Search

Donors with resolved hepatitis B virus (HBV) infection may be a solution for the organ shortage for kidney transplantation (KT). The purpose of this study was to clarify the current state of HBV markers after KT from donors with resolved HBV infection to HBV naïve recipients and the rate of HBV reactivation in recipients with resolved HBV infection. Furthermore, we investigated HBV covalently closed circular DNA (cccDNA) in transplanted organs from donors with resolved HBV infection and the capability of HBV replication in kidney cell lines. We retrospectively analysed the HBV status of 340 consecutive donors and recipients who underwent KT in a single centre. We prospectively measured cccDNA by real-time polymerase chain reaction in kidney biopsy specimens of 32 donors with resolved HBV infection. HBV reactivation was found in three recipients with resolved HBV infection (4.8%, 3/63) after KT. We analysed 45 cases of transplantation from donors with resolved HBV infection to HBV-naive recipients. One case (2.2%, 1/45) became seropositive for hepatitis B core antibody (anti-HBc) and in another case (2.2%, 1/45), HBV-DNA was detected qualitatively in an HBV naive recipient with a donor with resolved HBV infection. In the latter case, cccDNA was measured in the donor kidney during KT. HBV replication was observed in kidney cell lines with HBV plasmid transfection. In conclusion, the risk of reactivation in anti-HBc-positive donors is relatively low. However, post-transplant HBV monitoring should be conducted in all at-risk cases.

No prospective study on the efficacy of tenofovir alafenamide (TAF), a novel tenofovir prodrug, in preventing HBV reactivation has yet been reported.This multicenter prospective study enrolled HBV-carriers who received TAF to prevent HBV reactivation before antitumor or immunosuppressive therapy, and patients with resolved HBV infection who experienced HBV-reactivation and received TAF to prevent HBV reactivation-related hepatitis. The efficacy of prophylactic TAF in preventing HBV reactivation and HBV reactivation-related hepatitis was evaluated at 6 and 12 months after initiating TAF.Overall, 110 patients were administered TAF to prevent HBV reactivation or HBV reactivation-related hepatitis. Three patients died owing to primary disease, whereas one patient was transferred to another hospital within 6 months after initiating TAF. Seven patients died due to primary disease, and five patients were transferred to another hospital within 12 months after initiating TAF. Therefore, 106 and 94 (77 patients with HBV infection, 17 with previous-HBV infection) patients were evaluated at 6 and 12 months after initiating TAF, respectively. No patient experienced HBV reactivation, HBV reactivation-related hepatitis, or treatment discontinuation due to HBV reactivation or adverse events of TAF after 6 and 12 months.TAF could effectively prevent HBV reactivation and HBV reactivation-related hepatitis. This article is protected by copyright. All rights reserved.

Hepatitis C virus (HCV) infection can cause renal dysfunction, expected to improve upon HCV eradication. However, adverse effects of HCV eradication using direct-acting antiviral agents (DAAs) on renal function have been recently reported. This retrospective study aimed to evaluate renal function with glomerular filtration rate (eGFR) estimated using creatinine (eGFRcre) and cystatin C (eGFRcys). Complete clinical information and preserved serum samples were collected from 207 patients with HCV infection treated with interferon-free DAA at baseline and SVR48 (SVR48). Patients who underwent paired computed tomography (CT) at baseline and ≥12 months after DAA were evaluated for changes in skeletal muscle mass using the psoas muscle mass index (PMI). eGFRcre significantly worsened at SVR48, while eGFRcys was similar at baseline and SVR48. At baseline, eGFRcre was significantly higher than eGFRcys; eGFRcre and eGFRcys were similar at SVR48. Multivariate analysis revealed that the presence of liver cirrhosis and low-albumin level, as well as cirrhosis and age, was significantly associated with the overestimation of renal function by eGFRcre at baseline and SVR48, respectively. In the 57 patients who underwent paired CT at baseline and ≥12 months after DAA, relative values of PMI significantly increased after DAA. After DAA, in patients with increased PMI (65% 37/57), eGFRcre significantly worsened but did not change in patients without increased PMI. eGFRcre significantly worsened after DAAs; however, this might not reflect accurate changes in renal function, partially because of changes in skeletal muscle mass. eGFRcys did not change after DAAs, and it is a potential alternative to eGFRcre.

