Atsushi Nagasaka

Prevalence and characteristics of naturally occurring sofosbuvir resistance-associated variants in patients with hepatitis C virus genotype 1b infection.

Sofosbuvir (SOF), a nucleotide analog pro‐drug, targets hepatitis C virus (HCV) NS5B polymerase and shows potential for treating HCV infection, given its high efficacy and good barrier to resistance. However, in addition to the rare resistant‐associated variant (RAV) of non‐structural protein NS5B S282T, several new potential RAVs of SOF have been reported, especially related to HCV genotype 1b. However, the prevalence and characteristics of these RAVs have not been clarified.

Changes in hepatitis C virus quasispecies and density populations in patients before and after interferon therapy.

Some chronic hepatitis C patients show sustained response to interferon (IFN) therapy despite viremia. This condition seems to be related to the density populations of hepatitis C virus (HCV) [Kanto et al. (1995): J Med Virol 46:230–237]. To investigate further the relationship between alanine aminotransferase (ALT) levels after IFN therapy and the HCV density populations, we undertook differential flotation centrifugation of HCV and single strand conformation polymorphism targeted the hypervariable region (HVR) of E2 glycoprotein, which seems to be related to the density populations. Sera were obtained serially from 12 patients who had undergone IFN therapy (six sustained responders with viremia, six nonresponders). During the follow‐up after interferon therapy, the HVR heterogeneities changed in 9 of the 12 patients. The remaining three patients whose heterogeneities did not changed persistently showed normal ALT. The changes in HVR heterogeneities were less pronounced in the sustained responders with viremia than in nonresponders; however, their density populations were prominently high in both responders. In two cases, changes in HVR heterogeneities and increase in low‐density virion were observed before the hepatitis flare‐up. These data indicate that HVR quasispecies show more relation to ALT levels after IFN therapy than HCV density populations and that the changes in the HVR sequences and HCV density populations may be associated with ALT elevation in some patients.

Safety and efficacy of daclatasvir and asunaprevir in hepatitis C virus‐infected patients with renal impairment

Hepatitis C virus (HCV) infection is a risk factor for end‐stage renal disease, renal graft failure, and hemodialysis patient mortality. However, the efficacy of direct‐acting antiviral therapy for HCV‐infected patients with renal impairment is unclear. Additionally, the promising NS5B inhibitor sofosbuvir has not been recommended for patients with severe renal impairment. In this prospective, multicenter study, we evaluated the efficacy and safety of daclatasvir and asunaprevir combination therapy, with a focus on patients with renal impairment.

Differential flotation centrifugation study of hepatitis C virus and response to interferon therapy

Hepatitis C virus (HCV) appears to circulate in various forms such as native virion, immune complexes, and nucleocapsids during chronic infections. To determine the association of the physicochemical properties of HCV and its response to interferon therapy in patients with chronic hepatitis C, we examined pretreatment serum samples from 43 patients with HCV RNA who had received interferon therapy, using differential flotation centrifugation in a NaCl solution with a density of 1.063 g/ml. After centrifugation, the ratio of HCV RNA in the top and bottom fractions was determined by the polymerase chain reaction and expressed as T/B. Patients with a sustained response to IFN therapy were found to have higher T/B ratios than transient responders who relapsed after treatment (P < 0.01) and nonresponders (P < 0.01). With regards to HCV genotypes, patients with genotype 1b had higher T/B ratios in the sustained response group than in the nonsustained response group (P = 0.001), but patients with genotype 2 had a similar distribution of T/B among the 3 response groups (not significant). These findings indicate that the physicochemical properties of HCV affect the effectiveness of interferon therapy, particularly in patients with genotype 1b. J. Med. Virol. 52:190–194, 1997.

Nucleotide sequences of the hepatitis C virus core region in patients without anti-core antibody

Second‐generation assays for detection of hepatitis C virus (HCV) infection that include reactivity of antibodies to core, NS3, NS4 are used because of their high sensitivity. Among these antibodies, anti‐core antibody seems to be the most sensitive. However, there are some patients without anti‐core antibodies, although HCV RNA is detectable by reverse transcription‐polymerase chain reaction and branched DNA assay. The mechanism for the absence of anti‐core antibody on its own is unclear. We therefore determined the nucleotide and deduced amino acid sequences of the core region obtained from two anti‐core antibody‐negative patients with HCV RNA (genotype 1b) and compared them with those of four anti‐core antibody‐positive patients and a previously reported sequence. Amino acids spanning 1–47, which seemed to exist in major B cell epitopes, were found to be completely conserved among these patients. Furthermore, the predictive binding motif to HLA DR4 (a.a 81–90) was completely conserved in both of the anti‐core antibody‐negative patients. There were various mutations in the residual amino acids spanning 49–108, but specific mutations could not be found in anti‐core antibody‐negative patients.

