Recent advances in hepatitis E virus research and the Japanese clinical practice guidelines for hepatitis E virus infection.

Acute hepatitis E was considered rare until reports emerged affirming the existence of hepatitis E virus (HEV) genotypes 3 and 4 infections in Japan in the early 2000s. Extensive studies by Japanese researchers have highlighted the pivotal role of pigs and wild animals, such as wild boars and deer, as reservoirs for HEV, linking them to zoonotic infections in Japan. Currently, when hepatitis occurs subsequent to the consumption of undercooked or grilled pork, wild boar meat, or offal (including pig liver and intestines), HEV infection should be considered. Following the approval of anti-HEV immunoglobulin A antibody as a diagnostic tool for hepatitis E by Japan's Health Insurance System in 2011, the annual number of diagnosed cases of HEV infection has surged. Notably, the occurrence of post-transfusion hepatitis E promoted nationwide screening of blood products for HEV using nucleic acid amplification tests since 2020. Furthermore, chronic hepatitis E has been observed in immunosuppressed individuals. Considering the significance of hepatitis E, heightened preventive measures are essential. The Japan Agency for Medical Research and Development Hepatitis A and E viruses (HAV and HEV) Study Group, which includes special virologists and hepatologists, held a virtual meeting on February 17, 2024. Discussions encompassed pathogenesis, transmission routes, diagnosis, complications, severity factors, and ongoing and prospective vaccination or treatments for hepatitis E. Rigorous assessment of referenced studies culminated in the formulation of recommendations, which are detailed within this review. This comprehensive review presents recent advancements in HEV research and Japanese clinical practice guidelines for HEV infection.

Liver Diseases: From Bench to Bedside.

The human genome encodes at least 500 protein kinases, and among them, there are at least 90 tyrosine kinases [...].

Liver biopsy as a useful diagnostic tool for hepatic sarcoidosis: A case report.

In certain cases, it is difficult to distinguish hepatic sarcoidosis from malignant lymphoma or drug-induced liver injury and to select the proper treatment for this condition. The present study describes the case of a female patient in her 30s who was referred to the hospital due to fever, arthralgia, myalgia and abnormal liver function test results for 4 months. A laboratory examination revealed elevated levels of serum angiotensin-converting enzyme (ACE) and soluble interleukin-2 receptor (sIL-2R), as well as an increase in serum hepatic and biliary tract enzymes. Gallium scintigraphy revealed a marked uptake in the liver, as well as an uptake in the mediastinal, inguinal and external iliac lymph nodes. Magnetic resonance imaging revealed extensive hepatosplenomegaly with multiple non-enhancing splenic nodules. Hepatic sarcoidosis was diagnosed by a liver biopsy as non-caseating hepatic granulomas, and multinucleated giant cells were observed. The patient responded to treatment with 20 mg prednisolone daily, and exhibited an improvement in her symptoms. An improvement was also observed in her serum levels of ACE, sIL-2R, and serum hepatic and biliary tract enzymes; decreased gallium uptake in the liver was also observed. On the whole, the present case report reconfirms that liver biopsy is a useful diagnostic tool for hepatic sarcoidosis.

English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology.

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

Elderly patient with unresectable advanced­stage hepatocellular carcinoma who received atezolizumab plus bevacizumab and achieved a complete response: A case report.

Hepatocellular carcinoma (HCC) is a common malignancy with a poor prognosis, particularly in patients with advanced-stage disease, elderly individuals and/or in those with poor liver function. Immune checkpoint inhibitor-containing therapies, such as atezolizumab, an anti-programmed death ligand-1 monoclonal antibody, plus bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, may be effective and safe therapeutic options for elderly patients with advanced-stage HCC. The present study reports the case of a male patient his 80s who consumed alcohol with unresectable advanced-stage HCC who received combination therapy comprising atezolizumab plus bevacizumab for 6 months. The patient achieved a complete response despite the discontinuation of treatment due to nephrotoxicity. It is critical for patients with HCC and a Child-Pugh A grade to continue therapy for HCC, even if they are older. The development of more effective therapies is required for patients with advanced-stage HCC with a worse liver function than those with a Child-Pugh A grade. The case described in the present study demonstrates the need for obtaining further evidence regarding the efficacy and safety of the combination therapy including atezolizumab plus bevacizumab for elderly patients with advanced-stage HCC.

Severe hepatitis E virus genotype 3b in a patient with alcohol­associated liver disease: A case report.

