Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Naoki Morishita is active.

Publication


Featured researches published by Naoki Morishita.


Journal of Gastroenterology | 2015

Emergence of hepatitis C virus NS5A L31V plus Y93H variant upon treatment failure of daclatasvir and asunaprevir is relatively resistant to ledipasvir and NS5B polymerase nucleotide inhibitor GS-558093 in human hepatocyte chimeric mice.

Yugo Kai; Hayato Hikita; Tomohide Tatsumi; Tasuku Nakabori; Yoshinobu Saito; Naoki Morishita; Satoshi Tanaka; Takatoshi Nawa; Tsugiko Oze; Ryotaro Sakamori; Takayuki Yakushijin; Naoki Hiramatsu; Hiroshi Suemizu; Tetsuo Takehara

BackgroundResistance-associated variants (RAVs) emerge at multiple positions spanning hepatitis C virus (HCV) NS3/4A and NS5A regions upon failure of asunaprevir/daclatasvir combination therapy. It has not been determined whether the emergence of such RAVs have an impact on re-treatment by a combination of ledipasvir and sofosbuvir, a potent regimen for HCV genotype 1 infection.MethodsTK-NOG human hepatocyte chimeric mice were inoculated with sera from a patient with treatment failure of asunaprevir/daclatasvir therapy.ResultsThey developed persistent HCV infection with triple variants of NS3/4A D168V, NS5A L31V plus Y93H. Administration of ledipasvir/GS-558093 (a NS5B nucleotide analog) in these mice failed to achieve end-of-treatment response or sustained virologic response, which was in sharp contrast to the results in mice with wild-type virus infection. The administration of telaprevir/GS-558093 successfully achieved it in those mice.ConclusionsTreatment failure with asunaprevir/daclatasvir may limit further treatment options. This population may represent a growing unmet medical need.


Hepatology Research | 2017

Frequency of, and factors associated with, hepatitis B virus reactivation in hepatitis C patients treated with all-oral direct-acting antivirals: Analysis of a Japanese prospective cohort

Akira Doi; Ryotaro Sakamori; Yuki Tahata; Ayako Urabe; Naoki Morishita; Ryoko Yamada; Kunimaro Furuta; Takahiro Kodama; Hayato Hikita; Takayuki Yakushijin; Kazuyoshi Ohkawa; Akira Kaneko; Yasuharu Imai; Tomohide Tatsumi; Tetsuo Takehara

Several case reports have shown that hepatitis B virus (HBV) reactivation developed in hepatitis C patients with a current or previous HBV infection during direct‐acting antiviral (DAA) treatment, which led to severe hepatitis or death in some cases. However, its precise frequency and risk factors are not entirely clear. We analyzed a prospective cohort.


Journal of Medical Virology | 2014

Significance of liver stiffness measurement by acoustic radiation force impulse (ARFI) among hepatitis C patients

Ryoko Yamada; Naoki Hiramatsu; Tsugiko Oze; Naoki Morishita; Naoki Harada; Masanori Miyazaki; Takayuki Yakushijin; Takuya Miyagi; Yuichi Yoshida; Tomohide Tatsumi; Tatsuya Kanto; Norio Hayashi; Tetsuo Takehara

The degree of liver fibrosis is strongly associated with the antiviral effect of interferon on chronic hepatitis C patients. In this study, the accuracy of acoustic radiation force impulse (ARFI) in assessing liver fibrosis and the association between liver stiffness using ARFI and antiviral effects were investigated. The 124 patients with chronic hepatitis C enrolled in this study included 94 with HCV genotype 1 and 40 (30%) with moderate fibrosis (METAVIR fibrosis score ≥ F2). Sixty‐one patients received pegylated interferon (peg‐IFN) plus ribavirin combination therapy and the treatment responses were assessed. The shear wave velocity (Vs value) by ARFI had a strong correlation with the histological fibrosis stage (P < 0.001). The AUROC of the Vs value, aspartate aminotransferase platelet ratio index and FIB4 for the diagnoses of moderate fibrosis (≥F2) were 0.890, 0.779, and 0.737, respectively. HCV genotype 1 patients with the TT allele of IL28B and with a low Vs value (<1.40 m/sec) who were treated with peg‐IFN plus ribavirin therapy achieved a sustained virologic response at a rate of 79% (15/19), while all patients with the TG/GG allele of IL28B and a high Vs value (≥1.40 m/sec) experienced a non‐virologic response (6/6). The Vs value measured by ARFI could not predict the treatment response for patients with HCV genotype 2. It is concluded that the combination of ARFI at cut off of 1.4 m/sec and IL28B may be useful for patients with chronic hepatitis C with genotype 1 treated with peg‐IFN/ribavirin combination therapy. J. Med. Virol. 86:241–247, 2014.


