Lay Summaries - Volume 66 Issue 6

Lay Summary: The price of Harvoni® has led to restrictions and access limitations in many developing and even developed countries with limited healthcare budgets. Gilead approved generic ledipasvir-sofosbuvir costs far less than Harvoni® and presents a similar cure rate for patients with chronic hepatitis C.
Lay Summary: We show here that hepatitis C virus (HCV) activates natural killer (NK) lymphocytes which, as a consequence, loose their Fc receptor for IgG (CD16), an essential molecule for antibody binding. We show that this occurs through the action of enzymes named metzincins, resulting in altered NK-mediated antibody-dependent killing (ADCC) of target cells. This mechanism may contribute to HCV persistence and may represent a general phenomenon whereby some viruses can escape host’s immune responses.
Lay Summary: In clinical trials, second-generation direct-acting antiviral agents (DAAs) have been shown to cure over 90% of patients chronically infected with the genotype 1 hepatitis C virus and have been better tolerated than previous treatment regimens. However, patients enrolled in clinical trials do not reflect the real patient population encountered in routine practice. The current study, which includes almost 4,000 patients, demonstrates comparable rates of cure with two increasingly used DAA combinations as those observed in the clinical trial environment, confirming that clinical trial findings with DAAs translate into the real-world setting, where patient populations are more diverse and complex.
Lay Summary: To establish a mouse model that supports cccDNA-dependent transcription, a novel tool named HBVcircle, was developed with minicircle technology. HBVcircle formed authentic cccDNA-like molecules in hepatocytes, and supported high levels and persistent HBV replication in vivo. The HBVcircle is a close mimic of cccDNA, and it represents a novel tool for addressing HBV cccDNA related biological questions and for anti-HBV drug discovery.
Lay Summary: Blood fibrosis tests and transient elastography accurately diagnose advanced liver fibrosis in the large population of patients having chronic liver disease, but these non-invasive tests are only currently available in specialized centers. We have developed an algorithm including the easy liver fibrosis test (eLIFT), a new simple and widely available blood test. It is used as a first-line procedure that selects at-risk patients who need further evaluation with the FibroMeterVCTE, an accurate fibrosis test combining blood markers and transient elastography result. This new algorithm, called the eLIFT-FMVCTE, accurately identifies the patients with advanced chronic liver disease who need referral to a specialist, and those with no or mild liver lesions who can remain under the care of their usual physician.
Lay Summary: There is a need to identify surrogate end-points for overall survival in advanced hepatocellular carcinoma. We studied patients from the phase III BRISK trial, comparing brivanib treatment with placebo after sorafenib progression. We demonstrate that objective response is an independent predictor of survival and qualifies as a potential surrogate end-point for overall survival in this patient population.
Lay Summary: The new medications for hepatitis C have excellent cure rates. However, our study shows that in patients with both liver cancer and hepatitis C, they do not achieve these cure rates. Patients with liver cancer are almost 8 times more likely to fail hepatitis C treatment than patients without liver cancer.
Lay Summary: Activation of the nuclear receptor, FXR, leads to the production of a hormone called fibroblast growth factor 19 (FGF19) and subsequently regulation of multiple metabolic processes. Synthetic activators of FXR have been recently approved or are currently in clinical development for treatment of chronic liver diseases, including primary biliary cholangitis (PBC) and non-alcoholic steatohepatitis (NASH). The safety of these activators was partly assessed in mice exposed for prolonged periods of time. However, the results of this study show that mouse FGF15 and human FGF19 exhibit fundamentally different biological activities in mice. This could raise the concern of relying on rodent models for safety assessment of FXR activators. The potential risk of HCC development in patients treated with FXR agonists may need to be monitored.
Lay Summary: Erbin expression is significantly elevated in human hepatocellular carcinoma (HCC) tissue. This elevated expression of Erbin contributes to tumorigenesis of HCC by negatively regulating ERa signaling. However, restoring ERa signaling by inhibiting Erbin expression enhances the sensitivity of HCC cells to tamoxifen treatment, providing a new approach for tamoxifen treatment in HCC.
Lay Summary: Excessive death of hepatocytes is a characteristic of liver injury. A new programmed cell death pathway has been described involving upstream death ligands such as TNF and downstream kinases such as RIPK1. Here, we show that in the presence of LPS liver induced hepatic injury was due to secretion of TNF by liver macrophages, and that RIPK1 acts as a powerful protector of hepatocyte death. This newly identified pathway in the liver may be helpful in the management of patients to predict their risk of developing acute liver failure.
Lay Summary: Prognostic biomarkers are lacking in primary sclerosing cholangitis, hampering patient care and the development of therapy. We have identified inflammatory proteins including calprotectin and IL-8 as important indicators of disease severity and prognosis in bile and serum from patients with primary sclerosing cholangitis.
Lay Summary: Primary biliary cholangitis (PBC) is an autoimmune liver disease, but the causes are unknown. MicroRNAs are molecules known to regulate biological signals. In this study, four microRNAs were identified as being decreased in PBC patients, leading to activation of T cell receptor signalling pathways, involved in inflammation. One particular target, N-Ras, could be an attractive and novel immunotherapeutic option for PBC.
Lay Summary: Bile canaliculi expand and contract in response to the amount of secreted bile, and resistance from the surrounding actin bundles. Further expansion due to bile duct blockade leads to the formation of inward blebs, which carry away excess bile to prevent bile build up in the canaliculi.
Lay Summary: Non-alcoholic fatty liver (NAFL) is the hepatic consequence of metabolic syndrome and can lead to non-alcoholic steatohepatitis (NASH). The current study demonstrated that a specific murine dendritic cell subtype possesses a potent regulatory role to influence the inflammatory milieu of the liver in this process.
Lay Summary: The mucosal addressin cell adhesion molecule 1 (MAdCAM-1) is expressed in livers upon diet-induced non-alcoholic steatohepatitis (NASH). Loss of MAdCAM-1 has beneficial effects regarding the development of NASH - manifested by reduced hepatic oxidative stress and decreased inflammation. In contrast, ß7-Integrin-deficiency results in increased steatohepatitis.
Lay Summary: Macrophages (Greek for “big eaters”) are a frequent non-parenchymal cell type of the liver that ensures homeostasis, antimicrobial defense and proper metabolism. However, liver macrophages consist of different subtypes regarding their ontogeny (developmental origin), differentiation and function. Understanding this heterogeneity and the critical regulation of inflammation, fibrosis and cancer by macrophage subsets opens promising new options for treating liver diseases.