[A case of gastric cancer with peritoneal dissemination who achieved long survival from control of ascites for over 2 years by successive treatments with S-1 in combination with docetaxel as first-line followed by irinotecan in combination with cisplatin as second-line].

The patient was a 66-year-old male, admitted and diagnosed as having advanced gastric cancer with peritoneal dissemination, leading to ascites and obstructive jaundice. After reducing the degree of obstructive jaundice, combination chemotherapy of S-1 80mg/m2/day(2 weeks administration and 1 week rest)and docetaxel(TXT)40mg/m2(day 1)was administered from February, 2008. After 3 courses of this regimen, CT revealed no evidence of ascites, and this chemotherapy was successively continued on an outpatient basis until June, 2009. After the relapse of ascites from July, 2009, combination chemotherapy of irinotecan(CPT-11)60mg/m2 and cisplatin(CDDP)30mg/m2 biweekly was performed as second-line chemotherapy, and the ascites disappeared again after around 2 courses of this regimen. This chemotherapy was continued on an outpatient basis until February, 2010. No major adverse reaction to either chemotherapy was observed. This case suggests that these chemotherapies, such as the combination chemotherapy of S-1 plus TXT as a first-line treatment and CPT-11 plus CDDP as the following second-line treatment, can be administered to an outpatient, can keep good patient's QOL and can be one of the effective chemotherapy options for advanced gastric cancer with peritoneal dissemination.

Positive selection of core 70Q variant genotype 1b hepatitis C virus strains induced by pegylated interferon and ribavirin.

BACKGROUND: Approximately 20% of patients with hepatitis C virus (HCV) genotype 1b infection have nonresponse to the most current treatment, pegylated interferon with ribavirin. Mutations in the HCV core region were recently proposed to be associated with nonresponse. Our aim was to evaluate the viral factors associated with treatment failure. METHODS: HCV variants were determined directly and after cloning in 66 HCV-1b-infected Japanese patients and in 5 urokinase-type plasminogen activator transgenic severe combined immunodeficiency mice with human hepatocytes (chimeric mice), at baseline, during treatment, and after treatment. RESULTS: At baseline, glutamine at position 70 of the HCV core protein (70Q) was detected by direct sequencing in 20% of patients with virologic response and in 43.8% of patients with nonresponse. Among patients with nonresponse, who were examined during and after treatment, the prevalence of the 70Q substitution increased to 56.3%, which indicates that treatment-induced selection occurred in all patients with nonresponse who had 70Q quasispecies detectable by cloning. This observation was reinforced by the results from experimentally infected chimeric mice. Logistic regression analysis indicated that detection of 70Q quasispecies was associated with a statistically significantly increased risk of nonresponse (odds ratio, 15.1; P = .004) in the studied cohort. CONCLUSION: Presence of the 70Q quasispecies at baseline was associated with an increased risk of treatment failure, as indicated by the positive selection of the 70Q clones induced by treatment with pegylated interferon with ribavirin. These results urge further investigation of the mechanisms of this association.

Abbott RealTime hepatitis C virus (HCV) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assays for prediction of sustained virological response to pegylated interferon and ribavirin in chronic hepatitis C patients.

