Aim Hepatitis B virus genotype B (HBV/B) has been reported to have less risk of liver cirrhosis and hepatocellular carcinoma (HCC), but long‐term observation has rarely been reported. We aimed to clarify the characteristics of HBV/B in nucleos(t)ide analog‐treated patients in an area where HBV/B is more prevalent than in other areas of Japan. Methods A total of 498 chronically HBV‐infected patients treated with nucleos(t)ide analog (lamivudine, entecavir, tenofovir disoproxil fumarate, or tenofovir alafenamide fumarate) for >6 months (mean 70.6 months) were included from nine hospitals in northeast Japan. The frequencies of hepatitis B surface antigen loss and HCC occurrence were analyzed. Results Among 427 patients whose genotype could be determined, 34.0% and 64.4% were infected with HBV/B and genotype C (HBV/C), respectively. The age of patients with HBV/B was significantly older than those with HBV/C (57.7 vs. 48.1). The cumulative rate of hepatitis B surface antigen loss was significantly higher in HBV/B than in HBV/C (3.6% vs. 0.7% at 10 years). Among 480 patients without HCC history, HCC occurrence was found in 40 patients (13.4% at 10 years). There was no cumulative rate difference of HCC occurrence among the genotypes, but after propensity score matching for age/sex, it was significantly lower in HBV/B than in HBV/C (5.3% vs. 18.5% at 10 years). Conclusions Although a lower rate of HCC occurrence in HBV/B was shown by an age/sex‐matched analysis than that in HBV/C, patients with HBV/B were significantly older and had a comparative risk of HCC occurrence in nucleos(t)ide analog‐treated patients.

Hepatitis B virus (HBV) infection is a worldwide health problem because of its potential to cause liver cirrhosis and hepatocellular carcinoma. Silibinin is a constituent of an extract of milk thistle, which is empirically used as a herbal medicine for the protection of liver, but its detailed effects on HBV are unknown. Because a previous study reported that silibinin hinders clathlin-mediated endocytosis (CME), we aimed to test whether silibinin inhibits the entry of HBV into hepatocytes. Using HepG2-NTCP-C4 cells, which overexpress sodium taurocholate cotransporting polypeptide (NTCP), it was shown that silibinin inhibited HBV infection dose-dependently. Similar effects were observed using human primary hepatocytes (PXB-cells). Additionally, a combination of silibinin and entecavir reduced HBV DNA in the culture supernatant more than either mono-treatment alone in HepG2-NTCP-C4 cells that had already been infected with HBV. Silibinin decreased transferrin uptake but did not affect the interaction between the HBV envelope and NTCP, suggesting that silibinin might inhibit HBV infection by hindering CME. In conclusion, this study showed that silibinin inhibits HBV entry in vitro.

Aim Macrovesicular steatosis around the central vein (zone 3) is one of the pathological features of non‐alcoholic fatty liver disease or steatohepatitis (NAFLD/NASH). The aim of this study is to elucidate precisely the association between the area of lipid droplets (LDs) and the plasma metabolic parameters in patients with NAFLD/NASH. Methods Eighty patients with NAFLD/NASH diagnosed by needle biopsy were enrolled. The LDs around zone 3 were counted automatically by image processing software, the total area of LDs (TLDs), the maximum area of LDs (MAXLDs), the average area of LDs (AVELDs) and the heterogeneity by the coefficient of variation (CV [%]) were quantified. The correlations between these values and plasma metabolic parameters were analyzed. We evaluated the association between branched chain amino acids (BCAAs) and the heterogeneity of LDs in hepatocytes in vitro and in vivo. Results The MAXLDs was significantly correlated with more metabolic parameters than AVELDs and TLDs. The level of BCAAs was independently associated with the CV among the metabolic parameters. In early stage NAFLD, aspartate and alanine aminotransferase were significantly higher in the high CV group than in the low CV group. The high concentration of BCAAs increased the CV of LDs in hepatocytes accompanied by the expression of phosphor‐p70 S6 kinase and sterol regulatory element‐binding protein 1 in vitro. A high BCAA diet induced high heterogeneity of LDs around zone 3 in ob/ob mice. Conclusions The levels of BCAAs were associated with the LD heterogeneity of hepatocytes around zone 3 in patients with NAFLD/NASH.

Hepatitis B virus (HBV) reactivation from resolved infection is a serious problem which can frequently lead to severe hepatitis. Generally, it occurs several months after the start of immunosuppressive therapy; however, it sometimes occurs a few years later, even after cessation of therapy. Here we report a patient with de novo HBV infection who had received corticosteroid therapy for pemphigus vulgaris for 6 years. Full-genome HBV sequence analysis using serial serum samples revealed that the patient was infected with HBV subgenotype C2, which had the G1896R mixed mutation in the precore region. Interestingly, it had the immune escape mutations P120A and G145R in the S gene. Because both hepatitis B surface antigen and antibodies to hepatitis B surface antigen (HBsAb) were positive at the onset of the de novo infection, it was considered that HBV with these mutations escaped from neutralization by the pre-existing HBsAbs. This case indicates that HBV reactivation with an immune escape mutant can occur long after immunosuppressive therapy.

