High serum gamma-glutamyltransferase level after hepatitis C virus elimination is a risk factor for the development of hepatocellular carcinoma.

AIM: Gamma-glutamyltransferase (GGT) is known as an oxidative stress marker, induced by alcohol consumption and metabolic disorders, and is reported as a predictor of hepatocellular carcinoma (HCC) development after hepatitis C virus (HCV) elimination. However, it is not clear whether GGT serves simply as a surrogate marker for overlapping metabolic diseases or reflects HCV-specific carcinogenicity. We investigated the association between GGT and hepatocarcinogenesis after achieving a sustained viral response (SVR), accounting for drinking habits or diabetes, and examined predisposing factors associated with GGT levels after SVR. METHODS: This is a prospective, multicenter, and observational study using the database of 1001 patients after HCV eradication with direct-acting antiviral agents. The association of GGT at SVR with cumulative HCC development was examined in a multivariate analysis using Cox proportional hazard models after adjustment for covariates including alcohol and diabetes. The association between oxidative stress markers or genetic factors and GGT levels was analyzed. RESULTS: High GGT levels at SVR were associated with HCC development (HR] 2.38, 95% CI 1.10-5.17). This association was also significant when restricted to patients without alcohol consumption or diabetes (HR 8.38, 95% CI 2.87-24.47). GGT levels were correlated with serum growth differentiation factor 15 levels, a marker of mitochondrial dysfunction. Single-nucleotide polymorphisms of ZNF827 and GDF15 were associated with high GGT levels. CONCLUSIONS: High GGT levels at SVR were associated with HCC development after accounting for alcohol consumption and diabetes. GGT levels are influenced by genetic predisposition and may reflect mitochondrial dysfunction after HCV eradication.

Clinical outcomes of endoscopic detachable snare ligation for colonic diverticular hemorrhage: Multicenter cohort study.

OBJECTIVES: The hemostatic mechanism of endoscopic detachable snare ligation (EDSL) for colonic diverticular hemorrhage (CDH) is similar to that of endoscopic band ligation, which is effective and safe. However, because reports on EDSL are scarce, we conducted a two-center cohort study to evaluate its effectiveness. METHODS: This study analyzed 283 patients with CDH treated with EDSL at two Japanese hospitals between July 2015 and November 2021. Patient characteristics and clinical outcomes were retrospectively evaluated. A Kaplan-Meier analysis was performed to evaluate the cumulative probability of rebleeding after EDSL. A Cox proportional hazards regression analysis was performed to compare the effects of complete and incomplete ligation on rebleeding. RESULTS: The initial hemostasis success and early rebleeding rates were 97.9% and 11.0%, respectively. The time to hemostasis after identification of the bleeding site and total procedure time were 9 min and 44 min, respectively. Red blood cell transfusion was required for 32.9% of patients. The median hospital length of stay after EDSL was 5 days. The complete ligation rate of the early rebleeding group was significantly lower than that of the group without early rebleeding (P < 0.01). The 1-year cumulative rebleeding rate with EDSL was 28.2%. Complete ligation was associated with decreased cumulative rebleeding after EDSL (P < 0.01). One patient experienced colonic diverticulitis; however, colonic perforation was not observed. CONCLUSION: Complete ligation is associated with reduced short-term and long-term rebleeding. EDSL could be valuable for CDH because of its low rebleeding rate and the absence of serious adverse events.

Anticoagulation against portal vein thrombosis reduces mortality and liver cirrhosis-related complications: A propensity score-matched study.

AIM: Portal vein thrombosis (PVT) is one of the common complications of liver cirrhosis. Although anticoagulation contributes to thrombus resolution and is considered the first-choice treatment, its impact on patients' prognosis is still controversial. This study aimed to clarify the benefit of anticoagulation on mortality, liver function, and the incidence of liver cirrhosis-related complications in cirrhotic PVT patients. METHODS: We conducted a multicenter retrospective review in which we included 78 eligible patients with PVT out of 439. After propensity score matching, 21 cirrhotic PVT patients were included in each one of the untreated control and anticoagulation groups. RESULTS: Overall survival was significantly improved in the anticoagulation group compared with the control group (p = 0.041), along with PVT size reduction (53.3% vs. 108.2%, p = 0.009). At the time of CT follow-up, the anticoagulation group showed a lower ALBI score (p = 0.037) and its prevalence of massive ascites was significantly lower (p = 0.043) compared with the control group. The incidence of overt encephalopathy was also lower in the anticoagulation group (p = 0.041). The cumulative incidence of bleeding events did not differ significantly between the two groups. CONCLUSIONS: Anticoagulation improves the survival of patients with cirrhotic PVT. Preserved liver function and reduced risks of cirrhosis-related complications under the treatment may have contributed to a better prognosis. Given its efficacy and safety, anticoagulation is worth initiating in patients with PVT.