Scientific Reports | 2017

Baseline quasispecies selection and novel mutations contribute to emerging resistance-associated substitutions in hepatitis C virus after direct-acting antiviral treatment

Yugo Kai; Hayato Hikita; Naoki Morishita; Kazuhiro Murai; Tasuku Nakabori; Sadaharu Iio; Hideki Hagiwara; Yasuharu Imai; Shinji Tamura; Syusaku Tsutsui; Masafumi Naito; Meiko Nishiuchi; Yasuteru Kondo; Takanobu Kato; Hiroshi Suemizu; Ryoko Yamada; Tsugiko Oze; Takayuki Yakushijin; Naoki Hiramatsu; Ryotaro Sakamori; Tomohide Tatsumi; Tetsuo Takehara

Resistance-associated substitutions (RASs) in hepatitis C virus (HCV) appear upon failure of treatment with direct-acting antivirals (DAAs). However, their origin has not been clarified in detail. Among 11 HCV genotype 1b patients who experienced virologic failure with asunaprevir (ASV)/daclatasvir (DCV), 10 had major NS5A L31M/V-Y93H variants after treatment. L31M/V-Y93H variants were detected as a minor clone before therapy in 6 patients and were the most closely related to the post-treatment variants by phylogenetic tree analysis in 4 patients. Next, to consider the involvement of a trace amount of pre-existing variants below the detection limit, we analysed human hepatocyte chimeric mice infected with DAA-naïve patient serum. L31V-Y93H variants emerged after treatment with ledipasvir (LDV)/GS-558093 (nucleotide NS5B inhibitor) and decreased under the detection limit, but these variants were dissimilar to the L31V-Y93H variants reappearing after ASV/DCV re-treatment. Finally, to develop an infection derived from a single HCV clone, we intrahepatically injected full-genome HCV RNA (engineered based on the wild-type genotype 1b sequence) into chimeric mice. A new Y93H mutation actually occurred in this model after LDV monotherapy failure. In conclusion, post-treatment RASs appear by 2 mechanisms: the selection of pre-existing substitutions among quasispecies and the generation of novel mutations during therapy.


Journal of Viral Hepatitis | 2014

Risk factors for hepatocellular carcinoma in hepatitis C patients with normal alanine aminotransferase treated with pegylated interferon and ribavirin

Naoki Harada; Naoki Hiramatsu; Tsugiko Oze; Naoki Morishita; Ryoko Yamada; Hayato Hikita; Masanori Miyazaki; Takayuki Yakushijin; Takuya Miyagi; Yuichi Yoshida; Tomohide Tatsumi; Tatsuya Kanto; Akinori Kasahara; Masahide Oshita; Eiji Mita; Hideki Hagiwara; Yoshiaki Inui; Kazuhiro Katayama; Shinji Tamura; Harumasa Yoshihara; Yasuharu Imai; Atsuo Inoue; Norio Hayashi; Tetsuo Takehara

Pegylated interferon (Peg‐IFN) plus ribavirin combination therapy is effective in patients with hepatitis C virus (HCV) infection and normal alanine aminotransferase levels (NALT). However, it remains unclear whether the risk of hepatocellular carcinoma (HCC) incidence is actually reduced in virological responders. In this study, HCC incidence was examined for 809 patients with NALT (ALT ≤ 40 IU/mL) treated with Peg‐IFN alpha‐2b and ribavirin for a mean observation period of 36.2 ± 16.5 months. The risk factors for HCC incidence were analysed by Kaplan–Meier method and Cox proportional hazards model. On multivariate analysis among NALT patients, the risk of HCC incidence was significantly reduced in patients with sustained virological response (SVR) or relapse compared with those showing nonresponse (NR) (SVR vs NR, hazard ratio (HR): 0.16, P = 0.009, relapse vs NR, HR: 0.11, P = 0.037). Other risk factors were older age (≥65 years vs <60 years, HR: 6.0, P = 0.032, 60–64 vs <60 years, HR: 3.2, P = 0.212) and male gender (HR: 3.9, P = 0.031). Among 176 patients with PNALT (ALT ≤ 30 IU/mL), only one patient developed HCC and no significant risk factors associated with HCC development were found. In conclusion, antiviral therapy for NALT patients with HCV infection can lower the HCC incidence in responders, particularly for aged and male patients. The indication of antiviral therapy for PNALT (ALT ≤ 30 IU/mL) patients should be carefully determined.


