Deep learning and digital pathology powers prediction of HCC development in steatotic liver disease.

BACKGROUND AND AIMS: Identifying patients with steatotic liver disease who are at a high risk of developing HCC remains challenging. We present a deep learning (DL) model to predict HCC development using hematoxylin and eosin-stained whole-slide images of biopsy-proven steatotic liver disease. APPROACH AND RESULTS: We included 639 patients who did not develop HCC for ≥7 years after biopsy (non-HCC class) and 46 patients who developed HCC <7 years after biopsy (HCC class). Paired cases of the HCC and non-HCC classes matched by biopsy date and institution were used for training, and the remaining nonpaired cases were used for validation. The DL model was trained using deep convolutional neural networks with 28,000 image tiles cropped from whole-slide images of the paired cases, with an accuracy of 81.0% and an AUC of 0.80 for predicting HCC development. Validation using the nonpaired cases also demonstrated a good accuracy of 82.3% and an AUC of 0.84. These results were comparable to the predictive ability of logistic regression model using fibrosis stage. Notably, the DL model also detected the cases of HCC development in patients with mild fibrosis. The saliency maps generated by the DL model highlighted various pathological features associated with HCC development, including nuclear atypia, hepatocytes with a high nuclear-cytoplasmic ratio, immune cell infiltration, fibrosis, and a lack of large fat droplets. CONCLUSIONS: The ability of the DL model to capture subtle pathological features beyond fibrosis suggests its potential for identifying early signs of hepatocarcinogenesis in patients with steatotic liver disease.

Predictive factors of portal hypertensive enteropathy exacerbations based on long-term outcomes.

BACKGROUND: Portal hypertensive enteropathy (PHE) is a small-bowel lesion observed in patients with portal hypertension. The clinical significance of endoscopic findings in PHE remains unclear. We aimed to clarify the clinical significance and predictive factors of capsule endoscopic findings in patients with PHE based on long-term outcomes. METHODS: This retrospective study enrolled 55 patients with PHE (33 males and 22 females; median age, 64 years; range, 23-87) followed for > 3 years using capsule endoscopy (CE) between February 2009 and May 2023. We evaluated the clinical factors affecting PHE exacerbations and the effects of PHE exacerbations on gastrointestinal bleeding by comparing exacerbated and unchanged PHE groups. RESULTS: Overall, 3 (5%) patients showed improvement, 33 (60%) remained unchanged, and 19 (35%) showed exacerbation on follow-up CE. In the exacerbated group, the rates of worsened fibrosis-4 index, exacerbated esophageal varices, and exacerbated portal hypertensive gastropathy were significantly higher than those in the unchanged group (21%, 32%, and 42% vs. 3%, 6%, and 12%, respectively; P < 0.05), and the rate of splenectomy was significantly lower in the exacerbated group than in the unchanged group (5% vs. 39%, respectively; P < 0.01). In multivariate analysis, exacerbation of esophageal varices and absence of splenectomy were significantly associated with PHE exacerbation. The rate of gastrointestinal bleeding after follow-up CE was significantly high in the exacerbated group (log-rank, P = 0.037). CONCLUSIONS: Exacerbation of esophageal varices and splenectomy were significantly associated with exacerbation of PHE. Exacerbated PHE requires specific attention to prevent gastrointestinal bleeding.

Value of autotaxin for hepatocellular carcinoma risk assessment in chronic hepatitis B patients treated with nucleos(t)ide analogs.

