Tetsuya Ichijo
Shinshu University
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Featured researches published by Tetsuya Ichijo.
Journal of Gastroenterology | 2009
Takeji Umemura; Tetsuya Ichijo; Kaname Yoshizawa; Eiji Tanaka; Kendo Kiyosawa
Primary liver cancer, 95% of which is hepatocellular carcinoma (HCC), is ranked third in men and fifth in women as a cause of death from malignant neoplasms in Japan. The number of deaths and death rate of HCC began to increase sharply in 1975. These numbers peaked at 34 510 and 27.4/100 000, respectively, in 2004, but decreased to 33 662 annual deaths and a 26.7/100 000 death rate in 2006. Although hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are both major causes of HCC, HCV-related HCC represents 70% of all cases. The incidence of HCC without hepatitis B surface antigen (HBsAg) or antibodies to HCV (anti-HCV) accounts for 8%–15% of HCC patients nationwide. Geographically, HCC is more frequent in western than eastern Japan, and death rates of HCC in each prefecture correlate with anti-HCV, but not HBsAg, prevalence. Interferon therapy for chronic hepatitis C reduces the risk of development of HCC, especially among patients with sustained virological response. Further research should focus on the mechanisms of carcinogenesis by HCV and HBV, development of more effective treatments, and establishment of early detection and preventative approaches. Better understanding of HCC unrelated to HCV and HBV, possibly caused by steatohepatitis and diabetes, should also be a major concern in future studies.
Hepatology | 2008
Haruaki Shirakawa; Akihiro Matsumoto; Satoru Joshita; Michiharu Komatsu; Naoki Tanaka; Takeji Umemura; Tetsuya Ichijo; Kaname Yoshizawa; Kendo Kiyosawa; Eiji Tanaka
The interferon sensitivity determining region (ISDR) of the hepatitis C virus (HCV) and T‐helper type 1 and type 2 (Th1/Th2) ratio were analyzed along with other host and viral factors for their ability to predict the response of patients with chronic hepatitis C to pegylated interferon alpha‐2b (Peg‐IFN) and ribavirin (RBV) combination therapy. A total of 120 chronic hepatitis C patients with genotype 1 HCV and high baseline viral loads who were to undergo combination therapy scheduled for 48 weeks were enrolled. Sustained virologic response (SVR) was achieved in 54 (45%) of the 120 patients. The pretreatment factors significantly associated with SVR by logistic regression analysis were ISDR mutant [odds ratio (OR) = 86.0, P = 0.0008], Th1/Th2 ratio ≤ 15.5 (OR = 9.6, P = 0.0021), body weight 59 kg, and neutrophil count 2,300/μL. A logistic regression model to estimate SVR before combination therapy was constructed using these four factors. Patients fell into three groups when plotted according to estimated and actual SVR rates: actual SVR rate was 91% (32/35) in the high sensitivity group, 41% (15/37) in the intermediate sensitivity group, and 15% (7/48) in the low sensitivity group. Rapid or early virological responses were seen in 80% of patients with high sensitivity and who achieved SVR but were found in only 40% of patients with intermediate or low sensitivity. Null‐ and very late virological responses were quite rare in the high sensitivity group. In conclusion, a logistic regression model that includes the sequence of ISDR of the HCV, Th1/Th2 ratio, body weight, and neutrophil count can be useful for accurately predicting actual SVR rate before combination therapy. (HEPATOLOGY 2008;48:1753‐1760.)