Journal of Viral Hepatitis | 2015

The real impact of telaprevir dosage on the antiviral and side effects of telaprevir, pegylated interferon and ribavirin therapy for chronic hepatitis C patients with HCV genotype 1

Tsugiko Oze; Naoki Hiramatsu; Takayuki Yakushijin; Ryoko Yamada; Naoki Harada; Naoki Morishita; Masahide Oshita; Eiji Mita; Toshifumi Ito; Yoshiaki Inui; Masami Inada; Shinji Tamura; Harumasa Yoshihara; Yasuharu Imai; Motohiko Kato; Takuya Miyagi; Yuichi Yoshida; Tomohide Tatsumi; Akinori Kasahara; Norio Hayashi; Tetsuo Takehara

Triple therapy with telaprevir, pegylated interferon and ribavirin has been reported to improve antiviral efficacy but have potentially severe adverse effects in patients with chronic hepatitis C. To avoid the severe effects of telaprevir, lowering the dose has been suggested. However, impact of dosage changes on antiviral and adverse effects remains unclear. One hundred and sixty‐six Japanese patients with HCV genotype 1 were treated with triple therapy. The drug exposure of each medication was calculated by averaging the dose actually taken. The overall SVR rate was 82%. The telaprevir discontinuation rate was 26%. The factors associated with discontinuation were an older age (≥65 y.o.) and a higher average dose during treatment. The telaprevir discontinuation rates were 42%, 25% and 14% in patients at ≥35, 25–35 and <25 mg/kg/day of telaprevir and 58% in older patients at ≥35 mg/kg/day of TVR. The factors associated with SVR were treatment‐naïve, relapse to previous treatment, higher average telaprevir dose during treatment and completion of treatment. The SVR rate was higher, at 91%, in patients at 25–35 mg/kg/day of telaprevir than the 71% and 78% observed in those at <25 and ≥35 mg/kg/day of drug. In Japanese patients, a mean telaprevir dose of 25–35 mg/kg/day during treatment can augment its efficacy in triple therapy for patients with HCV genotype 1.


Hepatology Research | 2017

Ultra-deep sequencing analysis of resistance-associated variants during retreatment with simeprevir-based triple therapy after failure of telaprevir-based triple therapy in patients with genotype 1 hepatitis C virus infection

Naoki Morishita; Naoki Hiramatsu; Tsugiko Oze; Ayako Urabe; Yuki Tahata; Ryoko Yamada; Takayuki Yakushijin; Atsushi Hosui; Sadaharu Iio; Akira Yamada; Hideki Hagiwara; Eiji Mita; Yukinori Yamada; Toshifumi Ito; Masami Inada; Kazuhiro Katayama; Iwao Yabuuchi; Yasuharu Imai; Hayato Hikita; Ryotaro Sakamori; Yuichi Yoshida; Tomohide Tatsumi; Norio Hayashi; Tetsuo Takehara

Simeprevir (SMV)‐based triple therapy is an effective retreatment option following failure of telaprevir (TVR)‐based triple therapy. However, it is unclear whether the persistence of resistance‐associated variants (RAVs) induced by TVR‐based therapy may reduce the treatment effect of SMV‐based therapy.


Journal of Medical Virology | 2016

Impact of ribavirin dosage in chronic hepatitis C patients treated with simeprevir, pegylated interferon plus ribavirin combination therapy

Yuki Tahata; Naoki Hiramatsu; Tsugiko Oze; Ayako Urabe; Naoki Morishita; Ryoko Yamada; Takayuki Yakushijin; Atsushi Hosui; Masahide Oshita; Akira Kaneko; Hideki Hagiwara; Eiji Mita; Toshifumi Ito; Yukinori Yamada; Masami Inada; Kazuhiro Katayama; Shinji Tamura; Yasuharu Imai; Hayato Hikita; Ryotaro Sakamori; Yuichi Yoshida; Tomohide Tatsumi; Norio Hayashi; Tetsuo Takehara