AIM: Autotaxin (ATX) is a newly identified liver fibrosis biomarker; however, its clinical usefulness remains unclear. Therefore, we analyzed the changes in patients with chronic hepatitis B virus infection treated with nucleos(t)ide analogs (NAs) to evaluate its usefulness. We also investigated the predictors of hepatocellular carcinoma development, including ATX, in patients with chronic hepatitis B based on their clinical characteristics. METHODS: This retrospective study included 179 patients with hepatitis B virus infection treated with NAs for >2 years. First, we measured the ATX levels before and up to 10 years after initiating entecavir (therapy for 88 patients whose serial ATX levels could be measured before and during entecavir therapy. Subsequently, for 179 patients whose ATX levels could be measured at the commencement of NAs, we examined the factors involved in developing hepatocellular carcinoma, including ATX. RESULTS: The ATX levels showed a gradual and significant decrease during the observation period of up to 10 years. Multivariable analysis showed that a baseline ATX/upper limits of normal ratio ≥1.214, age, and alkaline phosphatase levels were independent risk factors for hepatocellular carcinoma development. The combination of age and ATX/upper limits of normal ratio was used to stratify the high-risk groups for liver carcinogenesis. CONCLUSIONS: A decrease in ATX levels up to 10 years after the commencement of therapy suggested that ATX is a helpful biomarker in evaluating fibrosis in patients undergoing long-term NA therapy. Furthermore, this study showed that combining age and the baseline ATX/upper limits of normal ratio may help identify high-risk carcinogenesis groups.

Significance of changes in tumor markers in patients treated with durvalumab plus tremelimumab combination therapy as a surrogate marker for tumor response to unresectable hepatocellular carcinoma.

AIM: When evaluating response to immune checkpoint inhibitor therapy, the tumor sometimes initially swells before shrinking and ultimately responding, also called pseudo-progression. In this study, we analyzed whether tumor markers were useful for reflecting the treatment response. METHODS: Thirty-three patients who were treated with durvalumab plus tremelimumab combination therapy (Dur + Tre) were enrolled. Their functional reserve was Child-Pugh grade A. Their tumor markers α-fetoprotein (AFP), des-γ-carboxy prothrombin (DCP), or AFP-Lectin 3 fraction (AFP-L3) were positive. Tumor markers were evaluated before treatment and at 1, 4, and 8 weeks after the start of treatment. The first radiological evaluation was carried out at 4 weeks and the second evaluation at 8-12 weeks. The responders included those with complete response and partial response and the nonresponders included those with stable disease (SD) and progression disease at best response evaluated by Response Evaluation Criteria in Solid Tumors. RESULTS: In the responder group, the change ratio of AFP, DCP, and AFP-L3 specifically decreased at 8 weeks. In the nonresponder group, the change ratio of DCP specifically increased at 4 weeks. The optimal cut-off value to divide responders and nonresponders at 4 weeks was approximately -40%. The ratio of responders was 72.7% in the patients whose AFP or DCP decreased over 40% at 4 weeks. CONCLUSIONS: The change in tumor markers is a more useful predicter of tumor response to Dur + Tre than imaging evaluation alone.

Time trend of outcomes according to systemic therapy for patients with unresectable hepatocellular carcinoma: A single-institution study.

BACKGROUND: We have been able to use molecular targeted agents for unresectable hepatocellular carcinoma since 2009, and immune checkpoint inhibitors have been approved in recent years. We assessed the efficacy of systemic therapy in Hiroshima University Hospital by each era. METHODS: A total of 357 patients who were treated with sorafenib, lenvatinib, atezolizumab plus bevacizumab combination therapy, or durvalumab plus tremeliumab combination therapy as first-line systemic therapy in our hospital from November 2009 to December 2023 were enrolled in this retrospective cohort study. We divided the years from 2009 to 2023 into the following three periods: cohort I, 2009-2016, the single-molecular targeted agent era; cohort II, 2017-2020, the multi-molecular targeted agent era; and cohort III, 2020-2023, the immuno-oncology era. RESULTS: The median survival time was 9.5 months in cohort I, 15.8 months in cohort II, and 20.2 months in cohort III. The median survival time in cohort III was significantly (p < 0.01) longer than in the other cohorts. The overall response rate by mRECIST was 4.1% in cohort I, 28.7% in cohort II, and 47.2% in cohort III. The disease control rate was 41.6% in cohort I, 61.2% in cohort II, and 73.6% in cohort III. Both overall response rate and disease control rate significantly increased by era. CONCLUSIONS: We consider that advancements in systemic therapy, along with changes in treatment strategies, such as sequential therapy after progression, contribute to the prolonged prognosis across different eras.

Hepatitis B Virus (HBV) Upregulates TRAIL-R3 Expression in Hepatocytes Resulting in Escape From Both Cell Apoptosis and Suppression of HBV Replication by TRAIL.

