村田 一素

Previous studies have emphasized the necessity of surveillance and control measures for hepatitis E virus (HEV) infection in wild boars, an important reservoir of HEV. To assess the current situation of HEV infection in wild boars in Japan, this study investigated the prevalence and genetic diversity of HEV among wild boars captured in 16 prefectures of Japan during 2018-2023. Serum samples from 968 wild boars were examined for anti-HEV IgG antibodies and HEV RNA. The prevalence of anti-HEV IgG varied geographically from 0 % to 35.0 %. HEV RNA was detected in 3.6 % of boars, with prevalence varying by prefecture from 0 % to 22.2 %. Genotype 3 was the most prevalent genotype (91.9 %), followed by genotype 4 (5.4 %), with one strain closely related to genotype 6. The prevalence of HEV infection among wild boars decreased from 2018/2019 to 2022/2023 with significant declines in levels of anti-HEV IgG antibodies (14.5 % vs. 6.2 %, P < 0.0001) and HEV RNA (7.6 % vs. 1.5 %, P < 0.0001). Regional analysis showed varying trends, with no HEV RNA-positive boars found in several regions in recent years. A plausible factor contributing to the decline in HEV infection is the application of countermeasures, including installing fences to prevent intrusion into pig farms, implemented in response to the emergence of classical swine fever virus (CSFV) infection in wild boars and domestic pigs, with incidents reported annually since 2018. Further investigation is warranted to explore the association between countermeasures to CSFV infection and the decrease in HEV infection among wild boars.

Previously, we developed an infectious hepatitis E virus (HEV) harboring the nanoKAZ gene in the hypervariable region of the open reading frame 1 (ORF1) of the HEV3b (JE03-1760F/P10) genome and demonstrated the usefulness for screening anti-HEV drugs that inhibit the early infection process. In the present study, we constructed another reporter HEV (HEV3b-HiBiT) by placing a minimized HiBiT tag derived from NanoLuc luciferase at the 3 & PRIME;-end of the viral capsid (ORF2) coding sequence. It replicated efficiently in PLC/PRF/5 cells, produced membrane-associated particles identical to those of the parental virus, and was genetically stable and infectious. The HiBiT tag was fused to both secreted ORF2s (ORF2s-HiBiT) and ORF2c capsid protein (ORF2c-HiBiT). The ORF2c-HiBiT formed membrane-associated HEV particles (eHEV3b-HiBiT). By treating these particles with digitonin, we demonstrated that the HiBiT tag was expressed on the surface of capsid and was present inside the lipid membrane. To simplify the measurement of luciferase activity and provide a more convenient screening platform, we constructed an ORF2s-defective mutant (HEV3b-HiBiT/& UDelta;ORF2s) in which the secreted ORF2s are suppressed. We used this system to evaluate the effects of introducing small interfering RNAs and treatment with an inhibitor or accelerator of exosomal release on HEV egress and demonstrated that the effects on virus release can readily be analyzed. Therefore, HEV3b-HiBiT and HEV3b-HiBiT/& UDelta;ORF2s reporters may be useful for investigating the virus life cycle and can serve as a more convenient screening platform to search for candidate drugs targeting the late stage of HEV infection such as particle formation and release.

Hepatitis E virus (HEV) causes acute or chronic hepatitis in humans. Pigs are the primary reservoir for zoonotic HEV genotypes 3 and 4 worldwide. This study investigated the infection dynamics and genomic mutations of HEV in domestic pigs on a farrow-to-finish pig farm in Japan between 2012 and 2021. A high prevalence of anti-HEV IgG antibodies was noted among pigs on this farm in 2012, when the survey started, and persisted for at least nine years. During 2012-2021, HEV RNA was detected in both serum and fecal samples, indicating active viral replication. Environmental samples, including slurry samples in manure pits, feces on the floor, floor and wall swabs in pens, and dust samples, also tested positive for HEV RNA, suggesting potential sources of infection within the farm environment. Indeed, pigs raised in HEV-contaminated houses had a higher rate of HEV infection than those in an HEV-free house. All 104 HEV strains belonged to subgenotype 3b, showing a gradual decrease in nucleotide identities over time. The 2012 (swEJM1201802S) and 2021 (swEJM2100729F) HEV strains shared 97.9% sequence identity over the entire genome. Importantly, the swEJM2100729F strain efficiently propagated in human hepatoma cells, demonstrating its infectivity. These findings contribute to our understanding of the prevalence, transmission dynamics, and genetic characteristics of HEV in domestic pigs, emphasizing the potential risks associated with HEV infections and are crucial for developing effective strategies to mitigate the risk of HEV infection in both animals and humans.

Hepatitis B virus (HBV) is a life-threatening infectious virus associated with the risk of liver failure and hepatocellular carcinoma (HCC). Regarding HBV treatment, the recent development of nucleoside/nucleotide analogs (NUC), HBV reverse transcriptase inhibitors, enabled favorable viral control as well as improved prognosis in patients with chronic hepatitis B. However, NUC fails to clear HBV because the formation of covalently closed circular DNA or HBV surface antigen occurs upstream of the point of action of NUC. Recently, we found that acyclic nucleoside phosphonates (ANP) such as adefovir or tenofovir, but not lamivudine or entecavir, induced IFN-λ3 productions in the gastrointestinal tract and modulated lipopolysaccharide (LPS)-mediated cytokine profiles in peripheral blood mononuclear cells, such as interleukin (IL)-12p70 induction and IL-10 inhibition, which are immunologically favorable cytokine profiles for HBV elimination. Furthermore, IFN-α, in combination with ANP, showed additional and synergistic effects on IFN-λ3 and IL-12p70 production, respectively, while not affecting IL-10 levels. Mechanistic analyses of the cytokine modulation by ANP revealed that ANP blocked the mammalian target of the rapamycin (mTOR) pathway by inhibiting Akt translocation to the plasma membrane, thereby inhibiting Akt phosphorylation. As it has been reported that IFN-λ inhibits tumor growth directly or indirectly and the mTOR pathway is generally activated in most cancer cells, ANP might have potential anti-HCC effects. Our in vitro and ex vivo findings might stir the debate on whether types of NUC affect the risk of HBV-related HCC incidence.