The factors associated with sustained virologic response (SVR) in chronic hepatitis C (CH‐C) genotype 1 patients treated with simeprevir (SMV), pegylated interferon (Peg‐IFN) plus ribavirin (RBV) triple therapy have not been fully investigated. Two hundred and twenty‐nine treatment‐naïve CH‐C patients treated with SMV triple therapy were enrolled in this study. The overall SVR rate was 87% in per‐protocol analysis. In multivariate analysis, the interleukin (IL) 28B genotype (rs8099917, TT vs. non‐TT, odds ratio [OR]: 0.044, P = 0.001) and RBV dose (< 10/10–12/ ≥ 12 mg/kg/day, OR: 4.513, P = 0.041) were significant factors associated with SVR. In patients with the IL28B non‐TT genotype, RBV dose affected SVR dose‐dependently in stratified analysis of RBV dose (P = 0.015); it was 44% (8/18) for patients administered <10 mg/kg/day of RBV, 78% (14/18) for those administered 10–12 mg/kg/day of RBV, and 100% (3/3) for those administered ≥12 mg/kg/day of RBV, whereas in patients with the IL28B TT genotype, a significant correlation between SVR and RBV dose was not observed (P = 0.229). Regarding RBV dose reduction of less than 10 mg/kg/day, the inosine triphosphate pyrophosphatase (ITPA) genotype (rs1127354, CC vs. non‐CC, OR: 0.239, P = 0.003) and age (by 1 y.o., OR: 1.084, P = 0.002) were significant independent factors. RBV dosage affected SVR dose‐dependently in patients with the IL28B non‐TT genotype treated with SMV triple therapy. Special attention to anemia progression and RBV dosage should be paid to aged patients with the ITPA CC genotype. J. Med. Virol. 88:1776–1784, 2016.


Hepatology Communications | 2018

Liver Fibrosis Is Associated With Corrected QT Prolongation During Ledipasvir/Sofosbuvir Treatment for Patients With Chronic Hepatitis C

Yuki Tahata; Ryotaro Sakamori; Ayako Urabe; Naoki Morishita; Ryoko Yamada; Takayuki Yakushijin; Naoki Hiramatsu; Yoshinori Doi; Akira Kaneko; Hideki Hagiwara; Yukinori Yamada; Taizo Hijioka; Masami Inada; Shinji Tamura; Yasuharu Imai; Kunimaro Furuta; Takahiro Kodama; Hayato Hikita; Tomohide Tatsumi; Tetsuo Takehara

Combination treatment of ledipasvir and sofosbuvir (LDV/SOF) is first‐line treatment for patients with chronic hepatitis C genotype 1 in the United States, Europe, and Japan. However, the influence of LDV/SOF on the cardiovascular system is poorly characterized. A total of 470 chronic hepatitis C patients who started LDV/SOF treatment between September 2015 and February 2016 at nine hospitals in Japan were prospectively enrolled in this study. Corrected QT (QTc) prolongation was defined as a QTc interval ≥450 milliseconds. The sustained virologic response rate was 96.0% (451/470), and the discontinuance rate due to adverse effects was 0.9% (4/470). Among 395 patients whose electrocardiogram was evaluated over time and compared with baseline, the QTc interval was significantly prolonged during treatment and returned to baseline levels 12 weeks after the end of treatment. Twenty‐four of 376 patients with baseline QTc intervals <450 milliseconds experienced on‐treatment QTc prolongation. Higher aspartate aminotransferase‐to‐platelet ratio index scores (≥0.76; odds ratio, 4.375; P = 0.005) and longer QTc intervals (≥416 milliseconds; odds ratio, 4.823; P = 0.003) at baseline were significantly associated with on‐treatment QTc prolongation on multivariate analysis. Patients with cirrhosis showed significantly longer QTc intervals than those without cirrhosis during treatment but not at baseline, and they developed on‐treatment QTc prolongation at a higher rate than patients without cirrhosis. No cardiovascular events occurred, except for 1 patient who developed paroxysmal supraventricular tachycardia. Conclusion: Newly developed QTc prolongation was observed in 6.4% of Japanese patients during treatment and was associated with more advanced fibrosis. (Hepatology Communications 2018; 00:000‐000)


Journal of Gastroenterology | 2014

Liver stiffness measurement by acoustic radiation force impulse is useful in predicting the presence of esophageal varices or high-risk esophageal varices among patients with HCV-related cirrhosis

Naoki Morishita; Naoki Hiramatsu; Tsugiko Oze; Naoki Harada; Ryoko Yamada; Masanori Miyazaki; Takayuki Yakushijin; Takuya Miyagi; Yuichi Yoshida; Tomohide Tatsumi; Tatsuya Kanto; Tetsuo Takehara

Collaboration


Dive into the Naoki Morishita's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge