Correlation of YMDD mutation and breakthrough hepatitis with hepatitis B virus DNA and serum ALT during lamivudine treatment

Elimination of the hepatitis B virus: A goal, a challenge

The hepatitis B elimination is a goal proposed by the WHO to be achieved by 2030 through the adoption of synergistic measures for the prevention and chronic HBV infection treatment. Complete cure is characterized by the HBV elimination from the body and is the goal of the chronic hepatitis B treatment, which once achieved, will enable the hepatitis B elimination. This, today, has been a scientific challenge. The difficulty in achieving a complete cure is due to the indefinite maintenance of a covalently closed episomal circular DNA (cccDNA) reservoir and the maintenance and persistence of an insufficient and dysfunctional immune response in chronically infected patients. Among the measures adopted to eliminate hepatitis B, two have the potential to directly interfere with the virus cycle, but with limited effect on HBV control. These are conventional vaccines-blocking transmission and antiviral therapy-inhibiting replication. Vaccines, despite their effectiveness in protecting against horizontal transmission and preventing mother-to-child vertical transmission, have no effect on chronic infection or potential to eliminate the virus. Treatment with antivirals suppresses viral replication, but has no curative effect, as it has no action against cccDNA. Therapeutic vaccines comprise an additional approach in the chronic infection treatment, however, they have only a modest effect on the immune system, enhancing it temporarily. This manuscript aims to address (1) the cccDNA persistence in the hepatocyte nucleus and the immune response dysfunction in chronically infected individuals as two primary factors that have hampered the treatment and HBV elimination from the human body; (2) the limitations of antiviral therapy and therapeutic vaccines, as strategies to control hepatitis B; and (3) the possibly promising therapeutic approaches for the complete cure and elimination of hepatitis B.

Dynamic profile of the HBeAg-anti-HBe system in acute and chronic hepatitis B virus infection: A clinical-laboratory approach

Wild-type HBV infection is followed by the blood expression of its widely known serological markers of infection, and designated as, hepatitis B virus surface antigen (HBsAg) and its antibody (anti-HBs), anti-HBc antibodies (IgM/IgG), and hepatitis B virus 'e' antigen (HBeAg) and its antibody (anti-HBe). These markers are detected as the infection develops and its kinetic behavior serves as a basis for monitoring the disorder and for diagnosing the clinical form or infection phase. Among these, the HBeAg-anti-HBe system markers demonstrate a dynamic profile whose interpretation, both in the acute or chronic HBV infection context, can offer greater difficulty to the health professionals, due to its particularities. This review offers a revisit to the markers dynamics of this system in the acute and chronic HBV infection and to the clinical and laboratory significance of its expression in these two clinical contexts.

The association between serum cytokine and chemokine levels and antiviral response by entecavir treatment in chronic hepatitis B patients

BACKGROUND

Although nucleoside/nucleotide analogue therapy is thought to suppress chronic hepatitis B (CHB) via regulation of inflammatory cytokines/chemokines, the mechanism is still unclear. In this study, serum cytokine/chemokine levels were measured in CHB patients treated with entecavir, and the association with antiviral response was analysed.

METHODS

A total of 78 Japanese patients with CHB were enrolled, and serum cytokine/chemokine levels were measured at baseline and at 12, 24 and 48 weeks of entecavir treatment using the MULTIPLEX kit.

RESULTS

Antiviral response to entecavir treatment was significantly associated with hepatitis B surface antigen (HBsAg) titre and serum interferon-gamma-inducible protein 10 (IP-10) level (12w; P=0.0002; OR=0.020 [95% CI 0.002, 0.156], P=0.003; OR=0.042 [95% CI 0.005, 0.336], respectively). HBe-positive patients whose serum macrophage-derived chemokine (MDC) level was lower (<582.83 pg/ml) and IP-10 level was higher (≥1,323.13 pg/ml) achieved hepatitis B e antigen (HBeAg) loss earlier than those who remained HBeAg-positive (P=0.044). HBsAg reduction by entecavir treatment was significantly associated with higher initial tumour necrosis factor-alpha (TNF-α) level (≥15.20 pg/ml) and higher alanine aminotransferase level (≥73 IU/l; P=0.009; OR=18.460 [95% CI 2.044, 166.709], P=0.022; OR=7.709 [95% CI 1.341, 44.327], respectively).