Time course alterations of virus sequences and immunoglobulin titers in a chronic hepatitis E patient.

AIM: Hepatitis E virus (HEV) can cause chronic infection in immunocompromised hosts. However, the dynamics of HEV during persistent infection is not well understood. To elucidate time course alterations in virus sequences and anti-HEV antibodies during persistent infection, we analyzed the HEV sequences and titers of anti-HEV antibodies from a chronic hepatitis E patient. METHODS: Serum samples were obtained from a chronic hepatitis E patient under corticosteroid therapy for neurological disease. The titers of anti-HEV antibodies (immunoglobulin A, immunoglobulin M, and immunoglobulin G) in serum samples were detected by enzyme immunoassay. The full or near-full nucleotide sequences of HEV isolated from consecutive serum samples were identified and compared. Phylogenetic analysis was also performed. RESULTS: Alterations of anti-HEV antibodies from a chronic hepatitis E patient were different from those previously reported in acute hepatitis E patients. The virus sequence was unchanged in the period without treatment, but nucleotide mutations were observed after ribavirin treatment was started. In addition, the sequence of this strain had extremely high identity to that isolated from swine liver in Japan. CONCLUSIONS: Virus mutations in HEV emerged after ribavirin treatment was started. Sequence analysis may useful for deciding the treatment strategy for chronic hepatitis E patients who did not eliminate the virus with 3 months of RBV treatment and inferring the origin of the infection. This report provides insights into the chronicity of hepatitis E, and the impact of persistent infection and ribavirin treatment on the emergence of virus mutations.

Loss of fibrocystin promotes interleukin-8-dependent proliferation and CTGF production of biliary epithelium.

BACKGROUND & AIMS: Congenital hepatic fibrosis (CHF) is a genetic liver disease resulting in abnormal proliferation of cholangiocytes and progressive hepatic fibrosis. CHF is caused by mutations in the PKHD1 gene and the subsequent dysfunction of the protein it encodes, fibrocystin. However, the underlying molecular mechanism of CHF, which is quite different from liver cirrhosis, remains unclear. This study investigated the molecular mechanism of CHF pathophysiology using a genetically engineered human induced pluripotent stem (iPS) cell model to aid the discovery of novel therapeutic agents for CHF. METHODS: PKHD1-knockout (PKHD1-KO) and heterozygously mutated PKHD1 iPS clones were established by RNA-guided genome editing using the CRISPR/Cas9 system. The iPS clones were differentiated into cholangiocyte-like cells in cysts (cholangiocytic cysts [CCs]) in a 3D-culture system. RESULTS: The CCs were composed of a monolayer of cholangiocyte-like cells. The proliferation of PKHD1-KO CCs was significantly increased by interleukin-8 (IL-8) secreted in an autocrine manner. IL-8 production was significantly elevated in PKHD1-KO CCs due to mitogen-activated protein kinase pathway activation caused by fibrocystin deficiency. The production of connective tissue growth factor (CTGF) was also increased in PKHD1-KO CCs in an IL-8-dependent manner. Furthermore, validation analysis demonstrated that both the serum IL-8 level and the expression of IL-8 and CTGF in the liver samples were significantly increased in patients with CHF, consistent with our in vitro human iPS-disease model of CHF. CONCLUSIONS: Loss of fibrocystin function promotes IL-8-dependent proliferation of, and CTGF production by, human cholangiocytes, suggesting that IL-8 and CTGF are essential for the pathogenesis of CHF. IL-8 and CTGF are candidate molecular targets for the treatment of CHF. LAY SUMMARY: Congenital hepatic fibrosis (CHF) is a genetic liver disease caused by mutations of the PKHD1 gene. Dysfunction of the protein it encodes, fibrocystin, is closely associated with CHF pathogenesis. Using an in vitro human induced pluripotent stem cell model and patient samples, we showed that the loss of fibrocystin function promotes proliferation of cholangiocytes and the production of connective tissue growth factor (CTGF) in an interleukin 8 (IL-8)-dependent manner. These results suggest that IL-8 and CTGF are essential for the pathogenesis of CHF.

Diabetic Retinopathy as a Risk Factor Associated with the Development of Hepatocellular Carcinoma in Nonalcoholic Fatty Liver Disease.