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis globally. Genotype 1 HEV (HEV-1) is responsible for multiple outbreaks in developing countries, causing high mortality rates in pregnant women. However, studies on HEV-1 have been hindered by its poor replication in cultured cells. The JE04-1601S strain recovered from a Japanese patient with fulminant hepatitis E who contracted HEV-1 while traveling to India was serially passaged 12 times in human cell lines. The cell-culture-generated viruses (passage 12; p12) grew efficiently in human cell lines, but the replication was not fully supported in porcine cells. A full-length cDNA clone was constructed using JE04-1601S_p12 as a template. It was able to produce an infectious virus, and viral protein expression was detectable in the transfected PLC/PRF/5 cells and culture supernatants. Consistently, HEV-1 growth was also not fully supported in the cell culture of cDNA-derived JE04-1601S_p12 progenies, potentially recapitulating the narrow tropism of HEV-1 observed in vivo. The availability of an efficient cell culture system for HEV-1 and its infectious cDNA clone will be useful for studying HEV species tropism and mechanisms underlying severe hepatitis in HEV-1-infected pregnant women as well as for discovering and developing safer treatment options for this condition.

A woman in her late 70 s was diagnosed with liver injury at a health examination. Despite treatment with ursodeoxycholic acid at a nearby hospital, her transaminase levels elevated in two peaks. She was transferred to our hospital 77 days after the health examination. She weighed 42 kg and had a low body mass index of 19.8 kg/m2. Viral markers, including immunoglobulin A (IgA) against hepatitis E virus (anti-HEV IgA), were negative. Drug-induced liver injury was negligible. We suspected autoimmune hepatitis because of the patient's female gender and positive antinuclear antibody. However, prednisolone and azathioprine failed to completely improve her hepatitis. On day 643, anti-HEV IgA was re-evaluated and found to be positive. She was diagnosed with autochthonous chronic hepatitis E because the virus strains in the preserved serum on day 77 and the serum on day 643 had identical nucleotide sequences (genotype 3a). Following prednisolone and azathioprine discontinuation, ribavirin (RBV) was administered for 3 months. HEV RNA disappeared and remained negative for more than 6 months after the cessation of RBV. The HEV RNA titer of 6.2 log10 copies/mL on day 77 was unusually high 2.5 months after the onset, suggesting that hepatitis E had already been chronic before immunosuppressive treatment for possible autoimmune hepatitis. After getting married at 23 years old, she had been a housewife and had no comorbidities that might deteriorate her immunity. Chronicity should be kept in mind when encountering HEV infection in elderly and underweight patients.

Hepatitis E virus (HEV) is increasingly recognized as the leading cause of acute hepatitis. Although HEV infections are mostly self-limiting, a chronic course can develop especially in those with immunocompromised state. Ribavirin is currently used to treat such patients. According to various reports on chronic HEV infections, a sustained virological response (SVR) was achieved in approximately 80% of patients receiving ribavirin monotherapy. To increase the SVR rate, drug combination might be a viable strategy, which we attempted in the current study. Ritonavir was identified in our previous drug screening while searching for candidate novel anti-HEV drugs. It demonstrated potent inhibition of HEV growth in cultured cells. In the present study, ritonavir blocked HEV internalization as shown through time-of-addition and immunofluorescence assays. Its combination with ribavirin significantly increased the efficiency of inhibiting HEV growth compared to that shown by ribavirin monotherapy, even in PLC/PRF/5 cells with robust HEV production, and resulted in viral clearance. Similar efficiency was seen for HEV genotypes 3 and 4, the main causes of chronic infection. The present findings provide insight concerning the advantage of combination therapy using drugs blocking different steps in the HEV life cycle (internalization and RNA replication) as a potential novel treatment strategy for chronic hepatitis E.

It is well-known that sustained virological response (SVR) by interferon (IFN)-based therapy against hepatitis C virus (HCV) infection reduced the incidence of hepatocellular carcinoma (HCC). However, whether IFN-free direct-acting antivirals reduce the risk of HCC is controversial. Therefore, this study aims to compare the incidence of HCC after the achievement of SVR between sofosbuvir combined with ledipasvir (SOF/LDV) and simeprevir with pegylated interferon plus ribavirin (Sim+IFN). Japanese patients with HCV infection (genotype 1) who achieved SVR between January 2013 and December 2014 by SOF/LDV (NCT01975675, n = 320) or Sim+IFN (000015933, n = 289) therapy in two nationwide, multicenter, phase III studies were prospectively monitored for the development of HCC by ultrasonography for 5 years after the end of treatment (EOT). No HCC was detected before the treatment. HCC was detected in 9 and 7 patients in the SOF/LDV and the Sim+IFN group in 5 years, respectively. The cumulative incidences of HCC rates 1, 3, and 5 years after EOT were similar between the two groups (1.5%, 2.7%, and 3.2% for the SOF/LDV and 1.8%, 2.8%, and 3.0% for the Sim+IFN group, respectively). No HCC was developed 3.5 years after EOT. Interestingly, a retrospective careful review of imaging taken before therapy revealed hepatic nodules in 50% of HCC patients, suggesting HCC was pre-existed before therapy. In conclusion, we could not find any differences in the incidence of HCC after the HCV eradication between the two therapeutic regimens, suggesting no enhancement of HCC development by DAA.

Rat hepatitis E virus (HEV-C1) in the Orthohepevirus C species has been reported to cause zoonotic infection and hepatitis in humans. HEV-C1 strains have been detected from wild rats in many countries in Europe, Asia, and North America. However, in Japan, no HEV-C1 strains have been identified. In the present study, 5 (1.2%) of 428 wild rats (Rattus norvegicus or R. rattus) were positive for anti-HEV-C1 IgG. Although all 428 rat sera were negative for HEV-C1 RNA, it was detectable in 20 (19.8%) of 101 rat fecal samples collected on a swine farm, where HEV (genotype 3b, HEV-3b) was prevalent and wild rats were present. In addition, HEV-C1 RNA was detectable in the intestinal contents and liver tissues of 7 (18.9%) of 37 additional rats captured on the same farm. The HEV-C1 strain (ratEJM1703495L) obtained in this study shared only 75.8-84.7% identity with reported HEV-C1 strains over the entire genome but propagated efficiently in cultured cells. HEV-3b strains were detected in the rats' intestinal contents, with 97.3-99.5% identity to those in pigs on the same farm, but were undetectable in rat liver tissues, suggesting that wild rats do not support the replication of HEV-3b of swine origin.

