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Dive into the research topics where Susumu Morita is active.

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Featured researches published by Susumu Morita.


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.


Hepatology Research | 2014

Serum levels of interleukin-22 and hepatitis B core-related antigen are associated with treatment response to entecavir therapy in chronic hepatitis B

Sadahisa Okuhara; Takeji Umemura; Satoru Joshita; Soichiro Shibata; Takefumi Kimura; Susumu Morita; Michiharu Komatsu; Akihiro Matsumoto; Kaname Yoshizawa; Yoshihiko Katsuyama; Masao Ota; Eiji Tanaka

We sought to clarify the associations between serum cytokines and chemokines, hepatitis B surface antigen (HBsAg), hepatitis B core‐related antigen (HBcrAg), and hepatitis B virus (HBV) DNA and response to entecavir therapy in chronic hepatitis B.


Hepatology Research | 2016

Incidence and prevalence of autoimmune hepatitis in the Ueda area, Japan

Kaname Yoshizawa; Satoru Joshita; Akihiro Matsumoto; Takeji Umemura; Eiji Tanaka; Susumu Morita; Toshitaka Maejima; Masao Ota

Although autoimmune hepatitis (AIH) is considered to be rare in Japan, precise data on the incidence and prevalence of this disease are scarce due to the lack of a nationwide registry. We therefore conducted a study of these factors over a secondary medical care area.


Disease Markers | 2014

STAT4 Gene Polymorphisms Are Associated with Susceptibility and ANA Status in Primary Biliary Cirrhosis

Satoru Joshita; Takeji Umemura; Minoru Nakamura; Yoshihiko Katsuyama; Soichiro Shibata; Takefumi Kimura; Susumu Morita; Michiharu Komatsu; Akihiro Matsumoto; Kaname Yoshizawa; Hiromi Ishibashi; Eiji Tanaka; Masao Ota

Recent genome-wide association studies suggest that genetic factors contribute to primary biliary cirrhosis (PBC) susceptibility. Although several reports have demonstrated that the interleukin (IL) 12 signaling pathway is involved in PBC pathogenesis, its precise genetic factors have not been fully clarified. Here, we performed an association analysis between IL12A, IL12RB, and signal transducer and activator of transcription 4 (STAT4) genetic variations and susceptibility to PBC. Single nucleotide polymorphisms (SNPs) were genotyped in 395 PBC patients and 458 healthy subjects of Japanese ethnicity and evaluated for associations with PBC susceptibility, anti-nuclear antibody (ANA) status, and anti-mitochondrial antibody (AMA) status. We detected significant associations with PBC susceptibility for several STAT4 SNPs (rs10168266; P = 9.4 × 10−3, rs11889341; P = 1.2 × 10−3, rs7574865; P = 4.0 × 10−4, rs8179673; P = 2.0 × 10−4, and rs10181656; P = 4.2 × 10−5). Three risk alleles (rs7574865; P = 0.040, rs8179673; P = 0.032, and rs10181656; P = 0.031) were associated with ANA status, but not with AMA positivity. Our findings confirm that STAT4 is involved in PBC susceptibility and may play a role in ANA status in the Japanese population.


PLOS ONE | 2013

KIR, HLA, and IL28B Variant Predict Response to Antiviral Therapy in Genotype 1 Chronic Hepatitis C Patients in Japan

Yuichi Nozawa; Takeji Umemura; Satoru Joshita; Yoshihiko Katsuyama; Soichiro Shibata; Takefumi Kimura; Susumu Morita; Michiharu Komatsu; Akihiro Matsumoto; Eiji Tanaka; Masao Ota

