Efficacy and safety of telbivudine in different trimesters of pregnancy with high viremia for interrupting perinatal transmission of hepatitis B virus

Addressing hepatitis delta in primary care practices in the US: a narrative review

OBJECTIVE

Infection with the hepatitis delta virus (HDV), a unique RNA virus that requires hepatitis B virus (HBV) antigens for its assembly, replication, and transmission, causes severe viral hepatitis. Compared to HBV monoinfection, HDV infection increases the risk of severe liver disease, necessity for liver transplant, and mortality. Global HDV prevalence estimates vary from 5% to 15% among persons with HBV, but screening guidelines for HDV are inconsistent; some recommend risk-based screening, while others recommend universal screening for all people with HBV. Among primary care providers (PCPs) in the US, there is a lack of awareness and/or insufficient adherence to current recommendations for the screening of HDV infection and management of chronic HDV.

METHODS

Publications were obtained by conducting literature searches between July and August 2022 using the PubMed database and by manual searches of the retrieved literature for additional references. Information was synthesized to highlight HDV screening and management strategies for PCPs. Best practices for PCPs based on current guidelines and comanagement strategies for patients with HBV and HDV infection were summarized.

RESULTS

We recommend universal screening for HDV in patients positive for hepatitis B surface antigen. Confirmed HDV infection should prompt evaluation by a liver specialist, if available, with whom the PCP can comanage the patient. PCPs should counsel patients on the expected course of the disease, lifestyle factors that may influence liver health, need for consistent disease monitoring and follow-up, and risk of disease transmission. Screening is suggested for sexual partners, household contacts, and family members, with HBV immunization recommended for those found to be susceptible. There are currently no US Food and Drug Administration-approved therapies for HDV infection; thus, management is limited to treatments for chronic HBV infection plus long-term monitoring of liver health.

CONCLUSIONS

PCPs can be a valuable point of care for patients to access HDV/HBV screening, HBV immunization, and education, and can comanage patients with HBV and/or HDV infection.

Maternal-to-Child Transmission of Hepatitis B Virus and Hepatitis Delta Virus

Maternal-to-child transmission of hepatitis B virus (HBV) and hepatitis delta virus (HDV) can lead to the risk of progressive liver disease in infants, but fortunately effective interventions exist to decrease transmission. Counseling on the risk of maternal-to-child transmission, care pathways to decrease transmission, and the implications of HBV and HDV on pregnancy outcomes are the key components of caring for pregnant people living with HBV and HDV.

Overview of the development of HBV small molecule inhibitors

Like tuberculosis and Acquired Immune Deficiency Syndrome (AIDS), hepatitis B is a globally recognized major public health threat. Although there are many small-molecule drugs for the treatment of hepatitis B, the approved drugs cannot eradicate the pathogenic culprit covalently closed circular DNA in patients, so the patients need long-term medication to control HBV amplification. Driven by a high unmet medical need, many pharmaceutical companies and research institutions have been engaged in the development of anti-HBV drugs to achieve a functional cure for chronic hepatitis B as soon as possible. This review summarizes the pathogenesis of hepatitis B virus and the research progress in the development of anti-HBV small molecule drugs, and introduces the cccDNA formation and transcription inhibitors and core inhibitors in detail, especially emphasizes the role of chinese herbal medicine in the treatment of chronic hepatitis B. Furthermore, this review proposes three potential strategies for cccDNA eradication in the future. We believe this review will provide meaningful guidance to achieve a functional cure for viral hepatitis B in the future.

Tenofovir alafenamide in blocking mother-to-child transmission of hepatitis B virus: a multi-center, prospective study

BACKGROUND

Data of tenofovir alafenamide (TAF) in preventing mother-to-child transmission (MTCT) of hepatitis B virus (HBV) are limited. This study aimed to evaluate the effectiveness and safety of TAF for preventing MTCT.

METHODS

Pregnant women with chronic HBV infection, positive for HBeAg and high-level HBV DNA, received oral TAF from gestational weeks 24-28 until postpartum week 4. All infants received HBV immunoprophylaxis. All mothers and infants were followed up until postpartum seven month. The primary outcome was the rate of MTCT at seven month.