A case of subclinical hepatitis E virus (HEV) infection was detected by nucleic acid amplification test on blood donation. The patient was followed-up until day 220 after the blood donation but showed no symptoms throughout the observation period. Aspartate aminotransferase and alanine aminotransferase levels reached the maximum values on day 37 with a slight increase but remained in normal ranges from day 67 to 220. The quantity of HEV RNA at the initial examination on day 13 was 1.1 × 102 copies/mL, which increased to 2.8 × 103 copies/mL by day 37. It was not detected from day 67 to 220. Immunoglobulin G class antibody to HEV (anti-HEV IgG) was below the cut-off value until day 37 and exceeded the cut-off value to positive on day 67, accompanied by normalization of liver function and negative conversion of HEV RNA. Thereafter, the titer decreased gradually, falling below the cut-off value on day 163, and continuing negative until day 220. Although the persistent duration of anti-HEV IgG positive is believed to be generally long, it was within only 126 days for this subclinical case. Further investigation is needed to determine whether short-term positivity for anti-HEV IgG is typical in subclinical HEV infection.

The association between lactic acid bacteria (LAB) and their immunostimulatory effects has attracted considerable attention; however, it remains unclear whether LAB can induce interferon-lambdas (IFN-λs) in human epithelial cells under conditions that do not mimic infection. In this study, we first employed a reporter assay to screen for a potential strain capable of inducing IFN-λ3 among 135 LAB strains derived from traditional Japanese pickles. Next, we assessed the strain's ability to induce the expression of IFN-λ genes and interferon-stimulated genes (ISGs), and to produce IFN-λs. As a result, we screened and isolated Enterococcus casseliflavus KB1733 (KB1733) as a potential strain capable of inducing IFN-λ3 expression. Furthermore, we clarified that KB1733 induced the expression of IFN-λ genes and ISGs related to antiviral functions, and that KB1733 induced IFN-λ1 and -λ3 expression in a dose-dependent manner up to 10 μg/mL. In addition, KB1733 significantly increased IFN-λ1 production compared to Enterococcus casseliflavus JCM8723T, which belongs to the same genera and species as KB1733. In conclusion, we isolated a unique LAB strain from traditional Japanese pickles that is capable of stimulating IFN-λ production, although further study is needed to investigate how KB1733 protects against viruses in mice and humans.

Bioluminescent reporter viruses are essential tools in molecular virological research. They have been widely used to investigate viral life cycles and in the development of antiviral drugs.Hepatitis E virus (HEV) is a quasi-enveloped virus with a single-stranded positive-sense RNA genome belonging to the family Hepeviridae. Studies of the molecular aspects of HEV and drug screening have benefited from the discovery of bioluminescent reporter genes. However, the stability of large foreign genes is difficult to maintain after insertion into the viral genome. Currently, ribavirin is used to treat HEV-infected patients who require antiviral therapy. This has several major drawbacks. Thus, the development of novel anti-HEV drugs is of great importance. We developed a system consisting of recombinant infectious HEV harboring a small luciferase gene (nanoKAZ) in the hypervariable region (HVR) of the open reading frame 1 (ORF1) (HEV-nanoKAZ). It replicated efficiently in cultured cells, was genetically stable, and had morphological characteristics similar to those of the parental virus. Both membrane-associated (eHEV-nanoKAZ) and membrane-unassociated (neHEV-nanoKAZ) particles were infectious. HEV particles circulating in the bloodstream and attaching to hepatocytes in HEV-infected patients are membrane-associated; thus, eHEV-nanoKAZ was applied in drug screening. The eHEV-nanoKAZ system covers at least the inhibitor of HEV entry and inhibitor of HEV RNA replication. Four drugs with anti-HEV activity were identified. Their effectiveness in cultured cells was confirmed in naive and HEV-producing PLC/PRF/5 cells. Two hit drugs (azithromycin and ritonavir) strongly inhibited HEV production in culture supernatants, as well as intracellular expression of ORF2 protein, and may therefore be candidate novel anti-HEV drugs. The HEV-nanoKAZ system was developed and applied in drug screening and is expected to be useful for investigating the HEV life cycle. IMPORTANCE Bioluminescent reporter viruses are essential tools in molecular virological research. They have been widely used to investigate viral life cycles and in the development of antiviral drugs. For drug screening, the use of a bioluminescent reporter virus helps shorten the time required to perform the assay. A system, consisting of recombinant infectious HEV harboring the nanoKAZ gene in the HVR of ORF1 (HEV-nanoKAZ), was developed in this study and was successfully applied to drug screening in which four hit drugs with anti-HEV activity were identified. The results of this study provide evidence supporting the use of this system in more variable HEV studies. In addition, both forms of viral particles (eHEV-nanoKAZ and neHEV-nanoKAZ) are infectious, which will enable their application in HEV studies requiring both forms of viral particles, such as in the investigation of unknown HEV receptors and the elucidation of host factors important for HEV entry.

Hepatitis E virus (HEV) is a zoonotic agent mainly transmitted through the consumption of uncooked or undercooked meat products derived from infected animals. In Japan, domestic pigs and wild boars are the major animal reservoirs, and whether or not deer are an HEV reservoir remains controversial. We analyzed 395 serum and 199 liver samples from 405 sika deer (Cervus nippon) caught in the wild between 1997 and 2020 in 11 prefectures of Japan for markers of HEV infection. Overall, 17 deer had anti-HEV IgG (4.3%), while 1 (0.2%) had HEV RNA (genotype 3b), indicating the occurrence of ongoing HEV infection in wild deer in Japan. An analysis of the complete HEV genome (deJOI_14) recovered from a viremic deer in Oita Prefecture revealed only 88.8% identity with the first HEV strain in sika deer (JDEER-Hyo03L) in Japan, being closest (96.3%) to the HEV obtained from a hepatitis patient living in the same prefecture. Of note, the deJOI_14 strain was 8.7-9.0% different from the wild boar HEV strains obtained in the same habitat and the same year, suggesting that difference in infected HEV strains between boar and deer may be explained by the limited possibility of close contact with each other, although boars are a known source of HEV infection. Increased numbers of hepatitis E cases after consumption of raw or undercooked meat products of wild deer have been reported in Japan. These results suggest a low but nonnegligible zoonotic risk of HEV infection in wild deer in this country.

