for immune fitness/exhaustion of patients with brain tumor in comparison to pancreatic cancer and healthy individuals and (ii) EBV/CMV-induced IFNγ production as a potential marker of survival in patients with brain tumor.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1557-9) contains supplementary material, which is available to authorized users.

Cardiovascular Involvement in Chronic Hepatitis C Virus Infections - Insight from Novel Antiviral Therapies

Whereas statistical association of hepatitis C virus (HCV) infection with cardiomyopathy is long known, establishment of a causal relationship has not been achieved so far. Patients with advanced heart failure (HF) are mostly unable to tolerate interferon (IFN)-based treatment, resulting in limited experience regarding the possible pathogenic role of HCV in this patient group. HCV infection often triggers disease in a broad spectrum of extrahepatic organs, with innate immune and autoimmune pathogenic processes involved. The fact that worldwide more than 70 million patients are chronically infected with HCV illustrates the possible clinical impact arising if cardiomyopathies were induced or aggravated by HCV, resulting in progressive HF or severe arrhythmias. A novel path has been opened to finally resolve the long-standing question of cause-effect relationship between HCV infection and cardiac dysfunction, by the recent development of IFN-free, highly efficient, and well tolerable anti-HCV regimens. The new direct-acting antiviral (DAA) agents are highly virus-specific and lack unspecific side-effects upon cardiac function which have always confounded the interpretation of IFN treatment data. The actual frequency of unexplained HF in chronic HCV infection will be determined from a planned large-scale study. Whereas such patients probably constitute a rather small fraction of all those harboring HCV, they have major clinical relevance. It is not yet known which fraction of these patients will significantly benefit from HCV eradication, but this issue will be addressed now in a prospective study.

Interferon alpha as antiviral therapy in chronic active Epstein-Barr virus disease with interstitial pneumonia - case report

BACKGROUND

Chronic active Epstein-Barr virus (EBV) disease (CAEBV) is defined as a severe, progressive lymphoproliferative disorder associated with active EBV infection persisting longer than 6 months and developing in patients without recognised immunodeficiency. Rarely, interstitial pneumonitis (IP) occurs as a serious complication in CAEBV patients. The standard therapeutic regimen for IP in CAEBV has not yet been defined. Although interferon alpha (IFN-alpha) is known to suppress viral DNA replication by affecting its basal promoter activation process, it is rarely used in CAEBV patients.

CASE PRESENTATION

A 22-year-old Caucasian woman, diagnosed with CAEBV 1.5 years earlier, was admitted to the Immunology Clinic due to a 4-week history of productive cough, fever and general weakness. Cultures of blood, urine and sputum were negative, but EBV DNA copies were found in the sputum, whole blood, isolated peripheral blood lymphocytes as well as in the blood plasma. Cytokine assessment in peripheral blood revealed the lack of IFN-alpha synthesis. Disseminated maculate infiltrative areas in both lungs were observed on a computed tomography (CT) chest scan. The patient was not qualified for the allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to the risk of immunosuppression-related complications of infectious IP. Inhaled (1.5 million units 3 times a day) and subcutaneous (6 million units 3 times a week) IFN-alpha was implemented. To the best of our knowledge, this was the first documented use of inhaled IFN-alpha in a patient with CAEBV and concomitant IP. Patient's status has improved, and she was eventually qualified to allo-HSCT with reduced conditioning. Currently, the patient feels well, no EBV was detected and further regression of pulmonary changes was documented.

CONCLUSIONS

CAEBV should be considered in patients who present with interstitial lung infiltration and involvement of other organs. Although more promising results have been obtained with allo-HSCT, inhaled IFN-alpha may also be a therapeutic option in patients with CAEBV and a concomitant IP.

Interferon-free therapy of chronic hepatitis C with direct-acting antivirals does not change the short-term risk for de novo hepatocellular carcinoma in patients with liver cirrhosis

BACKGROUND

Hepatitis C virus (HCV) clearance with IFN-based therapies reduces the incidence of hepatocellular carcinoma (HCC). There has been some debate if IFN-free therapy with direct-acting antivirals alters the risk for HCC.