BACKGROUND: The risk factors associated with the development of hepatocellular carcinoma (HCC) in nonalcoholic fatty liver disease (NAFLD) are still unclear. The aim of the present study was to identify such risk factors in NAFLD patients who developed HCC. METHODS: Between April 2000 and -December 2016, a total of 182 patients with NAFLD were enrolled in this study; of these, only 22 patients had HCC. To identify risk factors, univariate and multivariate analyses were performed. To identify risk factors other than the degree of fibrosis, propensity matched analysis adjusted by the NAFLD fibrosis score (NFS) was carried out on 44 patients. Multivariate and survival analyses were also performed in HCC patients. RESULTS: In 182 patients, multivariate analysis highlighted the NFS (OR 2.275; p < 0.001) and hypertension (OR 5.868; p = 0.037) as independent factors that were significantly associated with the development of HCC. After adjustment for the NFS, multivariate analysis identified diabetic retinopathy (OR 8.654; p = 0.017) as an independent factor that was significantly associated with the development of HCC. For predicting the development of HCC, the area under the receiver operating characteristic curve of diabetic retinopathy was significantly higher than that of diabetes (0.731 vs. 0.615; p < 0.001). In patients with HCC, multivariate analysis indicated that the NFS were significantly associated with diabetic retinopathy. CONCLUSIONS: Diabetic retinopathy as well as liver fibrosis is a risk factor that associates with the development of HCC in NAFLD patients. Therefore, NAFLD patients with diabetic retinopathy should undergo careful screening for HCC.

Association of serum interferon-λ3 levels with hepatocarcinogenesis in chronic hepatitis C patients treated with direct-acting antiviral agents.

AIM: Although the efficacy of hepatitis C virus (HCV) treatment is improved dramatically by direct-acting antiviral agents (DAAs), the assessment of hepatocellular carcinoma (HCC) remains important. Interferon lambda 3 (IFN-λ3) is associated with liver fibrosis and inflammation in chronic hepatitis C (CHC) patients, but its impact on carcinogenesis remains controversial and little is known about its effects after viral clearance. To determine the contribution of IFN-λ3 to hepatocarcinogenesis after HCV clearance, we analyzed IFNL3 genotypes and serial serum IFN-λ3 levels in CHC patients who achieved sustained virologic responses (SVR). METHODS: This study comprised 201 CHC patients treated with DAAs. Serum samples were collected sequentially and IFN-λ3 levels were quantified by chemiluminescence enzyme immunoassay. The IFNL3 polymorphism (rs8099917) was genotyped in 195 patients. RESULTS: One hundred and twenty-five patients were rs8099917 T/T and 70 were non-T/T. Serum IFN-λ3 levels did not differ significantly with IFNL3 genotype, dropped markedly by 1 week and remained low up to 24 weeks after the end of treatment. Interferon-λ3 levels were significantly higher after viral clearance in patients who developed HCC and were associated with a higher potential for hepatocarcinogenesis, such as a higher frequency of non-hypervascular hypointensive nodules (P = 0.046), higher stages of liver fibrosis (P < 0.001), and higher post-treatment levels of Wisteria floribunda agglutinin positive Mac-2 binding protein (P < 0.001) and alanine aminotransferase (P < 0.001). CONCLUSIONS: Serum IFN-λ3 levels after HCV clearance are associated with the potential for HCC development. Interferon-λ3 could be helpful for elucidating the relationships among immunologic status, liver fibrosis, liver inflammation, and hepatocarcinogenesis, after achieving SVR.

Comprehensive genetic analysis of cholangiolocellular carcinoma with a coexistent hepatocellular carcinoma-like area and metachronous hepatocellular carcinoma.

AIM: The genetic profile of cholangiolocellular carcinoma (CLC) and its origin in relation to hepatocellular carcinoma (HCC) remain unclear. To elucidate the genetic profile of CLC, a comprehensive analysis of genetic mutations was carried out in a case of CLC with an HCC-like focal area and metachronous HCC. METHOD: Liver tissue was obtained from CLC, a co-existent HCC-like area, and metachronously developed HCC by laser capture microdissection of formalin-fixed paraffin-embedded specimens obtained by hepatectomy. Gene mutational profiles were analyzed comprehensively by next-generation sequencing and digital PCR. Relationships among gene profiles, immunohistochemistry, and clinicopathological findings were investigated. RESULTS: Mutations in EGFR, PTEN, RB1, TP53, and ERBB2 were found in CLC, whereas mutations in KIT, BRAF, PTEN, TP53, and SMAD4 were found in the coexistent HCC-like area. Only the mutation in PTEN has a common Catalogue of Somatic Mutations in Cancer ID in the CLC and coexistent HCC-like area, and is related to the kinase-RAS module. In contrast, no cancer-related mutations were found in the metachronous HCC. No TERT mutations were found in any of the regions by digital PCR. Immunohistochemical staining for p53 was negative in CLC, although ≤10% positive in the coexistent HCC-like area. Immunostaining of C-kit, HER2, PTEN, and SMAD4 were negative. CONCLUSION: The genomic features of CLC and the focal area of an HCC-like region differ, but are related to the kinase-RAS module. The development of carcinogenesis in the CLC and HCC-like areas in this case might differ, following a common PTEN mutation, although alteration of the kinase-RAS module is the most common molecular event in CLC.