A 66-year-old man, who had undergone plasma exchange 30 years previously in Egypt for the treatment of falciparum malaria, was referred to our hospital for treatment of chronic hepatitis C (HCV). An analysis of the 655-nucleotide 5'-untranslated region-core region sequence revealed infection with HCV subtype 1g. A phylogenetic analysis of the full-length HCV genome confirmed that the patient's HCV was subtype 1g, which was the first case identified in Japan. Although his HCV possessed several naturally occurring resistance-associated substitutions in the nonstructural (NS) 3 and NS5A regions, he was successfully treated by combination therapy with glecaprevir/pibrentasvir.

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease associated with eosinophilic infiltration of the esophageal mucosa mostly due to exposure to allergens. However, the causes and pathogenesis of EoE are not fully understood. We encountered a case of EoE that was triggered by sublingual immunotherapy (SLIT) for cedar pollen allergy. A 40-year-old man who was treated with Japanese cedar pollen tablet SLIT for cedar pollen allergy developed heartburn 3 weeks after the initiation of the treatment. He took vonoprazan for the heartburn, but the heartburn did not improve. Then, esophagogastroduodenoscopy was performed; it revealed longitudinal furrows and white spots on the esophageal mucosa, decreased vascular permeability, and erosions. Consequently, the patient was diagnosed with EoE. Heartburn and chest discomfort disappeared 1 week after the discontinuation of Japanese cedar pollen tablet SLIT, and the patient tested positive for drug allergy to Japanese cedar pollen tablet SLIT. In this study, we found that if heartburn persists during SLIT for cedar pollen allergy, and does not improve on administration of vonoprazan or proton pump inhibitors, EoE should be suspected. In addition, the occurrence of EoE due to drug allergy is indicated.

Rat hepatitis E virus (HEV) has been isolated from wild rats worldwide and the potential of zoonotic transmission has been documented. Escherichia coli (E. coli) is utilized as an effective system for producing HEV-like particles. However, the production of rat HEV ORF2 proteins in E. coli forming virus-like particles (VLPs) has not yet been reported. In this study, nine rat HEV ORF2 proteins of the ratELOMB-131L strain with truncated N- and C-termini (amino acids 339-594, 349-594, 351-594, 354-594, 357-594, 357-599, 357-604, 357-609, and 357-614 of ORF2 protein) were expressed in E. coli and the 357-614 protein self-assembled most efficiently. A bioanalyzer showed that the purified 357-614 protein has a molecular weight of 33.5 kDa and a purity of 93.2%. Electron microscopy revealed that the purified 33.5 kDa protein formed VLPs with a diameter of 21-52 (average 32) nm, and immunoelectron microscopy using an anti-rat HEV ORF2 monoclonal antibody (TA7014) indicated that the observed VLPs were derived from rat HEV ORF2. The VLPs attached to and entered the PLC/PRF/5 cells and blocked the neutralization of rat HEV by TA7014, suggesting that the VLPs possess the antigenic structure of infectious rat HEV particles. In addition, rat HEV VLPs showed high immunogenicity in mice. The present results would be useful for future studies on the development of VLP-based vaccines for HEV prevention in a rat model and for the prevention of rat HEV infection in humans.

We report a novel pegivirus in pet cats (Felis silvestris catus) in Japan. This virus was only 44.0–49.6 % identical to the reported viruses in the 11 current Pegivirus species and an unclassified pegivirus in dolphins within the entire protein-coding nucleotide sequence and was detected in 1.6 % of pet cats.

A 76-year-old woman with spontaneous reactivation of hepatitis B virus (HBV) without any immunosuppressants who had been successfully treated with tenofovir alafenamide fumarate (TAF) was reported. The patient was admitted to our hospital because of acute exacerbation of the liver function and jaundice. She had been found to have chronic HBV infection with a normal liver function and had been treated for lifestyle-related diseases, such as diabetes mellitus, dyslipidemia and hypertension, for over 10 years at a local clinic. At admission, her serum HBV DNA was high (7.3 log IU/mL), and anti-hepatitis B core protein immunoglobulin M was slightly elevated (1.47 S/CO). Due to the absence of known risk factors for HBV reactivation, the reactivation was regarded as "spontaneous". After the initiation of the nucleotide analog TAF, her liver function gradually improved with a decrease in the HBV DNA load. Her HBV genome was typed as subgenotype B1 and possessed a frameshift mutation due to an insertion of T after nucleotide (nt) 1817 and G to A mutations at nt 1896 and nt 1899 (G1896A/G1899A) in the precore region as well as serine to glutamine substitution of amino acid 21 in the core protein. In addition to these viral mutations, aging and complications of lifestyle-related diseases in the present case may have been responsible for the spontaneous HBV reactivation. Careful observation and management of aged HBV carriers with underlying diseases are needed even when persistent HBV infection is free from symptoms and liver dysfunction and no immunosuppressive conditions are involved.

Hepatitis E virus (HEV) infects humans and a wide variety of other mammalian hosts. Recently, HEV strains belonging to genotype 8 (G8) within the Orthohepevirus A species of the Hepeviridae family, were identified in Bactrian camels (Camelus bactrianus) in China. The Bactrian camel (also known as the Mongolian camel) is native to the steppes of Central Asia. However, the HEV strains of Mongolian camels have not been examined. Among 200 serum samples from domestic Bactrian camels raised on 6 farms, in 6 soums in 3 provinces; 71 (35.5 %) were positive for anti-HEV IgG, with prevalence differing by farm (soum) (4.2-75.0 %); and 2 camels (1.0 %) that had been raised in Bogd, Bayankhongor Province, which had the highest seroprevalence among the six studied areas, were positive for HEV RNA. The two HEV strains (BcHEV-MNG140 and BcHEV-MNG146) obtained from the viremic camels in the present study shared 97.7 % nucleotide identity. They were closest to the reported G8 Chinese camel HEV strains but differed from them by 13.9-14.3 % over the entire genome, with a nucleotide difference of 24.0-26.5 % from the reported G1-G7 HEV strains. A phylogenetic tree indicated that the BcHEVMNG140 and BcHEV-MNG146 strains were located upstream of a clade consisting of the Chinese camel HEV strains and formed a cluster with them, with a bootstrap value of 100 %, suggesting that they may represent a novel subtype within G8. These results indicate a high prevalence of HEV infection in Mongolian camels and suggest that the variability of camel HEV genomes is markedly high.