BACKGROUND: Hepatitis B virus (HBV) evades host immunity by regulating intracellular signals. To clarify this immune tolerance mechanism, we performed gene expression analysis using HBV-infected humanized mouse livers. METHODS: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 3 (TRAIL-R3) was significantly upregulated in livers of HBV-infected human hepatocyte transplanted mice by cDNA microarray and next-generation sequencing. We analyzed the significance of TRAIL-R3 upregulation in HBV infection using human hepatocyte transplanted mice and HepG2 cell lines. RESULTS: TRAIL-R3 induction by HBV infection was verified by in vitro and in vivo HBV replication models, and induction was inhibited by antiviral nucleot(s)ide analogue treatment. TRAIL-R3 transcription was regulated by the TRAIL-R3 promoter at -969 to -479 nucleotides upstream from the transcription start site, and by hepatitis B x (HBx) via activation of nuclear factor-κB (NF-κB) signal. TRAIL not only induced cell apoptosis but also inhibited HBV replication. TRAIL-R3 upregulation could inhibit both TRAIL-dependent apoptosis in HBV-infected hepatocytes and TRAIL-mediated suppression of HBV replication. CONCLUSIONS: These results suggest a mechanism by which HBV persists by escaping host immunity through upregulation of TRAIL-R3. Development of novel drugs to inhibit this escape system might lead to complete HBV elimination from human hepatocytes.

Molecular Signature Predictive of Long-Term Liver Fibrosis Progression to Inform Antifibrotic Drug Development.

BACKGROUND & AIMS: There is a major unmet need to assess the prognostic impact of antifibrotics in clinical trials because of the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression. METHODS: A fibrosis progression signature (FPS) was defined to predict fibrosis progression within 5 years in patients with hepatitis C virus and nonalcoholic fatty liver disease (NAFLD) with no to minimal fibrosis at baseline (n = 421) and was validated in an independent NAFLD cohort (n = 78). The FPS was used to assess response to 13 candidate antifibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n = 78) and cenicriviroc in patients with nonalcoholic steatohepatitis enrolled in a clinical trial (n = 19, NCT02217475). A serum protein-based surrogate FPS was developed and tested in a cohort of compensated cirrhosis patients (n = 122). RESULTS: A 20-gene FPS was defined and validated in an independent NAFLD cohort (adjusted odds ratio, 10.93; area under the receiver operating characteristic curve, 0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacologic target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate antifibrotics identified rational combination therapies based on epigallocatechin gallate, which were validated for enhanced antifibrotic effect in ex vivo culture of clinical liver tissues. In patients with nonalcoholic steatohepatitis treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of the PPARα pathway was absent in patients without fibrosis improvement, suggesting a benefit of combining PPARα agonism to improve the antifibrotic efficacy of cenicriviroc. A 7-protein serum protein-based surrogate FPS was associated with the development of decompensation in cirrhosis patients. CONCLUSION: The FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform antifibrotic drug development.

The Analysis of Muscle Volume Measured by Bioelectrical Impedance in Patients with Hepatocellular Carcinoma Treated with First-Line Atezolizumab plus Bevacizumab Combination Therapy or First-Line Lenvatinib.

INTRODUCTION: Measurements of body composition, such as the skeletal muscle index (SMI), are useful for predicting prognosis in hepatocellular carcinoma (HCC). This study aimed to analyze the relationship between skeletal muscle changes during therapy with atezolizumab plus bevacizumab (Atezo + Beva) or lenvatinib (Len) and the association between SMI and prognosis. METHODS: Patients with advanced HCC and Child-Pugh A status received Atezo + Beva or Len as first-line systemic chemotherapy. We assessed prognosis and body composition obtained by bioelectrical impedance analysis. RESULTS: A total of 109 patients received treatment (Atezo + Beva, n = 47; Len, n = 62). During treatment, the arm SMI was reduced in the Len group and maintained in the Atezo + Beva group. The extracellular water to total body water ratio (ECW/TBW) increased significantly in both groups during treatment. In the Atezo + Beva group, no factor was associated with prognosis. Multivariate analysis showed that in the Len group, the arm SMI (hazard ratio [HR], 0.5; 95% CI: 0.26-0.89; p = 0.02), ECW/TBW (HR: 2.7; 95% CI: 1.21-6.01; p = 0.01), and Child-Pugh score (HR: 2.3; 95% CI: 1.31-6.13; p = 0.004) were associated with progression-free survival. CONCLUSION: Assessing body composition with BIA before Atezo + Beva and Len treatment may be useful.