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Viruses are considered to use vesicular trafficking in infected cells, but the details of assembly/release pathways of hepatitis B virus (HBV) are still unknown. To identify key regulators of HBV production, we performed short interfering RNA (siRNA) screening for Rab proteins, which are considered to act as molecular switches in vesicular trafficking using HepG2.2.15 cells. Among 62 Rab proteins, the suppression of Rab5B most significantly increased HBV DNA in the culture supernatant. Surprisingly, 5 days after the transfection of Rab5B siRNA, HBV DNA in the supernatant was increased more than 30-fold, reflecting the increase of infectious HBV particles. Northern blotting showed that transcription of 2.4/2.1-kb mRNA coding envelope proteins containing large hepatitis B surface protein (LHBs) was increased. Analysis of hepatocyte nuclear factors (HNFs) showed that transcription of HNF4␣, which is known to enhance 2.4-kb mRNA transcription, was regulated by Rab5B. Also, it was revealed that LHBs had accumulated in the endoplasmic reticulum (ER) after Rab5B depletion but not in the multivesicular body (MVB), which is thought to be an organelle utilized for HBV envelope formation. Therefore, it was considered that Rab5B is required for the transport of LHBs from the ER to MVB. Immunofluorescent microscopy showed that HBs proteins, including LHBs, colocalized with HBc in the ER of Rab5Bdepleted cells, suggesting that HBV envelopment occurs not only in the MVB but also in the ER. In conclusion, Rab5B is a key regulator of HBV production and could be a target of antiviral therapy. IMPORTANCE HBV infection is a worldwide health problem, but the mechanisms of how HBV utilizes cellular machinery for its life cycle are poorly understood. In particular, it has been unclear how the viral components and virions are transported among the organelles. The HBV budding site has been reported to be the ER or MVB, but it has not been clearly determined. In this study, siRNA-based screening of Rab proteins using HBV-expressing cells showed that Rab5B, one of the Rab5 isoforms, has important roles in late steps of the HBV life cycle. Although Rab5 is known to work on early endosomes, this study showed that Rab5B plays a role in the transport of LHBs between the ER and MVB. Furthermore, it affects the transcription of LHBs. This is the first report on the mechanisms of HBV envelope protein

Objectives We evaluated whether the treatment history of low‐dose rituximab affected safety profiles, and humoral and cellular responses induced by severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccine in healthy controls and kidney transplant recipients. Methods We enrolled 10 healthcare workers as controls, 22 kidney transplant recipients with rituximab, and 36 kidney transplant recipients without rituximab without history of coronavirus disease 2019 who received two doses of vaccine. We assessed anti‐severe acute respiratory syndrome coronavirus 2 spike antibody and the antigen‐specific T cells using enzyme‐linked immunospot against spike protein at baseline and after two doses of vaccine. Results All controls showed anti‐severe acute respiratory syndrome coronavirus 2 antibody seroconversion and enzyme‐linked immunospot positivity. Only 19/58 (33%) kidney transplant recipients experienced anti‐severe acute respiratory syndrome coronavirus 2 antibody seroconversion and 31/58 (53%) kidney transplant recipients developed enzyme‐linked immunospot assay positivity after vaccination. The anti‐severe acute respiratory syndrome coronavirus 2 antibody seroconversion rate and enzyme‐linked immunospot assay positivity rate after vaccination were not significantly different between kidney transplant recipients with or without rituximab. Multivariate regression analysis demonstrated rituximab was not associated with a lack of humoral and cellular responses to the vaccine. Conclusions Low‐dose rituximab in kidney transplant recipients did not affect humoral or cellular responses to the severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccine without severe systemic adverse events including the deterioration of kidney function.

Background High-grade meningioma (HGM) is difficult to treat, and recurrent HGM after radiotherapy has an especially poor prognosis. We retrospectively analyzed the cases of 44 consecutive patients with recurrent and refractory HGM who were treated by reactor-based boron neutron capture therapy (BNCT). Methods In 2005–2019, we treated 44 recurrent and refractory HGMs by reactor-based BNCT. We analyzed the patients’ tumor shrinkage, overall survival (OS) after initial diagnosis, OS after BNCT, progression-free survival (PFS) post-BNCT, and treatment failure patterns. Results The median OS (mOS) after BNCT and mOS after initial diagnosis were 29.6 (95%CI: 16.1–40.4) and 98.4 (95%CI: 68.7–169.4) months, respectively. The median follow-up after BNCT was 26 (6.4–103) months. The grade 2 (20 cases) and 3 (24 cases) post-BNCT mOS values were 44.4 (95%CI: 27.4–not determined) and 21.55 (10.6–30.6) months, respectively (p=0.0009). Follow-up images were obtained from 36 cases at >3 months post-BNCT; 35 showed tumor shrinkage during the observation period. The post-BNCT median PFS (mPFS) of 36 cases was 13.7 (95%CI: 8.3–28.6) months. The post-BNCT mPFS values in patients with grade 2 and 3 disease were 24.3 (95%CI: 9.8–not determined) and 9.4 (6.3–14.4) months, respectively (p=0.0024). Local recurrence was observed in only 22.2% of cases. These results showed good local tumor control and prolonged survival for recurrent HGM cases. Conclusions Most of these cases had relatively large tumor volumes. The proportion of grade 3 patients was extremely high. Our patients thus seemed to have poor prognoses. Nevertheless, reactor-based BNCT exerted relatively good local control and favorable survival for recurrent and refractory HGMs.