AIM

To investigate the HCC incidence in cirrhotic HCV patients who cleared HCV with direct-acting antivirals vs untreated controls.

METHODS

We prospectively monitored 373 patients with chronic hepatitis C who received IFN-free therapies with direct-acting antiviral after January 2014. A retrospective control cohort of untreated cirrhotic patients was recruited out of 3715 HCV patients who were followed at our centre between 2007 and 2013, with similar HCC screening protocols.

RESULTS

158 direct-acting antiviral-treated and 184 control patients with liver cirrhosis were included in this analysis. The groups did not differ in gender and genotype distribution, severity of liver disease and prevalence of diabetes mellitus. Patients were followed up for a median of 440 (range 91-908) and 592 (range 90-1000) days. HCCs developed in 6 and 14 patients during follow-up, resulting in an incidence of 2.90 vs 4.48 HCCs per 100 person-years. In the direct-acting antiviral-treated group, there was no new case of HCC later than 450 days after treatment initiation. In multivariate analysis, higher MELD-Scores and AFP-levels were independently associated with HCC development. Transplant-free patient survival was similar in both groups.

CONCLUSIONS

IFN-free direct-acting antiviral therapy of chronic hepatitis C does not alter the short-term risk for HCC in patients with liver cirrhosis. A reduced HCC incidence may become evident after more than 1.5 years of follow-up.

Wound healing: time to look for intelligent, 'natural' immunological approaches?

There is now good evidence that cytokines and growth factors are key factors in tissue repair and often exert anti-infective activities. However, engineering such factors for global use, even in the most remote places, is not realistic. Instead, we propose to examine how such factors work and to evaluate the reparative tools generously provided by 'nature.' We used two approaches to address these objectives. The first approach was to reappraise the internal capacity of the factors contributing the most to healing in the body, i.e., blood platelets. The second was to revisit natural agents such as whey proteins, (honey) bee venom and propolis. The platelet approach elucidates the inflammation spectrum from physiology to pathology, whereas milk and honey derivatives accelerate diabetic wound healing. Thus, this review aims at offering a fresh view of how wound healing can be addressed by natural means.

Ledipasvir plus sofosbuvir fixed-dose combination for 6 weeks in patients with acute hepatitis C virus genotype 1 monoinfection (HepNet Acute HCV IV): an open-label, single-arm, phase 2 study

BACKGROUND

Early treatment of acute hepatitis C virus (HCV) infection with interferon alfa is highly effective, but can be associated with frequent side-effects. We investigated the safety and efficacy of an interferon-free regimen for treatment of acute HCV infection.

METHODS

In this prospective, open-label, multicentre, single-arm pilot study, we enrolled adults (≥18 years) with acute HCV genotype 1 monoinfection from ten centres in Germany. Patients were given ledipasvir (90 mg) plus sofosbuvir (400 mg) as a fixed-dose combination tablet once daily for 6 weeks. The primary efficacy outcome was the proportion of patients with sustained virological response (defined as undetectable HCV RNA 12 weeks after the end of treatment; other primary outcomes were safety and tolerability of ledipasvir plus sofosbuvir. The primary analysis population consisted of all patients who received at least one dose of study drug. Safety was also assessed in all patients who received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov, number NCT02309918.

FINDINGS

Between Nov 19, 2014, and Nov 10, 2015, we enrolled 20 patients. Median HCV RNA viral load at baseline was 4·04 log₁₀ IU/mL (1·71-7·20); 11 patients were infected with HCV genotype 1a and nine patients with genotype 1b. All patients achieved a sustained virological response 12 weeks after the end of treatment (20 [100%] of 20 patients). Treatment was well tolerated; there were no drug-related serious adverse events. Up to 12 weeks after treatment, 22 possible or probable drug-related adverse events were reported. There was one serious adverse event, which was judged unrelated to the study drug; one patient was admitted to hospital for surgery of a ruptured cruciate ligament.

INTERPRETATION

Treatment for 6 weeks with ledipasvir plus sofosbuvir was well tolerated and highly effective in patients with acute HCV genotype 1 monoinfection. Short-duration treatment of acute hepatitis C might prevent the spread of HCV in high-risk populations.