Two commercial real-time PCR assays are currently available for sensitive hepatitis C virus (HCV) RNA quantification: the Abbott RealTime HCV assay (ART) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM). We assessed whether the two real-time PCR assays were more effective than Roche Cobas Amplicor HCV Monitor test, v.2.0 (CAM) for prediction of the sustained virological response (SVR) to pegylated interferon (PEG-IFN) plus ribavirin (RBV) in chronic hepatitis C. Sixty patients chronically infected with HCV genotype 1b (37 males and 23 females, 53 +/- 12 years of age) were treated with PEG-IFNalpha2b plus RBV for 48 weeks. Stored specimens at nine time points for each patient (at baseline, on treatment, and 24 weeks after treatment) were tested by the two real-time PCR assays and CAM. Twenty-six (43.3%) patients reached SVR. The positive predictive values (PPVs) for SVR of undetectable HCV RNA at week 12 by CAM, ART, and CAP/CTM were 74.3%, 88.0%, and 95.2%, respectively. An undetectable HCV RNA level by CAM, ART, and CAP/CTM correctly predicted SVR at week 4 in 100%, 100%, and 100% of patients, at weeks 5 to 8 in 91.7%, 100%, and 100% of patients, at weeks 9 to 12 in 55.6%, 75%, and 87.5% of patients, and at weeks 13 to 24 in 0%, 26.7%, and 40% of patients, respectively. Of 16 patients who relapsed after treatment, HCV RNA was detectable in 2 patients at the end of treatment by CAP/CTM but undetectable by ART and CAM. HCV RNA tests using ART and CAP/CTM are considered to be more effective at predicting SVR than CAM, and the PPV for SVR was slightly higher in CAP/CTM than in ART.

Knowledge of Vibrio vulnificus infection among Japanese patients with liver diseases: a prospective multicenter study.

BACKGROUND: Vibrio vulnificus (V. vulnificus) is a seafood-borne infectious pathogen that can be lethal to humans. The infection has been correlated with pre-existing liver disease, particularly liver cirrhosis. Awareness of V. vulnificus infection among Japanese citizens is low, despite the increasing number of patients with hepatocellular carcinoma (HCC). The present study was conducted to assess the level of knowledge of patients with liver disease regarding V. vulnificus infection. MATERIAL/METHODS: Questionnaires were sent to patients with chronic liver disease who had been treated by liver specialists at 14 medical institutes. RESULTS: Of 1,336 patients, 304 (22.8%) had liver cirrhosis, and 732 (54.8%) had comorbidities of this disease. Only 14.5% (194/1,336) of patients had knowledge of V. vulnificus infection. Of 304 patients with liver cirrhosis, 17.4% (53/304) of the patients had knowledge of V. vulnificus infection. Of 60 patients with liver cirrhosis and diabetes mellitus, 11 (18.3%) patients had knowledge of V. vulnificus infections. Even when the patients with high risk factors such as liver cirrhosis and diabetes mellitus had knowledge of V. vulnificus infections, most ate raw seafood without regard to season. CONCLUSIONS: Patients with chronic liver diseases and their physicians need to be better educated about V. vulnificus infection and its prevention.

[A case of advanced ampullary carcinoma successfully resected after primary chemotherapy with s-1 and gemcitabine].

The patient was a 53-year-old male who was admitted on an emergency basis with obstructive jaundice. He was diagnosed as having advanced ampullary carcinoma(T4 N0 H1, Stage IV b). To reduce the degree of obstructive jaundice, a self-expandable metallic stent was placed in the area of the biliary obstruction. Immediately after relief from obstructive jaundice, combination chemotherapy of S-1 and gemcitabine was given. Subsequently, CA19-9, the tumormarker level was reduced, the metastatic liver tumor disappeared, and the size of the primary lesion was remarkably reduced. Therefore, a curative surgical resection was done. This is a very instructive case for developing effective chemotherapy options to treat biliary tract cancers involving ampullary carcinoma.

Suppressive effect of oral administration of branched-chain amino acid granules on oxidative stress and inflammation in HCV-positive patients with liver cirrhosis.