Hepatitis E virus (HEV) infection occasionally causes acute-on-chronic liver failure in patients with alcohol-associated cirrhosis. These reports have been published mainly from highly HEV genotype 1-endemic countries. The present study describes the case of a patient with severe HEV genotype 3b infection and alcohol-associated liver disease. A male patient in his 70s who consumed alcohol, and who had begun consuming alcohol at the age of 12, had high levels of alanine aminotransferase (ALT) and total bilirubin. The peak levels of ALT and total bilirubin were 1,067 IU/l and 26.3 mg/dl, respectively. A computed tomography scan revealed an atrophic liver. Upon admission, both anti-HEV immunoglobulin A and HEV RNA were positive, and his HEV was genotype 3b. He also had chronic kidney disease, as his estimated glomerular filtration rate was <45 ml/min/1.73 m2, and ribavirin could not be used. The abnormal levels of the liver function parameters of the patient gradually improved due to conservative treatment, and he was discharged on day 43. On the whole, the present study demonstrates that careful attention should be paid to patients with viral hepatitis, including hepatitis E, when alcohol-associated liver disease is present. Novel anti-HEV drugs need to be developed for severe HEV infections with chronic kidney disease.

Complete response and long­term survival after stereotactic body radiotherapy in a patient with liver metastasis from α­fetoprotein­producing gastric cancer: A case report.

α-Fetoprotein (AFP)-producing gastric carcinoma (GC) (AFPGC) is a special subtype of GC that is clinically characterized by a high incidence of liver metastasis and poor prognosis. The present study reported the case of a patient with AFPGC who showed complete response (CR) after stereotactic body radiotherapy (SBRT) for liver metastasis. A 76-year-old male patient underwent total gastrectomy with D2 lymph node dissection for GC. The excised tumor was diagnosed as AFPGC due to the patient's high serum AFP level (3,763 ng/ml) and AFP expression on immunohistochemistry. The patient was diagnosed with liver metastasis two months after the surgery. 18F-fluorodeoxyglucose positron emission tomography indicated that the metastasis was a single recurrent focus. Although the patient underwent seven cycles of chemotherapy with S-1-based regimens, the metastatic tumor showed only a minor response despite the decrease in serum AFP levels. To realize high-quality disease control, SBRT was performed on the liver tumor (total dose of 48 Gy in four fractions). The metastasis showed a significant response two weeks after the completion of SBRT and CR two years later. CR was sustained and the patient survived with no evidence of recurrence 62 months after the diagnosis of liver metastasis. Literature data on the efficacy of radiotherapy for liver metastasis from AFPGC remain scarce. The present case report suggests that SBRT has high efficacy for oligometastatic diseases and may be included as an indication for the treatment of liver metastasis from AFPGC.

Recent advances in hepatitis A virus research and clinical practice guidelines for hepatitis A virus infection in Japan.

In 2018, there was a hepatitis A outbreak in Japan, and hepatitis A virus (HAV) infection is considered a sexually transmitted disease. In general, patients with hepatitis A should be given attention, and this disease should be prevented more than ever. The Japan Agency for Medical Research and Development (AMED) Hepatitis A and E viruses (HAV and HEV) Study Group has worked on the project to create "Recent Advances in Hepatitis A Virus (HAV) Research and Clinical Practice Guidelines for HAV Infection in Japan". The group consists of expert hepatologists and virologists who gathered at virtual meeting on August 5, 2023. Data about the pathogenesis, infection routes, diagnosis, complications, several factors for the severities, vaccination, and current and future treatments for hepatitis A were discussed and debated for a draft version. The participants assessed the quality of cited studies. The finalized recommendations are presented in this review. The recent advances in HAV research and clinical practice for HAV infection in Japan, have been reviewed by the AMED HAV and HEV Study Group.

Involvement of proliferation of atypical hepatocytes and CDT 1 in the liver cancer of rats administered the diethylnitrosamine.