Natural killer cell responses play a crucial role in virus clearance by the innate immune system. Although the killer immunoglobulin-like receptor (KIR) in combination with its cognate human leukocyte antigen (HLA) ligand, especially KIR2DL3-HLA-C1, is associated with both treatment-induced and spontaneous clearance of hepatitis C virus (HCV) infection in Caucasians, these innate immunity genes have not been fully clarified in Japanese patients. We therefore investigated 16 KIR genotypes along with HLA-B and -C ligands and a genetic variant of interleukin (IL) 28B (rs8099917) in 115 chronic hepatitis C genotype 1 patients who underwent pegylated-interferon-α2b (PEG-IFN) and ribavirin therapy. HLA-Bw4 was significantly associated with a sustained virological response (SVR) to treatment (P = 0.017; odds ratio [OR] = 2.50, ), as was the centromeric A/A haplotype of KIR (P = 0.015; OR 3.37). In contrast, SVR rates were significantly decreased in patients with KIR2DL2 or KIR2DS2 (P = 0.015; OR = 0.30, and P = 0.025; OR = 0.32, respectively). Multivariate logistic regression analysis subsequently identified the IL28B TT genotype (P = 0.00009; OR = 6.87, 95% confidence interval [CI] = 2.62 - 18.01), KIR2DL2/HLA-C1 (P = 0.014; OR = 0.24, 95% CI = 0.08 - 0.75), KIR3DL1/HLA-Bw4 (P = 0.008, OR = 3.32, 95% CI = 1.37 - 8.05), and white blood cell count at baseline (P = 0.009; OR = 3.32, 95% CI = 1.35 - 8.16) as independent predictive factors of an SVR. We observed a significant association between the combination of IL28B TT genotype and KIR3DL1-HLA-Bw4 in responders (P = 0.0019), whereas IL28B TT along with KIR2DL2-HLA-C1 was related to a non-response (P = 0.0067). In conclusion, combinations of KIR3DL1/HLA-Bw4, KIR2DL2/HLA-C1, and a genetic variant of the IL28B gene are predictive of the response to PEG-IFN and ribavirin therapy in Japanese patients infected with genotype 1b HCV.


Human Immunology | 2014

KIR3DL1-HLA-Bw4 combination and IL28B polymorphism predict response to Peg-IFN and ribavirin with and without telaprevir in chronic hepatitis C.

Takeji Umemura; Masao Ota; Yoshihiko Katsuyama; Shuichi Wada; Hiromitsu Mori; Atsushi Maruyama; Soichiro Shibata; Yuichi Nozawa; Takefumi Kimura; Susumu Morita; Satoru Joshita; Michiharu Komatsu; Akihiro Matsumoto; Atsushi Kamijo; Masakazu Kobayashi; Masato Takamatsu; Kaname Yoshizawa; Kendo Kiyosawa; Eiji Tanaka

Natural killer cells play a key role in the immune control of viral infections. Killer immunoglobulin-like receptors (KIRs) regulate natural killer cell activation and inhibition through the recognition of their cognate HLA class I ligands. We assessed the predictive factors of a sustained virological response (SVR) in 200 Japanese patients with chronic genotype 1b hepatitis C who were treated with telaprevir (TVR), pegylated-interferon-α2b (PEG-IFN), and ribavirin (RBV) triple therapy (92 patients) or PEG-IFN/RBV therapy alone (108 patients). Sixteen KIR genotypes, HLA-A, -B and -C ligands, and an interleukin (IL) 28B polymorphism (rs8099917) were analyzed. We observed that triple therapy, white blood cell count, hemoglobin value, hepatitis C viral load, a rapid virological response (RVR), IL28B TT genotype, and KIR3DL1-HLA-Bw4 genotype were associated with an SVR. In multivariate regression analysis, we identified an RVR (P < 0.000001; odds ratio [OR] = 20.95), the IL28B TT genotype (P = 0.00014; OR = 5.53), and KIR3DL1-HLA-Bw4 (P = 0.004, OR = 3.42) as significant independent predictive factors of an SVR. In conclusion, IL28B and KIR3DL1/HLA-Bw4 are independent predictors of an SVR in Japanese patients infected with genotype 1b HCV receiving TVR/PEG-IFN/RBV or PEG-IFN/RBV therapy.


