Interferon lambda-3 is not associated with clinical outcome in patients with HCV-induced compensated cirrhosis: a long-term cohort study

Interferon Lambda and Liver Fibrosis

Fibrosis is a highly conserved and coordinated wound healing response to injury. In the liver, injury is promoted by immune effector mechanisms that are common across various disease etiologies and even between organs such as lungs, kidneys, heart, and other organs. Thus, the liver represents a useful model to study inflammation and repair, particularly as it is frequently biopsied in clinical contexts. Currently, strong evidence implicates IFNL3/4 polymorphisms and interferon (IFN)-λ3 levels as determinants of the extent of hepatic inflammation and fibrosis in viral and nonviral liver diseases, as well as in governing the severity of nonhepatotropic viral diseases. Interestingly, IFNL3/4 polymorphisms and IFN-λ3 levels correlate with fibrosis extent in other organs such as the lung and kidney. In this review, we discuss the association between IFN-λ and tissue inflammation and fibrosis in human disease and the potential clinical utility of the findings.

A multicenter study of entecavir vs. tenofovir on prognosis of treatment-naïve chronic hepatitis B in South Korea

BACKGROUND & AIMS

It is currently unclear which antiviral agent, entecavir (ETV) or tenofovir disoproxil fumarate (TDF), is superior for improving prognosis in patients with chronic hepatitis B (CHB). Here, we assessed the ability of these 2 antivirals to prevent liver-disease progression in treatment-naïve patients with CHB.

METHODS

From 2012 to 2014, treatment-naïve patients with CHB who received ETV or TDF as a first-line antiviral agent were recruited from 4 academic teaching hospitals. Patients with decompensated cirrhosis or hepatocellular carcinoma (HCC) at enrollment were excluded. Cumulative probabilities of HCC and death or orthotopic liver transplant (OLT) were assessed.

RESULTS

In total, 2,897 patients (1,484 and 1,413 in the ETV and TDF groups, respectively) were recruited. The annual HCC incidence was not statistically different between the ETV and TDF groups (1.92 vs. 1.69 per 100 person-years [PY], respectively; adjusted hazard ratio [HR] 0.975 [p = 0.852] by multivariate analysis). Propensity score (PS)-matched and inverse probability of treatment weighting (ITPW) analyses yielded similar patterns of results (HR 1.021 [p = 0.884] and 0.998 [p = 0.988], respectively). The annual incidence of death or OLT was not statistically different between the ETV and TDF groups (0.52 vs. 0.53 per 100 PY, respectively; adjusted HR 1.202 [p = 0.451]). PS-matched and ITPW analyses yielded similar patterns of results (HR 1.248 [p = 0.385] and 1.239 [p = 0.360], respectively). These findings were consistently reproduced in patients with compensated cirrhosis (all p >0.05).

CONCLUSIONS

The overall prognosis in terms of HCC and death or OLT was not statistically different between the ETV and TDF groups. Further studies are needed to validate our results.

LAY SUMMARY

It is currently unclear which antiviral agent, entecavir or tenofovir disoproxil fumarate, is superior for improving prognosis in patients with chronic hepatitis B virus infection. In this analysis we found that there was no difference in terms of overall prognosis, including risk of hepatocellular carcinoma, death, or the need for a liver transplant, in patients receiving either antiviral.

Helicobacter Pylori Serology in Relation to Hepatitis C Virus Infection and IL28B Single Nucleotide Polymorphism

The aim of the study was to evaluate the serological rate of Helicobacter pylori (H. pylori) infection in patients with chronic hepatitis C virus (HCV) infection and determine any correlations with liver damage and IL28B single-nucleotide polymorphism (SNP). One hundred eighty-nine patients with chronic HCV infection were included in the study, and H. pylori status was defined based on anti-H. pylori-IgG or anti-CagA-IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Liver damage was assessed using histology or transient elastography. IL28B C/T polymorphism (rs12979860) was evaluated in circulating blood cells using a PCR-based restriction fragment length polymorphism assay. Overall H. pylori serology was positive in 38.1% of our HCV-infected subjects. Among those, the anti-CagA-IgG positivity rate was 43.1% and was within the range of previously described populations of the same region. Highest prevalence of H. pylori was found in patients between 31 and 40 years compared to other age subgroups. The seropositivity rate was higher in the non-cirrhotic group than the cirrhotic one (45.4% vs. 20.0%, p < 0.05). No difference was found in IL28B genotype between H. pylori-positive and -negative cohorts. However, we observed a trend for the lower anti-CagA-IgG expression level in relation to the IL28B T-allele. Our results do not support an association between HCV and H. pylori infection. Whether IL28B SNP has a functional role in modulation of serological response to H. pylori CagA needs further investigation.