We have reported that extent of proliferation of atypical hepatocytes (POAH) in non-cancerous liver in hepatocellular carcinoma and chromatin licensing and DNA replication factor 1 (CDT1) are associated with postoperative recurrence. Here, we investigated whether extent of POAH and expression of CDT1 in liver are also associated with chemically induced liver cancer in rats. Male Fisher strain rats were orally administered diethylnitrosamine (DEN) in their drinking water and sacrificed at 6, 8, 12, or 14 weeks after start of DEN administration. We serially monitored changes in extent of POAH, CDT1 expression by immunohistochemistry (IHC), and CDT1 mRNA expression in liver by real-time quantitative PCR. The extent of POAH in liver progressed in a time-dependent manner after start of DEN administration. CDT1 expression was higher at 8 weeks than at 6 weeks by IHC, suggesting that CDT1 expression may be a marker of POAH severity. CDT1 mRNA expression in liver was significantly higher at 12 weeks than at 6 weeks (p<0.0001). We found that extent of POAH and the expression of CDT1 are also important factors in the development of chemical carcinogen-induced hepatocarcinogenesis. Furthermore, the association with POAH and CDT1 expression in carcinogenic process is important regardless of the cause of hepatocarcinogenesis.

Muscle Cramps in Outpatients with Liver Diseases in Tokyo, Japan.

Background and Objectives: Muscle cramps are often observed in patients with liver diseases, especially advanced liver fibrosis. The exact prevalence of muscle cramps in outpatients with liver diseases in Japan is unknown. Patients and Methods: This study examined the prevalence of, and therapies for, muscle cramps in outpatients with liver diseases in Tokyo, Japan. A total of 238 outpatients with liver diseases were retrospectively examined. We investigated whether they had muscle cramps using a visual analog scale (VAS) (from 0, none, to 10, strongest), and also investigated their therapies. Results: Muscle cramps were observed in 34 outpatients with liver diseases (14.3%); their mean VAS score was 5.53. A multivariate analysis demonstrated that older age (equal to or older than 66 years) was the only significant factor as-sociated with muscle cramps. The prevalence of muscle cramps among patients with liver diseases seemed not to be higher. The problem was that only 11 (32.4%) of 34 outpatients received therapy for their muscle cramps. Conclusions: Only age is related to muscle cramps, which is rather weak, and it is possible that this common symptom may not be limited to liver disease patients.

Masitinib Inhibits Hepatitis A Virus Replication.

The hepatitis A virus (HAV) infection causes acute hepatitis. HAV also induces acute liver failure or acute-on-chronic liver failure; however, no potent anti-HAV drugs are currently available in clinical situations. For anti-HAV drug screening, more convenient and useful models that mimic HAV replication are needed. In the present study, we established HuhT7-HAV/Luc cells, which are HuhT7 cells stably expressing the HAV HM175-18f genotype IB subgenomic replicon RNA harboring the firefly luciferase gene. This system was made by using a PiggyBac-based gene transfer system that introduces nonviral transposon DNA into mammalian cells. Then, we investigated whether 1134 US Food and Drug Administration (FDA)-approved drugs exhibited in vitro anti-HAV activity. We further demonstrated that treatment with tyrosine kinase inhibitor masitinib significantly reduced both HAV HM175-18f genotype IB replication and HAV HA11-1299 genotype IIIA replication. Masitinib also significantly inhibited HAV HM175 internal ribosomal entry-site (IRES) activity. In conclusion, HuhT7-HAV/Luc cells are adequate for anti-HAV drug screening, and masitinib may be useful for the treatment of severe HAV infection.

Molecular Mechanisms, Diagnosis and Treatments in Digestive Malignancy.

In this Special Issue, "Molecular Mechanisms, Diagnosis and Treatments in Digestive Malignancy", of the International Journal of Molecular Sciences, a total of 10 impactful articles have been published [...].

Molecular Mechanism of Chronic Viral and Non-Viral Liver Diseases.

In this Special Issue, "Molecular Mechanism of Chronic Viral and Non-viral Liver Diseases", invaluable articles have been published [...].

Gut-Microbiota Dysbiosis in Stroke-Prone Spontaneously Hypertensive Rats with Diet-Induced Steatohepatitis.

Metabolic-dysfunction-associated fatty-liver disease (MAFLD) is the principal worldwide cause of liver disease. Individuals with nonalcoholic steatohepatitis (NASH) have a higher prevalence of small-intestinal bacterial overgrowth (SIBO). We examined gut-microbiota isolated from 12-week-old stroke-prone spontaneously hypertensive-5 rats (SHRSP5) fed on a normal diet (ND) or a high-fat- and high-cholesterol-containing diet (HFCD) and clarified the differences between their gut-microbiota. We observed that the Firmicute/Bacteroidetes (F/B) ratio in both the small intestines and the feces of the SHRSP5 rats fed HFCD increased compared to that of the SHRSP5 rats fed ND. Notably, the quantities of the 16S rRNA genes in small intestines of the SHRSP5 rats fed HFCD were significantly lower than those of the SHRSP5 rats fed ND. As in SIBO syndrome, the SHRSP5 rats fed HFCD presented with diarrhea and body-weight loss with abnormal types of bacteria in the small intestine, although the number of bacteria in the small intestine did not increase. The microbiota of the feces in the SHRSP5 rats fed HFCD was different from those in the SHRP5 rats fed ND. In conclusion, there is an association between MAFLD and gut-microbiota alteration. Gut-microbiota alteration may be a therapeutic target for MAFLD.