CONCLUSIONS

Results of the present study indicate that changes in cytokine/chemokine levels following entecavir therapy are associated with response to antiviral therapy in CHB patients. Monitoring of serum cytokine/chemokine levels could be useful for predicting reduction of HBV DNA and HBsAg and HBe seroconversion.

Endoplasmic reticulum-mediated induction of interleukin-8 occurs by hepatitis B virus infection and contributes to suppression of interferon responsiveness in human hepatocytes

The events in the immune response to hepatitis B virus (HBV) remain unclear. We analyzed the direct influence of HBV on gene expression in human hepatocytes under immunodeficient conditions using a human hepatocyte chimeric mouse model. HBV-infected or non-infected chimeric mouse livers were collected, and gene expression profiles were compared. Since IL-8 was the most significantly up-regulated gene at 8 weeks after HBV infection, we focused on IL-8 and found that HBx and the large HBs (L-HBs) protein induce transcription of IL-8 via endoplasmic reticulum stress. This stress induces IL-8 transcription via NFAT activation and contributes to suppression of interferon responsiveness in HBV-infected human hepatocytes. In the present study, we identified a novel regulatory mechanism in which the L-HBs protein activates IL-8 via endoplasmic reticulum stress, suggesting a key role for IL-8 in the immune response to HBV and a potential new target for antiviral treatments of HBV infection.

Tenofovir disoproxil fumarate is superior to lamivudine plus adefovir in lamivudine-resistant chronic hepatitis B patients

AIM: To assess the efficacy of tenofovir disoproxil fumarate (TDF) in lamivudine (LAM)-resistant patients with a suboptimal response to LAM plus adefovir (ADV).

METHODS: We retrospectively analyzed the efficacy of switching to tenofovir disoproxil fumarate in suboptimal responders to lamivudine plus adefovir. Charts were reviewed for LAM-resistant chronic hepatitis B (CHB) patients who visited the Zhejiang Province People’s Hospital and The First Affiliated Hospital, College of Medicine, Zhejiang University, from June 2009 to May 2013. Patients whose serum hepatitis B virus (HBV) DNA remained detectable despite at least 6 mo of LAM plus ADV combination therapy were included. Patients with a suboptimal response to LAM plus ADV were randomized to switch to TDF monotherapy (300 mg/d orally; TDF group) or to continuation with LAM (100 mg/d orally) plus ADV (10 mg/d orally; LAM plus ADV group) and were followed for 48 wk. Serum HBV DNA was determined at baseline and weeks 4, 12, 24, 36, and 48. HBV serological markers and biochemistry were assessed at baseline and weeks 12, 24, and 48. Resistance surveillance and side effects were monitored during therapy.

RESULTS: Fifty-nine patient were randomized to switch to TDF (n = 28) or continuation with LAM plus ADV (n = 31). No significant differences were found between the groups at baseline. Prior to TDF therapy, all patients had been exposed to LAM plus ADV for a median of 11 mo (range: 6-24 mo). No difference was seen in baseline serum HBV DNA between the two groups [5.13 ± 1.08 log₁₀ copies/mL (TDF) vs 5.04 ± 31.16 log₁₀ copies/mL (LAM + ADV), P = 0.639]. There was no significant difference in the rates of achieving complete virological response (CVR) at week 4 between the TDF and LAM + ADV groups (17.86% vs 6.45%, P = 0.24). The rate of achieving CVR in the TDF and LAM plus ADV groups was 75% vs 16.13% at week 12, 82.14% vs 22.58% at week 24, 89.29% vs 25.81% at week 36, and 96.43% vs 29.03% at week 48, respectively (P < 0.001). The rate of alanine aminotransferase normalization was significantly higher in the TDF than in the LAM plus ADV group at week 12 (75% vs 17.86%, P < 0.001), but not at week 24 (78.57% vs 54.84%, P = 0.097) or 48 (89.26% vs 67.74%, P = 0.062). Patients were hepatitis B e antigen (HBeAg) positive at baseline. There was no significant difference in HBeAg negativity between the TDF and LAM plus ADV groups at week 48 (4% vs 0%, P = 0.481). There were no drug-related adverse effects at week 48 in either group.

CONCLUSION: Switching to TDF monotherapy was superior to continuous add-on therapy in patients with LAM-resistant CHB with a suboptimal response to LAM plus ADV.

Serum HBV RNA and HBeAg are useful markers for the safe discontinuation of nucleotide analogue treatments in chronic hepatitis B patients

BACKGROUND

Treatment for chronic hepatitis B has improved drastically with the use of nucleot(s)ide analogues (NAs). However, NA therapy typically fails to eliminate Hepatitis B virus (HBV) completely, and it is difficult to discontinue these therapies. We previously demonstrated that NA therapy induced immature viral particles, including HBV RNA in sera of chronic hepatitis B patients. In the study reported here, we analyzed the association between HBV RNA titer and the recurrence rate of hepatitis after discontinuation of NA therapy.

METHODS

The study cohort comprised 36 patients who had discontinued NA therapy. Serum HBV DNA or DNA plus RNA levels were measured by real time PCR and statistical analyses were performed using clinical data and HBV markers.

RESULTS

At 24 weeks after discontinuation of NA therapy, HBV DNA rebound was observed in 19 of the 36 patients (52.8 %), and alanine aminotransferase (ALT) rebound was observed in 12 of 36 patients (33.3 %). Multivariate statistical analysis was used to identify factors predictive of HBV DNA rebound. The HBV DNA + RNA titer following 3 months of treatment was significantly associated with HBV DNA rebound [P = 0.043, odds ratio (OR) 9.474, 95 % confidence interval (CI) 1.069-83.957)]. Absence of hepatitis B e antigen (HBeAg) at the end of treatment was significantly associated with ALT rebound (P = 0.003, OR 13.500, 95 % CI 2.473-73.705). In HBeAg-positive patients, the HBV DNA + RNA titer after 3 months of treatment was marginally associated with ALT rebound (P = 0.050, OR 8.032, 95 % CI 0.997-64.683).

CONCLUSIONS

Monitoring of serum HBV DNA + RNA levels may be a useful method for predicting re-activation of chronic hepatitis B after discontinuation of NA therapy.

Hepatitis B e antigen predicts delayed reduction of HBV DNA without viral breakthrough with adefovir dipivoxil and lamivudine: a 5-year study of patients with hepatitis B with lamivudine resistance

To clarify the factors associated with delayed reduction of HBV DNA during combination treatment with adefovir dipivoxil (ADV) and lamivudine (LAM) for patients with LAM-resistant hepatitis B virus (HBV), factors including patient characteristics, viral mutations, and drug metabolism were investigated during a 5-year observation period. Delayed reduction of HBV DNA was defined as delayed viral response of detectable HBV DNA after 3 years of combination therapy. Of 67 consecutive patients, 47 attained undetectable HBV DNA after 3 years of combination therapy, and the mean therapeutic duration was 5 years (range: 3.0-8.4 years). The patients with delayed viral response had high levels of HBV DNA and HBe antigen, while those with negative or low levels of HBe antigen were also negative for HBV DNA, even if they had high levels of HBV DNA. In the multivariate analysis with the proportional hazards model, a high baseline level of HBe antigen was negatively associated with viral decline to an undetectable level (P = 0.013). A higher baseline of HBe antigen corresponded to a lower annual decline in HBV DNA (R = -0.38, P = 0.004). No patients showed ADV-resistant mutations in the HBV reverse transcriptase region. Trough concentrations of LAM and ADV showed no clear associations with viral response. HBe antigen levels at the initiation of therapy, and reductions in these levels during therapy are predictive of the therapeutic response to combination therapy with ADV and LAM for patients with LAM-resistant HBV.