Gut | 2007
Takeji Umemura; Yoh Zen; Hideaki Hamano; Tetsuya Ichijo; Shigeyuki Kawa; Yasuni Nakanuma; Kendo Kiyosawa
Autoimmune pancreatitis is characterised by raised serum levels of IgG4 and IgG4-bearing plasma cells in the inflammatory tissue.1 Similar pathology can also occur in the larger bile ducts, resembling sclerosing cholangitis.2 We report a patient with hepatitis and chronic cholecystitis, raised IgG4 level, and IgG4-bearing plasma cells in the liver and gall bladder wall, but no evident pancreatic disease. In January 2003, a cholecystectomy was undertaken on a 54 year old woman for chronic cholecystitis. The extracted gall bladder showed lymphoplasmacytic infiltration and subserosal fibrosis. A liver biopsy was done because of abnormal liver function tests and showed severe lobular hepatitis with mild portal inflammation. Plasma cell infiltration was observed in the portal tracts and parenchyma, though fibrosis was not significant. IgG4 bearing plasma cell infiltration was found both in the liver and the gall bladder wall. After six months, liver function was still abnormal: aspartate …
Journal of Hepatology | 2010
Tadanobu Nagaya; Naoki Tanaka; Takefumi Suzuki; Kenji Sano; Akira Horiuchi; Michiharu Komatsu; Takero Nakajima; Tomoko Nishizawa; Satoru Joshita; Takeji Umemura; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Jun Nakayama; Eiji Tanaka; Toshifumi Aoyama
BACKGROUND & AIMS It is well-known that hepatic triglycerides (TG) diminish with the progression of non-alcoholic steatohepatitis (NASH), which has been designated as burned-out NASH, but its mechanism remains unclear. We aimed to explore the changes in hepatic fatty acid (FA) and TG metabolism with disease progression. METHODS Hepatic expression of key genes in healthy individuals (n=6) and patients with simple steatosis (SS, n=10), mild NASH (fibrosis stage 1-2, n=20), and advanced NASH (fibrosis stage 3-4, n=20) were assessed by quantitative polymerase chain reaction. RESULTS Hepatic expression of genes related to FA uptake and oxidation and very-low-density lipoprotein synthesis/export did not differ among the groups. However, the mRNA levels of sterol regulatory element-binding protein (SREBP)-1c and its downstream genes FA synthase, acetyl-coenzyme A carboxylase 1, and diacylglycerol acyltransferase 1 were inversely correlated with fibrosis stage. Immunoblot analysis revealed a remarkable reduction in mature SREBP-1c levels in advanced NASH. Furthermore, hepatic expression of tumor necrosis factor-alpha increased in accordance with fibrosis progression, which was possibly related to the decrease in hepatic SREBP-1c expression. CONCLUSIONS Down-regulation of SREBP-1c and lipogenic enzymes may be associated with the development of burned-out NASH.
Hepatology | 2012
Kaname Yoshizawa; Akihiro Matsumoto; Tetsuya Ichijo; Takeji Umemura; Satoru Joshita; Michiharu Komatsu; Naoki Tanaka; Eiji Tanaka; Masao Ota; Yoshihiko Katsuyama; Kendo Kiyosawa; Masanori Abe; Morikazu Onji
The long‐term outcome of patients with autoimmune hepatitis (AIH) in Japan has not been well‐defined. The aim of this study was to clarify the outcome of this disease over a long follow‐up period compared with that of the general Japanese population as well as that among patients. A total of 203 AIH patients were enrolled for a mean follow‐up period of 131 months. All patients were treated with corticosteroids with or without azathioprine. The overall survival of AIH patients was similar to that of the general population in Japan. The prognosis of AIH subgroups divided according to disease severity, sex, incidence of relapse, liver histology, presence of cirrhosis, probable or definite AIH score, antibody to hepatitis B core antigen antibody positivity, or human leukocyte antigen DR4–positivity did not differ greatly among patients. However, the prognosis of patients experiencing two or more relapses was significantly poorer than that of patients with remission or a single relapse both in univariate (P < 0.001) and multivariate (P = 0.020) analyses. The development of liver malignancy was also a possibility among AIH patients with multiple relapses. Severe adverse effects of corticosteroids were rare, even in patients who underwent long‐term treatment. Conclusion: Repeated relapses of AIH are significantly associated with a poorer long‐term prognosis in Japan. AIH patients can expect a similar prognosis to that of the general population, provided they are adequately managed with continuous low doses of immunosuppressive therapy, especially after the first relapse. (HEPATOLOGY 2012)