Impact and usefulness of the transition to the new MAFLD classification for non-B, non-C HCC: a retrospective cohort study.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) represents a new classification system for fatty liver disease. In this study, we investigated the clinical characteristics of patients with MAFLD-hepatocellular carcinoma (HCC) in comparison with those with nonalcoholic fatty liver disease (NAFLD) and considered the validity and challenges of the new criteria. METHODS: This study included 237 untreated non-B, non-C HCC patients with hepatic steatosis. We examined the profile and laboratory findings of patients with MAFLD-HCC and NAFLD-HCC. We also classified MAFLD-HCC patients according to the factors on which the diagnosis was based and compared their clinical characteristics. RESULTS: A total of 222 (94%) and 101 (43%) patients were diagnosed with MAFLD and NAFLD, respectively. MAFLD-HCC patients were more likely to be male than NAFLD-HCC, but there were no significant differences in metabolic indices, noninvasive liver fibrosis score or HCC status. In a study of MAFLD-HCC patients by diagnostic factor, those with overweight only were younger and had advanced liver fibrosis histologically, and when limited to patients younger than 70 years, the majority were overweight. Redefinition of overweight as BMI ≥ 25 reduced the number of MAFLD-HCC patients by only 5, from 222 to 217. CONCLUSIONS: MAFLD accounted for the majority of non-B, non-C HCC cases with hepatic steatosis. Examination of additional cases and revision of the detailed criteria is needed so that it can be used to efficiently select patients with fatty liver who are at high risk of developing HCC.

Correlation between serum pro-inflammatory cytokine levels and the prognosis of the patients with acute liver failure.

BACKGROUND AND AIM: The prognosis of acute liver failure (ALF) remains poor, and liver transplantation is an alternative treatment option. Assessing the prognosis of ALF is important in determining treatment strategies. Here, we investigated clinical factors including serum pro-inflammatory cytokine levels that are associated with the prognosis of ALF. METHODS: Sixty-six patients who developed ALF were enrolled in this study. Serum concentrations of 12 pro-inflammatory cytokines were measured on admission. The prognosis and factors associated with survival and development of hepatic coma were analyzed. RESULTS: Of 66 patients, 4 patients underwent liver transplantation, and 49 patients were rescued without liver transplantation, while the remaining 13 patients died. Serum concentrations of interleukin (IL)-1ß, IL-4, IL-6, IL-8, IL-13, TNF, IFN -γ, IP-10, and G-CSF were significantly elevated in ALF patients. IL-4 and IL-8 levels were higher in patients who underwent liver transplantation or died than in rescued patients. Multivariable analysis identified age ≥ 55 years and IL-4 ≥ 1.2 pg/mL on admission as independent factors for mortality. Serum IL-8 levels were higher in patients with hepatic coma, and prothrombin-international normalized ratio ≥ 3.5 and IL-8 ≥ 77.2 pg/mL on admission were associated with development of hepatic coma after admission. CONCLUSION: Serum levels of several pro-inflammatory cytokines were elevated in ALF patients. IL-4 and IL-8 were correlated with survival and development of hepatic coma after admission, respectively. Measurement of serum pro-inflammatory cytokines seems to be useful for the management of ALF.

The presence of vessels encapsulating tumor clusters is associated with an immunosuppressive tumor microenvironment in hepatocellular carcinoma.