AIM: In chronic hepatitis C virus (HCV) infection, it is thought that both chronic persistent inflammation and oxidative stress contribute to the development of hepatocellular carcinoma (HCC), and it has been reported that long-term oral supplementation with branched-chain amino acid (BCAA) granules could inhibit liver carcinogenesis. However, the extent of the involvement of these factors remains obscure. METHODS: To clarify the involvement of inflammation and oxidative stress in the inhibition of liver carcinogenesis, we evaluated the effect of oral administration of BCAA granules on oxidative stress and inflammation in HCV-positive patients with liver cirrhosis. RESULTS: Twenty-seven patients were enrolled in the study: 18 of the patients were treated with BCAA granules (administered group) and nine were observed without BCAA granules (non-administered group). In the non-administered group, the production of oxidative stress, as indicated by urine 8-hydroxydeoxyguanosine (8-OHdG) and 15-F2t-Isoprostane (8-IsoPs), significantly increased with time, while in the administered group the levels of ferritin and 8-OHdG decreased significantly. Comparison of the two groups demonstrated that highly sensitive CRP, ferritin, 8-OHdG and 8-IsoPs were significantly reduced by taking BCAA granules. The time-course analysis showed that ferritin and highly sensitive CRP seemed to decrease first, followed by a decrease of 8-OHdG and 8-IsoPs. CONCLUSION: These findings indicated that the administration of BCAA granules influenced microinflammation and the metabolism of iron in HCV-positive patients with liver cirrhosis, and subsequently seemed to reduce the production of oxidative stress, possibly leading to a decrease in the occurrence of HCC.

A weak association between occult HBV infection and non-B non-C hepatocellular carcinoma in Japan.

BACKGROUND: In Japan, approximately 10% of hepatocellular carcinoma (HCC) patients are negative for both hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV), i.e., they constitute the so-called category of non-B non-C (NBNC) HCC. Little is known about the characteristics of NBNC-HCC. METHODS: Potential risk factors for carcinogenesis (including occult HBV infection [HBsAg is negative but HBV DNA is positive by polymerase chain reaction (PCR)], obesity, and diabetes) were assessed in 233 HCC patients grouped according to hepatitis virus serological status (152 with HCV-HCC, 36 with HBV-HCC, and 45 with NBNC-HCC). RESULTS: The prevalence of patients with obesity or diabetes was significantly higher in the NBNC-HCC group than in the HBV-HCC group. The same trend was observed even when patients with massive alcohol intake were excluded from the analysis. Only 8 patients (18%) in the NBNC-HCC group had detectable serum HBV DNA, and this was at very low levels (HBV/Ce/C2 and HBV/D were determined in 7 and 1 patients, respectively). In the NBNC-HCC group, the determined nucleotide sequences of the enhancer II/core promoter/precore/core region did not contain any HCC-associated mutations, whereas 25 of 30 patients in the HBV-HCC group carried strains with C1653T, T1753V, and/or A1762T/G1764A mutations. CONCLUSIONS: A weak association between occult HBV infection and HCC development was observed in the NBNC patients. This study indicates that nonalcoholic steato-hepatitis should be further investigated to assess its contribution to HCC development in this category of patients.

Impaired cytotoxic T lymphocyte inductivity by dendritic cells derived from patients with hepatitis C virus-positive hepatocellular carcinoma.

AIM: Peptide-based therapeutic vaccines are being developed. The aim of this study was to determine the feasibility of immunotherapy to hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) by assessing the inductivity of peptide-specific cytotoxic T lymphocyte (CTL) by dendritic cells. METHODS: The inductivity of CTL was characterized in six patients with HCV-positive HCC, and compared to seven healthy volunteers and six patients with chronic HCV hepatitis (control). RESULTS: Peptide-specific CTL was comparably induced in controls, but not induced in any patients with HCC. To characterize this, the cytokine profile and the expression of surface molecules interacting between dendritic and T cells were evaluated. Among the cytokines, production of interferon (IFN)-gamma was found to be impaired and closely related to the results of CTL assays, while the expression of surface molecules showed no significant changes. CONCLUSIONS: In HCV-positive HCC patients, CTL inductivity by dendritic cells is impaired. This may be related to the impaired production of IFN-gamma.

Accidental exposure to HCV antibody-positive blood in hospital and pre-emptive one-shot interferon alpha-2b treatment.