Effect of interferon-based and -free therapy on early occurrence and recurrence of hepatocellular carcinoma in chronic hepatitis C.

BACKGROUND AND AIMS: Although treatment for hepatitis C virus has been dramatically improved by the development of direct-acting antiviral agents (DAAs), whether interferon (IFN)-free therapy reduces hepatocarcinogenesis in an equivalent manner to IFN-based therapy remains controversial. The aims of this study were to evaluate the occurrence and recurrence of hepatocellular carcinoma (HCC) in chronic hepatitis C (CHC) patients treated with DAAs and to identify biomarkers of HCC development after antiviral treatment. METHODS: A restrospective review of a prospective database of 1,897 CHC patients who were treated with IFN-based (1,145) or IFN-free therapies (752) was carried out. Cumulative HCC occurrence and recurrence rates were compared using propensity score-matched analysis. Predictors of HCC development after viral eradication were identified by multivariate analysis. RESULTS: Propensity score-matched analysis showed no significant difference in HCC occurrence (p=0.49) and recurrence rates (p=0.54) between groups treated with IFN-based or IFN-free therapies. In multivariate analysis, higher levels of post-treatment α-fetoprotein (AFP) or Wisteria floribunda agglutinin positive Mac-2 binding protein (WFA+M2BP) were independently associated with HCC occurrence and recurrence after viral eradication. Only post-treatment WFA+M2BP level was significantly associated with HCC occurrence and recurrence among patients without severe fibrosis. The area under the receiver operating characteristic (ROC) curve for WFA+M2BP levels was greater than that for AFP levels in ROC analysis. CONCLUSION: The risks of early HCC occurrence and recurrence after viral eradication were similar between IFN-based and IFN-free therapies. Post-treatment levels of WFA+M2BP may be helpful screening biomarkers for assessing the risk of HCC after IFN-free therapy. Patients with high WFA+M2BP levels after antiviral treatment, even without severe fibrosis, must be followed up carefully for HCC development. Lay summary: The risks of early HCC occurrence and recurrence after viral eradication were similar between IFN-based and IFN-free therapies. Post-treatment levels of WFA+M2BP may be helpful screening biomarkers for assessing the risk of HCC after IFN-free therapy.

Hepatic IFNL4 expression is associated with non-response to interferon-based therapy through the regulation of basal interferon-stimulated gene expression in chronic hepatitis C patients.

Single nucleotide polymorphisms (SNPs) within or near interferon lambda 4 (IFNL4) gene located upstream of IFNL3 are associated with response to anti-HCV therapy both in interferon (IFN)-based and IFN-free regimens. IFNL4 encodes IFNλ4, a newly discovered type III IFN, and its expression is controlled by rs368234815-TT/ΔG, which is in strong linkage disequilibrium (LD) with other tag SNPs within or near IFNL4 such as rs12979860 and rs8099917. Intrahepatic expression levels of IFN-stimulated genes (ISGs) affect the responsiveness to IFNα and are also associated with IFNL4 genotype. However, IFNL4 expressions and its role in intrinsic antiviral innate immunity remain unclear. This study evaluated the effect of IFNL4 on intrahepatic ISG expression and investigated its relationship with treatment outcomes in liver samples obtained from 49 chronic hepatitis C patients treated with pegylated (PEG)-IFN/ribavirin therapy. IFNL4 mRNA was detected in 11 of 22 patients with IFNL4-unfavorable SNPs but not in patients with favorable genotypes. IFNL4 expression was associated with non-response to PEG-IFN/ribavirin therapy. Intrahepatic expression of antiviral ISGs (ISG15 and MX1) was significantly higher in IFNL4-unfavorable patients with detectable IFNL4 mRNA than in patients with undetectable IFNL4 mRNA, whereas the expression of suppressive ISGs (RNF125, SOCS1, SOCS3, and RNF11) was lower in patients with detectable IFNL4 mRNA. In summary, intrahepatic expression of IFNL4 was associated with increased antiviral ISG expression and decreased suppressive ISG expression at baseline, resulting in poor responsiveness to IFNα-based therapy in HCV infection.