ZEB1 expression is associated with prognosis of intrahepatic cholangiocarcinoma

Background/Aim Intrahepatic cholangiocarcinoma (ICC) is one of the most aggressive malignant tumours, so the identification of molecular targets for ICC is an important issue. Zinc finger E-box binding homeobox 1 (ZEB1) is a key inducer of epithelial–mesenchymal transition (EMT). The aim of the present study was to clarify the clinical significance of ZEB1 in ICC and the associations between ZEB1 expression and EMT-related proteins. Methods We immunohistochemically examined the expression of EMT-related proteins, namely ZEB1, vimentin and E-cadherin, in ICC specimens from 102 patients. The clinicopathological and prognostic values of these markers were evaluated. Results ZEB1 and vimentin were expressed in 46.1% and 43.1% of tumours, respectively, and E-cadherin expression was lost in 44.1% of tumours. ZEB1 expression showed a significant inverse correlation with E-cadherin expression (p=0.004) and a positive correlation with vimentin expression (p=0.022). Altered expression of ZEB1 was associated with aggressive tumour characteristics, including advanced tumour stage (p=0.037), undifferentiated-type histology (p=0.017), lymph node metastasis (p=0.024) and portal vein invasion (p=0.037). Moreover, overall survival rates were significantly lower for patients with high ZEB1 expression than for patients with low ZEB1 expression (p=0.027). Kaplan–Meier analysis also identified E-cadherin expression (p=0.041) and vimentin expression (p=0.049) as prognostic indicators for overall survival. Conclusions ZEB1 expression is associated with tumour progression and poor prognosis in patients with ICC through positive correlations with vimentin and negative correlations with E-cadherin. ZEB1 expression is associated with a poor prognosis and might be an attractive target for the treatment of ICC.

Safety and efficacy of sofosbuvir and ribavirin for genotype 2 hepatitis C Japanese patients with renal dysfunction: SOF/RBV for patients with renal dysfunction

The safety and efficacy of sofosbuvir (SOF) and ribavirin (RBV) have not been well clarified in patients with renal dysfunction because clinical trials have not included such patients. We evaluated the safety and efficacy of SOF and RBV for genotype 2 hepatitis C virus (HCV)‐infected patients with renal dysfunction.

A Prospective Observational Study on Effect of Short‐Term Periodic Steroid Premedication on Bone Metabolism in Gastrointestinal Cancer (ESPRESSO‐01)

This study is an evaluation of the effect of gastrointestinal cancer chemotherapy with short‐term periodic steroid premedication on bone metabolism. Primary endpoints were changes in bone mineral densities and metabolic bone turnover 16 weeks after initiation of chemotherapy.

Add-on effects of fluvastatin in simeprevir/pegylated-interferon/ribavirin combination therapy for patients with genotype 1 hepatitis C virus infection: A randomized controlled study: FLV add-on SMV/Peg-IFN/RBV therapy

The Japan Society of Hepatology guidelines indicate that hepatitis C virus (HCV) protease inhibitor combination therapy with simeprevir (SMV), pegylated‐interferon (Peg‐IFN), and ribavirin (RBV) is a therapeutic option for patients who fail to respond to a direct direct‐acting antiviral‐containing regimen. However, treatment outcomes have room for improvement. Fluvastatin (FLV) add‐on treatment in Peg‐IFN and RBV combination therapy for HCV‐infected patients significantly improved the sustained virologic response (SVR), but the add‐on effect of FLV on SMV combination therapy is not well understood.

Update analysis: Thromboembolism in gastrointestinal tract cancer patients receiving chemotherapy.

e15156Background: We previously reported that TE incidence (TEi) was 14 % among Japanese gastrointestinal tract cancer (GTC) patients (pts) receiving chemotherapy (CTx), and it was significantly hi...