In Mie Prefecture, autochthonous hepatitis E cases occurred via homologous hepatitis E virus subgenotype 3e (HEV-3e), namely, Mie indigenous HEV-3e, from 2004 through 2014. We experienced three cases of autochthonous hepatitis E in 2020 in Mie Prefecture, and analyzed the partial HEV genomes recovered from them. The three HEV isolates clustered with Mie indigenous HEV-3e in the phylogenetic tree and exhibited high similarities to it. Mie indigenous HEV-3e had thus reemerged for the first time in six years. One affected patient often consumed meat of wild animals, and another ate undercooked pork liver, although the third case had no clear risk factors. Mie indigenous HEV-3e appears to be maintained in wild animals or domestic pigs.

The entire genome sequences of two pegivirus strains recovered from serum samples of wild rats (Rattus rattus) in Indonesia were determined. They possessed 11,013 to 11,014 nucleotides and differed from the reported rodent pegivirus strains within the Pegivirus J species of the genus Pegivirus by 12.7% to 40.9% in the near-entire coding region sequences.

To further investigate the prevalence of hepatitis E virus (HEV) infection and characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 1880 boars captured in 17 prefectures in Japan from 2013 to 2019 were studied. Overall, anti-HEV IgG was detected in 8.9 % and HEV RNA was detected in 3.9 % of boars, which was comparable with our previous studies during 2003-2013 (10.3 % and 3.5 %, respectively). Among 74 boar HEV strains obtained from infected boars in the present study, 50 (68 %) were classified into genotype 3 (3a and 3b), 23 (31 %) were classified into genotype 4 (4i), and the remaining strain (wbJGF_19-1) was classified into genotype 5. The wbGF_19-1 strain shared 92.7 % identity over the entire genome with the prototype genotype 5 strain (JBOAR135-Shiz09). The identification of the second genotype 5 HEV strain in a place that is located only 100 km from the site at which JBOAR135-Shiz09 was identified, suggests that genotype 5 HEV circulates within a relatively close range in Japan. Genetically similar HEV strains forming a clade were identified from wild boars living in each area during the observation period of 11-13 years, although the nucleotide sequence changed gradually, accounting for up to 3.4-3.6 % within the 412-nucleotide ORF2 sequence. Eight groups of boars with a cluster of HEV infections were observed, consisting of two, three or four infected offspring, presumably born to the same mother or offspring with their mother. These results suggest that wild boars continue to be important reservoirs for HEV infection in humans in Japan.

BACKGROUND: A prospective pilot study of tenofovir disoproxil fumarate (TDF) and pegylated interferon alpha 2a (P-IFN) add-on therapy was conducted to evaluate its efficacy in reducing viral antigen levels in Japanese patients with chronic hepatitis B (UMIN 000020179). METHODS: Patients with chronic hepatitis B receiving maintenance TDF therapy and exhibiting hepatitis B surface antigen (HBsAg) level > 800 IU/ml were divided into two arms. P-IFN was added for 48 weeks in the add-on arm (n = 32), while TDF monotherapy was maintained in the control arm (n = 51). Both groups were followed for 96 weeks after baseline measurements. RESULTS: Almost all patients in the control arm displayed a slow and constant reduction in HBsAg during follow-up. In contrast, roughly half of the add-on arm exhibited a sharp decline in HBsAg during P-IFN administration, which disappeared after halting P-IFN. At 96 weeks after baseline, 41% (13/32) of patients in the add-on arm had shown a rapid decrease in HBsAg, versus 2% (1/51) in the control arm (p < 0.001). Add-on therapy and increased cytotoxic T-cell response were significant factors associated with a rapid decrease in HBsAg according to multivariate analysis. In addition, higher HB core-related antigen (HBcrAg) level at baseline (p = 0.001) and add-on therapy (p = 0.036) were significant factors associated with a rapid reduction in HBcrAg. CONCLUSIONS: TDF and P-IFN add-on therapy in Japanese patients with chronic hepatitis B facilitated rapid decreases in HBsAg and HBcrAg. Further studies are needed to improve early HBsAg clearance rate.

BACKGROUND AND AIMS: Current treatment with nucleos(t)ide analogs (NUCs) safely controls the replication of hepatitis B virus (HBV) and improves prognosis in patients with HBV. However, the inability to completely clear HBV is problematic, and novel therapies are desired. It has been believed that all NUCs have similar functions to inhibit HBV reverse transcriptase. However, our recent findings that only acyclic nucleoside phosphonates (ANPs; adefovir dipivoxil and tenofovir disoproxil fumarate) had an additional effect of inducing interferon (IFN)-λ3 in the gastrointestinal tract suggests that ANPs are not only distinct from nucleoside analogs (lamivudine and entecavir) in their structures but also in their functions. Because enteric lipopolysaccharide (LPS) can cross the intestine and affect peripheral blood mononuclear cells (PBMCs), we hypothesized that orally administered ANPs could have further additional effects to modulate LPS-mediated cytokine profile in PBMCs. APPROACH AND RESULTS: This study showed that pretreatment of PBMCs, from either healthy volunteers or patients with HBV, with ANPs inhibited LPS-mediated interleukin (IL)-10 production, which reciprocally induced IL-12p70 and tumor necrosis factor-α production in a dose-dependent manner. Furthermore, the combination of IFN-α and ANPs synergistically enhanced LPS-mediated IL-12p70 production in PBMCs. Mechanistic analyses revealed that cellular metabolites of ANPs directly bound the Akt protein, inhibiting its translocation to the plasma membrane, thereby impairing Akt phosphorylation. Therefore, pretreatment of PBMCs with ANPs impairs LPS-mediated IL-10 production. CONCLUSIONS: Among NUCs, only ANPs have an additional pharmacological effect modulating LPS-mediated cytokine production, which is expected to produce favorable immune responses toward HBV elimination. This additional immunomodulation by ANPs in PBMCs, as well as IFN-λ3 induction in the gastrointestinal tract, provides insights into HBV treatment.