Recently, a distinct vascular pattern in hepatocellular carcinoma (HCC) called vessels encapsulating tumor-forming clusters (VETC) has received attention because of its association with poor prognosis. However, little is known about the mechanism by which VETC promotes an aggressive phenotype at the molecular level. In our study, the association between differences in stepwise signal intensity in the HB phase and molecular subtypes and somatic mutations associated with the immune microenvironment were investigated using the International Cancer Genome Consortium (ICGC) cohort (66 patients). To our knowledge, this is the first study to analyze the molecular patterns of VETC using RNA-Seq data. The VETC+ HCC group showed significantly lower overall survival and higher cumulative incidence of extrahepatic metastasis after curative hepatic resection than the VETC- HCC group. The VETC+ group exhibited molecular features indicative of lower immune activation than the VETC- group, suggesting that tumor cells in the VETC+ group were more likely to escape from the immune response, which could lead to the shorter OS (Overall survival) and higher risk of metastasis. On the other hand, gene expression levels of fibroblast growth factor receptors were upregulated in VETC+ HCC, suggesting that VETC+ HCC might benefit from lenvatinib treatment. Our results demonstrate that VETC+ HCC was associated with the suppression of tumor immune responses at the molecular level.

Hepatic venous pressure gradient after balloon-occluded retrograde transvenous obliteration and liver stiffness measurement predict the prognosis of patients with gastric varices.

BACKGROUND: Balloon-occluded retrograde transvenous obliteration (BRTO) is a treatment option for patients with gastric varices (GVs). This study aimed to clarify the clinical significance of portal hypertension estimated by the hepatic venous pressure gradient (HVPG), subsequent exacerbation of esophageal varices (EVs), and prognosis of patients who underwent BRTO for GVs. METHODS: Thirty-six patients with GVs treated with BRTO were enrolled in this study, and their HVPG was measured before (pre-HVPG) and on the day after BRTO (post-HVPG). After BRTO, patients were followed-up for a median interval of 24.5 (3-140) months. Clinical factors related to EVs exacerbation and prognosis after BRTO were retrospectively analyzed. RESULTS: Post-HVPG increased compared to pre-HVPG in 21 out of 36 patients (58%), and post-HVPG was overall significantly higher compared to pre-HVPG (P = 0.009). During the observation period, 19 patients (53%) developed EVs exacerbation, and the cumulative EVs exacerbation rates at 1, 3 and 5 years after BRTO were 27%, 67%, and 73%, respectively. Pre-HVPG was not related to EVs exacerbation, although elevation of post-HVPG to ≥ 13 mmHg (P < 0.01) and high level of serum aspartate aminotransferase (P < 0.05) were significant independent risk factors for EVs exacerbation after BRTO. Fourteen patients (38.9%) died during the observation period. An elevated value of liver stiffness measurement (LSM) of ≥ 21 kPa was a significant independent risk factor for poor prognosis after BRTO (P < 0.05). CONCLUSIONS: HVPG increases after BRTO. HVPG after BRTO has greater predictive ability for subsequent EVs exacerbation than HVPG before BRTO. LSM is a potential prognostic parameter in patients who undergo BRTO.

Efficacy and safety of chemoradiation therapy using one-shot cisplatin via hepatic arterial infusion for advanced hepatocellular carcinoma with major macrovascular invasion: a single-arm retrospective cohort study.

BACKGROUND: Patients with hepatocellular carcinoma (HCC) and macrovascular invasion (MVI) who receive systemic chemotherapy have a poor prognosis. This study aimed to determine if one-shot cisplatin (CDDP) chemotherapy via hepatic arterial infusion (HAI) combined with radiation therapy (RT) prior to systemic chemotherapy could improve the outcomes of these patients. METHODS: This study consisted of 32 HCC patients with the following eligibility criteria: (i) portal vein invasion 3/4 and/or hepatic vein invasion 2/3; (ii) received one-shot CDDP via HAI; (iii) received RT for MVI, (iv) a Child-Pugh score ≤ 7; and (v) an Eastern Clinical Oncology Group Performance Status score of 0 or 1. To determine the therapeutic effect, we collected information on patient characteristics and took contrast-enhanced computed tomography at the start of the therapy and every 2 to 4 months after the start of therapy. We evaluated the overall response of the tumor and tumor thrombosis according to modified Response Evaluation Criteria in Solid Tumors. We assessed patient data using the Mann-Whitney U and Fisher exact tests and evaluated overall survival and progression-free survival using the log-rank test. RESULTS: The overall response rate at the first evaluation performed a median of 1.4 weeks after HAI was 16% for the main intrahepatic tumor and 59% for the MVI. The best responses were the same as those of the first-time responses. The duration of median survival was 8.6 months, and progression-free survival of the main intrahepatic tumor was 3.2 months. Predictive factors for overall survival were the relative tumor volume in the liver and the first therapeutic response of MVI. There were no severe adverse events or radiation-induced hepatic complications. CONCLUSIONS: One-shot CDDP via HAI and RT were well tolerated and showed immediate and favorable control of MVI. Thus, this combination shows potential as a bridging therapy to systemic chemotherapy.

