Daryl Lau

IL-1β production through the NLRP3 inflammasome by hepatic macrophages links hepatitis C virus infection with liver inflammation and disease.

Chronic hepatitis C virus (HCV) infection is a leading cause of liver disease. Liver inflammation underlies infection-induced fibrosis, cirrhosis and liver cancer but the processes that promote hepatic inflammation by HCV are not defined. We provide a systems biology analysis with multiple lines of evidence to indicate that interleukin-1β (IL-1β) production by intrahepatic macrophages confers liver inflammation through HCV-induced inflammasome signaling. Chronic hepatitis C patients exhibited elevated levels of serum IL-1β compared to healthy controls. Immunohistochemical analysis of healthy control and chronic hepatitis C liver sections revealed that Kupffer cells, resident hepatic macrophages, are the primary cellular source of hepatic IL-1β during HCV infection. Accordingly, we found that both blood monocyte-derived primary human macrophages, and Kupffer cells recovered from normal donor liver, produce IL-1β after HCV exposure. Using the THP-1 macrophage cell-culture model, we found that HCV drives a rapid but transient caspase-1 activation to stimulate IL-1β secretion. HCV can enter macrophages through non-CD81 mediated phagocytic uptake that is independent of productive infection. Viral RNA triggers MyD88-mediated TLR7 signaling to induce IL-1β mRNA expression. HCV uptake concomitantly induces a potassium efflux that activates the NLRP3 inflammasome for IL-1β processing and secretion. RNA sequencing analysis comparing THP1 cells and chronic hepatitis C patient liver demonstrates that viral engagement of the NLRP3 inflammasome stimulates IL-1β production to drive proinflammatory cytokine, chemokine, and immune-regulatory gene expression networks linked with HCV disease severity. These studies identify intrahepatic IL-1β production as a central feature of liver inflammation during HCV infection. Thus, strategies to suppress NLRP3 or IL-1β activity could offer therapeutic actions to reduce hepatic inflammation and mitigate disease.

Evaluation of APRI and FIB-4 scoring systems for non-invasive assessment of hepatic fibrosis in chronic hepatitis B patients

BACKGROUND & AIMS While the gold standard in the assessment of liver fibrosis remains liver biopsy, non-invasive methods have been increasingly used for chronic hepatitis B (CHB). This study aimed to evaluate the performance of two commonly used non-invasive scoring systems (aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4)) to predict fibrosis stage in CHB patients. METHODS Demographic, histologic and clinical laboratory data from two trials investigating tenofovir disoproxil fumarate in CHB were analyzed. Predicted fibrosis stage, based on established scales and cut-off values for APRI and FIB-4 scores, was compared with Ishak scores obtained from liver biopsy at baseline and at 240 week follow-up. RESULTS In the 575 patients with a baseline liver biopsy, APRI and FIB-4 scores correlated with Ishak stage (p<0.01); however extensive overlap in the distribution of both scores across Ishak stages prevented accurate determination of fibrosis. The majority (81-89%) of patients with advanced fibrosis or cirrhosis were missed by the scores. Similarly, 71% patients without fibrosis were misclassified as having clinically significant fibrosis. APRI and FIB-4 scores at week 240 tended to be low and underestimate fibrosis stage in the patients with liver biopsies after 240 weeks of therapy. APRI or FIB-4 reduction did not correlate with fibrosis regression after 240 weeks of antiviral therapy. CONCLUSIONS APRI and FIB-4 scores are not suitable for use in clinical practice in CHB patients for assessment of hepatic fibrosis according to Ishak stage, especially in gauging improvements in liver fibrosis following therapy.

Recent advances in micro/nanotechnologies for global control of hepatitis B infection

The control of hepatitis B virus (HBV) infection is a challenging task, specifically in developing countries there is limited access to diagnostics and antiviral treatment mainly due to high costs and insufficient healthcare infrastructure. Although the current diagnostic technologies can reliably detect HBV, they are relatively laborious, impractical and require expensive resources that are not suitable for resource-limited settings. Advances in micro/nanotechnology are pioneering the development of new generation methodologies in diagnosis and screening of HBV. Owing to combination of nanomaterials (metal/inorganic nanoparticles, carbon nanotubes, etc.) with microfabrication technologies, utilization of miniaturized sensors detecting HBV and other viruses from ultra-low volume of blood, serum and plasma is realized. The state-of-the-art microfluidic devices with integrated nanotechnologies potentially allow for inexpensive HBV screening at low cost. This review aims to highlight recent advances in nanotechnology and microfabrication processes that are employed for developing point-of-care (POC) HBV assays.