Bone morphogenetic protein-4 modulates proliferation and terminal differentiation of fetal hepatic stem/progenitor cells.

Fetal hepatic stem/progenitor cells, called hepatoblasts, play central roles in liver organogenesis; however, molecular mechanisms regulating proliferation and terminal differentiation of such cells have not been completely elucidated. Bone morphogenetic protein-4 (BMP-4) is essential for the development of stem cells in various tissues, but its function in regulating the phenotype of hepatoblasts after the mid-gestational fetal stage remains unclear. The aim of this study is to clarify a functional role for BMP-4 in proliferation and terminal differentiation of murine hepatoblasts in mid-gestational fetal livers. METHODS: A functional role for BMP-4 in proliferation and terminal differentiation of murine hepatoblasts was validated by assay of colony formation, biliary luminal formation, and hepatic maturation using primary hepatoblasts in vitro. Molecular mechanisms regulating such effects of BMP-4 on primary hepatoblasts were also analyzed. RESULTS: Stimulation of BMP-4 upregulated phosphorylation of Smad1/5 in hepatoblasts. Bone morphogenetic protein-4 significantly suppressed colony formation of primary hepatoblasts in a dose-dependent manner, significantly suppressed cholangiocytic luminal formation of hepatoblasts, and promoted hepatic maturation of primary hepatoblasts. Stimulation of BMP-4 regulated the activation of several mitogen-activated protein kinases, such as extracellular signal-regulated kinase, Akt, p38 mitogen-activated protein kinase, and calcium/calmodulin-dependent protein kinase IIα in primary hepatoblasts. Moreover, Wnt5a, a molecule regulating cholangiocytic luminal formation, and BMP-4 coordinately suppressed proliferation and cholangiocytic luminal formation of hepatoblasts. CONCLUSION: This study shows that BMP-4-mediated signaling controls proliferation and terminal differentiation of fetal hepatic stem/progenitor cells.

ITPA gene variation and ribavirin-induced anemia in patients with genotype 2 chronic hepatitis C treated with sofosbuvir plus ribavirin.

AIM: Sofosbuvir (SOF) and ribavirin (RBV) combination therapy produces a sustained response in many patients with genotype 2 chronic hepatitis C. However, RBV-induced anemia is a troublesome side-effect that may limit this treatment. Genetic variation leading to inosine triphosphatase (ITPA) deficiency is known to protect against RBV-induced hemolytic anemia. This study aimed to evaluate the relationships between the efficacy and safety of SOF/RBV treatment and ITPA gene variants. METHODS: Ninety patients with genotype 2 chronic hepatitis C treated with SOF/RBV were studied. The relationships among genetic polymorphisms of ITPA and the decline in hemoglobin levels from baseline, RBV dose reduction, and sustained virological response (SVR) rates were analyzed. RESULTS: Overall SVR at 12 weeks was 94.4% (85/90). Patients with the ITPA CA/AA genotypes had a lower degree of anemia throughout the therapy than those with the ITPA CC genotype. The percentage of patients requiring RBV dose reduction was significantly lower for those with the ITPA CA/AA variation, a difference even more apparent when the pretreatment hemoglobin level was <12 g/dL. The dose reduction of RBV and serum albumin level were significantly associated with SVR. CONCLUSIONS: Patients with the ITPA CA/AA genotype were less likely to develop anemia than those with the ITPA CC genotype and were more likely to complete SOF/RBV therapy. These results may provide a valuable pharmacogenetic diagnostic tool to predict drug-induced adverse events, particularly in patients with pre-existing anemia.

Matrix metalloproteinase-14 mediates formation of bile ducts and hepatic maturation of fetal hepatic progenitor cells.