Background Sarcopenia is associated with poor prognosis in patients with chronic liver disease (CLD). As rapid skeletal muscle wasting predicts worse prognosis and a novel therapy for sarcopenia needs to be evaluated for validation, accurate evaluation methods for relative changes in muscle mass are crucial. Methods We screened CLD patients who had skeletal muscle mass evaluation between June 2015 and December 2017. Patients were included if they had adequate information, were followed for >6 months, and had skeletal muscle mass evaluation by both bioelectrical impedance analysis (BIA) and computed tomography (CT) imaging at baseline and the second evaluation point. We compared BIA and CT imaging in terms of their ability to quantify skeletal muscle mass and identify relative changes in muscle mass in CLD patients. Results Of the screened 447 CLD patients, 110 were included in this study, and 71 (64.5%) were men. The median age was 68 (range 21 to 90) years. In total, 83 (75.5%) and 32 (29.1%) patients had liver cirrhosis and hepatocellular carcinoma, respectively. Of them, 50 (45.5%) patients were liver cirrhosis patients without hepatocellular carcinoma through the observation period. Skeletal muscle mass index (SMI) by BIA, psoas muscle mass index (PMI), and SMI based on CT imaging were significantly correlated at baseline [SMI by simple CT method and SMI by BIA (r = 0.61, P

This study aimed to determine the optimal psoas muscle mass index (PMI) cut-off values for diagnosis of skeletal muscle mass loss. Methods We evaluated PMI in two groups of normal controls: a medical check-up group and a liver donation candidate group. We analyzed two novel PMI cut-off values, one based on the mean - two standard deviations (2SD) and one based on the lower 5%. Skeletal muscle mass index (SMI) evaluations using computed tomography (sliceOmatic; TomoVision) and bioelectrical impedance analysis and PMI evaluation were undertaken simultaneously. We analyzed the correlation between our PMI cut-off values and the Japan Society of Hepatology-defined SMI cut-off values. The prevalence of skeletal muscle mass loss in patients with liver disease was assessed using the novel PMI cut-off values. Results In 504 normal controls aged ≤50 years, the PMI cut-off values based on mean -2SD and the lower 5% were set at 3.30 cm2 /m2 for men and 1.69 cm2 /m2 for women and 3.74 cm2 /m2 for men and 2.29 cm2 /m2 for women, respectively. The PMI cut-off values based on the lower 5% alone showed that skeletal muscle mass loss increased with age. Furthermore, they correlated well with Japan Society of Hepatology-defined SMI (sliceOmatic) cut-off values and showed a significantly higher prevalence of skeletal muscle mass loss in patients with liver cirrhosis than those without liver cirrhosis. Conclusions We propose the following PMI cut-off values: 3.74 cm2 /m2 for male individuals and 2.29 cm2 /m2 for female individuals. These cut-off values can facilitate accurate diagnosis and management of sarcopenia in patients with chronic liver disease.

Background and Aim Immune checkpoint inhibitors (ICI) have revolutionized anti-malignancy therapy and thus have been increasingly used. Although ICI may cause immune-related adverse events (irAE) in various organs, including the liver, the prevalence and predictive factors of irAE have not been clarified. Methods In this retrospective study, consecutive patients who had malignancies and were treated with ICI without other chemotherapeutic agents at Hokkaido University Hospital between 2014 and 2019 were screened. Patients were excluded if they were Of the 233 patients screened, 202 patients met the inclusion criteria and were included in the analysis. The patients were aged 25-92 years, and 60.9% were male. The patients received nivolumab (n = 137), pembrolizumab (n = 45), ipilimumab (n = 17), atezolizumab (n = 2), and avelumab (n = 1). The prevalence of any grade and grade >= 3 irAE hepatitis was 8.4% (17/202) and 4.0% (8/202), respectively. irAE hepatitis occurred at a median duration of 42 days in any grade and 36 days in grade >= 3 after ICI initiation. The clinical course of grade >= 3 irAE hepatitis was generally favorable; however, 50% required corticosteroid treatment and two patients required additional mycophenolate mofetil. Female sex and history of ICI treatment were significantly associated with the incidence of grade >= 3 irAE hepatitis. Conclusions Grade >= 3 irAE hepatitis was observed in 4.0% of the patients who were treated with ICI. Female sex and history of ICI treatment were significantly associated with the incidence of grade >= 3 irAE hepatitis.