AIMS: Infection with hepatitis viruses following blood exposure accidents, such as needle stick injuries, is a serious issue for medical staff. In particular, although accidental exposure to hepatitis C virus (HCV) occurs frequently, postexposure prophylactic measures have not been established yet. In this study we investigate the efficacy of recombinant alpha-2b interferon (IFN) as a single, 10 MU intramuscular injection for preventing transmission. METHODS: 264 incidents of accidental blood to HCV antibody-positive blood, occurring between 1993 and 2003 in the Social Insurance Chukyo Hospital, were surveyed. Accident reports, which described in detail the circumstances and the presence or absence of infectious disease in the blood, and accidental exposure to HCV antibody-positive blood was investigated. RESULTS: Pre-emptive IFN treatment was given in 115 out of 157 cases occurring between 1993 and 1998. One case developed acute HCV. Phylogenetic analysis provided evidence that the accident caused the infection and the patient was cured by immediate IFN therapy. Between 1999 and 2003, the exposed were in principle followed-up without IFN treatment; IFN treatment was only given when requested. As a result, IFN was given in 14 of 107 cases. During this period, no transmission was observed. CONCLUSION: Taken together, the benefits of pre-emptive IFN treatment were considered unremarkable and a follow-up without treatment, or immediate IFN therapy after confirmation of the onset, was recommended.

Measurement of hepatitis B virus core-related antigen as predicting factor for relapse after cessation of lamivudine therapy for chronic hepatitis B virus infection.

BACKGROUND: Prolonged lamivudine therapy has two major problems: breakthrough hepatitis during treatment and relapse of aminotransferase (ALT) after cessation of the therapy. The aim of this study was to examine factors that could predict ALT flare after stopping lamivudine therapy. METHODS: We analyzed 22 Japanese patients with chronic hepatitis B infection, in whom lamivudine therapy was stopped after HBV DNA level had been gone undetectable (<3.7LGE/ml) during at least six consecutive months. The post-treatment followed up was carried for 28 months in median (range 9-41). HBV core-related antigen (HBcrAg) assay was assessed using newly developed assay. RESULTS: After cessation of lamivudine therapy, 11 patients (50%) had relapsed (reactivation of serum ALT >80IU/l, relapsers) and remaining 11 (50%) did not relapse (non-relapsers). In the univariate comparison of relapsers versus non-relapsers, HBcrAg level at lamivudine cessation point (4.5+/-1.0 versus 3.4+/-0.9; p=0.0145) has been shown as a significant predictive factor for non-relapse. All patients with HBcrAg <3.0logU/ml at the cessation point had no ALT flares. Multivariate analysis on effects of 10 factors (age, sex, cirrhosis, pretreatment ALT level, HBV DNA level, HBcrAg level, mean months till undetectable HBV DNA, duration of undetectable HBV DNA and HBcrAg level at lamivudine cessation point), indicated that HBcrAg level at lamivudine cessation point <3.4log U/ml was the only independent predictive factor for absence of the post-treatment relapse. CONCLUSIONS: HBcrAg level at lamivudine cessation point might be useful as a prognostic predictor of response to lamivudine therapy cessation. The measurement of HBcrAg is a useful additional test for monitoring chronic HBV infection.

Spatial and chronological differences in hepatitis B virus genotypes from patients with acute hepatitis B in Japan.

Genotypes of hepatitis B virus (HBV) were determined in 485 patients with acute hepatitis B from all over Japan. They were A in 92 (19%), Ba in 26 (5%), Bj in 32 (7%), C in 330 (68%) and D in 5 (1%). Sexual contacts were the main route of transmission in them. Overall, HBV persisted in only 5 of the 464 (1%) followed patients. Genotypes C accounted for more than 68% in northern as well as southern areas, contrasting with genotype A accounting for 34% in and around the Metropolitan areas. During 24 years from 1982 to 2005, genotype A increased from 5% to 33%, while genotype B gradually decreased from 26% to 8%. Fulminant hepatitis was significantly more frequent in infection with genotype Bj (41%) than those with the other genotypes (p<0.01). The core-promoter double mutation (T1762/A1764) and precore stop-codon mutation (A1896) were more frequent in patients with fulminant than acute self-limited hepatitis (57% versus 15% and 58% versus 10%, respectively, p<0.01 for both). In conclusion, genotype A distributes unevenly over Japan, prevails in younger patients through sexual transmission and has increased with years. Furthermore, fulminant outcome was more frequent in patients with genotype Bj than those with the other genotypes.

Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E.

AIM: To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype. METHODS: Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing. RESULTS: HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E. CONCLUSION: HBV/E is predominant in the Republic of Benin,and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP,which might influence the virological characteristics, is observed in HBV/E.

Prediction of treatment outcome with daily high-dose IFN alpha-2b plus ribavirin in patients with chronic hepatitis C with genotype 1b and high HCV RNA levels: relationship of baseline viral levels and viral dynamics during and after therapy.

Data on 334 patients with HCV genotype 1b and high viral levels were extracted from two multicenter double-blind studies conducted in Japan comparing IFN alpha-2b plus ribavirin (n = 209) with IFN alpha-2b alone (n = 125) for 24 weeks. HCV RNA assay was conducted before and 4, 12, and 24 weeks after the start and 4, 12, and 24 weeks after the end of treatment. Both sustained viral response (SVR) rate and relapse rate after the end of treatment were analyzed in relation to baseline viral levels and the time of first disappearance of virus. In the combination treatment group, the percentage of patients who were HCV RNA-negative within 4 weeks decreased with increase in baseline viral levels (i.e. 42%, 15%, and 11% were HCV RNA-negative in the groups exhibiting <500, 500 to <850, and >/=850kcopies/mL, respectively). In the IFN monotherapy group, the response rates were lower at 13%, 15%, and 1%, respectively. Disappearance of virus within 12 weeks after the start of combination treatment was indicative of higher probability of SVR. The risk of relapse was more highly correlated with the timing of initial viral disappearance than with baseline HCV levels; it was 4.8 and 10.3 times higher in patients who became HCV-negative at 4-12 and 13-24 weeks compared with in those who were HCV-negative within 4 weeks.

A randomized controlled trial of consensus interferon with or without lactoferrin for chronic hepatitis C patients with genotype 1b and high viral load.

Recently, lactoferrin has been reported to have anti-HCV effects. The aim of this study was to investigate the effect of combination therapy using consensus interferon (CIFN) and lactoferrin in patients with chronic hepatitis C. Twenty-one patients with chronic HCV infection, who were positive for HCV-RNA genotype 1b with serum viral loads from 100 to 700KIU/ml, were randomly assigned to two groups; the CIFN + Lac group received CIFN with lactoferrin and the CIFN group received CIFN alone. Nine patients in each group completed this trial; the other patients dropped out because of side effects. Three, two and four patients were categorized as complete responders, relapsers and non-responders, respectively, in the CIFN + Lac group, and four, one and four in the CIFN group, respectively. There was no statistically significant difference in virologic response between the two groups. During the follow up after CIFN therapy with continued lactoferrin, there were two relapsers in the CIFN + Lac group and their HCV-RNA titers before treatment were over 400KIU/ml. In conclusion, the combination therapy of CIFN and lactoferrin did not increase the response rate or prevent relapse after discontinuation of IFN.

Hepatitis B virus genotype G is an extremely rare genotype in Japan.