RESULTS

Eighty-nine mothers delivered and 91 infants were born. All were followed up to postpartum seven month. TAF was initiated at a mean gestational age of 25.0 (±1.0) weeks with the mean treatment duration of 14.3 (±1.2) weeks before delivery; 92.1% (82/89) mothers discontinued TAF, the median [IQR] time was 5.9 [4.7] weeks postpartum. The HBsAg positive rate was 0% at seven months in 91 infants, no growth retardation and congenital defects. All mothers were tolerated during TAF treatment. At delivery, 82.02% (73/89) mothers achieved HBV DNA < 200,000 IU/ml, 21.35% (19/89) achieved HBV DNA < 500 IU/ml. No significant changes on the mean (±SD) serum phosphate between baseline (1.20 ± 0.10 mmol/L) and at delivery (1.21 ± 0.13 mmol/L, p > .05). Serum creatinine at delivery (52.23 ± 8.50 µmol/L) was higher than baseline (45.97 ± 5.60 µmol/L, p < .05), but within normal range. Nine of 82 mothers stopped TAF treatment after delivery had mild ALT elevation.

CONCLUSION

TAF therapy initiated during the second trimester was effective in preventing MTCT with no safety concerns for mothers and infants (ClinicalTrials.gov number, NCT04065230).

Safety and Efficacy of Tenofovir Alafenamide Fumarate in Early-Middle Pregnancy for Mothers With Chronic Hepatitis B

Background

Tenofovir alafenamide fumarate has been used in late pregnancy; however, no data exist regarding its safety and effectiveness in early and middle pregnancy for mothers with hepatitis B virus infection.

Aims

To design a prospective study to investigate the efficacy and safety of TAF in pregnant women with chronic HBV infection during early-middle pregnancy.

Methods

Pregnant women with active chronic hepatitis B who received tenofovir alafenamide fumarate during early and middle pregnancy were enrolled and followed up until 6 months postpartum. Infants received immunoprophylaxis. The primary endpoint was the safety of mothers and infants. The secondary endpoints were maternal hepatitis B virus DNA reduction at delivery and mother-to-child transmission rate.

Results

Among 98 mothers enrolled, 31 initiated tenofovir alafenamide fumarate in early pregnancy, and 57 in middle pregnancy. The mean (± standard deviation) age was 29.00 (±3.81) years. At delivery, 100% (98/98) of the mothers achieved hepatitis B virus DNA levels <200,000 IU/L. Ninety-eight infants were born, and none had congenital defects or malformations. All infants received hepatitis B virus immunoprophylaxis. The mother-to-child transmission rate was 0%. Growth parameters including body weight, height, and head circumference were comparable to the national standards for physical development. No severe adverse effects were reported in either mothers or infants. No severe liver function damage occurred in any of the mothers.

Conclusions

Initiating tenofovir alafenamide fumarate in early and middle pregnancy appears safe for both mothers and infants, and it is effective for controlling maternal disease as well as interrupting mother-to-child transmission.

Comparison of the efficacy and safety of tenofovir and telbivudine in interrupting mother-to-child transmission of hepatitis B virus

The present study is aimed to evaluate and compare the efficacy and safety of tenofovir (TDF) and telbivudine (TBV) in interrupting hepatitis B virus (HBV) mother-to-child transmission (MTCT), and to provide evidence-based treatment options to clinicians and patients.Hepatitis B e-antigen (HBeAg)-positive pregnant women (644 in total) with high HBV DNA load (≥2 × 105 IU/mL) and who received TDF (n = 214) or TBV (n = 380) in the second or third trimester, or received no treatment (n = 50) were included in this retrospective analysis.HBV DNA levels in mothers at delivery were significantly lower than baseline in the 2 treatment groups. HBV DNA levels in the TDF group were significantly different between the mothers receiving treatment in the second trimester and those receiving treatment in the third trimester; however, significant difference was not observed in the TBV group. The proportion of hepatitis B surface antigen (HBsAg)-positive infants at the age of 7 to 12 months in the TDF, TBV, and control groups were 0.00% (0/174), 0.30% (1/331), and 5.0% (2/40) with a significant difference between the treatment groups and the control group, but no difference between the TDF and TBV group (P > .05). However, no serious adverse events were observed in infants and mothers of all groups.TBV and TDF can effectively reduce the HBV DNA level and MTCT rate in pregnant women with high HBV DNA load (≥2 × 105 IU/mL); both antiviral drugs are safe for infants and mothers. Since TDF was more effective in reducing HBV DNA levels during the second trimester, its use during the period is recommended to prevent HBV MTCT.

