Lay Summaries - Volume 71 Issue 2

Lay Summary: Individuals that are chronically infected with hepatitis B virus (HBV) possess an increased number of immune cells, called natural killer (NK) cells expressing the surface marker KLRG1 in the blood and liver. Here, we demonstrate that these specific NK cells are able to kill activated stellate cells in the liver. Because activated stellate cells contribute to liver scarring, i.e. fibrosis, and subsequent liver dysfunction in individuals with chronic HBV infection, KLRG1+ NK cells are a novel immune cell type that can limit liver scarring.
Lay Summary: We aimed to determine whether direct-acting antivirals (DAAs) significantly improve overall survival in patients with hepatitis C virus-related compensated cirrhosis and a first diagnosis of hepatocellular carcinoma (HCC) which has been successfully treated with curative resection or ablation. Using propensity-score matched patients, we found that DAAs improved overall survival and reduced the risk of hepatic decompensation. However, the risk of HCC recurrence was not significantly reduced.
Lay Summary: We investigated the incidence of hepatocellular carcinoma in HIV/hepatitis B virus-coinfected individuals from a large multi-cohort study in Europe. Over 32,673 patient-years, 60 individuals (1.7%) developed hepatocellular carcinoma. The incidence of hepatocellular carcinoma remained low in patients without cirrhosis, who started on tenofovir disoproxil fumarate when aged <46 years old.
Lay Summary: Rising hepatitis C-related morbidity and mortality is a major public health issue. However, development of highly effective medicines against hepatitis C (called direct-acting antivirals or DAAs) means hepatitis C could be eliminated as a public health threat by 2030. This study shows a sharp decline in liver disease morbidity and mortality since the introduction of DAAs in New South Wales, Australia. Despite this, heavy alcohol use remains an important risk factor for liver disease among people with hepatitis C. To ensure that the benefits of new antiviral treatments are not compromised, management of major comorbidities, including heavy alcohol use must improve among people with hepatitis C.
Lay Summary: Currently available laboratory systems are unable to reproduce the dynamics of hepatitis B virus (HBV) spread through the infected liver and release into the blood. We developed a slowly dividing liver-derived cell line which multiplies infectious viral particles upon inoculation with patient- or cell culture-derived HBV. This new infection model can improve therapy by measuring, in advance, the sensitivity of a patient’s HBV strain to specific antiviral drugs.
Lay Summary: Hepatitis delta virus (HDV) infection is the most severe form of viral hepatitis. We found that in patients with HDV, a subset of innate-like T cells called mucosa-associated invariant T cells (or MAIT cells), which are normally abundant in peripheral blood and the liver, are activated, functionally impaired and severely depleted.
Lay Summary: The prevalence of non-alcoholic fatty liver disease has increased dramatically in parallel with the worldwide increase in obesity and diabetes. Its progressive form, non-alcoholic steatohepatitis, is a growing indication for liver transplantation in Europe, with good overall outcomes reported. However, careful risk factor assessment is required to maintain favourable post-transplant outcomes in patients with non-alcoholic steatohepatitis.
Lay Summary: Hepatocellular carcinoma (HCC) is a heterogeneous disease driven by the concomitant deregulation of several genes functionally organized as networks. Here, we identified a gene regulatory network involved in a subset of HCCs. This subset is characterized by increased proliferation and poor prognosis. We developed a mathematical model which uncovers the dynamics of the network and allows us to predict the impact of a therapeutic agent, not only on its specific target but on all the genes belonging to the network.
Lay Summary: Programmed cell death 1 ligand 1 (PD-L1) expressed on antigen-presenting cells, rather than tumor cells, has been reported to play an essential role in checkpoint blockade therapy. A fundamental understanding of mechanisms that regulate the expression of PD-L1 on tumor-infiltrating monocytes/macrophages will undoubtedly lead to the possibility of developing novel PD-L1 blockade strategies with high specificity and efficiency. The current study unveils a novel mechanism by which metabolic switching links immune activation responses to immune tolerance in the tumor milieu, identifying potential targets for future immune-based anti-cancer therapies.
Lay Summary: This study demonstrates that cells that are isolated from urine can be reprogrammed in a dish towards hepatocytes that display architectural characteristics similar to those seen in the intact liver. The application of this methodology to cells from patients diagnosed with inherited copper metabolism-related liver diseases (that is, Wilson disease and MEDNIK syndrome) revealed unexpected and novel insights into patient mutation-specific disease mechanisms and drug responses.
Lay Summary: In this international multicenter study of 3,902 patients with primary biliary cholangitis, we found that treatment with ursodeoxycholic acid is associated with prolonged liver transplant-free survival. This association was significant, irrespective of sex, age, or disease stage. The survival benefit remained statistically significant in patients with an incomplete biochemical response to ursodeoxycholic acid therapy.
Lay Summary: Non-alcoholic fatty liver disease (NAFLD) is a common multifactorial disorder with a strong genetic component. Inherited forms of NAFLD have been suspected but, their molecular pathogenesis has not been disclosed. Here we report a heritable form of NAFLD with clinical expression after 40 years of age, associated with monoallelic ABHD5 mutations.
Lay Summary: Non-alcoholic fatty liver disease effects up to 30% of the population but only a minority of cases develop liver disease. Our study has shown that established blood tests can be used in primary care to stratify patients with fatty liver disease, leading to a reduction in unnecessary referrals by 80% and greatly improving the detection of cases of advanced fibrosis and cirrhosis.
Lay Summary: High hepatic fat content is associated with metabolic syndrome, type 2 diabetes mellitus, and coronary heart disease. In the CENTRAL 18-month intervention trial, a Mediterranean/low-carbohydrate diet induced a greater decrease in hepatic fat content than a low-fat diet, conferring beneficial health effects that were beyond the favorable effects of visceral fat loss.
Lay Summary: The evaluation of liver fibrosis is mandatory in non-alcoholic fatty liver disease (NAFLD), as advanced fibrosis identifies the subgroup of patients with impaired prognosis. FibroMeterVCTE is a new fibrosis test combining blood markers and the result of vibration controlled transient elastography (VCTE) into a single diagnostic test. Our results show that FibroMeterVCTE outperforms other blood fibrosis tests and VCTE alone for the diagnosis of advanced fibrosis in a large multi-centric cohort of 938 patients with biopsy-proven NAFLD. Sequential algorithms using a simple blood test or VCTE as a first-line procedure, then FibroMeterVCTE as a second-line test accurately classified 90% of patients.