Hepatology | 2012
Takeji Umemura; Satoru Joshita; Tetsuya Ichijo; Kaname Yoshizawa; Yoshihiko Katsuyama; Eiji Tanaka; Masao Ota
Along with twin and family studies, recent genome‐wide association studies suggest that genetic factors contribute to the susceptibility and severity of primary biliary cirrhosis (PBC). Although several reports have demonstrated that the human leukocyte antigen (HLA) DRB1*08:03 allele is associated with disease susceptibility in Japan, the precise analysis of HLA haplotypes and the role of amino acid alignment have not been fully clarified. We investigated HLA class I A, B, and C and HLA class II DRB1 and DQB1 alleles and haplotypes in 229 Japanese patients with PBC and compared them with the published data of 523 healthy subjects. Significant associations were found with PBC susceptibility for the DRB1*08:03‐DQB1*06:01 (13% versus 6%; P = 0.000025; odds ratio [OR] = 2.22) and DRB1*04:05‐DQB1*04:01 haplotypes (17% versus 13%; P = 0.044; OR = 1.38). Conversely, there were significant protective associations with the DRB1*13:02‐DQB1*06:04 (2% versus 5%; P = 0.00093; OR = 0.27) and DRB1*11:01‐DQB1*03:01 haplotypes (1% versus 4%; P = 0.03; OR = 0.37). The frequency of the DRB1*09:01‐DQB1*03:03 haplotype was significantly higher in patients who had received orthotopic liver transplantation (33% versus 11%; P = 0.0012; OR = 3.96). Furthermore, the frequency of serine at position 57 (P = 0.0000015; OR = 1.83) of the DRβchain differed the most in patients with PBC, compared with healthy subjects. Conclusion: This study established the role of HLA haplotypes in determining PBC susceptibility and progression in the Japanese population. Further resequencing of the HLA region is required to more precisely identify the genetic components of PBC. (HEPATOLOGY 2012)
Journal of Clinical Gastroenterology | 2010
Masaru Tsutsui; Naoki Tanaka; Masatomo Kawakubo; Yo Sheena; Akira Horiuchi; Michiharu Komatsu; Tadanobu Nagaya; Satoru Joshita; Takeji Umemura; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Toshifumi Aoyama; Eiji Tanaka; Kenji Sano
Background and Goals Reliable noninvasive biomarkers to assess the histologic activity of nonalcoholic fatty liver disease (NAFLD) have not been established. As the frequency of Mallory bodies is known to be closely associated with the disease severity, we hypothesized that serum levels of Mallory body-related proteins were correlated with NAFLD histologic activity and evaluated this possibility. Study Serum levels of total and fragmented cytokeratin (CK) 18, heat shock protein (Hsp) 70, Hsp90α, ubiquitin+1, and p38α at the time of liver biopsy were measured in 118 NAFLD patients and their association with histologic findings and NAFLD histologic activity score (NAS) was investigated. Results Serum levels of both forms of CK18 and Hsp90α were markedly higher in patients having nonalcoholic steatohepatitis (NASH) compared with non-NASH ones. Both forms of CK18 significantly correlated with degree of steatosis, lobular inflammation, and ballooning, and showed stronger positive correlations with NAS than serum aspartate and alanine aminotransferase (AST and ALT). Multiple regression analysis further revealed that fragmented CK18 and AST were effective predictors of NAS, with the former being the more definitive of the two (P<0.001 vs. 0.005). In 20 NAFLD patients who received a follow-up biopsy, changes in fragmented CK18 levels, but not AST or ALT levels, closely paralleled those in NAS. Conclusions These results establish the usefulness of fragmented CK18 measurement for assessing and monitoring the histologic activity of NAFLD.