Aim Factors associated with improvement of liver fibrosis after successful hepatitis C virus (HCV) eradication by interferon (IFN)-free direct-acting antiviral agents (DAAs) have been not clarified well. Angiopoietin-2 (Ang2) is reported to be associated with vascular leak and inflammation observed in patients with advanced liver fibrosis. Methods In this retrospective study, patients treated with IFN-free DAAs who underwent transient elastography before and at 24-weeks post-treatment and achieved sustained viral response were enrolled. Baseline serum Ang2 was measured, and its relationship with other clinical factors was analyzed. Liver fibrosis stage was defined based on liver stiffness according to a previous report. Predictive factors for regression of liver fibrosis stage after DAA therapy were evaluated. Results Overall, 116 patients were analyzed. Baseline serum Ang2 levels were significantly associated with liver stiffness, spleen index, and liver stiffness-based liver fibrosis stage. Moreover, 75% of patients experienced regression of liver fibrosis stage after DAA therapy. Multivariate analysis revealed that advanced liver fibrosis stage and Ang2 levels were significantly associated with regression of liver fibrosis stage after DAA therapy. In patients with advanced liver fibrosis (F3/4), baseline Ang2 level alone could predict regression of liver fibrosis stage. A baseline Ang2 cut-off value (354 pg/ML) could predict regression of liver fibrosis stage after DAA therapy with high accuracy (sensitivity 0.882, specificity 0.733). Conclusions Evaluation of serum Ang2 levels before DAA therapy is important. Our results provide a novel mechanistic insight into non-regression of liver stiffness after DAA therapy. Long-term and larger studies are required.

AIMS Development of direct-acting antivirals (DAAs) has made antihepatitis C virus (HCV) treatment highly safe and effective. However, the emergence of resistant-associated variants (RAVs) after failure of DAA therapy affects retreatment outcomes. In particular, genotype 1 HCV with P32 deletion has been reported to be highly resistant to all approved non-structural protein (NS)5A inhibitors. However, analysis of RAVs in genotype 2 HCV has been limited. Accordingly, in this study, we evaluated the roles of genotype 2 HCV variants in antiviral drug efficacy. METHODS We utilized HCV-2b/2a (JFH-1) chimeric virus (genotype 2a), which replicates more robustly than JFH-1. We constructed various genotype 2a JFH-1-based HCV cell culture systems with NS3 (D168E), NS5A (F28S, F28S/M31I, P32 deletion, and Y93H), and NS5B (S282 T) RAVs and analyzed the replication ability and sensitivity to various anti-HCV reagents. RESULTS Genotype 2a-based HCV with NS5A-P32 deletion could not replicate even in long-term cultures. Genotype 2a-based HCV with NS5A-F28S/M31I showed significantly higher replication ability than the wild-type strain, and replication could not be suppressed, even with high concentrations of NS5A inhibitors, including pibrentasvir and velpatasvir (

Aim Coronavirus disease 2019 (COVID-19) is a serious public health concern, with unclarified prevalence in Japan. Concomitant liver disease could increase the severity of COVID-19 disease, and chronic liver disease patients sometimes require frequent admission and gastrointestinal endoscopy. Thus, clarifying the prevalence of asymptomatic COVID-19 in outpatients with liver disease is essential for preventing nosocomial infections. We aimed to clarify the time-dependent changes in COVID-19 seroprevalence in liver disease outpatients, who were asymptomatic for COVID-19, in an area of Japan experiencing a second wave of COVID-19. Methods We included the preserved sera of 100, 300, and 300 consecutive liver disease outpatients, who were asymptomatic for COVID-19, from May 2019, March 2020, and May 2020, respectively. The sera were analyzed immunochromatographically to detect immunoglobulin G against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (KURABO) and by Elecsys Anti-SARS-CoV-2-assay (Roche Diagnostics). Results Analysis of 100 cases from May 2019, before COVID-19 became pandemic, revealed that the specificity of immunochromatographic tests and Elecsys were 98% (95% confidence interval [CI], 93-99.8%) and 100% (95% CI, 97-100%), respectively. Analysis of 300 cases from March 2020 revealed a seroprevalence of 0.3% (1/300; 95% CI, 0-1.8%) for COVID-19 by Elecsys Anti-SARS-CoV-2 assay. Analysis of 300 cases from May 2020 revealed a seroprevalence of 0% (0/300; 95% CI, 0-1.0%). Conclusions The Elecsys Anti-SARS-CoV-2 assay has high specificity. The cumulative seroprevalence of COVID-19 by the Elecsys Anti-SARS-CoV-2 assay in outpatients with liver disease in Sapporo, who were asymptomatic for COVID-19, was 0.17% (1/600; 95% CI, 0.0-0.9%) until May 2020.