Human Immunology | 2013

Association analysis of toll-like receptor 4 polymorphisms in Japanese primary biliary cirrhosis

Susumu Morita; Satoru Joshita; Takeji Umemura; Yoshihiko Katsuyama; Takefumi Kimura; Michiharu Komatsu; Akihiro Matsumoto; Kaname Yoshizawa; Astushi Kamijo; Nobuyoshi Yamamura; Eiji Tanaka; Masao Ota

Primary biliary cirrhosis (PBC) is characterized by portal inflammation and immune-mediated destruction of intrahepatic bile ducts that often result in liver failure. Toll-like receptor (TLR) 4 recognizes lipopolysaccharides of Gram-negative bacteria. Infectious agents have been suspected to play a crucial role in PBC pathogenesis since TLR4 expression was found in bile duct epithelial cells and periportal hepatocytes in liver tissues of PBC. To assess the potential contribution of TLR4 SNPs to the development of this disease, we genotyped five SNPs in TLR4 in 261 PBC patients and 359 controls using a TaqMan assay. No significant positive associations with either PBC susceptibility or progression were uncovered. These results indicate that TLR4 polymorphisms do not play a prominent role in the development of PBC in Japanese patients.


Hepatology Research | 2014

characteristics and prediction of hepatitis B e-antigen negative hepatitis following seroconversion in patients with chronic hepatitis B

Susumu Morita; Akihiro Matsumoto; Takeji Umemura; Soichiro Shibata; Nozomi Kamijo; Yuki Ichikawa; Takefumi Kimura; Satoru Joshita; Michiharu Komatsu; Kaname Yoshizawa; Eiji Tanaka

We analyzed the characteristics of alanine aminotransferase (ALT) abnormality after achieving hepatitis B e‐antigen (HBeAg) seroconversion (SC) and other factors associated with the occurrence of HBeAg negative hepatitis.


Hepatology Research | 2011

Early detection of interstitial pneumonia by monitoring KL-6 in a chronic hepatitis C patient undergoing pegylated interferon and ribavirin therapy

Yuki Ichikawa-Yamada; Satoru Joshita; Yoshinori Tsukahara; Takefumi Kimura; Susumu Morita; Atsushi Kamijo; Takeji Umemura; Tetsuya Ichijo; Akihiro Matsumoto; Kaname Yoshizawa; Eiji Tanaka

A 58‐year‐old woman with chronic hepatitis C developed interstitial pneumonia (IP) while undergoing pegylated interferon (PEG IFN)‐α‐2a and ribavirin (RBV) therapy. Serum levels of sialylated carbohydrate antigen KL‐6 (KL‐6), a known marker of disease activity in fibrosing lung disorders, had been regularly measured once a month for early detection of IP, and had begun rising noticeably from 12 weeks to 540 U/mL at 33 weeks of treatment. On examination, remarkable fine crackles were detected by dorsal auscultation and bilateral ground‐glass opacities and reticular shadows were depicted by computed tomography. The patient successfully recovered from her early‐stage pneumonia by immediate discontinuation of therapy, which indicates that regular monitoring of serum KL‐6 may be effective for avoidance of IP progression induced by PEG IFN and RBV therapy.


Internal Medicine | 2017

Autoimmune Hepatitis Associated with Immune Thrombocytopenic Purpura

Akihiro Ito; Kaname Yoshizawa; Kazuya Fujimori; Susumu Morita; Takashi Shigeno; Toshitaka Maejima

Although autoimmune hepatitis (AIH) is frequently complicated with chronic thyroiditis or other autoimmune disorders, reports on its association with immune thrombocytopenic purpura (ITP) are scarce. We herein describe a case of AIH associated with ITP. A 75-year-old Japanese woman was admitted to our hospital due to increased aminotransferase levels and severe thrombocytopenia. Elevated serum immunoglobulin G (IgG) was detected, and tests for platelet-associated IgG and anti-nuclear antibody were positive. Following the diagnosis of AIH-associated ITP, prednisolone treatment of 0.6 mg/kg/day resulted in a decrease in the aminotransferase levels and an increased platelet count.

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