Fetal hepatic stem/progenitor cells, called hepatoblasts, play central roles in liver development; however, the molecular mechanisms regulating the phenotype of these cells have not been completely elucidated. Matrix metalloproteinase (MMP)-14 is a type I transmembrane proteinase regulating pericellular proteolysis of the extracellular matrix and is essential for the activation of several MMPs and cytokines. However, the physiological functions of MMP-14 in liver development are unknown. Here we describe a functional role for MMP-14 in hepatic and biliary differentiation of mouse hepatoblasts. MMP-14 was upregulated in cells around the portal vein in perinatal stage liver. Formation of bile duct-like structures in MMP-14-deficient livers was significantly delayed compared with wild-type livers in vivo. In vitro biliary differentiation assays showed that formation of cholangiocytic cysts derived from MMP-14-deficient hepatoblasts was completely impaired, and that overexpression of MMP-14 in hepatoblasts promoted the formation of bile duct-like cysts. In contrast, the expression of molecules associated with metabolic functions in hepatocytes, including hepatic nuclear factor 4α and tryptophan 2,3-dioxygenase, were significantly increased in MMP-14-deficient livers. Expression of the epidermal growth factor receptor and phosphorylation of mitogen-activated protein kinases were significantly upregulated in MMP-14-deficient livers. We demonstrate that MMP-14-mediated signaling in fetal hepatic progenitor cells promotes biliary luminal formation around the portal vein and negatively controls the maturation of hepatocytes.

Efficacy of additional radiofrequency ablation after transcatheter arterial chemoembolization for intermediate hepatocellular carcinoma.

AIM: For intermediate hepatocellular carcinoma (HCC), transcatheter arterial chemoembolization (TACE) therapy is recommended in the guidelines as a monotherapy, although TACE is a non-curative therapy. The aims of the present study were to evaluate the efficacy of adding radiofrequency ablation (RFA) to TACE in patients with intermediate HCC, and to identify the factors that were associated with favorable survival in these patients. METHODS: Fifty-nine patients with intermediate HCC were enrolled in this retrospective study. Thirty-nine patients were treated with TACE alone and 20 patients were treated with additional RFA after TACE. RESULTS: The recurrence-free survival rates at 0.5, 1 and 2 years for the additional RFA group were 32%, 19% and 13%, respectively, and these were significantly higher than those of the TACE group (8%, 3% and 0%, respectively; log-rank test, P = 0.001). The cumulative survival rates of the additional RFA group were significantly higher than those of the TACE group (log-rank test, P = 0.002), although this significant difference was not found in the subgroup of treatment naive patients because of small sample size. Multivariate analysis indicated male sex, lower total bilirubin, lower α-fetoprotein, lower des-γ-carboxyprothrombin, newly recurrent HCC nodules within the last 12 months and additional RFA as independent factors that were significantly associated with favorable overall survival. CONCLUSION: Additional RFA of nodules insufficiently treated by TACE is effective therapy for obtaining favorable disease-free survival in patients with intermediate HCC, and leads to better overall survival particularly in recurrent patients.

Impaired induction of interleukin 28B and expression of interferon λ 4 associated with nonresponse to interferon-based therapy in chronic hepatitis C.

BACKGROUND AND AIM: Interferon (IFN) λ plays an important role in innate immunity to protect against hepatitis C viral (HCV) infection. Single nucleotide polymorphisms (SNPs) near IL28B (IFNλ3) are strongly associated with treatment response to IFNα therapy in chronic hepatitis C (CHC) patients. Recently, IFNλ4 related to IL28B-unfavorable allele was discovered. However, the impact of IFNλs on CHC is unknown. We aimed to investigate the mechanism underlying responsiveness to IFN-based therapy in CHC associated with SNPs near IL28B. METHODS: We evaluated the basal mRNA levels and ex-vivo induction of IFNλ expression including IFNλ4 in peripheral blood mononuclear cells (PBMCs) from 50 CHC patients treated with pegylated-IFNα/RBV. Furthermore, we investigated the effect of IFNλ4 on induction of IL28B in vitro. RESULTS: When PBMCs were stimulated with IFNα and polyinosinic-polycytidylic acid, IL28B induction was significantly lower in patients with IL28B-unfavorable genotype (rs12979860 CT/TT) than those with IL28B-favorable genotype (rs12979860 CC; P=0.049). IL28B induction was lower in nonresponders than in relapsers (P = 0.04), and it was also lower in nonsustained virological responder patients for triple therapy including NS3 protease inhibitors. IFNλ4 mRNA was detected in 12 of 26 patients with IL28B-unfavorable SNP, and IFNλ4 expression was associated with lower IL28B induction in patients with IL28B-unfavorable genotype (P=0.04) and nonresponse to IFNα therapy (P=0.003). Overexpression of IFNλ4 suppressed IL28B induction and promoter activation. CONCLUSIONS: Impaired induction of IL28B, related to IFNλ4 expression in PBMCs of IL28B-unfavorable patients, is associated with nonresponse to IFNα-based therapy for hepatitis C viral infection.

Hepatitis C virus NS4B protein targets STING and abrogates RIG-I-mediated type I interferon-dependent innate immunity.

UNLABELLED: Hepatitis C virus (HCV) infection blocks cellular interferon (IFN)-mediated antiviral signaling through cleavage of Cardif by HCV-NS3/4A serine protease. Like NS3/4A, NS4B protein strongly blocks IFN-ß production signaling mediated by retinoic acid-inducible gene I (RIG-I); however, the underlying molecular mechanisms are not well understood. Recently, the stimulator of interferon genes (STING) was identified as an activator of RIG-I signaling. STING possesses a structural homology domain with flaviviral NS4B, which suggests a direct protein-protein interaction. In the present study, we investigated the molecular mechanisms by which NS4B targets RIG-I-induced and STING-mediated IFN-ß production signaling. IFN-ß promoter reporter assay showed that IFN-ß promoter activation induced by RIG-I or Cardif was significantly suppressed by both NS4B and NS3/4A, whereas STING-induced IFN-ß activation was suppressed by NS4B but not by NS3/4A, suggesting that NS4B had a distinct point of interaction. Immunostaining showed that STING colocalized with NS4B in the endoplasmic reticulum. Immunoprecipitation and bimolecular fluorescence complementation (BiFC) assays demonstrated that NS4B specifically bound STING. Intriguingly, NS4B expression blocked the protein interaction between STING and Cardif, which is required for robust IFN-ß activation. NS4B truncation assays showed that its N terminus, containing the STING homology domain, was necessary for the suppression of IFN-ß promoter activation. NS4B suppressed residual IFN-ß activation by an NS3/4A-cleaved Cardif (Cardif1-508), suggesting that NS3/4A and NS4B may cooperate in the blockade of IFN-ß production. CONCLUSION: NS4B suppresses RIG-I-mediated IFN-ß production signaling through a direct protein interaction with STING. Disruption of that interaction may restore cellular antiviral responses and may constitute a novel therapeutic strategy for the eradication of HCV.

Wnt5a signaling mediates biliary differentiation of fetal hepatic stem/progenitor cells in mice.

UNLABELLED: The molecular mechanisms regulating differentiation of fetal hepatic stem/progenitor cells, called hepatoblasts, which play pivotal roles in liver development, remain obscure. Wnt signaling pathways regulate the development and differentiation of stem cells in various organs. Although a ß-catenin-independent noncanonical Wnt pathway is essential for cell adhesion and polarity, the physiological functions of noncanonical Wnt pathways in liver development are unknown. Here we describe a functional role for Wnt5a, a noncanonical Wnt ligand, in the differentiation of mouse hepatoblasts. Wnt5a was expressed in mesenchymal cells and other cells of wild-type (WT) midgestational fetal liver. We analyzed fetal liver phenotypes in Wnt5a-deficient mice using a combination of histological and molecular techniques. Expression levels of Sox9 and the number of hepatocyte nuclear factor (HNF)1ß(+) HNF4α(-) biliary precursor cells were significantly higher in Wnt5a-deficient liver relative to WT liver. In Wnt5a-deficient fetal liver, in vivo formation of primitive bile ductal structures was significantly enhanced relative to WT littermates. We also investigated the function of Wnt5a protein and downstream signaling molecules using a three-dimensional culture system that included primary hepatoblasts or a hepatic progenitor cell line. In vitro differentiation assays showed that Wnt5a retarded the formation of bile duct-like structures in hepatoblasts, leading instead to hepatic maturation of such cells. Whereas Wnt5a signaling increased steady-state levels of phosphorylated calcium/calmodulin-dependent protein kinase II (CaMKII) in fetal liver, inhibition of CaMKII activity resulted in the formation of significantly more and larger-sized bile duct-like structures in vitro compared with those in vehicle-supplemented controls. CONCLUSION: Wnt5a-mediated signaling in fetal hepatic stem/progenitor cells suppresses biliary differentiation. These findings also suggest that activation of CaMKII by Wnt5a signaling suppresses biliary differentiation. (HEPATOLOGY 2013;).

Analysis of prognosis and background liver disease in non-advanced hepatocellular carcinoma in two decades.