Correlation between pretreatment viral sequences and the emergence of lamivudine resistance in hepatitis B virus infection

The emergence of amino acid or nucleotide substitutions leads to lamivudine resistance in hepatitis B virus (HBV) infected patients. The aim of this study was to investigate whether viral sequences help predict the emergence of lamivudine resistance. The study subjects comprised 59 consecutive patients infected with HBV treated with daily therapy of 100 mg lamivudine. Among those, 32 patients with adequate pretreatment serum preservation were investigated for the correlation between viral amino acid substitutions and the appearance of lamivudine resistance with consideration of clinical background by determining dominant HBV full open reading frames. Viral resistance to lamivudine emerged in 28 of 59 patients (47%) in a median period of 2.45 years. Sequence comparisons of HBV genomes between patients who later developed lamivudine resistance and patients who did not revealed the existence of significant differences between the two groups in the pre-S1 84 (P = 0.042), pre-S2 1 (P = 0.017) and 22 (P = 0.015), and polymerase tp 95 (P = 0.046), judged by a log-rank test. Viral sequence analyses revealed the presence of amino acid substitutions in HBV pre-S1 and pre-S2 that may be associated with the emergence of lamivudine resistance during chronic HBV infection.

Correlation of the occurrence of YMDD mutations with HBV genotypes, HBV-DNA levels, and HBeAg status in Chinese patients with chronic hepatitis B during lamivudine treatment

BACKGROUND

Continuous lamivudine therapy is associated with high rates of YMDD mutations, which are the main causes of drug resistance. The current study explores the association of the emergence of YMDD mutations with pretherapy HBV genotype, HBV-DNA levels, HBeAg status, and serum alanine aminotransferase (ALT) levels in Chinese patients receiving lamivudine therapy for chronic hepatitis B.

METHODS

A total of 319 chronic hepatitis B patients who received lamivudine therapy for more than a year were enrolled in this study. YMDD mutations, HBV genotype, HBV-DNA levels, HBeAg status, and ALT levels were determined prior to their lamivudine treatment and every three months for a year of this therapy.

RESULTS

Among the 319 patients, 137 (42.95%) were infected with genotype B and 182 (57.05%) with genotype C. Up to 94 patients (29.47%) developed YMDD mutations within one year of lamivudine therapy. Furthermore, 50 patients with HBV genotype B and 44 patients with genotype C developed YMDD mutations (36.50% vs 24.18%, P<0.05). Logistic regression analysis showed that pretherapy HBV genotype, HBV-DNA levels, and HBeAg status are independent factors for the emergence of YMDD mutations (HBV genotype: OR=2.159, 95% CI 1.291-3.609, P=0.003; HBV-DNA: OR=1.653, 95% CI 1.231-2.218, P=0.001; HBeAg: OR=2.021, 95% CI 1.201-3.399, P=0.008).

CONCLUSIONS

HBV genotype, HBV-DNA levels, and HBeAg status at baseline are the independent factors associated with the emergence of YMDD mutations among Chinese patients receiving lamivudine therapy for chronic hepatitis B. These findings are helpful to the development of therapeutic strategies for these patients.

Longitudinal assessment of liver stiffness by transient elastography for chronic hepatitis B patients treated with nucleoside analog

AIM

  To evaluate the association between liver stiffness measured by transient elastography (FibroScan) and the efficacy of long-term nucleoside analog (NA) treatment for patients with chronic hepatitis B.

METHODS

  Study 1: Forty-four chronic HBV patients had liver stiffness measured by FibroScan and underwent liver biopsy. Study 2: Group A: 22 patients started NA treatment at entry and FibroScan was done annually for 3 years. Group B: 23 patients started NA treatment prior to pretreatment FibroScan measurement, and FibroScan was done for from 3 to 5 years after the start of NA treatment.

RESULTS

  Study 1: The FibroScan values were significantly correlated with fibrosis stage (r = 0.672, P < 0.0001). Optimal cutoff of FibroScan values were 6.1 kPa for ≥ F1, 6.3 kPa for ≥ F2, 8.9 kPa for ≥ F3 and 12.0 kPa for F4. Study 2: For Group A, the baseline median FibroScan value was 8.2 kPa. FibroScan values significantly decreased annually for 3 years after the start of NA treatment (6.4 kPa, 5.8 kPa and 5.3 kPa at years 1, 2 and 3, respectively). For Group B, the FibroScan values did not significantly improve over the 3 years after the start of NA treatment.

CONCLUSIONS

  Liver stiffness, measured by transient elastography, of chronic hepatitis B patients treated with NA showed a rapid decline in the first 3 years followed by a more steady transition for from 3 to 5 years irrespective of long term virological effect.

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.