Clinical and virological features of non-breakthrough and severe exacerbation due to lamivudine-resistant hepatitis B virus mutants.

Patients who develop YMDD mutant during lamivudine therapy for hepatitis B virus (HBV) infection exhibit various clinical courses. Some patients show normal ALT levels, whereas others develop severe hepatitis exacerbations (SHEs) due to YMDD mutants. We studied 136 patients with YMDD mutant among 362 Japanese adult patients on lamivudine therapy. Clinical and virological features of patients without elevated HBV DNA after emergence of YMDD mutant (non-elevated group) were investigated. Moreover, virological analysis was also performed in patients with SHE due to YMDD mutants. Patients in the non-elevated group were characterized by HBeAg-negative pretreatment, HBeAg loss during therapy, a longer duration from commencement of therapy until emergence of YMDD mutant, and no mixed-type YMDD mutants. Patients with SHE had more substitutions in the reverse transcriptase (rt) region within the polymerase gene at the time of exacerbation than those without SHE, although no specific substitutions were noted. Sequence analysis of full-length HBV genome showed more substitutions in X, rt, and surface proteins in patients with SHE than in those without elevated HBV DNA level. In conclusion, negativity for HBeAg at commencement of therapy or before emergence of YMDD mutant was an important factor among non-elevated group. More substitutions in the rt region and the other proteins may be related to the emergence of severe hepatitis caused by lamivudine-resistant virus.

Association of amino acid substitution pattern in core protein of hepatitis C virus genotype 1b high viral load and non-virological response to interferon-ribavirin combination therapy.

OBJECTIVE: Patients with high titer (>/=100 kIU/ml) of hepatitis C virus (HCV) genotype 1b do not achieve highly sustained virological response rates to combination therapy with interferon plus ribavirin. Non-virological responders (NVRs, namely ultimate resistant cases) who do not achieve HCV-RNA negativity during treatment are also encountered. We investigated the pretreatment virological features of NVRs. METHODS: We evaluated 50 consecutive Japanese adults with high titer of HCV genotype 1b who received combination therapy for 48 weeks. We investigated the pretreatment substitution patterns in amino acids 1-191 of the core region and amino acids 2209-2248 of NS5A, and early viral kinetics. RESULTS: Overall, a non-virological response was noted in 12 (24%) patients. Multivariate analysis identified serum albumin <3.9 g/dl, substitutions of amino acid 70 in the core region, and substitutions of amino acid 91 as independent and significant factors associated with a non-virological response. Especially, substitutions of arginine (R) by glutamine (Q) at amino acid 70, and/or leucine (L) by methionine (M) at amino acid 91 were significantly more common in NVRs. The falls in HCV-RNA levels during treatment in patients with specific substitutions in the core region were significantly less than in those without such substitutions. CONCLUSIONS: Our results suggest that serum albumin and amino acid substitution patterns in the core region in patients with high titers of HCV genotype 1b may have an effect on combination therapy in NVRs. Further large-scale studies are required to examine the role of amino acid substitutions specific to a non-virological response to combination therapy.

Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B.

BACKGROUND: Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined. METHODS: During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C. RESULTS: Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years. CONCLUSIONS: Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.

Virological and biochemical relapse after discontinuation of lamivudine monotherapy for chronic hepatitis B in Japan: comparison with breakthrough hepatitis during long-term treatment.

OBJECTIVE: Comparison of virological and biochemical relapse in patients with chronic hepatitis B, based on continuation or discontinuation of lamivudine monotherapy. METHODS: In Japanese genotype C-dominant hepatitis B patients, 25 patients who stopped treatment at normal levels of alanine transferase (ALT) were retrospectively compared with 75 patients who continued treatment. Both groups were matched for age, sex, and observation period after start of treatment. We investigated the relapse rates, and evaluated predictive factors for relapse and efficacy of retreatment of the discontinuous group. RESULTS: Virological and biochemical relapse occurred significantly earlier in the discontinuous than continuous group, and the peak levels and ratios of peak to pretreatment levels of serum bilirubin and ALT after relapse were not significantly different between the two groups. Multivariate analysis identified three independent factors at discontinuation of treatment associated with early biochemical relapse: HBeAg positivity, presence of liver cirrhosis, detection of basic core promoter mutant. Normalization of ALT levels with retreatment occurred in 62.5% of patients, but 2 HBeAg-positive patients retreated after the emergence of YMDD motif mutant developed severe relapse with hyperbilirubinemia. CONCLUSION: Our results in Japanese patients with genotype C-dominant hepatitis B suggest that discontinuation of lamivudine monotherapy, and retreatment after the emergence of YMDD mutant should be given attention.