BACKGROUND/AIM: Antiviral hepatitis and systemic therapies for hepatocellular carcinoma (HCC) remarkably progressed in the recent 10 years. This study aimed to reveal the actual transition and changes in the prognosis and background liver disease in non-advanced HCC in the past 20 years. METHODS: This retrospectively recruited 566 patients who were diagnosed with non-advanced HCC from February 2002 to February 2022. The prognosis was analyzed by subdividing according to the diagnosis date (period I: February 2002-April 2009 and period Ⅱ: May 2009-February 2022). RESULTS: Patients in period II (n = 351) were significantly older, with lower albumin-bilirubin (ALBI) scores and alpha-fetoprotein (AFP) and more anti-viral therapy, systemic therapy, and hepatic arterial infusion chemotherapy as compared with those in period I (n = 215). The etiology ratio of the background liver disease revealed decreased hepatitis C virus from 70.6% to 49.0% and increased non-B, non-C from 17.7% to 39.9% from periods I to Ⅱ. The multivariate analysis revealed older age and higher ALBI score in Barcelona Clinic Liver Cancer (BCLC) 0/A stage, AFP of >20 ng/mL, and higher ALBI score in BCLC B stage as independent prognosis factors. Fine-Gray competing risk model analysis revealed that liver-related deaths significantly decreased in period II as compared to period I, especially for BCLC stage 0/A (HR: 0.656; 95%CI: 0.442-0.972, P = 0.036). CONCLUSION: The characteristics of patients with non-advanced HCC have changed over time. Appropriate background liver management led to better liver-related prognoses in BCLC 0/A.

A case of refractory immune checkpoint inhibitor-induced colitis with Clostridioides difficile infection.

The clinical symptoms of an immune checkpoint inhibitor (ICI)-induced colitis are similar to those of ulcerative colitis. ICI-induced colitis, like ulcerative colitis, may be complicated by other colitis, such as Clostridioides difficile infection (CDI). A 72-year-old man was admitted because of watery and bloody stools 10 times a day after three courses of nivolumab (antibodies against programmed death 1) and ipilimumab (cytotoxic T-lymphocyte-associated antigen-4) for stage IV renal cell carcinoma. Colonoscopy revealed erythema and multiple erosions in the colon. Histopathological examination of colonic mucosa revealed diffuse inflammatory cell infiltration and apoptosis. The initial cytomegalovirus antigen test and C. difficile detection assay results were negative. Based on these findings, we diagnosed the patient with ICI-induced colitis and discontinued ICI therapy. The symptoms did not improve despite the administration of Prednisolone and infliximab. A repeat colonoscopy revealed a new appearance of pseudomembranes from the sigmoid colon to the rectum one month after the start of these treatments. At this point, the patient tested positive for C. difficile. With treatment with vancomycin for CDI, the abdominal symptoms gradually decreased. Nivolumab alone was cautiously restarted. However, no colitis recurrence and further tumor reduction were observed. Here, we report our experience of a case of refractory ICI-induced colitis complicated by CDI. ICI-induced colitis may be complicated by CDI and should be carefully treated with repeated CDI testing if refractory to treatment. We believe that our observation will provide helpful information for determining an appropriate treatment strategy for ICI-induced colitis.

COVID-19 severity is associated with the risk of gastrointestinal bleeding.

OBJECTIVE: The association between the severity of COVID-19 and gastrointestinal (GI) bleeding is unknown. This study aimed to determine whether the severity of COVID-19 is a risk factor for GI bleeding. DESIGN: A multicentre, retrospective cohort study was conducted on hospitalised patients with COVID-19 between January 2020 and December 2021. The severity of COVID-19 was classified according to the National Institute of Health severity classification. The primary outcome was the occurrence of GI bleeding during hospitalisation. The main analysis compared the relationship between the severity of COVID-19 and the occurrence of GI bleeding. Multivariable logistic regression analysis was performed to evaluate the association between the severity of COVID-19 and the occurrence of GI bleeding. RESULTS: 12 044 patients were included. 4165 (34.6%) and 1257 (10.4%) patients had severe and critical COVID-19, respectively, and 55 (0.5%) experienced GI bleeding. Multivariable analysis showed that patients with severe COVID-19 had a significantly higher risk of GI bleeding than patients with non-severe COVID-19 (OR: 3.013, 95% CI: 1.222 to 7.427). Patients with critical COVID-19 also had a significantly higher risk of GI bleeding (OR: 15.632, 95% CI: 6.581 to 37.130). Patients with severe COVID-19 had a significantly increased risk of lower GI bleeding (OR: 10.349, 95% CI: 1.253 to 85.463), but the risk of upper GI bleeding was unchanged (OR: 1.875, 95% CI: 0.658 to 5.342). CONCLUSION: The severity of COVID-19 is associated with GI bleeding, and especially lower GI bleeding was associated with the severity of COVID-19. Patients with severe or critical COVID-19 should be treated with caution as they are at higher risk for GI bleeding.