The Research Center for Hepatitis and Immunology

Ichikawa, Japan

The Research Center for Hepatitis and Immunology

Ichikawa, Japan
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Ide K.,University of Shizuoka | Kawasaki Y.,University of Shizuoka | Yamada H.,University of Shizuoka | Masaki N.,The Research Center for Hepatitis and Immunology
Drug Design, Development and Therapy | Year: 2016

Purpose: The aims of this study were to investigate regional differences in hepatitis C virus (HCV) infection treatment with peginterferon and ribavirin in Japan and to develop and validate statistical models for analysis of regional differences, using generalized linear mixed models. Methods: Individuals with chronic HCV infection were identified from the Japanese Interferon Database (registered from December 2009 to April 2013). The total sustained virologic response rate and the rate in each prefecture were calculated. In the analysis using generalized linear mixed models, the following four models were constructed: 1) prefecture as a fixed effect, 2) prefecture and other confounding variables as fixed effects, 3) prefecture as a random effect, and 4) prefecture as a random effect and other confounding variables as fixed effects. The quality of the model fit was assessed using the Akaike information criterion and the Bayesian information criterion. All statistical analyses were performed using SAS Version 9.4 for Windows. Results: From 36 prefectures, 16,349 cases were recorded in the study period. Of these, 4,677 were excluded according to certain criteria. The total sustained virologic response rate was 59.9% (range, 43.9%–71.6%). The statistical model including prefecture as a random effect and other confounding variables as fixed effects showed the best fit based on the Akaike information criterion (13,830.92) and Bayesian information criterion (13,845.17). Conclusion: Regional differences may exist in HCV infection treatment in Japan. The model including prefecture as a random effect and other confounding variables as fixed effects was appropriate for analysis of such regional differences. Additional studies considering the medical situations of each patient would provide useful information that could contribute to improve and standardize HCV infection treatment. © 2016 Ide et al.

Sato I.,Center for Clinical science | Shimbo T.,Ohta Nishinouchi Hospital | Kawasaki Y.,Tokyo University of Science | Masaki N.,The Research Center for Hepatitis and Immunology
Drug Design, Development and Therapy | Year: 2014

Results: A total of 16,349 patients were recorded in the Japanese Interferon Database. After application of the exclusion criteria, 12,706 patients (3,578 [1,710 males, 1,868 females] on PEG-IFN alfa-2a; and 9,128 [4,652 males, 4,476 females] on PEG-IFN alfa-2b) were included in this analysis. The SVR rate in the PEG-IFN alfa-2b group was 62.0%, as compared with a rate of 55.1% in the PEG-IFN alfa-2a group (crude odds ratio =1.31; 95% confidence interval [CI]: 1.23 to 1.44). There was no significant difference in the adjusted SVR rates between the two groups (adjusted odds ratio =0.96; 95% CI: 0.88 to 1.05). Similar proportions of adverse events were observed in the two groups, with the exception of thrombocytopenia, retinopathy, and anemia.Conclusion: There was no significant difference in the SVR rates and safety profile between chronic hepatitis C patients treated with the PEG-IFN alfa-2a and alfa-2b.Purpose: We aimed to compare the rates of sustained virologic response (SVR) achieved with peginterferon (PEG-IFN) alfa-2a and alfa-2b in combination with ribavinin (RBV) for chronic hepatitis C, using a large database of hepatitis cases to improve the generalizability of these results.Methods: We identified patients with chronic hepatitis C who were treated with PEG-IFN alfa-2a or alfa-2b and RBV, from the Japanese Interferon Database, between December 2009 and April 2013. This database contains the medical records of IFN treatment collected from 36 prefectures in Japan. Multivariable logistic regression analysis was used to compare SVR rates obtained with PEG-IFN alfa-2a and alfa-2b, in combination with RBV. © 2015 Sato et al.