Persistence of acute infection with hepatitis B virus genotype A and treatment in Japan.

Among the 97 adult patients with acute hepatitis B who were admitted to the Toranomon Hospital in Metropolitan Tokyo during 28 years from 1976 to 2003, 31 (32%) were infected with hepatitis B virus (HBV) genotype A, nine (9%) with genotype B, 44 (45%) with genotype C, one (1%) each with genotypes E and F. HBV in the remaining 11 (11%) patients were untypeable. All the 31 patients with acute hepatitis B caused by HBV genotype A infection were male with a median age of 31 years, and 16 (52%) contracted infection through extramarital sexual contacts. The baseline HBV DNA level was higher in the seven (23%) patients in whom infection with HBV genotype A persisted than the remaining 24 (77%) with spontaneous resolution (median: >8.7 vs. 6.0 log genome equivalents/ml, P = 0.004). Persistent infection was more frequent in patients with maximum alanine aminotransferase <500 IU/L than > or =500 IU/L (83% [5/6] vs. 4% [1/25], P = 0.0001). Of the six patients with persistent HBV genotype A infection who received interferon and/or lamivuidine for treatment of chronic active hepatitis, three (50%) responded with the loss of hepatitis B e antigen (HBeAg); hepatitis B surface antigen (HBsAg) was cleared from serum in one patient who received interferon and lamivudine in sequence. HBV genotype A persisted along with HBeAg in the remaining three patients given antiviral therapy as well as another who was not treated. In conclusion, infection with HBV genotype A prevails in patients with acute hepatitis B in Japan where genotypes B and C are common, is often contracted sexually (16/31 [52%]) and tends to persist (7/31 [23%]). Infection was cleared in only one of the six (17%) patients who received antiviral therapy.

Clinical and virological characteristics of untreated patients with chronic hepatitis C who develop serum alanine aminotransferase flare-up.

Among patients with chronic hepatitis C virus (HCV) infection, serum alanine aminotransferase (ALT) rarely increases above 500 IU/L. We examined the clinical and virological features of untreated patients with serum ALT > or = 500 IU/L. One thousand seven hundred and sixty adult patients with chronic HCV infection were followed-up. Among these patients, 22 developed ALT flare-up (M:F=13:9, median age, 50.5 years). We evaluated liver function tests, genotype, and viral titer in these patients and 44 randomly selected age- and sex-matched control without ALT flare-up. In four patients with ALT flare-up, we examined changes in viral loads and sequential changes in amino acid sequences of the core region, hypervariable region 1 (HVR1), and interferon sensitivity determining region (ISDR) before and after ALT flare-up. Multivariate analysis identified genotype 2 as the only significant determinant of ALT flare-up. ALT flare-up occurred in three of four patients without increase in viral load. Several alterations in amino acids were noted in HVR1 before and within 6 months of ALT flare-up. One or two alterations in the core region and many alterations in HVR1 were noted after ALT flare-up in some patients. Genotype 2 is an important factor for ALT flare-up. However, we could not directly relate ALT flare-up to these alterations in amino acids of the core region, HVR1, and ISDR.

Efficacy of lamivudine treatment in Japanese patients with hepatitis B virus-related cirrhosis.

BACKGROUND: Several clinical trials have suggested that lamivudine therapy is effective in patients with hepatitis B virus (HBV)-related cirrhosis. However, there are few studies of lamivudine therapy in Japanese patients with HBV cirrhosis. The aim of this study was to evaluate the efficacy of lamivudine therapy in Japanese patients with cirrhosis, and to evaluate the clinical course after the emergence of YMDD mutants. METHODS: Fifty-four consecutive adult Japanese patients with HBV-related cirrhosis were enrolled and continuously treated with lamivudine, daily for 6-35 months (median, 25 months). Twelve of the 54 patients were hepatitis B envelope antigen (HBeAg)-positive. The clinical courses of 21 of the patients were evaluated using the Child-Pugh-Turcott (CPT) score. RESULTS: Lamivudine suppressed serum HBV-DNA to undetectable levels (<3.7 LGE/ml) in 77.8% of patients at 12 months and in 61.3% at 24 months. Before the emergence of YMDD mutants, clinical improvement, defined as a decrease in the CPT score of 2 points or more, was apparent in 6 of 21 (29%) patients. No change in CPT score was evident in 14 of 21 patients (67%). YMDD mutants emerged in 19 of 54 (35%) patients. The cumulative emergence rates increased each year. The emergence rate of YMDD mutants in patients with HBV cirrhosis was higher than that in patients with chronic hepatitis. After the emergence of YMDD mutants, 3 of 12 (25%) patients with YMDD mutants showed CPT score increases of 2 points or more. CONCLUSIONS: Lamivudine therapy improved the clinical course in some cirrhotic patients. However, in patients with Child's B and C cirrhosis, the emergence of YMDD mutants sometimes led to deterioration of liver function.

Infection with hepatitis B virus genotype A in Tokyo, Japan during 1976 through 2001.

BACKGROUND: Because genotype A of hepatitis B virus (HBV) is not indigenous, there have been only few data on infection with it in Japan. METHODS: We examined clinical and virological features of the 66 Japanese patients who admitted Toranomon Hospital in Tokyo, Japan, between 1976 and 2001, who were found to have HBV/A infection. HBV genotype A was classified into subtype A (European type) and A' (South African type) by phylogenetic analysis of the preS1 and preS2 regions, and the S gene sequences. RESULTS: Of the 66 patients infected with HBV/A, 14 (21%) were asymptomatic carriers, 26 (39%) presented with acute hepatitis, 22 (33%) with chronic hepatitis, and 4 (6%) with liver cirrhosis. HBV/A infection persisted for more than 6 months in 5 of the 26 (19%) patients with acute hepatitis. The frequency of acute hepatitis in patients infected with HBV/A was higher after than before 1991 (2/22 [9%] vs 24/44 [55%]; P < 0.0001). The frequency of nucleotide 1858 of T was higher in asymptomatic carriers than in patients with acute hepatitis in whom infection was resolved (5/14 [36%] vs 0/21 [0%]; P = 0.008). Of the 57 patients for whom subtypes of genotype A were determined, subtype A was identified in 53 (93%) and subtype A' in only 4 (7%). All patients infected with subtype A' were persistently infected with HBV. CONCLUSIONS: HBV/A infection has become more frequent during recent years, predominantly presenting as acute hepatitis, and subtype A' is uncommon in the Tokyo metropolitan area.

Efficacy of 6-month interferon therapy in chronic hepatitis B virus infection in Japan.

BACKGROUND: In Japan, there are few studies of long-term (more than 1 month) interferon (IFN) therapy for chronic hepatitis B (CHB). In this retrospective study, we investigated the efficacy and predictors of response to 6-month IFN therapy. METHODS: We analyzed 66 Japanese patients with CHB who were treated with IFN for 6 months. They comprised patients who were hepatitis B e antigen (HBeAg)-positive (n=45) and -negative (n=21). One (2%), 8 (12%), and 51 (77%) patients were infected with hepatitis B virus (HBV) genotypes A, B, and C, respectively. Responders in patients positive for HBeAg were defined as those who showed normalization of serum alanine aminotransferase (ALT) level, HBeAg loss, and HBV DNA negativity at 6 months after completion of IFN therapy. In patients negative for HBeAg, responders were defined as those patients who showed normalization of ALT level and HBV DNA negativity at the same 6-month time point. RESULTS: Of the 45 patients with HBeAg at the commencement of IFN therapy, 9 (20%) were responders. Young patients, especially those with a high serum ALT level, were significantly more likely to respond to IFN therapy. Of the 21 patients negative for HBeAg, 13 (62%) were responders. There were no significant differences in clinical characteristics between responders and nonresponders among patients negative for HBeAg. Multivariate analyses identified HBeAg negativity and young age as independent factors associated with a positive response to 6-month IFN therapy. However, long-term follow-up of the treated patients showed a fall in the response rate. CONCLUSIONS: The response rate to 6-month IFN therapy among HBeAg-positive patients was low. However, young patients may require long-term IFN therapy.

Peripheral CD8+/CD25+ lymphocytes may be implicated in hepatocellular injuries in patients with acute-onset autoimmune hepatitis.

BACKGROUND: The mechanism of liver injuries in autoimmune hepatitis (AIH) is not fully understood, especially because the onset is insidious and the clinical courses fluctuate with spontaneous exacerbation and improvement even without immunosuppressive therapies. METHODS: Eleven patients with acute-onset AIH, some of whom were without hypergammaglobulinemia or anti-nuclear antibodies, and 41 patients with chronic AIH were compared serologically, biochemically, and histologically to determine differences in liver injuries between patients with acute-onset and chronic AIH. All patients fulfilled the diagnostic criteria according to a scoring system proposed in 1999. RESULTS: Lymphocytes with CD8+/CD25+ markers in pretreatment blood were significantly more prevalent in acute-onset than chronic AIH patients (24% vs 14%; P < 0.05). After treatment, however, CD8+/CD25+ lymphocytes were fewer in patients with acute-onset than in those with chronic AIH at 1 and 2 weeks ( P = 0.0001). No other differences were noted in clinical characteristics or immunological parameters between patients with acute-onset and those with chronic AIH. In a patient with typical acute-onset AIH, CD8+/CD25+ lymphocytes increased and decreased in parallel with the activity of liver disease. CONCLUSIONS: Activated CD8+ T lymphocytes with CD25 markers may be implicated in the development of acute-onset AIH.

YMDD mutants in patients with chronic hepatitis B before treatment are not selected by lamivudine.

Hepatitis B virus (HBV) mutants with mutations in the YMDD motif of viral DNA polymerase/reverse transcriptase are described in patients infected with HBV who have not received lamivudine therapy, but their pathogenetic potential is not clear. These mutants were detected by the polymerase chain reaction with peptide nucleic acid clamping in pretreatment sera from two patients who later received lamivudine. One patient developed acute exacerbation with hepatic encephalopathy and received lamivudine along with plasma exchange, which were effective on his illness. YIDD mutants were detected in all three pretreatment sera and both posttreatment sera from him. HBV DNA clones from pretreatment and posttreatment sera, however, did not have the same amino acid sequence. In the other patient who developed severe breakthrough hepatitis after receiving lamivudine, YIDD mutants were detected in two pretreatment and two posttreatment sera. When amino acid sequences of HBV DNA clones with the YIDD mutation were compared before and after he received lamivudine, however, they were not in accord. Hence, YIDD mutants in both patients with chronic hepatitis B before treatment were not selected by lamivudine after they had been placed on it. Numerous amino acid conversions were detected in HBV DNA clones with YIDD mutations, and some of them created stop codons in the overlapping S gene sequence. In Conclusion, HBV mutants with mutations in the YMDD motif in patients before treatment would not be selected by lamivudine or induce breakthrough hepatitis, and some of these would not be replication-competent due to stop codons in the S gene.

Hepatocellular carcinoma in noncirrhotic young adult patients with chronic hepatitis B viral infection.

BACKGROUND: The aims of this study were to define the clinical characteristics of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in young adult patients without cirrhosis and to evaluate the efficacy of interferon (IFN) therapy on HCC recurrence. METHODS: Of 187 patients with HBV-related HCC treated at our hospital, 4 had no liver cirrhosis and were less than 30 years of age (10, 22, 23, and 26 years). RESULTS: At the time of diagnosis of HCC, all cases had antibody to hepatitis B e antigen (anti-HBe) and histological staging of nontumorous liver was F0 or F1, i.e., low-grade hepatitis. The mothers of all 4 young adult patients with HCC had HBV-related liver disease. Three cases developed recurrence of HCC. In these patients, long-term intermittent IFN therapy after reresection of HCC resulted in long-term survival without recurrence for more than 3 years of follow-up. CONCLUSIONS: (1) Young adult patients with HCC are positive for anti-HBe, lack cirrhosis, and the route of infection seems to be mother-to-infant transmission. Transplacental transmission of HBV and HBV DNA integration into the cellular genomic DNA during fetal life is a possible explanation of HBV-related hepatocarcinogenesis in young adults; and (2) long-term IFN therapy seems to be useful for prevention of tumor recurrence after radical operation for HBV-related HCC.

Severe acute exacerbation of liver disease may reduce or delay emergence of YMDD motif mutants in long-term lamivudine therapy for hepatitis B e antigen-positive chronic hepatitis B.

The pretherapy factors that could influence the emergence of resistant hepatitis B virus (HBV) tyrosine-methionine-aspartate-aspartate (YMDD) motif mutants against lamivudine are not fully known in prolonged lamivudine therapy for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B. We analyzed prospectively 116 consecutive lamivudine-naïve patients who received long-term lamivudine therapy (>1 year) by using multivariate regression analyses. The cumulative HBeAg loss rates were 29, 44, and 47% at 1, 2, and 3 years of treatment, respectively. Stepwise Cox's regression analyses indicated that pretherapy viral load was a significant factor associated with HBeAg loss (P = 0.0068). The cumulative emergence rates of YMDD mutants were 23% at 1 year, 45% at 2 year, and 47% at 3 year of treatment. Stepwise Cox's regression analyses indicated that patient age and presence or absence of severe acute exacerbation of liver disease were independent significant factors associated with emergence of YMDD mutants (P = 0.018 and 0.048, respectively). For the development of virological breakthrough, patient age, the presence or absence of severe acute exacerbation, and pretherapy viral load were independent significant factors (P = 0.028, 0.043, and 0.044, respectively). Severe acute exacerbation tended to reduce or delay development of biochemical breakthrough. The present study provides important information for the development of more effective and rational long-term lamivudine therapy for HBeAg-positive chronic hepatitis B patients infected exclusively with genotype

Low rate of YMDD motif mutations in polymerase gene of hepatitis B virus in chronically infected patients not treated with lamivudine.

BACKGROUND: Lamivudine is used for the treatment of chronic hepatitis B (CH-B), and exhibits excellent antiviral activity. However, longterm administration increases the likelihood of the emergence of resistant viruses, with an accompanying relapse of hepatitis. However, recent studies have reported lamivudine-resistant viruses in patients with CH-B before such treatment. The aim of this study was to investigate whether YMDD mutants occur in nature. METHODS: The existence of lamivudine-resistant viruses was examined in 20 asymptomatic carriers of hepatitis B virus (ASC), 10 patients who lost hepatitis B surface antigen (HBsAg) during follow-up and in 20 lamivudine-treated patients with and without breakthrough hepatitis. Both polymerase chain reaction (PCR) restriction fragment length polymorphism and SMITEST hepatitis B virus (HBV)-YMDD mutation detection methods were used to detect resistant viruses. RESULTS: No YMDD mutants were detected in the sera of the 20 ASC at the initial and final medical examinations, nor were YMDD mutants detected in sera collected at the initial medical examination, about 6 months before, or immediately after the loss of HBsAg in the 10 patients. In the 20 patients treated with lamivudine, YMDD mutants were not detected in any of them before treatment, whereas mutants were detected in the sera of 10 patients during treatment. CONCLUSIONS: Our results suggest that lamivudine-resistant YMDD mutant viruses were present in a few patients with HBV infection before they have been treated with lamivudine.

Virological and biochemical relapse according to YMDD motif mutant type during long-term lamivudine monotherapy.

Whether the type of lamivudine-resistant virus in hepatitis B virus (HBV) influences the clinical outcome, it is not completely understood. We evaluated the serial changes in YMDD motif mutant in 60 Japanese genotype C-HBV patients who received long-term lamivudine monotherapy. YIDD or YVDD alone tended to stop shifting to the mixed type (YVDD and YIDD) within 12 months after the detection of mutant virus. Hence, the characteristics, virological relapse (DNA breakthrough) and biochemical relapse (breakthrough hepatitis) of 49 patients, who could be classified into three types (continuous YVDD, continuous YIDD, and the mixed type), were investigated. YVDD and YIDD type tended to have the opposite background with regard to age, histology, and viral load. The mixed and YIDD types tended to have similar backgrounds, except for viral load. In the mixed type, both the HBeAg-positive rate and viral load as risk factors for emergence of the mutant tended to be high. Mutant virus, DNA breakthrough and breakthrough hepatitis emerged significantly earlier in the mixed type than the two other types. The incidence of severe breakthrough hepatitis accompanied by icteric flare-up tended to be higher in the mixed type than the other types. Our results suggest that the YMDD motif mutant type might emerge from different backgrounds and modulate the virological and biochemical relapse after the emergence. Large-scale studies of each mutant type should be conducted in the future to confirm these findings.

Clinical features of hepatitis B virus genotype A in Japanese patients.

BACKGROUND: Hepatitis B virus (HBV) genotype A is predominant in northern Europe and central Africa. In the present study, we examined the clinical features associated with HBV genotype A disease in the Tokyo metropolitan area. METHODS: We investigated 53 cases of HBV surface antigen (HBsAg)-positive Japanese patients with HBV genotype A. The 53 cases were further classified as to their serum alanine aminotransferase (ALT) status being within the normal range (asymptomatic carriers, n = 17), chronic hepatitis (n = 15), liver cirrhosis (n = 4), and acute hepatitis (n = 17). RESULTS: Chronic hepatitis patients had significantly higher HBV DNA levels (P = 0.003) and hepatitis B e antigen (HBeAg) positivity rates at the initial visit than did asymptomatic carriers or patients with liver cirrhosis (P = 0.003 and P = 0.054, respectively). The efficacy of treatment (HBeAg seroconversion rate) was 75% in 12 chronic hepatitis patients, which was excellent. A family history of HBsAg positivity was identified in eight (15%) families (five asymptomatic carriers, three with chronic hepatitis). However, none of the mothers in the study was positive for HBV genotype A. CONCLUSIONS: Maternal transmission of HBV has often been reported in Japan, but our present findings suggest that horizontal infection of HBV genotype A is more prevalent in the Tokyo metropolitan area. Our data indicate that HBV genotype A exhibits a mode of infection different from that of conventional HBV previously seen in Japan.

Precore wild-type hepatitis B virus with G1896 in the resolution of persistent hepatitis B virus infection.

OBJECTIVE: Factors influencing the resolution of persistent hepatitis B virus (HBV) infection were sought for. METHODS: The loss of hepatitis B surface antigen (HBsAg) from serum was correlated with mutations in HBV DNA for a hepatitis B e antigen (HBeAg)-minus phenotype in patients infected with HBV genotype C and positive for HBeAg at presentation. RESULTS: HBeAg turned negative in all the 22 patients in whom HBV infection resolved, but only in 11 of the 25 patients with severe liver diseases (100 vs. 44%, p = 0.0001). The precore wild type (G1896) persisted significantly more frequently in the 22 patients in whom HBV infection resolved than in the 11 patients who developed decompensated liver cirrhosis or hepatocellular carcinoma (15/22 or 68% vs. 1/11 or 9%, p = 0.005). The double mutation in the core promoter (T1762/A1764) was comparably frequent in the two groups of patients at presentation (14/22 or 64% vs. 7/11 or 64%) and >15 years thereafter (18/22 or 82% vs. 10/11 or 91%). CONCLUSION: The precore wild type (G1896) would seem to facilitate the resolution of HBV infection, while the precore mutant (A1896) may induce severe liver diseases in patients with HBeAg-positive chronic hepatitis who have lost HBeAg from serum.

Efficacy of lamivudine therapy and factors associated with emergence of resistance in chronic hepatitis B virus infection in Japan.

OBJECTIVE: Several reports have examined the efficacy of long-term lamivudine therapy and the risk factors involved in emergence of viral resistance in Japanese patients with hepatitis B virus (HBV) infection. However, the patient cohorts in such studies are relatively small. METHODS: We analyzed 234 chronically HBV-infected Japanese patients who were treated with lamivudine for more than 12 months. They comprised patients with HBV genotype A (n = 8), genotype B (n = 21), genotype C (n = 203) and other HBV genotypes (n = 2). RESULTS: In most patients, lamivudine resulted in normalization of alanine transaminase (ALT) levels at 6 and 12 months, and suppression of serum HBV DNA to undetectable levels by the branched chain DNA probe assay (bDNA). Rates of ALT normalization and non-detection of HBV DNA were higher among patients with genotype B than genotype C disease. The proportions of patients who achieved HBeAg loss were 27, 42 and 45% after 6 months, 1 year and 2 years, respectively. The emergence of mutations was not different among genotypes A, B and C by the Kaplan-Meier method. Multivariate analyses identified high HBV DNA level (bDNA >or=100 MEq/ml) as an independent factor associated with emergence of the YMDD motif mutation in all patients. Among patients with genotype C disease, which is the predominant HBV genotype in Japan, multivariate analysis also identified high HBV DNA level and HBeAg positivity as factors associated with emergence of resistance. CONCLUSION: Patients exhibiting these factors at the commencement of lamivudine treatment must be monitored carefully at regular intervals for emergence of viral resistance.

HBe antigen loss during lamivudine therapy is not caused by mutations in precore and core promoter genes in patients with chronic hepatitis B.

HBe antigen (HBeAg) loss or seroconversion can occur during lamivudine therapy. The purpose of this study was to analyze nucleotide sequences in precore and core promoter regions, and examine the influence of mutations in these regions on the disappearance of HBeAg during lamivudine therapy. Serial serum samples were obtained from 51 patients (HBeAg loss in 26 patients) at commencement of therapy (baseline) and after 1 year of lamivudine therapy. Serum samples were amplified with PCR and nucleotide sequences of HBV were analyzed. At baseline, a precore stop codon mutation (A1896) was identified in 8 of 26 HBeAg loss patients and in 8 of 25 HBeAg non-loss patients. At 1 year, precore mutation was observed in 4 of 14 patients analyzed who showed HBeAg loss. At 1 year, however, a precore mutation was observed also in 3 of 9 analyzed patients who showed no HBeAg loss. Core promoter mutations were noted in 21 of 26 HBeAg loss patients and in 20 of 25 HBeAg non-loss patients. At 1 year, core promoter mutations were noted in 11 of 14 HBeAg loss patients and in 8 of 9 HBeAg non-loss patients. Our data suggested that during lamivudine therapy, core promoter and precore mutations do not influence HBeAg loss or seroconversion but may reduce the viral level upon HBeAg loss or seroconversion.

Viral genotypes and response to interferon in patients with acute prolonged hepatitis B virus infection of adulthood in Japan.

Acute hepatitis B virus (HBV) infection was diagnosed in 57 adults admitted to Toranomon Hospital in Tokyo, Japan. Genotypes of HBV were determined by a serological method and compared to those in 1,077 patients with chronic hepatitis B. The distribution of genotypes were: genotype A (acute, 22.8% vs. chronic, 1.9%; P < 0.00001); B (14.0% vs. 9.4%); C (43.9% vs. 87.7%, P = 0.004); D (1.8% vs. 0.2%); F (1.8% vs. 0.2%); and unable to be typed (15.8% vs. 0.6%, P = 0.001). The infection persisted in seven (12%) of them. They included six (86%) of the seven patients who received prednisolone or glycyrrhizin during an acute phase of illness and one of the 41 (2%) who did not (P = 0.01). Interferon was given to the seven patients with acute prolonged HBV infection, and four of them responded by clearing hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) from serum. Of the four responders, one was infected with HBV genotype B and three with genotype C. HBsAg persisted in the remaining three patients all of whom were infected with HBV genotype A, and HBeAg stayed positive in one of them. These results indicate that HBV genotype A prevails in Japanese patients with acute hepatitis B, and suggest a high efficacy of interferon in the adult patients with acute prolonged HBV infection, except in those infected with HBV genotype A.