Underestimation of impaired glucose tolerance and usefulness of a continuous glucose monitoring system in chronic liver disease.

BACKGROUND AND AIM: The prevalence of glucose intolerance in chronic liver disease patients is high, but glucose intolerance may be overlooked in a single blood test. The purpose of this study is to evaluate blood glucose variability in patients with chronic liver disease by a continuous glucose monitoring system (CGMS) and to examine the discrepancy between hemoglobin A1c (HbA1c) levels estimated from average blood glucose levels and HbA1c. METHODS: This study included 335 patients with chronic liver disease associated with glucose intolerance. A fasting blood test and 72-h CGMS were performed. The estimated HbA1c was calculated from the average blood glucose level, and the correlation between hepatic functional reserve and blood glucose-related parameters was analyzed. From the obtained data, we created a new formula to calculate HbA1c without using CGMS. RESULTS: As hepatic functional reserve decreased, average blood glucose and insulin resistance increased while HbA1c decreased (P < 0.0001). The discrepancy between the estimated HbA1c calculated from the mean blood glucose level and the serum HbA1c (ΔHbA1c) increased as the liver reserve decreased. Using multiple regression analysis, a formula based on fasting blood glucose, HbA1c, body mass index, albumin, and liver function was constructed, and its validity was demonstrated in a study using a different control group. CONCLUSIONS: Hemoglobin A1c may be underestimated because of decreased hepatic functional reserve. CGMS was useful in assessing accurate glycemic control of blood glucose and in detecting postprandial hyperglycemia and nocturnal hypoglycemia. Patients with chronic hepatic impairment should be corrected for hepatic functional reserve before glycemic control.

Off-Target In Vitro Profiling Demonstrates that Remdesivir Is a Highly Selective Antiviral Agent.

Remdesivir (RDV, GS-5734), the first FDA-approved antiviral for the treatment of COVID-19, is a single diastereomer monophosphoramidate prodrug of an adenosine analogue. It is intracellularly metabolized into the active triphosphate form, which in turn acts as a potent and selective inhibitor of multiple viral RNA polymerases. RDV has broad-spectrum activity against members of the coronavirus family, such as SARS-CoV-2, SARS-CoV, and MERS-CoV, as well as filoviruses and paramyxoviruses. To assess the potential for off-target toxicity, RDV was evaluated in a set of cellular and biochemical assays. Cytotoxicity was evaluated in a set of relevant human cell lines and primary cells. In addition, RDV was evaluated for mitochondrial toxicity under aerobic and anaerobic metabolic conditions, and for the effects on mitochondrial DNA content, mitochondrial protein synthesis, cellular respiration, and induction of reactive oxygen species. Last, the active 5'-triphosphate metabolite of RDV, GS-443902, was evaluated for potential interaction with human DNA and RNA polymerases. Among all of the human cells tested under 5 to 14 days of continuous exposure, the 50% cytotoxic concentration (CC50) values of RDV ranged from 1.7 to >20 µM, resulting in selectivity indices (SI, CC50/EC50) from >170 to 20,000, with respect to RDV anti-SARS-CoV-2 activity (50% effective concentration [EC50] of 9.9 nM in human airway epithelial cells). Overall, the cellular and biochemical assays demonstrated a low potential for RDV to elicit off-target toxicity, including mitochondria-specific toxicity, consistent with the reported clinical safety profile.

Key Metabolic Enzymes Involved in Remdesivir Activation in Human Lung Cells.

Remdesivir (RDV; GS-5734, Veklury), the first FDA-approved antiviral to treat COVID-19, is a single-diastereomer monophosphoramidate prodrug of an adenosine analogue. RDV is taken up in the target cells and metabolized in multiple steps to form the active nucleoside triphosphate (TP) (GS-443902), which, in turn, acts as a potent and selective inhibitor of multiple viral RNA polymerases. In this report, we profiled the key enzymes involved in the RDV metabolic pathway with multiple parallel approaches: (i) bioinformatic analysis of nucleoside/nucleotide metabolic enzyme mRNA expression using public human tissue and lung single-cell bulk mRNA sequence (RNA-seq) data sets, (ii) protein and mRNA quantification of enzymes in human lung tissue and primary lung cells, (iii) biochemical studies on the catalytic rate of key enzymes, (iv) effects of specific enzyme inhibitors on the GS-443902 formation, and (v) the effects of these inhibitors on RDV antiviral activity against SARS-CoV-2 in cell culture. Our data collectively demonstrated that carboxylesterase 1 (CES1) and cathepsin A (CatA) are enzymes involved in hydrolyzing RDV to its alanine intermediate MetX, which is further hydrolyzed to the monophosphate form by histidine triad nucleotide-binding protein 1 (HINT1). The monophosphate is then consecutively phosphorylated to diphosphate and triphosphate by cellular phosphotransferases. Our data support the hypothesis that the unique properties of RDV prodrug not only allow lung-specific accumulation critical for the treatment of respiratory viral infection such as COVID-19 but also enable efficient intracellular metabolism of RDV and its MetX to monophosphate and successive phosphorylation to form the active TP in disease-relevant cells.

Novel drug resistance-associated substitutions against pibrentasvir emerged in genotype 1b hepatitis C virus-infected human hepatocyte transplanted mice.

Combination therapy with glecaprevir and pibrentasvir (PIB) has high efficacy for patients with hepatitis C virus (HCV) infection except among those who experienced NS5A-P32 deletion (del) mutation during prior DAA treatment failure. However, some patients fail to achieve SVR through combination treatment even in the absence of NS5A-P32del. We analyzed emergence of NS5A resistance-associated substitutions (RASs) against PIB using HCV-infected mice. Male human hepatocyte transplanted mice were infected with genotype 1b wild-type HCV. Mice were treated with PIB, resulting in a transient decrease in serum HCV RNA levels but followed by relapse during the treatment. Direct sequence analysis showed emergences of various mutations in the NS5A region, including L31V/P32del, L31F/P32del/Y93H, NS5A-P29del/Y85C, and NS5A-F37Y. PIB was less effective in mice with NS5A-F37Y mutations compared to mice with wild-type HCV. NS5A-F37Y showed 5.4-fold resistance to PIB relative to wild-type based on analysis using HCV subgenomic replicon systems. The present in vivo and in vitro studies identified NS5A-F37Y as a novel RAS against PIB and showed the possibility of emergence of various NS5A RASs including P29del, P32del and F37Y following PIB treatment. These mutations might emerge and lead to failure to respond to DAA therapies including PIB-based regimens in chronic hepatitis C patients.

Serum PreS1 and HBsAg ratio reflects liver fibrosis and predicts the development of hepatocellular carcinoma in chronic hepatitis B patients.