Background and Aim Hepatitis C virus 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 hepatitis C virus-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. Methods The study included 322 genotype 1 hepatitis C virus-infected patients who received daclatasvir and asunaprevir combination therapy. The safety and sustained virological response was examined at 12 weeks after the end of treatment and safety was evaluated according to renal function. Results Of 322 patients, 5% (16/322) and 2.5% (8/322) had chronic kidney disease stage G3b (eGFR, 30–44 mL/min/1.73 m2) and stage G4/5 (eGFR, 15–29/ 45. Notably, the 12-week sustained viral response rate was comparable in patients with eGFR 45 (88.9%, 265/298; P = 0.07). Treatment discontinuation rates and adverse events, including ALT elevation, anemia, and renal disorders, were similar between the two groups. Conclusions Daclatasvir and asunaprevir combination therapy for patients with renal dysfunction was highly effective and safe

Hepatitis C virus (HCV) has been reported to hijack fatty acid metabolism in infected hepatocytes, taking advantage of lipid droplets for virus assembly. In this study, we analyzed the anti-HCV activity of l-carnitine, a substance involved in the transport of fatty acids into mitochondria. JFH-1 or HCV replicon-transfected Huh7.5.1 cells were treated with or without l-carnitine to examine its anti-HCV effects. The effects of l-carnitine on HCV entry, HCV-induced adipogenesis and lipid droplet formation, and HCV-induced oxidative stress were examined. Treatment of JFH-1-infected cells with l-carnitine inhibited HCV propagation in a concentration-dependent manner. In contrast, l-carnitine had no anti-HCV activity in the HCV replicon system, which is lacking viral assembly. In addition, l-carnitine did not affect HCV entry. However, l-carnitine treatment decreased intracellular lipid droplets, which are crucial for HCV assembly in JFH-1-infected cells. The expression level of CPT-1 was decreased in JFH-1-infected cells, and l-carnitine treatment restored this expression. HCV-infected cells exhibited increased production of reactive oxygen species and glutathione oxidation. l-carnitine decreased oxidative stress induced by JFH-1-infection, as shown by glutathione/glutathione disulfide assays and MitoSOX staining. l-carnitine exhibited anti-HCV activity, possibly by inhibiting HCV assembly and through its anti-adipogenic activity in HCV-infected cells. Moreover, l-carnitine has antioxidant properties in HCV-infected hepatocytes. Overall, these results indicated that l-carnitine may be an effective adjunctive agent in antiviral therapies to treat chronic hepatitis C. J. Med. Virol. 89:857-866, 2017. © 2016 Wiley Periodicals, Inc.

Aim 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. Methods We analyzed the prevalence of variants in the NS3/NS5A/NS5B regions in 96 patients treated with simeprevir (SMV) combination therapy, and the prevalence of RAVs in patients showing treatment failure was determined by direct- or deep-sequencing methods. Associations between these potential RAVs and clinical factors were also analyzed. Results Prevalence of NS5B RAV C316N was high (46.9%, 45/96), whereas that of NS5B L159F was relatively low (1.04%, 1/96); however, deep sequencing showed that 30.0% of patients with C316N also had NS5B RAV L159F. Additionally, there was no significant relationship between the existence of potential NS5B and NS5A or NS3 RAVs. However, the presence of NS5B C316N was significantly associated with an HCV core amino acid 91 substitution. No significant difference was detected between each RAV and sustained virological response in simeprevir combination therapy. Conclusion We provide clear evidence of the high prevalence of two potential naturally occurring NS5B RAVs (C316N and L159F) in Japan. It may be important to pay particular attention to these new potential RAVs, especially when using SOF-based therapy in patients with RAVs due to previous direct-acting antiviral therapy failure.