AIM: Interferon (IFN)-λ3 is known to have antiviral effects against various pathogens. Recently, it has been reported that the production of IFN-λ3 in colon cells after the administration of nucleotide analogs is expected to reduce hepatitis B surface antigen in chronic hepatitis B patients. Here, we aimed to prove the antiviral effects of IFN-λ3 on hepatitis B virus (HBV) by using an in vitro HBV production and infection system. METHODS: We used HepG2.2.15-derived HBV as an inoculum and the replication-competent molecular clone of HBV as a replication model. RESULTS: By administering IFN-λ3 to HepG2 cells transfected with the HBV molecular clone, the production of hepatitis B surface antigen and hepatitis B core-related antigen was reduced dose-dependently. IFN-λ3 treatment also reduced the number of HBV-positive cells and the synthesis of covalently closed circular DNA after infection of HepG2.2.15-derived HBV to sodium taurocholate cotransporting polypeptide-transduced HepG2 cells. The inhibitory effect on HBV infection by IFN-λ3 was confirmed by using a recombinant a HBV reporter virus system. To elucidate the underlying mechanisms of the anti-HBV effect of IFN-λ3, we assessed the transcription of HBV RNA and the production of core-associated HBV DNA in HBV molecular clone-transfected HepG2 cells, and found that both parameters were reduced by IFN-λ3. CONCLUSIONS: We observed that the administration of IFN-λ3 inhibits HBV infection and the production of HBV proteins at the HBV RNA transcription level. This finding provides novel insight into the treatment of chronic hepatitis B patients with the administration or induction of IFN-λ3.

Background and aim: Hepatitis E virus (HEV) is mainly transmitted orally, either waterborne or zoonotic foodbome. Intestinal viruses such as rotavirus are known to induce type III interferon (IFN) in the gastrointestinal (GI) tract where type III IFN dominantly functions in comparison with type I IFN. Therefore, the aim of this study is to investigate the significance of type III IFN (IFN-lambda 3) in acute hepatitis E.Methods: IFN-lambda 3 and HEV RNA levels in the sera of patients with acute HEV infection and in the supernatant of HEV-inoculated cells were measured, using an in-house high-sensitivity method and reverse transcription-polymerase chain reaction, respectively.Results: High serum IFN-lambda 3 levels were found in the early phase of acute HEV infection, which normalized after resolution. Interestingly, serum IFN-lambda 3 levels correlated well with serum HEV RNA titers in the same sera, both of which showed the peak before the robust increase of transaminases. In vitro experiments demonstrated that HEV replicated well in the cells with little IFN-lambda 3 induction (Caco-2, A549) and recombinant IFN-lambda 3 inhibited HEV replication in a dose-dependent manner. In contrast, in HT-29 cells, a colon cancer cell line, HEV poorly replicated and induced IFN-lambda 3 in a titer-dependent manner.Conclusions: These clinical and experimental observations suggest that HEV induced IFN-lambda 3 as a host innate immune response, which may play a protective role against HEV.

Primary biliary cholangitis (PBC) is a chronic and cholestatic autoimmune liver disease caused by the destruction of intrahepatic small bile ducts. Our previous genome-wide association study (GWAS) identified six susceptibility loci for PBC. Here, in order to further elucidate the genetic architecture of PBC, a GWAS was performed on an additional independent sample set, then a genome-wide meta-analysis with our previous GWAS was performed based on a whole-genome single nucleotide polymorphism (SNP) imputation analysis of a total of 4,045 Japanese individuals (2,060 cases and 1,985 healthy controls). A susceptibility locus on chromosome 3q13.33 (including ARHGAP31, TMEM39A, POGLUT1, TIMMDC1, and CD80) was previously identified both in the European and Chinese populations and was replicated in the Japanese population (OR = 0.7241, P = 3.5 × 10-9). Subsequent in silico and in vitro functional analyses identified rs2293370, previously reported as the top-hit SNP in this locus in the European population, as the primary functional SNP. Moreover, e-QTL analysis indicated that the effector gene of rs2293370 was Protein O-Glucosyltransferase 1 (POGLUT1) (P = 3.4 × 10-8). This is the first study to demonstrate that POGLUT1 and not CD80 is the effector gene regulated by the primary functional SNP rs2293370, and that increased expression of POGLUT1 might be involved in the pathogenesis of PBC.

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.

Approximately 5-10% of individuals who are vaccinated with a hepatitis B (HB) vaccine designed based on the hepatitis B virus (HBV) genotype C fail to acquire protective levels of antibodies. Here, host genetic factors behind low immune response to this HB vaccine were investigated by a genome-wide association study (GWAS) and Human Leukocyte Antigen (HLA) association tests. The GWAS and HLA association tests were carried out using a total of 1,193 Japanese individuals including 107 low responders, 351 intermediate responders, and 735 high responders. Classical HLA class II alleles were statistically imputed using the genome-wide SNP typing data. The GWAS identified independent associations of HLA-DRB1-DQB1, HLA-DPB1 and BTNL2 genes with immune response to a HB vaccine designed based on the HBV genotype C. Five HLA-DRB1-DQB1 haplotypes and two DPB1 alleles showed significant associations with response to the HB vaccine in a comparison of three groups of 1,193 HB vaccinated individuals. When frequencies of DRB1-DQB1 haplotypes and DPB1 alleles were compared between low immune responders and HBV patients, significant associations were identified for three DRB1-DQB1 haplotypes, and no association was identified for any of the DPB1 alleles. In contrast, no association was identified for DRB1-DQB1 haplotypes and DPB1 alleles in a comparison between high immune responders and healthy individuals. Conclusion: The findings in this study clearly show the importance of HLA-DR-DQ (i.e., recognition of a vaccine related HB surface antigen (HBsAg) by specific DR-DQ haplotypes) and BTNL2 molecules (i.e., high immune response to HB vaccine) for response to a HB vaccine designed based on the HBV genotype C. (Hepatology 2018).