While the preS1 region of the large hepatitis B surface protein plays an essential role in hepatitis B virus (HBV) infection, the effect of preS1 on liver fibrosis and hepatocarcinogenesis in chronic hepatitis B (CHB) patients is not well known. In this study, we measured serum preS1 levels by chemiluminescent immunoassay technology in 690 CHB patients and evaluated the correlation between serum preS1 levels and HBV, liver function markers and liver inflammation, fibrosis assessed by histological findings. Predictive factors for hepatocellular carcinoma (HCC) development in patients who had no previous history of HCC at the time of preS1 level measurement were also analysed. Median hepatitis B surface antigen (HBsAg) and preS1 levels were 3.08 log IU/mL and 98 ng/mL, respectively. PreS1 values were significantly correlated with serum HBsAg (p <0.001), hepatitis B core-related antigen (HBcrAg) (p <0.001) and HBV DNA levels (p <0.01). PreS1 values were also significantly correlated with serum alanine aminotransferase levels (p <0.001) and were significantly higher in patients who had higher grading of liver inflammatory activity (p <0.05). HBsAg level was correlated, but preS1/HBsAg ratio reflected liver fibrosis staging more directly than HBsAg alone. Multivariate analysis identified age ≥53 years (hazard ratio [HR], 18.360 for <53 years; p = 0.021) and preS1/HBsAg ratio ≥0.12 (HR, 6.205 for <0.12; p = 0.040) as significant and independent factors for HCC development in CHB patients. The preS1/HBsAg ratio directly reflects liver fibrosis, and the ratio might be a predictive marker for HCC development in CHB patients.

Abatacept treatment for patients with severe acute hepatitis caused by hepatitis B virus infection-Pilot study.

Although glucocorticoids have been used for immunosuppression of patients with primary hepatitis B virus (HBV) infection-induced severe hepatitis, the treatment is associated with a high frequency of adverse events. We conducted a pilot study for evaluating the efficacy and safety of abatacept, a cytotoxic T lymphocyte antigen-4 immunoglobulin (CTLA4), for acute hepatitis B. Five patients with severe acute hepatitis B (prothrombin activity ≤ 60%) were treated for immunosuppression by abatacept. Four patients received abatacept concurrently with methylprednisolone, and another patient was treated with abatacept alone. Rapid decrease in serum alanine aminotransferase levels, increase in prothrombin activity and improvement of general condition were obtained in four out of five patients. The patient with the most severe hepatitis underwent liver transplantation due to exacerbation of hepatitis in spite of treatment with both abatacept and methylprednisolone. None of the patients developed significant adverse events associated with the use of abatacept. Hepatitis B surface antigen (HBsAg) became negative in all five patients. The effect of abatacept and methylprednisolone for severe hepatitis B was compared using a mouse model. Rapid reduction in mouse serum HBV DNA and human albumin levels and elevation of serum interferon-gamma and granzyme A levels were observed in HBV-infected human hepatocyte-transplanted immunodeficient mice that were administered human peripheral blood mononuclear cells. These hepatocyte injuries were inhibited to a greater extent by abatacept compared to methylprednisolone. Abatacept might be an effective therapy alternative to methylprednisolone to reduce acute massive liver damage for patients with severe acute hepatitis caused by HBV infection.

Comparison of the Clinical Outcome of Ramucirumab for Unresectable Hepatocellular Carcinoma with That of Prior Tyrosine Kinase Inhibitor Therapy.

INTRODUCTION: The clinical outcome of ramucirumab in multi-molecular targeted agent (MTA) sequential therapy for unresectable hepatocellular carcinoma (u-HCC) was assessed in comparison with that of prior tyrosine kinase inhibitor (TKI) therapy. METHODS: Sixteen patients who received ramucirumab as part of multi-MTA sequential therapy for u-HCC were enrolled in a retrospective, cohort study. Ramucirumab was started as 2nd line in 7 patients, 3rd line in 5 patients, and 4th line in 4 patients. RESULTS: The overall response rate was 6.3%, the disease control rate (DCR) was 50.0%, median progression-free survival was 2.0 months (evaluated by mRECIST), median overall survival (OS) with ramucirumab was 7.9 months, and the median OS from 1st-line therapy was 28.1 months. One month after the start of ramucirumab, α-fetoprotein (AFP) decreased in 6 of 12 cases (50.0%), and the DCR in AFP-decreased cases was 83.3%. The DCR of ramucirumab was 66.7% in cases in which disease control was obtained by prior TKI therapy, whereas it was 0.0% in the cases in which disease control was not obtained by prior TKI therapy. Examining the adverse events, no new safety concerns were confirmed. CONCLUSION: The AFP response to ramucirumab and the treatment response to prior TKI therapy are associated with treatment response to ramucirumab.