Successful Identification of a Novel Therapeutic Compound for Hepatocellular Carcinoma Through Screening of ADAM9 Inhibitors.

BACKGROUND/AIM: MHC-class I-related chain A (MICA) functions as a ligand for natural killer group D, an activating receptor on natural killer (NK) cells, and its expression correlates with the carcinogenesis and progression of hepatocellular carcinoma (HCC). Although membranous MICA (mMICA) activates NK cells, soluble forms of MICA (sMICA), shed by cleaving enzymes, such as A disintegrin and metalloprotease (ADAM) 9, suppress NK cells. Therefore, the prevention of MICA shedding through the inhibition of ADAM9 has the potential to activate cancer immunity. Although we have discovered several ADAM inhibitors, many did not sufficiently activate NK cells without being cytotoxic, and, thus, new ADAM9 inhibitor candidates are needed. MATERIALS AND METHODS: To identify possible compounds for drug development, chemical library screening (a total of 741 compounds) was conducted using a fluorescence assay. Compounds with reduced fluorescence intensity were used as hit compounds in a subsequent analysis. Their impact on sMICA and mMICA in HCC cell lines was assessed using ELISA and flow cytometry, respectively. The cytotoxicity of NK cells was also evaluated by co-culturing NK cells with HCC cells. RESULTS: CCL347, a symmetrical compound with five benzene rings, was identified as a hit compound. CCL347 significantly reduced sMICA levels in the culture medium supernatant with negligible cytotoxicity. Although mMICA was also reduced, CCL347 successfully enhanced NK cell cytotoxicity in co-cultures of NK cells and HCC cells. CONCLUSION: CCL347 has potential as a novel therapeutic drug for HCC.

Drug Screening for Hepatitis A Virus (HAV): Nicotinamide Inhibits c-Jun Expression and HAV Replication.

Hepatitis A virus (HAV) infection often causes acute hepatitis, which results in a case fatality rate of 0.2% and fulminant hepatitis in 0.5% of cases. However, no specific potent anti-HAV drug is available on the market to date. In the present study, we focused on inhibition of HAV internal ribosomal entry site (IRES)-mediated translation and investigated novel therapeutic drugs through drug repurposing by screening for inhibitors of HAV IRES-mediated translation and cell viability using a reporter assay and cell viability assay, respectively. The initial screening of 1,158 drugs resulted in 77 candidate drugs. Among them, nicotinamide significantly inhibited HAV HA11-1299 genotype IIIA replication in Huh7 cells. This promising drug also inhibited HAV HM175 genotype IB subgenomic replicon and HAV HA11-1299 genotype IIIA replication in a dose-dependent manner. In the present study, we found that nicotinamide inhibited the activation of activator protein 1 (AP-1) and that knockdown of c-Jun, which is one of the components of AP-1, inhibited HAV HM175 genotype IB IRES-mediated translation and HAV HA11-1299 genotype IIIA and HAV HM175 genotype IB replication. Taken together, the results showed that nicotinamide inhibited c-Jun, resulting in the suppression of HAV IRES-mediated translation and HAV replication, and therefore, it could be useful for the treatment of HAV infection. IMPORTANCE Drug screening methods targeting HAV IRES-mediated translation with reporter assays are attractive and useful for drug repurposing. Nicotinamide (vitamin B3, niacin) has been shown to effectively inhibit HAV replication. Transcription complex activator protein 1 (AP-1) plays an important role in the transcriptional regulation of cellular immunity or viral replication. The results of this study provide evidence that AP-1 is involved in HAV replication and plays a role in the HAV life cycle. In addition, nicotinamide was shown to suppress HAV replication partly by inhibiting AP-1 activity and HAV IRES-mediated translation. Nicotinamide may be useful for the control of acute HAV infection by inhibiting cellular AP-1 activity during HAV infection processes.

Chronic Hepatitis C: Acute Exacerbation and Alanine Aminotransferase Flare.

