Miki Shirachi

Association of exogenous insulin or sulphonylurea treatment with an increased incidence of hepatoma in patients with hepatitis C virus infection.

Background: Diabetes mellitus is frequently seen in hepatitis C patients and is often treated with antidiabetic agents that increase serum insulin levels. Because insulin is a growth‐promoting hormone, antidiabetic agents could pose a risk for hepatocellular carcinoma (HCC).

Evaluation of Resistance-Associated Substitutions in NS5A Using Direct Sequence and Cycleave Method and Treatment Outcome with Daclatasvir and Asunaprevir for Chronic Hepatitis C Genotype 1.

Background The aim of this study was to evaluate the efficacy of daclatasvir plus asunaprevir therapy in patients infected with hepatitis C virus and determine its relevance to resistant variants. Methods A total of 629 consecutive patients infected with hepatitis C virus genotype 1 were assessed. Daclatasvir (60 mg/day) plus asunaprevir (200 mg/day) was given for 24 weeks. The virological responses and resistance-associated substitutions of hepatitis C virus mutants were examined by the direct sequence and cycleave methods were evaluated. Results Overall, 89.4% (555/621) of patients exhibited a sustained virological response (SVR). The SVR rates in the patients with wild type, mixed, and mutant type Y93 by direct sequencing were 92.5% (520/562), 70.3% (26/37), and 42.9% (9/21), respectively. The SVR rates in the patients with 100%, 90%, 80%-30%, and 20%-0% Y93 wild by the cycleave method were 93.4% (456/488), 88.2%(30/34), 56.0%(14/25), and 36.8%(7/19), respectively. In contrast, the SVR rates for the wild type and mixed/mutant type L31 by direct sequencing were 90.2% (534/592) and 72.4% (21/29), respectively. In the multivariate analyses, the wild type Y93, no history of simeprevir therapy, the wild type L31, and low HCV RNA level were independent factors of SVR. Conclusion NS5A resistance-associated substitutions, especially Y93H, were major factors predicting the SVR. Although direct sequencing can predict the SVR rate, the cycleave method is considered to be more useful for predicting the SVR when used in combination.

Liver-Associated Natural Killer Activity in Cirrhotic Rats

An impaired host defense mechanism is well known in patients with liver cirrhosis (LC). Using a sinusoidal lavage method, lymphocytes were obtained from LC rats that were administered thioacetamide, and natural killer (NK) activity was measured by 5lCr‐release assay. The NK cell count was measured by flow cytometric analysis using monoclonal antibody (Mab) 3.2.3 and/or CD 3‐8+ as markers for NK cells, and by immunohistochemical staining using Mab 3.2.3. Furthermore, interferon (IFN) α was administered to LC rats and the subsequent changes in hepatic NK activity and NK cell count were observed. In the large granular lymphocyte (LGL)‐rich fraction (Fr.1, LGLs: 60‐90%), the NK activity was significantly lower in the LC rats (40.0±3.8%) compared to that in the control rats (48.4±4.3%) (P<0.005). In addition, the number of NK cells in the liver tissues of the LC rats was significantly lower compared to that in the liver tissues of the control rats by morphometric analysis (P<0.05). For LC rats, NK activity of the Fr.1 24 hr after IFNα administration (5×104 IU / 100 g body weight) increased significantly (P<0.005). Hepatic NK activity and NK cell count were reduced in the LC rats, and recovered following IFNα administration. The results obtained in this study may give clues to better understanding the impaired host defense mechanism in LC patients.

Characteristics of complete responders to interferon among patients with chronic hepatitis C with high serum levels of RNA

Patients with chronic hepatitis C with high serum levels of HCV RNA are less likely to show a complete response to IFN therapy than those with a low serum levels of HCV RNA. The characteristics of patients with high serum levels of HCV RNA who show a complete response to IFN therapy have not been evaluated in detail. We retrospectively analyzed the 121 patients with high serum levels of HCV RNA (≥ 1.0 Meq/ml) before IFN therapy to determine the characteristics of complete responders. A complete response to IFN was observed in 12 (9.9%) of 121 patients. There was no difference between complete responders and non-responders in age, the result of liver function tests, or liver histology. In all complete responders, pretreatment serum level of HCV RNA was less than 5.0 Meq/ml, which was significantly lower than the level in the non-responders (P < 0.01). The fluctuation of HCV RNA level less than 0.5 Meq/ml was observed in ten of the 12 complete responders. The frequency of serotype 2 was significantly higher in the complete responders compared with the non-responders (P < 0.05). These findings suggest that complete responders are rare among patients with serum levels of HCV RNA ≥5.0 Meq/ml. In planning IFN therapy, fluctuations in the HCV RNA level, as well as the serotype, should be considered.

Natural Killer Cells in the Liver and Their Activators

An impaired host defense mechanism is well known in patients with liver cirrhosis. To clarify the sight of natural resistance in the liver, we investigated hepatic natural killer (NK) activity, and a proportion of the NK cells in the hepatic sinusoids of normal and cirrhotic rats. Using a sinusoidal lavage method, liver-associated lymphocytes were obtained from normal and cirrhotic rats that were established using thioacetamide. NK activity was measured by 51Cr-release assay, and the NK cell count was measured by flow cytometric analysis using monoclonal antibodies. In addition, OK432 (a pharmaceutical preparation of α-Streptococcus pyrogens), Shosaiko-to (a Chinese herbal medicine), and interferon-α were administered to experimental rats and the subsequent changes in hepatic NK activity and the NK cell count were also observed. Not only hepatic NK activity, but also the proportion of hepatic NK cells were significantly lower in cirrhotic rats than in control rats. Hepatic NK activity and NK cell count in the liver increased significantly after the administration of NK cell activators such as OK432 and Sho-saiko-to. After the administration of interferon-α, there was also as increase in the previously reduced hepatic NK activity and NK cell count of cirrhotic rats. The results of this study may lead to a clearer understanding of the host defense mechanism in cirrhotic patients.

GB virus C (GBV-C)/hepatitis G virus (HGV) infection in a hepatitis C virus hyper-endemic area in Japan

Abstract An epidemiologic study was performed to investigate GBV-C/HGV infection in 460 inhabitants of H town where hepatitis C virus (HCV) is hyper endemic. GBV-C/HGV RNA was detected by reverse transcription hemi-nested polymerase chain reaction (RT-heminested PCR) for the 5′ untranslated region (5′-UTR). The nucleotide sequences of GBV-C/HGV 5′-UTR were determined and phylogenetic analysis was performed. GBV-C/HGV RNA, antibody to HCV (anti-HCV), and HCV RNA were detected in 12 (2.6%), 108 (23.5%), and 87 of subjects (18.9%), respectively. The phylogenetic tree analysis indicated that the 12 GBV-C/HGV-positive isolates could be classified as a new GBV-C/HGV group (type 3). No intraspousal transmission of GBV-C/HGV was observed. Four subjects positive for GBV-C/HGV RNA without HCV RNA had normal mean aminotransferase concentration. This study indicated: 1, the prevalence of GBV-C/HGV was lower than that of HCV: 2, Type 3 GBV-C/HGV was the most prevalent; 3. No intraspousal transmission of GBV-C/HGV was observed; and 4, GBV-C/HGV alone may not cause severe liver injury.