Diabetes and prediabetes in patients with hepatitis B residing in North America

Diabetes is associated with liver disease progression and increased hepatocellular carcinoma risk, but factors associated with diabetes in patients with chronic hepatitis B virus (HBV) infection in North America are unknown. We aimed to determine factors predictive of diabetes and impaired fasting glucose (IFG) in a large HBV‐infected multiethnic cohort. Adults with chronic HBV not receiving antiviral therapy were enrolled from 21 centers in North America. Diabetes was defined by history/medication use or fasting glucose ≥126 mg/dL and IFG as fasting glucose 100‐125 mg/dL. Of 882 patients included, 47.2% were female, 71.3% Asian, 83.7% foreign born, median age was 44 years, and median body mass index BMI 24.3 kg/m2. In this cohort, 26.0% were hepatitis B envelope antigen (HBeAg) positive, 43.9% had HBV DNA ≥20,000 IU/mL, and 26.7% alanine aminotransferase (ALT) ≥2× upper limit of normal (≥40 U/L women, ≥60 U/L men). Overall, 12.5% had diabetes and 7.8% IFG. The combined prevalence of diabetes or IFG was highest among blacks (36.7%) and those either born in the United States/Canada or foreign born with migration >20 years ago (25.5%). Obesity (odds ratio [OR]: 2.13), hyperlipidemia (OR, 4.13), hypertension (OR, 3.67), high ALT level (OR, 1.86), and family history of diabetes (OR, 3.43) were associated with diabetes. Factors associated with IFG were obesity (OR, 4.13) and hypertension (OR, 3.27), but also HBeAg positivity (OR, 0.39). Recent migration was negatively associated with diabetes among non‐Asians (OR, 0.30). Conclusions: Diabetes is more prevalent in HBV‐infected North American adults than the general population and is associated with known metabolic risk factors and liver damage, as determined by ALT levels. Among the foreign born, longer duration of North America residence predicted diabetes risk in non‐Asians. These results highlight the opportunities for interventions to prevent diabetes especially among at‐risk ethnic groups with HBV. (Hepatology 2015;62:1364–1374)

Lower Observed Hepatocellular Carcinoma Incidence in Chronic Hepatitis B Patients Treated With Entecavir: Results of the ENUMERATE Study.

OBJECTIVES:Data from the United States are lacking regarding the impact of entecavir (ETV) on the risk of hepatocellular carcinoma (HCC). Our aim is to determine whether treatment with ETV is associated with a reduced HCC risk by calculating the expected HCC incidence based on the Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B (REACH-B) model and comparing it with the observed HCC incidence.METHODS:The incidence of HCC in US patients treated with ETV between 2005 and 2013 in a retrospective cohort was obtained. The predicted HCC incidence was calculated using the REACH-B model. The standardized incidence ratios (SIRs) were calculated as a ratio of observed over predicted HCC cases.RESULTS:Of 841 patients, 646 (65% male, 84% Asian, median age 47 years, 36% hepatitis B e antigen positive, 9.4% with cirrhosis) met the inclusion criteria. Over a median follow-up of 4 years, 17 (2.6%) cases of HCC were diagnosed, including 8 out of 61 (13.1%) patients with cirrhosis and 9 out of 585 (1.5%) without cirrhosis. Compared with those without HCC, the 17 patients with HCC were older at 53 years vs. 47 years and more likely to have cirrhosis at 47.1% vs. 8.4%. Among patients without cirrhosis, the observed HCC incidence was significantly lower than predicted by the fourth year (SIR, 0.37; 95% confidence interval: 0.166–0.82). A sensitivity analysis that comprised all patients, including those with cirrhosis, showed that at the maximum follow-up time of 8.2 years, a significantly lower than predicted HCC incidence was noted with an SIR of 0.56 (95% confidence interval: 0.35–0.905).CONCLUSIONS:Based on the REACH-B model, long-term ETV therapy was associated with a lower than predicted HCC incidence. However, the risk of HCC persisted, and careful HCC surveillance remains warranted despite the anti-viral treatment.

114 DIFFERENTIAL HEPATIC MICRORNA EXPRESSION PROFILES ASSOCIATED WITH INTERFERON ALPHA TREATMENT RESPONSE IN PATIENTS WITH CHRONIC HEPATITIS C

antiviral strategies. The tight junction protein claudin-1 (CLDN1) has been shown to be essential for HCV entry. Using genetic immunization, we produced six monoclonal antibodies efficiently inhibiting HCV infection by targeting host entry factor CLDN1. Monoclonal anti-CLDN1 antibodies bound to human CLDN1 on the cell surface of primary human hepatocytes and Huh7.5.1 with high affinity. Competition and binding studies demonstrated that antibodies target conformational epitopes of the first extracellular loop. Using an infectious HCV cell culture system we demonstrate that monoclonal anti-CLDN1 antibodies efficiently inhibit HCV Jc1-Luc and Con1-Luc infection of Huh7.5.1 cells in a dose-dependent manner. Anti-CLDN1 antibodies efficiently cross-neutralize infection of primary human hepatocytes by HCV pseudotypes (HCVpp) derived from genotypes 1–6. In patients with chronic HCV infection, anti-CLDN1 antibodies broadly crossinhibit entry of HCVpp bearing envelope glycoproteins of the viral quasispecies population. Furthermore, anti-CLDN1 antibodies markedly inhibit entry of HCV escape variants isolated from six patients undergoing liver transplantation which were resistant to autologous host responses. In conclusion, these results suggest that targeting HCV entry factor CLDN1 using monoclonal anti-CLDN1 antibodies constitutes a novel antiviral approach to prevent primary HCV infection, such as after liver transplantation and might also restrain virus spread in chronically infected patients. I.F and S.K. contributed equally to this work.