Vertical transmission of hepatitis B virus: propositions and future directions

ABSTRACT

Chronic hepatitis B virus (HBV) infection due to vertical transmission remains a critical concern with regards to eliminating HBV infection. Implementation of hepatitis B vaccine, the foundation to prevent perinatal and horizontal transmission, has reduced the prevalence of HBV by >80%. In countries where the hepatitis B immune globulin (HBIG) is available, such as China and the United States, the administration of HBIG and hepatitis B vaccine to the infants of mothers who are positive for hepatitis B surface antigen has become a standard practice and is effective in preventing vertical transmission. Accumulating evidence on the efficacy and safety of antiviral prophylaxis during pregnancy indicates the probability of attaining the goal of the World Health Organization to eliminate hepatitis by 2030. In this review, we discuss the transmission routes, diagnostic criteria, and preventive strategies for vertical transmission. A preventive program that includes screening before pregnancy, antiviral prophylaxis during pregnancy, and postpartum immunoprophylaxis provides "perfect strategies" to eliminate vertical transmission. However, there is still a notable gap between "perfect strategies" and real-world application, including insufficient coverage of timely birth dose vaccine and the efficacy and necessity of HBIG, especially in mothers who are negative for hepatitis B envelope antigen. In particular, there is a clear need for a comprehensive long-term safety profile of antiviral prophylaxis. Therefore, feasible and cost-effective preventive strategies need to be determined across regions. Access also needs to be scaled up to meet the demands for prophylaxis and prevalence targets.

Hepatitis B Virus Infection in Pregnancy: An Update on Evidence-Based Management

Importance

Vertical hepatitis B virus (HBV) transmission is the important route of chronic HBV infection. Although infant immunoprophylaxis is effective, a significant number of infants still become infected, most are associated with intrauterine infection. New evidences support intrauterine treatment in cases of high risk.

Objective

The aim of this study was to review the current evidences and recommendations for management of HBV infection in pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines were reviewed.

Results

The management can be summarized as follows: (1) all pregnant women should be screened for hepatitis B surface antigen (HBsAg) and antibody to HBsAg. High-risk HBsAg-negative pregnant women without immunity should be vaccinated during pregnancy. (2) HBsAg-positive pregnant women should undergo further workup for liver status and indicative factors for immunoprophylaxis failure. (3) Pregnant women should be treated with HBV DNA levels greater than 200,000 IU/mL or 6 log copies/mL. (4) Antiviral drug should be started around 28 to 32 weeks. The first-line drug is tenofovir disoproxil fumarate. (5) Delivery route should be chosen based only on obstetric indications. (6) Breastfeeding is not contraindicated because it does not increase the risk of transmission in neonates with HBV vaccine and immunoglobulin administration. (7) Neonates born to HBsAg-positive mothers should receive HBV vaccine and immunoglobulin after birth as soon as possible. (8) Follow-up of the mothers and neonates is important. Beware of hepatitis flare after birth and after antiretroviral drug discontinuation; alanine transaminase assessment every 1 to 3 months until 6 months is suggested. Also, the schedule of infant vaccination and follow-up of serologic testing at 9 to 12 months old is needed.

High Prevalence of Preexisting HBV Polymerase Mutations in Pregnant Women Does Not Limit the Antiviral Therapy Efficacy

Background

HBV-resistant mutants in treatment-naïve patients may lead to antiviral treatment failure. It is not clear if HBV mutants are present in pregnant women and about the influence of the preexisting mutants on the short-term antiviral therapy during pregnancy.

Method

We enrolled 73 pregnant women with high HBV DNA load and telbivudine (TBV) treatment during pregnancy in this retrospective study. The UDPS was used to detect the HBV mutations before and after the TBV treatment.

Results

Before TBV treatment, the complexity of HBV quasispecies of all subjects was 0.40 ± 0.09; 41.1% (30/73) and 53.4% (39/73) subjects had rtM204I/V and rtN236 T/A detected, respectively; and 9.6% (7/73) patients had more than 20% frequency mutation of rtM204I/V, which was also similar with high frequency of rtN236 T/A mutation (41.1% vs. 53.4%, P=0.136; frequencies >20%: 9.6% vs. 5.5%, P=0.347). After TBV treatment, 71.2% (52/73) subjects had HBV DNA load ≥ 10³ IU/mL at delivery. Among them, 75.0% of patients with rtM204I positive had HBV DNA load ≥10³ IU/mL at delivery, which was comparable with the subjects without rtM204I (75.0% vs. 70.8%, P=0.710). No changes were found in the frequencies and the complexity of HBV quasispecies of rtM204I mutation after the TVB treatment.

Conclusion

The prevalence of preexisting drug-resistant mutations among pregnant women was high using UPDS. However, the preexisting HBV mutation had limited influence on the efficacy of short-term TBV treatment, and TBV treatment during late pregnancy seemed not to increase the risk of emerging HBV-resistant mutants.

Efficacy and safety of antiviral prophylaxis during pregnancy to prevent mother-to-child transmission of hepatitis B virus: a systematic review and meta-analysis

BACKGROUND

To eliminate mother-to-child transmission (MTCT) of hepatitis B virus (HBV), peripartum antiviral prophylaxis might be required for pregnant women infected with HBV who have a high risk of MTCT despite infant immunoprophylaxis. We aimed to determine the efficacy and safety of peripartum antiviral prophylaxis to inform the 2020 WHO guidelines.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, CENTRAL, CNKI, and Wanfang for randomised controlled trials and non-randomised studies of peripartum antiviral prophylaxis versus placebo or no prophylaxis, with no language restriction, published from database inception until March 28, 2019. We used search terms covering HBV, antiviral therapy, and pregnancy. We included studies that enrolled pregnant women with chronic infection with HBV who received antiviral prophylaxis anytime during pregnancy; that included any of the following antivirals: adefovir, emtricitabine, entecavir, lamivudine, telbivudine, tenofovir alafenamide fumarate, and tenofovir disoproxil fumarate; and that reported the following outcomes: MTCT, indicated by infant HBsAg positivity or HBV DNA positivity, or both, at age 6-12 months, and any infant or maternal adverse events. Two reviewers independently extracted data. Our primary endpoint was MTCT based on infant HBsAg positivity. We assessed pooled odds ratios (ORs) of the efficacy of peripartum antiviral prophylaxis to reduce the risk of MTCT. We assessed safety of prophylaxis by pooling risk differences. The protocol for the systematic review was pre-registered in PROSPERO, CRD42019134614.

FINDINGS

Of 7463 articles identified, 595 articles were eligible for full-text review and 129 studies (in 157 articles) were included. The following antivirals were assessed in the meta-analysis: tenofovir disoproxil fumarate 300 mg (19 studies, with 1092 mothers and 1072 infants), lamivudine 100-150 mg (40 studies, with 2080 mothers and 2007 infants), and telbivudine 600 mg (83 studies, with 6036 mothers and 5971 infants). The pooled ORs for randomised controlled trials were similar, at 0·10 (95% CI 0·03-0·35) for tenofovir disoproxil fumarate, 0·16 (0·10-0·26) for lamivudine, and 0·14 (0·09-0·21) for telbivudine. The pooled ORs in non-randomised studies were 0·17 (0·10-0·29) for tenofovir disoproxil fumarate, 0·17 (0·12-0·24) for lamivudine, and 0·09 (0·06-0·12) for telbivudine. We found no increased risk of any infant or maternal safety outcomes after peripartum antiviral prophylaxis.

INTERPRETATION

Peripartum antiviral prophylaxis is highly effective at reducing the risk of HBV MTCT. Our findings support the 2020 WHO recommendation of administering antivirals during pregnancy, specifically tenofovir disoproxil fumarate, for the prevention of HBV MTCT.

FUNDING

World Health Organization.

Efficacy and safety of antiviral therapy for HBV in different trimesters of pregnancy: systematic review and network meta-analysis

BACKGROUND

Several antiviral agents licenced for blocking mother-to-child transmission (MTCT) of HBV, but their relative efficacy beginning from different trimesters has scarce been evaluated. We aimed to conduct a network meta-analysis to statistically differ the efficacy and safety of each antiviral agents initiating on different timings in preventing mother-to-infant transmission of HBV.

METHODS

Studies were included from PubMed, EMBASE, Web of Science, and Cochrane databases through July 1, 2019. Eligible studies recruited randomized controlled trials and nonrandomized studies reporting about infant or/and maternal efficacy and safety outcomes and were screened by two investigators independently. Extracted data were analyzed by pair-wised and network meta-analysis, respectively.

