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Dive into the research topics where Michiharu Komatsu is active.

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Featured researches published by Michiharu Komatsu.


Hepatology | 2008

Pretreatment prediction of virological response to peginterferon plus ribavirin therapy in chronic hepatitis C patients using viral and host factors

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.)


Journal of Hepatology | 2010

Down-regulation of SREBP-1c is associated with the development of burned-out NASH.

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.


The American Journal of Gastroenterology | 2015

Serum Wisteria floribunda Agglutinin-Positive Mac-2-Binding Protein Level Predicts Liver Fibrosis and Prognosis in Primary Biliary Cirrhosis

Takeji Umemura; Satoru Joshita; Tomohiro Sekiguchi; Yoko Usami; Soichiro Shibata; Takefumi Kimura; Michiharu Komatsu; Akihiro Matsumoto; Masao Ota; Eiji Tanaka

OBJECTIVES:Noninvasive markers of liver fibrosis in patients with primary biliary cirrhosis (PBC) are needed for predicting disease progression. As the Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP) was recently established as a liver fibrosis glycobiomarker in chronic hepatitis C, we assessed its efficacy in evaluating liver fibrosis stage and disease progression in PBC.METHODS:A total of 137 patients with PBC who underwent liver biopsy and serological tests for WFA+-M2BP were enrolled. All patients were treated with ursodeoxycholic acid. Clinical data were compared with those for other noninvasive markers (aspartate aminotransferase-to-platelet ratio, FIB-4 index, aspartate aminotransferase/alanine aminotransferase ratio, Forn’s index, and Mayo score) for estimating liver fibrosis using receiver operating characteristic analysis. The association between WFA+-M2BP and clinical outcome (liver decompensation, liver transplantation, or death) was evaluated using the Cox proportional hazards model with stepwise method.RESULTS:WFA+-M2BP was independently associated with liver fibrosis stage as determined by liver biopsy. The cutoff values of WFA+-M2BP for fibrosis stages ≥F1, ≥F2, ≥F3, and F4 were 0.7, 1.0, 1.4, and 2.0, respectively. The area under the receiver operating characteristic curve values for significant fibrosis, severe fibrosis, and cirrhosis were 0.979, 0.933, and 0.965, respectively. WFA+-M2BP was significantly superior to the other indices for the determination of significant and severe fibrosis stages. Furthermore, the WFA+-M2BP level at enrollment was strongly and independently associated with clinical outcome (hazard ratio 18.59, P=0.021).CONCLUSIONS:Baseline measurements of WFA+-M2BP represent a simple and reliable noninvasive surrogate marker of liver fibrosis and prognosis in patients with PBC.


Hepatology | 2012

Long‐term outcome of Japanese patients with type 1 autoimmune hepatitis

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)


Journal of Hepatology | 2008

Citrin deficiency as a cause of chronic liver disorder mimicking non-alcoholic fatty liver disease.

Michiharu Komatsu; Masahide Yazaki; Naoki Tanaka; Kenji Sano; Etsuko Hashimoto; Yo-ichi Takei; Yuan-Zong Song; Eiji Tanaka; Kendo Kiyosawa; Takeyori Saheki; Toshifumi Aoyama; Keiko Kobayashi

BACKGROUND/AIMS Citrin deficiency caused by SLC25A13 gene mutations develops into adult-onset type II citrullinemia (CTLN2) and may be accompanied with hepatic steatosis and steatohepatitis. As its clinical features remain unclear, we aimed to explore the characteristics of fatty liver disease associated with citrin deficiency. METHODS The prevalence of hepatic steatosis in 19 CTLN2 patients was examined, and clinical features were compared with those of non-alcoholic fatty liver disease (NAFLD) patients without known SLC25A13 gene mutations. RESULTS Seventeen (89%) CTLN2 patients had steatosis, and 4 (21%) had been diagnosed as having NAFLD before appearance of neuropsychological symptoms. One patient had steatohepatitis. Citrin deficiency-associated fatty livers showed a considerably lower prevalence of accompanying obesity and metabolic syndrome, higher prevalence of history of pancreatitis, and higher serum levels of pancreatic secretory trypsin inhibitor (PSTI) than fatty livers without the mutations. Receiver operating characteristic curve analyses revealed that a body mass index < 20kg/m(2) and serum PSTI>29ng/mL were associated with citrin deficiency. CONCLUSIONS Patients presenting with non-alcoholic fatty liver unrelated to obesity and metabolic syndrome might have citrin deficiency, and serum PSTI may be a useful indicator for distinguishing this from conventional NAFLD.