Aim: Telaprevir-based therapy for chronic hepatitis C patients is effective; however, the high prevalence of dermatological reactions is an outstanding issue. The mechanism and characteristics of such adverse reactions are unclear; moreover, predictive factors remain unknown. Granulysin was recently reported to be upregulated in the blisters of patients with Stevens-Johnson syndrome (SJS). Therefore, we investigated the risk factors for severe telaprevir-induced dermatological reactions as well as the association between serum granulysin levels and the severity of such reactions. Methods: A total of 89 patients who received telaprevir-based therapy and had complete clinical information were analyzed. We analyzed the associations between dermatological reactions and clinical factors. Next, we investigated the time-dependent changes in serum granulysin levels in five and 14 patients with grade 3 and non-grade 3 dermatological reactions, respectively. Results: Of the 89 patients, 57 patients had dermatological reactions, including nine patients with grade 3. Univariate analysis revealed that grade 3 dermatological reactions were significantly associated with male sex. Moreover, serum granulysin levels were significantly associated with the severity of dermatological reactions. Three patients with grade 3 dermatological reaction had severe systemic manifestations including SJS, drug-induced hypersensitivity syndrome, and systemic lymphoid swelling and high-grade fever; all were hospitalized. Importantly, among the three patients, two patients' serum granulysin levels exceeded 8ng/mL at onset and symptoms deteriorated within 6 days. Conclusion: Male patients are at high risk for severe telaprevir-induced dermatological reactions. Moreover, serum granulysin levels are significantly associated with the severity of dermatological reactions and may be a predictive factor in patients treated with telaprevir-based therapy.

BACKGROUND 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. METHODS This was a prospective, randomized, multicenter study in which a total of 61 HCV genotype 1b-infected patients were recruited and 60 eligible patients were randomly allocated to two groups that received 12 weeks of SMV/Peg-IFN/RBV followed by 12 weeks of Peg-IFN/RBV with or without 24 weeks of FLV. The SVR rate and adverse events were compared between the two groups. RESULTS Thirty-one patients were allocated to the FLV add-on group and 29 patients were allocated to the control group. Baseline clinical factors, including median age, baseline platelet count, alanine aminotransferase level, HCV RNA titer, Fibrosis-4 index, and rate of IL28B minor genotype, were all similar between the two groups. The rapid virologic response, end-of-treatment response rates, SVR rates at 24 weeks after treatment, and safety profiles were also similar between the two groups. CONCLUSIONS This prospective, randomized, multicenter study indicated that FLV had no add-on effect when given with SMV/Peg-IFN/RBV combination therapy for genotype 1b HCV-infected patients.

Aim Telaprevir-based therapy for chronic hepatitis C patients is effective; however, the high prevalence of dermatological reactions is an outstanding issue. The mechanism and characteristics of such adverse reactions are unclear; moreover, predictive factors remain unknown. Granulysin was recently reported to be upregulated in the blisters of patients with Stevens–Johnson syndrome (SJS). Therefore, we investigated the risk factors for severe telaprevir-induced dermatological reactions as well as the association between serum granulysin levels and the severity of such reactions. Methods A total of 89 patients who received telaprevir-based therapy and had complete clinical information were analyzed. We analyzed the associations between dermatological reactions and clinical factors. Next, we investigated the time-dependent changes in serum granulysin levels in five and 14 patients with grade 3 and non-grade 3 dermatological reactions, respectively. Results Of the 89 patients, 57 patients had dermatological reactions, including nine patients with grade 3. Univariate analysis revealed that grade 3 dermatological reactions were significantly associated with male sex. Moreover, serum granulysin levels were significantly associated with the severity of dermatological reactions. Three patients with grade 3 dermatological reaction had severe systemic manifestations including SJS, drug-induced hypersensitivity syndrome, and systemic lymphoid swelling and high-grade fever; all were hospitalized. Importantly, among the three patients, two patients' serum granulysin levels exceeded 8 ng/mL at onset and symptoms deteriorated within 6 days. Conclusion Male patients are at high risk for severe telaprevir-induced dermatological reactions. Moreover, serum granulysin levels are significantly associated with the severity of dermatological reactions and may be a predictive factor in patients treated with telaprevir-based therapy.