BACKGROUND:: Hepatitis B virus (HBV) has been classified into seven genotypes (A-G). HBV genotypes have a geographically characteristic distribution. Since HBV genotype G (HBV/G) was identified recently, little is known about the distribution of HBV/G in Japan. The aim of this study was to clarify this issue. PATIENTS AND METHODS:: Seven hundred and twenty-one serum samples obtained from patients with HBV in Japan were investigated. The patients included 149 asymptomatic carriers, 325 with chronic hepatitis, 129 with liver cirrhosis, and 118 with hepatocellular carcinoma. Six HBV genotypes (A-F) were determined by restriction fragment length polymorphim targeting to the S region of the HBV genome. Furthermore, HBV/G was investigated by polymerase chain reaction with hemi-nested primers derived from an HBV/G-specific nucleotide sequence. RESULTS:: Of the 721 serum samples investigated, 12 subjects were classified as having HBV/A, 88 HBV/B, 610 HBV/C, 3 HBV/D, and 1 HBV/F. Seven subjects had a mixed infection with distinct genotypes, two with HBV/A and HBV/D, and five with HBV/B and HBV/C. HBV/G was not identified among the 721 samples. CONCLUSION:: HBV/G was not identified in a large cohort of patients with HBV, either single or dual infection. HBV/G seems to be an extremely rare genotype in Japan.

Clinical factors related to long-term administration of sorafenib in patients with hepatocellular carcinoma.

BACKGROUND: Sorafenib has been approved in the indication of unresectable hepatocellular carcinoma, but there are many cases in which administration of the drug is discontinued due to severe side effects. In this study, we compared the characteristics of patients who continued and discontinued sorafenib. METHODS: Ninety-six patients (75 men and 21 women) were initiated on sorafenib from July 2009 through September 2011. The patient characteristics of interest included gender, age, etiology, Child-Pugh classification, treatment history and frequency, and levels of α-fetoprotein, des- gamma-carboxy prothrombin, aspartate amino acid transferase, and alanine aminotransferase. Duration of administration of sorafenib and reasons for its discontinuation were compared. RESULTS: Median overall survival was 11.8 months. Discontinuation of sorafenib within 90 days was identified as an independent prognostic factor for overall survival on multivariate analysis (P < 0.0001). Transarterial chemoembolization performed six times or more (P = 0.013) was also identified as an independent factor contributing to discontinuation of sorafenib within 90 days in multivariate analysis. Patients who received sorafenib for ≥90 days had significantly longer overall survival than those who discontinued it (P < 0.0001). CONCLUSION: Prolonged treatment with sorafenib is an important factor in achieving extended overall survival. We recommend starting sorafenib before latent liver damage has occurred as a result of too many transarterial chemoembolization procedures.

Recommendation of lamivudine-to-entecavir switching treatment in chronic hepatitis B responders: Randomized controlled trial.

AIM: In the 2007-2008 guidelines of the study group (Ministry of Health, Labor and Welfare of Japan), lamivudine (LAM)-continuous treatment was recommended in patients treated with LAM for more than 3 years who maintained hepatitis B virus (HBV) DNA less than 2.6 log copies/mL, because in these patients LAM resistance might exist and switching treatment to entecavir (ETV) might cause ETV resistance. However, there was no evidence on whether switching treatment to ETV- or LAM-continuous treatment was better in those patients. In the present study, we performed a randomized controlled trial of LAM-to-ETV switching treatment. METHODS: Twenty-seven patients treated with LAM for more than 3 years whose HBV DNA levels were less than 2.6 log copies/mL were enrolled and randomly divided into two groups, LAM-continued group or switching to ETV group. Then, we examined incidence of virological breakthrough (VBT) and breakthrough hepatitis (BTH) in each group. RESULTS: There was no BTH in any of the patients. VBT was observed in six patients of the LAM group (6/15, 40%), and no patient of the ETV group (0/11, 0%) (P = 0.02). The differences of the proportion of cumulated VBT using a log-rank test with Kaplan-Meier analysis were significant between the LAM and ETV groups (P = 0.025). CONCLUSION: In patients treated with LAM for more than 3 years maintaining HBV DNA less than 2.6 log copies/mL, switching treatment to ETV is recommended at least during the 2 years' follow-up period.

Molecular epidemiology and interferon susceptibility of the natural recombinant hepatitis C virus strain RF1_2k/1b.