症例は生来健康な48歳女性。倦怠感、嘔気を主訴に近医を受診し、血液検査にて肝障害を指摘されて紹介受診した。入院時血液検査では、AST 868IU/L、ALT 1,205IU/L、Alp 479IU/L、γ-GTP 254IU/Lと肝細胞障害型の肝胆道系酵素異常を認めた。飲酒歴・薬剤内服歴なく、かつ各種肝炎ウイルスマーカーは陰性であった。自己免疫性肝炎(AIH)の急性発症を疑い、肝生検を施行したところ、門脈域を中心としたIgG4陽性形質細胞の浸潤を認め、かつ血清IgG4値が669mg/dLと高値を示した。明らかな胆管への細胞浸潤は認めなかった。以上より、IgG4関連AIH(IgG4-AIH)と診断し、プレドニゾロン30mg/日を投与したところ、肝障害は速やかに改善した。IgG4-AIHの報告は少なく、その臨床病理学的特徴は解明されていない。今後の詳細な解析が期待される。(著者抄録)

We have performed a genome-wide association study (GWAS) including 473 Japanese HBV (hepatitis B virus)-positive HCC (hepatocellular carcinoma) patients and 516 HBV carriers including chronic hepatitis and asymptomatic carrier individuals to identify new host genetic factors associated with HBV-derived HCC in Japanese and other East Asian populations. We identified 65 SNPs with P values < 10-4 located within the HLA class I region and three SNPs were genotyped in three independent population-based replication sets. Meta-analysis confirmed the association of the three SNPs (rs2523961: OR = 1.73, P = 7.50 × 10-12; rs1110446: OR = 1.79, P = 1.66 × 10-13; and rs3094137: OR = 1.73, P = 7.09 × 10-9). We then performed two-field HLA genotype imputation for six HLA loci using genotyping data to investigate the association between HLA alleles and HCC. HLA allele association testing revealed that HLA-A * 33:03 (OR = 1.97, P = 4.58 × 10-4) was significantly associated with disease progression to HCC. Conditioning analysis of each of the three SNPs on the HLA class I region abolished the association of HLA-A*33:03 with disease progression to HCC. However, conditioning the HLA allele could not eliminate the association of the three SNPs, suggesting that additional genetic factors may exist in the HLA class I region.

<sec><title>Objective</title>The clinical significance of polymorphisms in the interleukin-28B gene encoding interferon (IFN)-λ3, which has antiviral effects, is known in chronic HCV but not in HBV infection. Thus, we measured IFN-λ3 levels in patients with HBV and investigated its clinical significance and association with nucleos(t)ide (NUC) analogue administration. </sec><sec><title>Design</title>Serum IFN-λ3 level was measured in 254 patients with HBV with varying clinical conditions using our own high sensitivity method. The resulting values were compared with various clinical variables. In addition, cell lines originating from various organs were cultured with NUCs, and the production of IFN-λ3 was evaluated. </sec><sec><title>Results</title>Higher serum IFN-λ3 levels were detected in the patients treated with nucleotide analogues (adefovir or tenofovir) compared with those treated with nucleoside analogues (lamivudine or entecavir). There were no other differences in the clinical background between the two groups. A rise in the serum IFN-λ3 levels was observed during additional administration of the nucleotide analogues. In vitro experiments showed that the nucleotide analogues directly and dose-dependently induced IFN-λ3 production only in colon cancer cells. Furthermore, the supernatant from cultured adefovir-treated colon cancer cells significantly induced IFN-stimulated genes (ISGs) and inhibited hepatitis B surface antigen (HBsAg) production in hepatoma cells, as compared with the supernatant from entecavir-treated cells. </sec><sec><title>Conclusions</title>We discovered that the nucleotide analogues show an additional pharmacological effect by inducing IFN-λ3 production, which further induces ISGs and results in a reduction of HBsAg production. These findings provide novel insights for HBV treatment and suggest IFN-λ3 induction as a possible target. </sec>

This prospective cohort study searched for factors associated with a response to nucleos(t)ide analogue/peg-interferon (NUC/peg-IFN) sequential therapy.A total of 95 patients with chronic hepatitis B being treated with NUCs were enrolled. Immediately following NUC cessation, peg-IFN was administered at 180 A mu g/dose weekly for 48 weeks.Twenty-six patients (27%) were judged to be responders at 48 weeks after the completion of peg-IFN. Analysis of baseline factors revealed that hepatitis B surface antigen (HBsAg) < 3.1 log IU/ml and HB core-related antigen (HBcrAg) < 3.9 log U/ml were significant indicators of a treatment response. The levels of the markers decreased in both responders and non-responders during peg-IFN therapy but continued falling in responders only after halting peg-IFN. Lower HBsAg (< 2.0 log IU/ml) and HBcrAg (< 3.8 log U/ml) levels at the time of response judgment were also significantly associated with a favorable response. While lower HBcrAg at baseline was the sole predictor of decreased HBcrAg levels at judgment, lower HBsAg, lower HBcrAg, and the use of adefovir dipivoxil at baseline predicted decreased HBsAg levels at the study endpoint. The use of adefovir dipivoxil was also associated with higher serum IFN-lambda 3, which might have contributed to the reduction in patient HBsAg levels.The combinational use of HBsAg and HBcrAg levels at baseline and their changes throughout sequential therapy may be useful for predicting a response to NUC/peg-IFN sequential therapy.

A previously healthy 48-year-old woman was referred to our hospital because of liver injury. Her laboratory data on admission showed hepatocyte injury (AST 868 IU/L, ALT 1,205 IU/L. Alp 479 IU/L, γ-GTP 254 IU/ L). She denied histories of alcohol intake or any medications. All viral markers related to hepatitis were negative. We suspected her having acute phase of autoimmune hepatitis despite of negative data in her serology. Liver biopsy revealed interface hepatitis with prominent infiltration of plasma cells. In addition, these plasma cells showed expressim of IgG4 by immunohistochemistry, and serum IgG4 levels were quite high (669 mg/mL). These findings leaded us to diagnose her as having IgG4-related autoimmune hepatitis (IgG4-AIH). Predoniso-lone (30 mg/day) promptly improved her liver injury and did not relapse even after reducing the dose. IgG4-AIH is a rare disease entity, and its precise pathogenesis is unknown yet. These issues should be addressed in the future.