Type III Interferons in Hepatitis C Virus Infection

The interferon (IFN)-λ family of type III cytokines includes the closely related interleukin (IL)-28A (IFN-λ2), IL-28B (IFN-λ3), and IL-29 (IFN-λ1). They signal through the Janus kinases (JAK)-signal transducers and activators of transcription pathway and promote an antiviral state by the induction of expression of several interferon-stimulated genes (ISGs). Contrary to type I IFNs, the effect of IFN-λ cytokines is largely limited to epithelial cells due to the restricted pattern of expression of their specific receptor. Several genome-wide association studies have established a strong correlation between polymorphism in the region of IL-28B gene (encoding for IFN-λ3) and both spontaneous and therapeutic IFN-mediated clearance of hepatitis C virus (HCV) infection, but the mechanism(s) underlying this enhanced viral clearance are not fully understood. IFN-λ3 directly inhibits HCV replication, and in vitro studies suggest that polymorphism in the IFN-λ3 and its recently identified overlapping IFN-λ4 govern the pattern of ISGs induced upon HCV infection of hepatocytes. IFN-λ can also be produced by dendritic cells, and apart from its antiviral action on hepatocytes, it can regulate the inflammatory response of monocytes/macrophages, thus acting at the interface between innate and adaptive immunity. Here, we review the current state of knowledge about the role of IFN-λ cytokines in mediating and regulating the immune response during acute and chronic HCV infections.

Host - hepatitis C viral interactions: The role of genetics

Hepatitis C virus (HCV) is a major cause of chronic viral hepatitis that can lead to cirrhosis and hepatocellular carcinoma. Only a minority of patients can clear the virus spontaneously. Elimination of HCV during acute infection correlates with a rapid induction of innate, especially interferon (IFN)-induced genes, and a delayed induction of adaptive immune responses. There is a strong association between genetic variants in the IFNλ (IL28B) locus with the rate of spontaneous clearance. Individuals with the ancestral IFNλ4 allele capable of producing a fully active IFNλ4 are paradoxically not able to clear HCV in the acute phase and develop chronic hepatitis C (CHC) with more than 90% probability. In the chronic phase of HCV infection, the wild-type IFNλ4 genotype is strongly associated with an induction of hundreds of classical type I/type III IFN stimulated genes in hepatocytes. However, the activation of the endogenous IFN system in the liver is ineffective in clearing HCV, and is even associated with impaired therapeutic responses to pegylated (Peg)IFNα containing treatments. While the role of genetic variation in the IFNλ locus to the outcome of CHC treatment has declined, it is clear that variation not only at this locus, but also at other loci, modulate clinically important liver phenotypes, including inflammation, fibrosis progression and the development of hepatocellular cancer. In this review, we summarize current knowledge about the role of genetics in the host response to viral hepatitis and the potential future evolution of knowledge in understanding host-viral interactions.

Is the benefit of treating patients with cirrhosis proven?

Hepatitis C virus (HCV)-related cirrhosis is an extremely heterogeneous pathological condition with a wide spectrum of clinical manifestations, ranging from pre-clinical to compensated and decompensated stages, each of which is characterized by a different clinical outcome. To measure the benefit of a sustained virological response (SVR) with interferon (IFN)-based therapy, several studies have been performed in patients with compensated disease, while only a few have been performed in decompensated disease. Nevertheless, these studies have certain methodological weaknesses that may limit the accuracy of results. Access to new, more effective and safe direct acting antivirals (DAAs) has significantly changed these outcomes, with SVR rates that were not seen previously, making antiviral treatment available to patients with end-stage liver disease. However, the clinical benefit of treating patients with late stage disease is still poorly understood and must be investigated. The existence of a point of no return beyond which a SVR is not beneficial has not yet been determined. All of these issues are discussed in this review.

Multiregion deep sequencing of hepatitis C virus: An improved approach for genetic relatedness studies

Hepatitis C virus (HCV) is a major public health problem that affects more than 180 million people worldwide. Identification of HCV transmission networks is of critical importance for disease control. HCV related cases are often difficult to identify due to the characteristic long incubation period and lack of symptoms during the acute phase of the disease, making it challenging to link related cases to a common source of infection. Additionally, HCV transmission chains are difficult to trace back since viral variants from epidemiologically linked cases are genetically related but rarely identical. Genetic relatedness studies primarily rely on information obtained from the rapidly evolving HCV hypervariable region 1 (HVR1). However, in some instances, the rapid divergence of this region can lead to loss of genetic links between related isolates, which represents an important challenge for outbreak investigations and genetic relatedness studies. Sequencing of multiple and longer sub-genomic regions has been proposed as an alternative to overcome the limitations imposed by the rapid molecular evolution of the HCV HVR1. Additionally, conventional molecular approaches required to characterize the HCV intra-host genetic variation are laborious, time-consuming, and expensive while providing limited information about the composition of the viral population. Next generation sequencing (NGS) approaches enormously facilitate the characterization of the HCV intra-host population by detecting rare variants at much lower frequencies. Thus, NGS approaches using multiple sub-genomic regions should improve the characterization of the HCV intra-host population. Here, we explore the usefulness of multiregion sequencing using a NGS platform for genetic relatedness studies among HCV cases.

Treatment discontinuation with peg-interferon: what to consider

Eradication of chronic hepatitis C virus infection improves the outcome of both liver and extrahepatic-related diseases and interferon-based regimens represented, for years, the standard of care to achieve this goal. Several baseline and on-treatment predictors of response, associated with a lower chance to achieve sustained virological response after interferon-based treatment, were developed. In the past few years, the advent of direct acting antivirals has dramatically modified the landscape of antiviral therapy, leading to an evolution from interferon-based to interferon-free therapies. This review will focus on the usefulness of futility stopping rules that allow the discontinuation of therapy in patients with a reduced chance to obtain sustained virological response if treated with interferon-containing regimens.