BACKGROUND: Hepatitis C virus (HCV) genotype is an important determinant of virological response to antiviral therapies. Currently, there are no data available on the molecular epidemiology and interferon susceptibility of the natural intergenotypic recombinant RF1_2k/1b (RF1) strain. METHODS: Genotyping and RF1-PCR screening were performed on samples from 604 HCV RNA-positive individuals from 7 countries. uPA/SCID mice carrying human hepatocytes (chimeric mice) were infected with the RF1_2k/1b strain, and the susceptibility of the strain to interferon and ribavirin was compared with the susceptibilities of 2 different strains of genotype B, used as references. RESULTS: Six new RF1 cases were identified in this study; 5 (2%) of 281 in Russia and 1 (1%) of 90 in Uzbekistan. Phylogenetic analyses based on Core/E1 and NS5b indicated that all RF1 representatives share a common evolutionary ancestor. Infection with RF1 was established in chimeric mice. Reduction of RF1 viral load was observed in response to 3 injections of 3 microg/kg pegylated-interferon alpha-2a alone or in combination with 50 mg/kg of ribavirin (0.5 or 1.4 log-copies/mL). CONCLUSIONS: All identified RF1-type strains appear to be introduced from a single source, suggesting that intergenotypic recombination in HCV is sporadic and not associated with cocirculation of different genotypes in a population. The RF1 strain in this study was responsive to interferon in vivo.

Variations in the viral NS5B region in Japanese patients with chronic hepatitis C virus genotype 1b infection. No specific amino acid substitution was identified as determinants of treatment response to interferon/ribavirin combination therapy.

OBJECTIVE: A recent study suggested that the substitution of amino acid 415 of HCV NS5B from phenylalanine to tyrosine in patients with HCV genotype 1a infection is induced by ribavirin and responsible for resistance to ribavirin therapy. The aim of this study was to evaluate whether specific variations in the HCV NS5B sequence in Japanese patients with HCV genotype 1b (HCV/1b) infection are associated with treatment response or selected by treatment with interferon-alpha/ribavirin combination therapy. METHODS: Eighteen Japanese patients with HCV/1b infection receiving interferon-alpha/ribavirin combination therapy for 24 weeks were studied. Five patients treated with interferon-alpha monotherapy for 24 weeks were also studied as controls. The entire HCV NS5B sequence before and after therapy was determined. RESULTS: All HCV isolates had tyrosine at position 415 of NS5B before and after therapy. Further analysis showed that no specific amino acid substitutions were identified to associate with clinical response and no specific amino acid substitutions were induced/selected by the clinical treatment. CONCLUSION: No specific HCV NS5B nucleotide/amino acid sequence variations, including amino acid 415 of NS5B, were identified as being associated with clinical treatment response or selected by the combination therapy in Japanese patients with HCV/1b infection.

Impact of occult hepatitis B virus infection on efficacy and prognosis of interferon-alpha therapy for patients with chronic hepatitis C.

BACKGROUND/AIMS: It is reported that some patients with undetectable hepatitis B surface antigen (HBsAg) have serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis C (HCV). The aim of this study was to elucidate the impact of occult HBV infection on the efficacy and prognosis of interferon-alpha (IFN) therapy in HCV patients. METHODS: One hundred and forty HCV patients without HBsAg who received IFN therapy were studied. Serum HBV DNA was quantified by real-time detection polymerase chain reaction. RESULTS: Of 140 patients, 11 (7.9%) were HBV DNA-positive before IFN therapy. The serum HBV DNA levels ranged from 106 to 884 copies/ml. Four of these 11 patients showed a sustained virologic response by IFN, compared with 39 of 129 without HBV DNA (P = NS). Interestingly, two of the 11 patients developed hepatocellular carcinoma (HCC) after therapy, compared with 16 of 129 without HBV DNA (P = NS). In the serial study, serum HBV DNA was transiently undetectable during and after IFN; however, most became positive during follow-up. CONCLUSIONS: Occult HBV infection may not have a significant impact on response to IFN therapy for chronic HCV and development of HCC after therapy. Occult HBV may be sensitive to IFN although HBV is not completely eradicated.