Aim: Few studies concerning the protective management of hepatitis B virus (HBV) infection among health-care personnel (HCP), excluding occult HBV or carriers, have been reported. Therefore, we undertook a cross-sectional study of the updated status of HBV vaccine management by measuring the antibody to hepatitis B surface antigen (anti-HBs) along with the antibody to hepatitis B core antigen (anti-HBc).Methods: Both anti-HBs and anti-HBc were assessed in 1085 HCP employed by our institute. Hepatitis B virus vaccination-related histories were recorded using self-administered questionnaires.Results: Of 1085 HCP, 27 (2.5%) were positive for anti-HBc, and its positive rate increased with age. Of the 1058 subjects with negative anti-HBc, 879 (83.1%) were positive for anti-HBs. The median titer of anti-HBs was 71.1 mIU/mL, which was higher in female subjects (P = 0.037). By age group, the positive rate of anti-HBs were 77.5%, 89.3%, 90.8%, and 81.6% in the groups aged <= 29, 30-39, 40-49, and >= 50 years, respectively (P<0.001). Of the 908 subjects who reported receiving HBV vaccination, 6 (0.7%) were positive for anti-HBc. Among them, one subject was suspected to have a possible subclinical HBV infection after the HBV vaccination.Conclusion: We report the current HBV vaccination-related seroprevalence of anti-HBs along with anti-HBc in a Japanese tertiary medical institution consisting of more than 1000 HCP, which was an level comparable to similar sized hospitals in developed countries. Anti-HBc would be important for understanding HBV status, but not necessary for general HBV vaccine management for HCP.

Aim: Telaprevir (TVR) remarkably improves the efficacy of interferon treatment for chronic hepatitis C. Interleukin-28B (IL28B) genotype and interferon-gamma-inducible protein-10 (IP-10) level predict virologic response to peg-interferon (Peg-IFN)/ribavirin (RBV) therapy. We aimed to investigate the usefulness of pretreatment serum IP-10 levels and IL28B genotyping in predicting sustained virologic response (SVR) to TVR-based triple therapy.Methods: In this multi-center study, patients infected with hepatitis C virus genotype 1 with high viral load ( >= 5.0 log IU/mL) were treated with TVR for 12 weeks. and Peg-IFN/RBV for 24 weeks in Japan. IL28B genotype, serum IP-10 levels, other clinical parameters, and drug dosages were assessed before treatment.Results: We included 121 patients who were treated with TVR for at least 8 weeks and Peg-IFN/RBV for 24 weeks. The median IP-10 levels were significantly lower in rapid virologic response (RVR) or SVR in the IL28B non-TT genotype group, with no significant difference in the TT genotype group. RVR rates were significantly lower in the group with higher serum IP-10 levels (>450 pg/mL). In the non-TT IL28B genotype group, RVR and SVR rates were significantly lower in the group with higher IP-10 levels. SVR rates in the group with lower IP-10 levels (<450 pg/mL) increased to 82% for those showing RVR, but reduced to 27% in the group with higher IP-10 levels for those not showing RVR.Conclusions: Determination of serum IP-10 levels before treatment could be useful for predicting favorable virologic response to TVR-based triple therapy, especially in patients with IL28B non-TT genotype. (C) 2016 Elsevier Ltd. All rights reserved.

BACKGROUND: Appropriate utilization of different diagnostic modalities is essential for the accurate liver stiffness measurements (LSM) in patients with chronic liver diseases. The aim of this study was to evaluate the efficacy of Virtual Touch Quantification (VTQ) and the FibroScan M and XL probes in term of accurate LSM and to identify factors associated with inadequate measurements in obese and non-obese Japanese patients. METHODS: A total of 664 consecutive patients with chronic liver disease were prospectively enrolled. LSM were evaluated concurrently with VTQ and the FibroScan M and XL probes. LSM quality was categorized as inadequate (success rate <60% and/or interquartile range/median value of ≥30%) or adequate. RESULTS: No significant differences in the rate of inadequate LSM were observed among the three diagnostic modalities. In multivariate analysis, skin capsule distance (SCD) was strongly associated with inadequate rates obtained with VTQ and the M probe [odds ratio (OR) 1.28, P < 0.0001 and OR 1.20, P < 0.0001, respectively]. Inadequate LSM rates with both VTQ and the M probe increased with longer SCD, with a significant difference between subgroups at an SCD of ≥22.5 mm (VTQ 54.0%; M probe 51.1%; XL probe 25.2%; P < 0.0001). The rates of inadequate LSM rates with VTQ were significantly lower than those with the XL probe at an SCD of <17.5 mm. A total of 15 liver biopsy specimens obtained from nonalcoholic fatty liver disease patients confirmed the diagnostic accuracy and high applicability of the XL probe. CONCLUSIONS: Long SCD reduced the diagnostic performance of the FibroScan® M probe and VTQ. LSM modalities should be selected according to SCD.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is an established independent risk factor for hepatocellular carcinoma (HCC). T2DM is associated with non-alcoholic steatohepatitis (NASH), which is a major cause of non-HBV and non-HCV-related HCC; nevertheless, it has been difficult to identify those patients with T2DM who have a high risk of developing HCC. The aim of this study was to identify genetic determinants that predispose T2DM patients to HCC by genotyping T2DM susceptibility loci and PNPLA3. METHODS: We recruited 389 patients with T2DM who satisfied the following three criteria: negative for HBs-Ag and anti-HCV Ab, alcohol intake <60 g/day, and history of T2DM >10 years. These patients were divided into two groups: T2DM patients with HCC (DM-HCC, n = 59) or those without HCC (DM-non-HCC, n = 330). We genotyped 51 single-nucleotide polymorphisms (SNPs) previously reported as T2DM or NASH susceptibility loci (PNPLA3) compared between the DM-HCC and DM-non-HCC groups with regard to allele frequencies at each SNP. RESULTS: The SNP rs738409 located in PNPLA3 was the greatest risk factor associated with HCC. The frequency of the PNPLA3 G allele was significantly higher among DM-HCC individuals than DM-non-HCC individuals (OR 2.53, p = 1.05 × 10(-5)). Among individuals homozygous for the PNPLA3 G allele (n = 115), the frequency of the JAZF1 rs864745 G allele was significantly higher among DM-HCC individuals than DM-non-HCC individuals (OR 3.44, p = 0.0002). CONCLUSIONS: PNPLA3 and JAZF1 were associated with non-HBV and non-HCV-related HCC development among Japanese patients with T2DM.