Journal of Clinical Gastroenterology | 2010

Serum fragmented cytokeratin 18 levels reflect the histologic activity score of nonalcoholic fatty liver disease more accurately than serum alanine aminotransferase levels.

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

Association of serum cytokine levels with treatment response to pegylated interferon and ribavirin therapy in genotype 1 chronic hepatitis C patients.

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.


Human Immunology | 2012

Association of IL28B gene polymorphism with development of hepatocellular carcinoma in Japanese patients with chronic hepatitis C virus infection

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.


PLOS ONE | 2014

Human leukocyte antigen class II haplotypes affect clinical characteristics and progression of type 1 autoimmune hepatitis in Japan.

Takeji Umemura; Yoshihiko Katsuyama; Kaname Yoshizawa; Takefumi Kimura; Satoru Joshita; Michiharu Komatsu; Akihiro Matsumoto; Eiji Tanaka; Masao Ota

Although we earlier demonstrated that the human leukocyte antigen (HLA) DRB1*04:05 allele was associated with susceptibility to autoimmune hepatitis (AIH) in Japan, the precise relationship of HLA haplotype and the role of amino acid alignment with disease susceptibility and progression has not been fully clarified. We reinvestigated HLA class I A, B, and C and HLA class II DRB1, DQB1, and DPB1 alleles and haplotypes in a larger new cohort of 156 Japanese patients with type 1 AIH and compared them with the published data of 210 healthy subjects. The DRB1*04:05-DQB1*04:01 haplotype was significantly associated with AIH susceptibility (30% vs. 11%, P = 1.2×10−10; odds ratio [OR]  = 3.51) and correlated with elevated serum IgG (3042 vs. 2606 mg/dL, P = 0.041) and anti-smooth muscle antigen positivity (77% vs. 34%, P = 0.000006). No associations with HLA-DPB1 alleles were found. The HLA A*24:02 and C*01:02 alleles were associated with disease susceptibility (corrected P = 0.0053 and 0.036, respectively), but this likely constituents of a long ranged haplotype including DRB1*04:05-DQB1*04:01 haplotype. Conversely, the DRB1*15:01-DQB1*06:02 haplotype was associated with protection from both disease onset (5% vs. 13%, P = 0.00057; OR = 0.38) and the development of hepatocellular carcinoma (25% vs. 5%, P = 0.017; OR = 6.81). The frequency of the DRB1*08:03-DQB1*06:01 haplotype was significantly higher in patients who developed hepatic failure (22% vs. 6%, P = 0.034; OR = 4.38). In conclusion, this study established the role of HLA haplotypes in determining AIH susceptibility and progression in the Japanese population. Additional sequencing of the entire HLA region is required to more precisely identify the genetic components of AIH.


Liver International | 2006

Useful parameters for distinguishing nonalcoholic steatohepatitis with mild steatosis from cryptogenic chronic hepatitis in the Japanese population

Naoki Tanaka; Eiji Tanaka; Yo Sheena; Michiharu Komatsu; Wataru Okiyama; Noriko Misawa; Hidetomo Muto; Takeji Umemura; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Akira Horiuchi; Kendo Kiyosawa

Abstract: Background/Aims: As detecting mild steatosis is difficult by abdominal ultrasonography (US), nonalcoholic steatohepatitis (NASH) with mild steatosis may sometimes be confused with cryptogenic chronic hepatitis. We aimed to test this possibility and to isolate factors that may indicate NASH.

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