Lay Summaries - Volume 69 Issue 3
Lay Summary: The prevalence of advanced liver disease in primary care managed hepatitis C is unknown. Our data suggests that rates of advanced fibrosis in the community are significant (16.5%), often underdiagnosed and comparable to rates seen in specialist referral centres. Liver stiffness measurement is a feasible community screening tool prior to hepatitis C therapy and can predict liver-related adverse events.
Lay Summary: Relapse of hepatitis B virus replication after discontinuation of nucleos(t)ide analogue therapy in certain patients with chronic hepatitis B may alter the phenotype of T cells and enhance the responsiveness of hepatitis B virus-specific T cells to in vitro peptide stimulation. Blocking PD-L1 can further augment these hepatitis B virus-specific T cell responses. Interestingly, T cells of patients that subsequently achieve hepatitis B surface antigen loss are less exhausted at all time-points after stopping treatment and display a higher proliferative capacity 12-weeks after treatment discontinuation. These findings contribute to the understanding of the immunological events that occur during discontinuation of nucleos(t)ide analogue therapy.
Lay Summary: In most cases hepatitis C virus (HCV) results in chronic infection and persistent viral replication, taking decades until development of overt disease. To achieve such a course, the respective virus must have developed mechanisms to circumvent antiviral response, to modulate the inflammatory response and to utilise the infrastructure of its host with moderate effect on its viability. The present study provides novel data indicating that HCV induces epidermal growth factor production in its host cell, enhancing epidermal growth factor-inducible expression of chemokines that bind to the CXCR2 receptor and recruit neutrophile granulocytes. Importantly, chemokines are critical mediators determining the pattern of immune cells recruited to the site of injury and thereby the local inflammatory and immunological milieu. These data strongly suggest that HCV triggers mechanisms that enable the virus to influence the inflammatory and immunological processes of its host.
Lay Summary: Sofosbuvir/velpatasvir is a combination of two drugs in one tablet that is approved for the treatment of patients with chronic hepatitis C virus (HCV) infection. When patients with chronic HCV infection receive a liver transplant, the HCV infection usually recurs, and damages the transplanted liver. This study tested the effects of 12?weeks of sofosbuvir/velpatasvir treatment in patients who had HCV recurrence after a liver transplant. Three months following the end of treatment, 96% of patients were cured of HCV infection.
Lay Summary: We looked at the importance of two of the main body compartments, skeletal muscle and adipose tissue (fat) on the prognosis of males and females with end-stage liver disease. Lower amounts of subcutaneous fat but not visceral fat (around internal organs), are associated with higher mortality in female patients with end-stage liver disease. However, low skeletal muscle predicts mortality in male patients with end-stage liver disease.
Lay Summary: In this study, we identify that among patients with decompensated cirrhosis, class III obesity (severe/morbid obesity) is a modifiable risk factor for the development of acute-on-chronic liver failure (ACLF). We further demonstrate that regarding the specific organ failures associated with ACLF, renal failure is significantly more prevalent in obese patients, particularly those with class III obesity. These findings underscore the importance of weight management in cirrhosis, to reduce the risk of ACLF. Patients with class III obesity should be monitored closely for the development of renal failure.
Lay Summary: A large proportion of adult liver transplant recipients who survive for a long time exhibit subclinical histological abnormalities. The expression profile (a measurement of the activity of genes) of liver tissue from a large fraction of these patients closely resembles the profile of T cell mediated rejection. Liver allografts showing the highest expression levels of rejection-related genes developed progressive damage over time.
Lay Summary: Dysregulation of the Keap1-Nrf2 molecular pathway has been observed in human tumors. In a nutritional model of hepatocarcinogenesis, the protein Nrf2 is frequently mutated/activated at early steps of the tumorigenic process. Herein, we show that Nrf2 is mandatory for the development of preneoplastic lesions. These results suggest that Nrf2 has a critical role in the onset of hepatocellular carcinoma.
Lay Summary: During chronic injury, the liver often repairs with fibrotic tissue, which impairs liver function, and for which there is currently no treatment. We found that a previously unexplored pathway involving the purinergic receptor P2X4, can modulate fibrotic liver repair. Therefore, this receptor could be of interest in the development of novel therapies for fibrotic liver diseases.
Lay Summary: γδ T cells are frequently enriched in many solid tissues, however the immunobiology of such tissue-associated subsets in humans has remained unclear. We show that intrahepatic γδ T cells are enriched for clonally expanded effector T cells, whereas naïve γδ T cells are largely excluded. Moreover, whereas a distinct proportion of circulating T cell clonotypes was present in both the liver tissue and peripheral blood, a functionally and clonotypically distinct population of liver-resident γδ T cells was also evident. Our findings suggest that factors triggering γδ T cell clonal selection and differentiation, such as infection, can drive enrichment of γδ T cells into liver tissue, allowing the development of functionally distinct tissue-restricted memory populations specialised in local hepatic immunosurveillance.
Lay Summary: Associating liver partition and portal vein ligation for staged hepatectomy (so called ALPPS), is a new two-staged approach to hepatectomy, which induces an unprecedented acceleration of liver regeneration, enabling treatment of patients with liver tumors that would otherwise be considered unresectable. Herein, we demonstrate that JNK1-IHH signaling from stellate cells is a key mechanism underlying the regenerative acceleration that is induced by ALPPS.
Lay Summary: Primary sclerosing cholangitis (PSC) is an inflammatory liver disease which often progresses to liver failure. The cause of the disease is unclear and therapeutic options are limited. Therefore, we explored the role of white blood cells termed macrophages in PSC given their frequent contribution to other human inflammatory diseases. Our results implicate macrophages in PSC and PSC-like diseases in mice. More importantly, we found that pharmacologic inhibition of macrophage recruitment to the liver reduces PSC-like liver injury in the mouse. These exciting observations highlight potential new strategies to treat PSC.
Lay Summary: Alcoholic hepatitis is a life-threatening condition with no approved therapy that occurs unexpectedly in people who consume excess alcohol. The liver makes many metabolites, and we demonstrate that loss of one such metabolite ß-hydroxybutyrate occurs in patients with alcoholic hepatitis. This loss can increase alcohol-induced liver injury, and ß-hydroxybutyrate can protect from alcohol-induced liver injury via a receptor on liver macrophages. This opens the possibility of metabolite-based therapy for alcoholic hepatitis.
Lay Summary: Alcoholic cirrhosis creates a large public health burden and is a risk factor for bone fractures. Based on data from England and Denmark, we found that hip fractures occur more than five times more frequently in people with alcoholic cirrhosis than in people without the disease. Additionally, the aftermath of the hip fracture is severe, such that up to 11% of patients with alcoholic cirrhosis die within 30?days after their hip fracture. These results suggest that efforts directed towards fracture prevention in people with alcoholic cirrhosis could be beneficial.
Lay Summary: Fatty acid translocase CD36 (CD36) is a multifunctional membrane protein which contributes to the development of liver steatosis. In the present study, we demonstrated that the localization of CD36 on the plasma membrane of hepatocytes is increased in patients with non-alcoholic steatohepatitis. Blocking the palmitoylation of CD36 reduces CD36 distribution in hepatocyte plasma membranes and protects mice from non-alcoholic steatohepatitis. The inhibition of CD36 palmitoylation not only improved fatty acid metabolic disorders but also reduced the inflammatory response in vitro and in vivo. The present study suggests that CD36 palmitoylation is important for non-alcoholic steatohepatitis development and inhibition of CD36 palmitoylation could be used to cure non-alcoholic steatohepatitis.