Ito K.,Aichi Medical University | Yoneda M.,Aichi Medical University | Sakamoto K.,Aichi Medical University | Mizokami M.,The Research Center for Hepatitis and Immunology
Journal of Gastroenterology | Year: 2017

Hepatitis B virus (HBV) infection is one of the most prevalent chronic viral infections in humans. The overall prevalence of hepatitis B surface antigen (HBsAg) is reported to be 3.6%; however, it varies depending upon the geographic area. HBV is classified into ten genotypes (A through J) on the basis of an intergroup genomic divergence of > 8%. Specifically, HBV genotype A exhibits several unique virological and clinical characteristics and can be further classified into seven subtypes. Among them, subtype A2 or Ae (A2/[e]) is occasionally responsible for nosocomial infection and among homosexual males. Regarding virological factors, the G1896A precore mutation is rarely observed in genotype A as it would disrupt an essential stem-loop structure in the ε signal essential for pregenomic RNA packaging. HBV genotype A also harbors a 6-nucleotide C-terminal insertion in the hepatitis B-e antigen (HBeAg) precursor, resulting in a variable-length HBeAg protein product observed in serum of positive patients. These molecular traits likely contribute to the specific clinical presentation of genotype A-infected patients, such as mild acute hepatitis B (AHB), longer persistence of HBsAg positivity in AHB, and increased chronicity after AHB in adults. However, genotype A shows a better response to interferon than other genotypes in chronic hepatitis B patients. Here, we review the virological and clinical characteristics of HBV genotype A that will be useful in elucidating the association among persistent viral infection, host genetic factors, and treatment in future studies. © 2017 Japanese Society of Gastroenterology

Nakano T.,Mie University | Lau G.M.G.,University of California at Berkeley | Lau G.M.L.,University of California at Los Angeles | Sugiyama M.,The Research Center for Hepatitis and Immunology | Mizokami M.,The Research Center for Hepatitis and Immunology
Liver International | Year: 2012

Background: The hepatitis C virus (HCV) genomic database is expanding rapidly. Aims: There is a need to provide an updated phylogenetic tree analysis based on the complete coding region of HCV. Methods: All available HCV complete genome sequences in the HCV databases available through October 2010 were analyzed. Results: The assignment of all known complete sequences up-to-date confirmed the previous six major genotypes and one new sequence, which have been provisionally assigned as subtype 7a. New recombinant forms of HCV, although uncommon, have been detected and were found to have different crossover points. Conclusion: This updated analysis based on the complete region of HCV confirmed the validity of the previously assigned genotypes/subtypes and provided an up-to-date reference for future basic research and clinical studies. © 2011 John Wiley & Sons A/S.

Sugiyama M.,The Research Center for Hepatitis and Immunology | Sugiyama M.,Nagoya City University | Sugiyama M.,Japan Society for the Promotion of Science | Tanaka Y.,Nagoya City University | And 3 more authors.
PLoS ONE | Year: 2011

The current standard of care for the treatment of chronic hepatitis C is pegylated interferon-α (PEG-IFNα) and ribavirin (RBV). The treatment achieves a sustained viral clearance in only approximately 50% of patients. Recent whole genome association studies revealed that single nucleotide polymorphisms (SNPs) around IL-28B have been associated with response to the standard therapy and could predict treatment responses at approximately 80%. However, it is not clear which SNP is most informative because the genomic region containing significant SNPs shows strong linkage disequilibrium. We focused on SNPs in close proximity to the IL-28B gene to evaluate the function of each and identify the SNP affecting the IL-28B expression level most. The structures of IL-28A/B from 5′ to 3′-UTR were determined by complete cDNA cloning. Both IL-28A and 28B genes consisted of 6 exons, differing from the CCDS data of NCBI. Two intron SNPs and a nonsynonymous SNP did not affect IL-28B gene function and expression levels but a SNP located in the proximal promoter region influenced gene expression. A (TA) dinucleotide repeat, rs72258881, located in the promoter region was discovered by our functional studies of the proximal SNPs upstream of IL-28B; the transcriptional activity of the promoter increased gradually in a (TA) n length-dependent manner following IFN-α and lipopolysaccharide stimulation. Healthy Japanese donors exhibited a broad range of (TA) dinucleotide repeat numbers from 10 to 18 and the most prevalent genotype was 12/12 (75%), differing from the database (13/13). However, genetic variation of IL-28A corresponding to that of IL-28B was not detected in these Japanese donors. These findings suggest that the dinucleotide repeat could be associated with the transcriptional activity of IL-28B as well as being a marker to improve the prediction of the response to interferon-based hepatitis C virus treatment. © 2011 Sugiyama et al.