Insulin-like growth factor binding protein (IGFBP)-3 regulates cell proliferation and apoptosis in esophageal squamous cell carcinoma (ESCC) cells. We have investigated how the hypoxic tumor microenvironment in ESCC fosters the induction of IGFBP3. RNA interference experiments revealed that hypoxia-inducible factor (HIF)-1α, but not HIF-2α, regulates IGFBP3 mRNA induction. By chromatin immunoprecipitation and transfection assays, HIF-1α was found to transactivate IGFBP3 through a novel hypoxia responsive element (HRE) located at 57 kb upstream from the transcription start site. Metabolic labeling experiments demonstrated hypoxia-mediated inhibition of global protein synthesis. 7-Methyl GTP-cap binding assays suggested that hypoxia suppresses cap-dependent translation. Experiments using pharmacological inhibitors for mammalian target of rapamycin (mTOR) suggested that a relatively weak mTOR activity may be sufficient for cap-dependent translation of IGFBP3 under hypoxic conditions. Bicistronic RNA reporter transfection assays did not validate the possibility of an internal ribosome entry site as a potential mechanism for cap-independent translation for IGFBP3 mRNA. Finally, IGFBP3 mRNA was found enriched to the polysomes. In aggregate, our study establishes IGFBP3 as a direct HIF-1α target gene and that polysome enrichment of IGFBP3 mRNA may permit continuous translation under hypoxic conditions.—Natsuizaka, M., Naganuma, S., Kagawa, S., Ohashi, S., Ahmadi, A., Subramanian, H., Chang, S., Nakagawa, K. J., Ji, X., Liebhaber, S. A., Klein-Szanto, A. J., Nakagawa, H. Hypoxia induces IGFBP3 in esophageal squamous cancer cells through HIF-1α-mediated mRNA transcription and continuous protein synthesis.

Background: There are few detailed clinical reports about extrahepatic metastases of hepatocellular carcinoma (HCC). The purpose of the present study was to elucidate the clinical features of extrahepatic metastases of HCC. Methods: The clinical records of 482 patients who had been diagnosed as having HCC during the period from January 1995 to March 2001 were retrospectively reviewed. Extrahepatic metastases had been detected in 65 patients. Clinical features of those 65 patients were analyzed. Results: Patients with extrahepatic metastases had more advanced intrahepatic tumors at the first diagnosis of HCC: 73.8% of the patients with extrahepatic metastases had tumors of intrahepatic tumor stage T3 or T4 according to the TNM classification, while only 28.5% of the patients without extrahepatic metastases had tumors of T3 or T4 (P

Treatment of chronic hepatitis B has been greatly improved by the use of lamivudine, but mutations occur in the polymerase region of hepatitis B virus (HBV) and lamivudine-resistant mutants frequently develop. The emergence of lamivudine-resistant strains of HBV is a problem for treating chronic hepatitis B using lamivudine. We observed biochemical and virological changes in 15 patients with chronic hepatitis B for a median period of 29 months (range: 4-42 months) after the emergence of lamivudine-resistant mutants of HBV. Patterns of mutation of the polymerase gene were examined by sequencing the LLAQ motif in domain B and the YMDD motif in domain C. Exacerbation of liver dysfunction occurred in 14 (93.3%) of the 15 patients at a median of 4 months after the emergence of mutations. However, exacerbation of liver dysfunction was observed only in four patients (26.7%) at the time of appearance of the first mutations and in 80.0% of the patients at the time of appearance of the second mutations. Increase in serum alanine aminotransferase (ALT) levels was significantly greater at the time of appearance of second mutations (P = 0.0096). In most cases, wild-type HBV was mutated with the substitution of only rtM204I at first, and rtL180M/M204I mutations and then rtL180M/M204V mutations subsequently appeared. Further mutations of the polymerase region caused clinical deterioration. Thus as mutations emerge in the polymerase region, the clinical outcome deteriorates. Thus, monitoring the patterns of mutation of the polymerase gene is useful when using lamivudine for treating HBV.