The Journal of Infectious Diseases | 2011
Suguru Yoneda; Takeji Umemura; Yoshihiko Katsuyama; Atsushi Kamijo; Satoru Joshita; Michiharu Komatsu; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Masao Ota; Eiji Tanaka
BACKGROUND We sought to clarify the associations among serum cytokines, amino acid substitutions in the interferon sensitivity-determining region (ISDR) and core region, and treatment outcome of pegylated interferon and ribavirin therapy in genotype 1 hepatitis C virus (HCV)-infected patients. METHODS We quantified a total of 8 serum cytokines before, during, and after treatment in 79 genotype 1 chronic HCV patients. Viral ISDR and core region variants were determined by direct sequencing. RESULTS High levels of interleukin (IL)-12 and IL-18 and more than 2 mutations in the ISDR were associated with a sustained virological response (SVR). Conversely, high baseline IL-10 levels and glutamine at amino acid 70 of the HCV core protein (Gln70) were significantly associated with a nonresponse to treatment, and patients with Gln70 had significantly higher IL-10 levels. In multivariate analysis, low IL-10, high IL-12, and high IL-18 levels were independently associated with an SVR. These 3 cytokine levels were decreased from baseline levels 4 weeks into treatment and remained low in patients with an SVR. CONCLUSION Serum IL-10, IL-12, and IL-18 levels are predictive of the response to HCV treatment with pegylated interferon and ribavirin and are associated with amino acid substitutions in the ISDR and core region.
Hepatology | 2007
Shuichi Yokosawa; Kaname Yoshizawa; Masao Ota; Yoshihiko Katsuyama; Shigeyuki Kawa; Tetsuya Ichijo; Takeji Umemura; Eiji Tanaka; Kendo Kiyosawa
Genetic predisposition to type 1 autoimmune hepatitis (AIH) is linked mainly to HLA class II genes. We previously searched the whole HLA region for AIH susceptibility genes using microsatellite markers and found only HLA‐DR/DQ to be a candidate region for this suspected multifactorial disease. As such, the aim of this study was to broaden our search and screen the whole genome for additional genes that might contribute to type 1 AIH susceptibility. Eighty‐one patients with type 1 AIH (15 men, 66 women, average age 55.9) and 80 healthy sex‐ and age‐matched Japanese controls were enrolled in this study. We performed a case‐control association study using 400 polymorphic microsatellite markers with an average spacing of 10.8 cM distributed throughout the whole genome. Two markers, one on chromosome 11 (D11S902, Pc = 0.013) and one on chromosome 18 (D18S464, Pc = 0.008), were revealed to have statistically significant associations with AIH. An additional 7 markers (D2S367, D6S309, D9S273, D11S1320, D16S423, D17S938, and D18S68) were also found to be candidate susceptibility regions. In addition, our results showed there were 17 regions that may contain genes of resistance to AIH. No specific markers were detected in HLA‐DR4‐negative patients, and no differences were seen in the clinical courses of patients (severe versus mild to moderate). Conclusion: This first genomewide scan of Japanese AIH patients revealed at least 26 candidate AIH susceptibility or resistance regions other than HLA class II loci. These results also suggested that the products of several genes interact to determine heritable susceptibility to AIH. (HEPATOLOGY 2007;45:384–390.)
Human Immunology | 2012
Satoru Joshita; Takeji Umemura; Yoshihiko Katsuyama; Yuki Ichikawa; Takefumi Kimura; Susumu Morita; Atsushi Kamijo; Michiharu Komatsu; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Nozomi Kamijo; Masao Ota; Eiji Tanaka
IL28B single nucleotide polymorphisms (SNPs) are associated with spontaneous and treatment-induced elimination of hepatitis C virus (HCV). To assess whether the IL28B rs8099917 SNP also affects the progression of chronic HCV infection, we genotyped 511 Japanese HCV patients, including 69 with hepatocellular carcinoma (HCC). The T/T genotype of rs8099917 was not associated with the development of HCC (p = 0.623), although stepwise logistic regression analysis showed that liver cirrhosis, age greater than 68 years, and serum albumin <4.2 mg/dl were associated with HCC onset. It appears that the IL28B SNP does not directly influence hepatocarcinogenesis in chronic HCV infection.