Kawashima M.,University of Tokyo | Ohashi J.,University of Tsukuba | Nishida N.,University of Tokyo | Nishida N.,The Research Center for Hepatitis and Immunology | Tokunaga K.,University of Tokyo
PLoS ONE | Year: 2012

The human leukocyte antigen (HLA) genes exhibit the highest degree of polymorphism in the human genome. This high degree of variation at classical HLA class I and class II loci has been maintained by balancing selection for a long evolutionary time. However, little is known about recent positive selection acting on specific HLA alleles in a local population. To detect the signature of recent positive selection, we genotyped six HLA loci, HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1, and HLA-DPB1 in 418 Japanese subjects, and then assessed the haplotype homozygosity (HH) of each HLA allele. There were 120 HLA alleles across the six loci. Among the 80 HLA alleles with frequencies of more than 1%, DPB1*04:01, which had a frequency of 6.1%, showed exceptionally high HH (0.53). This finding raises the possibility that recent positive selection has acted on DPB1*04:01. The DPB1*04:01 allele, which was present in the most common 6-locus HLA haplotype (4.4%), A*33:03-C*14:03-B*44:03-DRB1*13:02-DQB1*06:04-DPB1*04:01, seems to have flowed from the Korean peninsula to the Japanese archipelago in the Yayoi period. A stochastic simulation approach indicated that the strong linkage disequilibrium between DQB1*06:04 and DPB1*04:01 observed in Japanese cannot be explained without positive selection favoring DPB1*04:01. The selection coefficient of DPB1*04:01 was estimated as 0.041 (95% credible interval 0.021-0.077). Our results suggest that DPB1*04:01 has recently undergone strong positive selection in Japanese population. © 2012 Kawashima et al.

Mizokami M.,The Research Center for Hepatitis and Immunology
Journal of Gastroenterology and Hepatology (Australia) | Year: 2012

Chronic hepatitis C affects 2.2-3.0% of the world population (130 million-170 million). Pegylated interferon-α (PEG-IFN-α) in combination with ribavirin (RBV), the approved and standard therapy, leads to viral eradication in about 50% of treated patients. In 2009, genome-wide association studies (GWAS) identified host genetic variation to be critical for predicting treatment response and spontaneous clearance in patients infected with hepatitis C virus (HCV). A correlated set of polymorphisms in the region of the interleukin-28B (IL-28B) gene on chromosome 19, coding for interferon (IFN)-λ3 were associated with clearance of genotype 1 hepatitis C virus (HCV) in patients treated with PEG-IFN-α and RBV. The same polymorphisms were subsequently associated with spontaneous clearance of HCV in untreated patients. In addition, prediction of viral response to PEG-IFN-α and RBV therapy of patients with recurrent HCV infection after orthotopic liver transplantation depends on the IL-28B genotype of both recipient and donor tissues. Diagnosis of a patient's IL-28B genotype is likely to aid in clinical decision making with standard-of-care regimens. Future studies will investigate the possibility of individualizing treatment duration and novel regimens according to IL-28B genotype. As GWAS yield unexpected data, this approach could lead to the development of novel drug therapy, such as already appears promising with IFN-λ. In this Okuda lecture, I present the current understanding in regard to the relationship between host variations and clinical outcome of hepatitis C. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

Tatematsu K.,Nagoya City University | Tanaka Y.,Nagoya City University | Sugiyama M.,Nagoya City University | Sudoh M.,Chugai Pharmaceutical Co. | And 2 more authors.
Journal of Medical Virology | Year: 2011