FUNDING

Gilead Sciences, HepNet Study-House/German Liver Foundation, and German Centre for Infection Research (DZIF).

Direct-Acting Antiviral-Induced Hepatitis C Virus Clearance Does Not Completely Restore the Altered Cytokine and Chemokine Milieu in Patients With Chronic Hepatitis C

BACKGROUND

 Persistent infection with hepatitis C virus (HCV) causes profound alterations of the cytokine and chemokine milieu in peripheral blood. However, it is unknown to what extend these alterations affect the progression of liver disease and whether HCV clearance normalizes soluble inflammatory mediators.

METHODS

 We performed multianalyte profiling of 50 plasma proteins in 28 patients with persistent HCV infection and advanced stages of liver fibrosis or cirrhosis and 20 controls with fatty liver disease. The patients were treated for 24 weeks with sofosbuvir and ribavirin and underwent sampling longitudinally. Ten patients experienced viral relapse after treatment cessation.

RESULTS

 The cytokine and chemokine expression pattern was markedly altered in patients with chronic HCV infection as compared to healthy controls and patients with nonalcoholic steatohepatitis. Distinct soluble factors were associated with the level of fibrosis/cirrhosis, viral replication, or treatment outcome. The baseline expression level of 10 cytokines distinguished patients with a sustained viral response from those who experienced viral relapse. While the majority of upregulated analytes declined during and after successful therapy, HCV clearance did not lead to a restoration of parameters that were suppressed.

CONCLUSIONS

 Chronic HCV infection appears to disrupt the milieu of soluble inflammatory mediators even after viral clearance. Thus, HCV cure does not lead to complete immunological restitution.

Immune Exhaustion and Transplantation

Exhaustion of lymphocyte function through chronic exposure to a high load of foreign antigen is well established for chronic viral infection and antitumor immunity and has been found to be associated with a distinct molecular program and characteristic cell surface phenotype. Although exhaustion has most commonly been studied in the context of CD8 viral responses, recent studies indicate that chronic antigen exposure may affect B cells, NK cells and CD4 T cells in a parallel manner. Limited information is available regarding the extent of lymphocyte exhaustion development in the transplant setting and its impact on anti-graft alloreactivity. By analogy to the persistence of a foreign virus, the large mass of alloantigen presented by an allograft in chronic residence could provide an ideal setting for exhausting donor-reactive T cells. The extent of T cell exhaustion occurring with various allografts, the kinetics of its development, whether exhaustion is influenced positively or negatively by different immunosuppressants, and the impact of exhaustion on graft survival and tolerance development remains a fertile area for investigation. Harnessing or encouraging the natural processes of exhaustion may provide a novel means to promote graft survival and transplantation tolerance.

SLAM family receptors in normal immunity and immune pathologies

The signaling lymphocytic activation molecule (SLAM) family is a group of six receptors restricted to hematopoietic cells. Most of these receptors are self-ligands, and thus are triggered in the context of interactions between hematopoietic cells. By way of their cytoplasmic domain, SLAM-related receptors associate with the SLAM-associated protein (SAP) family of adaptors, which control the signals and functions of SLAM family receptors. Recent findings have provided new insights into the key roles of SLAM family receptors in normal immunity, their involvement in human diseases and their usefulness as drug targets to treat human malignancies. These data are reviewed herein.

Natural history and treatment of HCV/HIV coinfection: Is it time to change paradigms?

Evidence over the past decades have shown that HIV/HCV coinfected patients did not respond as well to HCV therapy as HCV mono-infected patients. However, these paradigms are being recently reassessed with the improvements of care for HIV and HCV patients. This article reviews these original paradigms and how the new data is impacting upon them. Treatment efficacy now appears comparable for HIV/HCV coinfected and HCV mono-infected patients, while liver fibrosis progression is increasingly similar in optimally managed patients. Additional importance of therapy is directed to drug-drug interactions and the impact of HCV reinfection, as well as the possibility of transmitted drug resistance.