The hepatitis C virus (HCV) causes acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma, as well as extrahepatic manifestations such as malignant lymphoma. Currently, direct-acting antiviral agents (DAAs) against HCV infection can lead to a sustained virological response (SVR) in almost all HCV-infected patients. In this review article, we discuss acute exacerbation and alanine aminotransferase (ALT) flare in patients with chronic HCV infection. Although acute liver failure caused by HCV infection is rare, careful attention should be paid to the cases with ALT elevation during the natural course of chronic HCV infection. HCV genotype 2 infection, the use of rituximab, and a higher dose of corticosteroid are factors associated with HCV acute exacerbation and ALT flare. Treatment regimens for cancer have been interrupted or changed due to ALT flare due to HCV infection in some patients undergoing chemotherapy for cancer. The pathogenesis of HCV acute exacerbation and ALT flare could involve cellular as well as humoral immune responses. In the DAA era, the earlier introduction of DAAs may prevent chronic HCV-infected patients with acute exacerbation and ALT flare from developing into a more severe form, although DAAs may not be effective for all of them.

Late recurrence of low-risk gastrointestinal stromal tumor of jejunum diagnosed 30 years after tumor resection: A case report and literature review.

Gastrointestinal stromal tumors (GISTs) have a significant risk of metastasis, although the degree varies in each case. The present report describes a case of late recurrence of GIST that was diagnosed 30 years after the primary tumor resection. An 80-year-old man was transported to Sanjo General Hospital (Sanjo, Japan) with hemorrhagic shock from gastrointestinal bleeding. Abdominal contrast-enhanced computed tomography revealed an 11.7-cm heterogenous tumor in the retroperitoneum adjacent to the third portion of the duodenum. The patient had a medical history of resection of 'leiomyoma' of the upper jejunum when he was 50 years old. Pathological examination using archival pathological samples revealed that the previously excised tumor was GIST because the tumor cells showed positive immunoreactivity for KIT and DOG1. Treatment was started with imatinib, a selective KIT tyrosine inhibitor, even though endoscopy failed to provide biopsy specimens. Positron emission tomography conducted on the 28th treatment day revealed that imatinib completely shut down 18F-fluorodeoxyglucose uptake in the tumor, confirming that the tumor was imatinib-sensitive. A literature review yielded 12 GIST cases wherein metastases were diagnosed >10 years after primary tumor resection. Of the 12, four were originally diagnosed as benign. Clinicians should keep in mind that GISTs were formerly confused with non-GIST tumors and that there is a risk of relapse 10 years or later after curative surgery.

Sunitinib therapy for imatinib-resistant and/or intolerant gastrointestinal stromal tumors: comparison of safety and efficacy between standard and reduced dosage regimens.

BACKGROUND: Sunitinib therapy for patients with imatinib-resistant and/or intolerant gastrointestinal stromal tumors (GISTs) often causes severe adverse events (AEs) that lead to treatment discontinuation. METHODS: We retrospectively reviewed the clinical records of imatinib-resistant and/or intolerant GIST patients who underwent sunitinib therapy in our institutions between 2007 and 2020. Forty-one patients were enrolled and divided into two groups on the basis of the starting dosage: the standard dosage group (50 mg/day, 21 patients) and the reduced dosage group (37.5 mg/day, 20 patients). Tolerability, safety and clinical efficacy of the two groups were compared. RESULTS: Three patients (14%) in the standard dosage group and another three (15%) in the reduced dosage group (P = 1.000) discontinued sunitinib therapy because of AEs. The incidences of grade 3 or more severe treatment-related AEs were 90 and 75%, respectively (P = 0.238). Two possible treatment-related deaths were noted in the standard dosage group. Clinical efficacy was comparable between the two groups: median time to treatment failure and overall survival were 4.5 months [interquartile range (IQR), 3.6-9.0] and 13.7 months (IQR, 7.5-22.9) in the standard dosage group and 4.6 months (IQR, 2.7-17.0) and 13.4 months (IQR, 9.3-36.8) in the reduced dosage group, respectively. CONCLUSIONS: The reduced dosage of 37.5 mg sunitinib tended to decrease toxicity and the incidences of severe AEs and treatment-related deaths. This reduced dosage regimen showed equivalent clinical efficacy including patient survival. The reduced dosage of 37.5 mg sunitinib can be adopted as an alternative therapy for patients with imatinib-resistant and/or intolerant GISTs.