Serine palmitoyltransferase (SPT) catalyzes the first step in the sphingolipid biosynthetic pathway. Myriocin inhibits SPT and was shown to suppress the replication of hepatitis C virus (HCV) in vitro and in vivo. However, its effect on hepatitis B virus (HBV) replication is unknown. In this study, the HBV DNA levels in HuH7 cell culture supernatants were lowered successfully by using myriocin and it was found that the 50% inhibitory concentration of myriocin is approximately 5μM. Myriocin and/or pegylated interferon (PEG-IFN) were also administered to chimeric mice for 2 weeks and the effects of these compounds on HBV DNA levels were determined. Myriocin alone did not reduce effectively the HBV DNA levels, whereas PEG-IFN alone reduced the DNA levels to 1/10th of the control levels. The combination of myriocin with PEG-IFN reduced the HBV levels to about 1/1,000th of the control levels and induced a 1.0log reduction in the levels of the HBV surface antigen and core protein. This latter effect was not observed in the other treatment groups. In conclusion, the combination of myriocin with PEG-IFN represses synergistically HBV replication in vivo without inducing hepatotoxicity. © 2011 Wiley-Liss, Inc.

Mizokami M.,The Research Center for Hepatitis and Immunology
Uirusu | Year: 2012

Hepatitis B virus (HBV) prevention program in Japan is considered one of the most successful and effective public anti-counter programs to HBV infection. However, almost all of population under twenty-five years is extremely susceptibility for HBV infection. HBV genotype A, which was not in Japan and has been from western countries, is increasing in chronic hepatitis B patients in Japan as a consequence of acute hepatitis B spreading in the younger generation through promiscuous sexual transmitted infection and the characteristics of HBV genotype A is a prolonged high HBVDNA viremia compared with other HBV genotypes. These data have strongly indicated that the main transmission route of HBV in Japan has been changed to a horizontal infection with sexual transmitted disease from perinatal transmission from HBsAg positive mothers. Although the HBV vaccine has tipped the balance in our favor, newly issues of HBV vaccine has been arisen such as vaccine escape mutant, efficacy and potency for the prevention of HBV infection, especially different HBV genotypes, HBV reactivation on the patients with HBsAg negative and anti-HBs antibody positive under systemic chemotherapy, and universal vaccination or selective vaccination and so on.

Yoshio S.,The Research Center for Hepatitis and Immunology | Kanto T.,The Research Center for Hepatitis and Immunology
Journal of Gastroenterology | Year: 2016

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are among the most endemic pathogens worldwide, with more than 500 million people globally currently infected with these viruses. These pathogens can cause acute and chronic hepatitis that progress to liver cirrhosis or hepatocellular carcinoma. Both viruses utilize multifaceted strategies to evade the host surveillance system and fall below the immunological radar. HBV has developed specific strategies to evade recognition by the innate immune system and is acknowledged to be a stealth virus. However, extensive research has revealed that HBV is recognized by dendritic cells (DCs) and natural killer (NK) cells. Indoleamine-2, 3-dioxygenase is an enforcer of sequential immune reactions in acute hepatitis B, and this molecule has been shown to be induced by the interaction of HBV-infected hepatocytes, DCs, and NK cells. The interleukin-28B genotype has been reported to influence HCV eradication either therapeutically or spontaneously, but the biological function of its gene product, a type-III interferon (IFN-λ3), remains to be elucidated. Human BDCA3+DCs have also been shown to be a potent producer of IFN-λ3 in HCV infection, suggesting the possibility that BDCA3+DCs could play a key role in developing therapeutic HCV vaccine. Here we review the current state of research on immune responses against HBV and HCV infection, with a specific focus on innate immunity. A comprehensive study based on clinical samples is urgently needed to improve our understanding of the immune mechanisms associated with viral control and thus to develop novel immune modulatory therapies to cure chronic HBV and HCV infection. © 2016, Japanese Society of Gastroenterology.

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