RESULTS

3 Randomized and 32 nonrandomized studies enrolling 6738 pregnant female were included. Using network analysis, any antiviral agent interrupted HBV vertical transmission much more effectively than placebo. No agent showed significant efficacy different from others, but a strong trend toward significance was found in telbivudine and tenofovir, of which had the highest probability of being ranked the first- or second-best treatment for reducing MTCT of HBV. The treatment applied in the first and second trimester had a similar efficacy in preventing MTCT. Compared with the initiation during the third trimester, lower rate of MTCT was revealed when antiviral therapy was administrated before third trimester, (RR = 0.045, 95% CI 0.0053 to 0.20); a similar effect at delivery on suppressing maternal HBV DNA level and converting serum HBeAg were achieved if the timing of antiviral treatment started prior, but an obvious improvement of normalizing ALT flare was calculated out; no statistically differences among maternal and fetal safety outcomes were found if mothers received antiviral agents before pregnant 28 weeks.

CONCLUSION

This network meta-analysis recommended the earlier use of telbivudine or tenofovir, tends to be better to prevent MTCT of HBV in pregnancy with no increased adverse maternal or fetal outcomes.

Efficacy of antiviral therapy during the second or the third trimester for preventing mother-to-child hepatitis B virus transmission: a systematic review and meta-analysis

For pregnant women with high viral load, antiviral therapy has been administered in addition to active and passive immune prophylaxis as a crucial adjunctive therapy to interrupt mother-to-child hepatitis B virus (HBV) transmission (MTCT). However, the time of antiviral therapy onset remains controversial. A systematic review and meta-analysis was conducted to compare the efficacy of antiviral therapy during the second or the third trimester for prevention of HBV vertical transmission. We searched nine databases for observational studies and randomized controlled trials that enrolled pregnant women with positive HBsAg treated with antivirals. The outcomes of interest were maternal HBV-DNA levels prior to delivery and the rates of HBV MTCT. We included nine studies that enrolled 1,502 pregnant women. The average HBV-DNA level before treatment was approximately 8 log₁₀ copies/mL. Compared to the onset of antiviral intervention in the third trimester, the beginning of treatment in the second trimester distinctly reduced maternal predelivery HBV-DNA levels. However, no significant difference in HBV MTCT was found between the second and third trimester groups. Furthermore, the subgroup analysis showed that there were no significant differences between groups beginning treatment at different times (second or third trimester) with regard to HBV MTCT or other evaluated endpoints. For pregnant women with HBV-DNA levels less than or equal to 8 log₁₀ copies/mL, the beginning of antiviral treatment can be delayed until the third trimester.

Comparing the Efficacy and Safety of Treating Chronic Hepatitis B Infection during Pregnancy with Lamivudine, Telbivudine, and Tenofovir: A Meta-analysis

Background and Aims: The perinatal transmission of hepatitis B virus (HBV) remains an important global health problem. Here, a systematic review and meta-analysis were conducted to evaluate the evidence regarding the efficacy and maternal/fetal safety of treating pregnant women with lamivudine, telbivudine (LdT), and tenofovir (TDF). Methods: A PubMed and Scopus search resulted in 1,076 records, which were reduced to 36, containing 7,717 pregnant women with chronic HBV infection and 7467 infants meeting the inclusion criteria. The latest search was in August 2019. Results: Treatment with LdT, but not lamivudine and TDF, could significantly reduce the hepatitis B virus surface antigen-positive rate (odds ratio (OR) = 0.37) in infants; it also led to higher rates of hepatitis B e antigen loss (OR = 12.14), hepatitis B e antigen seroconversion (OR = 8.93), and alanine aminotransferase normalization in mothers (OR = 1.49). Each of these treatments was able to significantly reduce HBV DNA positivity at birth (total OR = 0.19) and mother-to-child-transmission of HBV (total OR = 0.15), and to cause higher rates of HBV DNA suppression in mothers (total OR = 25.53). However, nucleos(t)ide analogues might also be involved in creatine kinase elevation (total OR = 7.48). In contrast, no significant association was found between nucleos(t)ide analogue therapy and preterm/premature births, congenital malformation, low birth weight, and abortion or fetal/infant death. The results suggested LdT's high capability of preventing mother-to-child-transmission. However, TDF failed to show significant associations to a reduced risk of mother-to-child-transmission, probably due to the low number of patients included. Conclusions: Although using either lamivudine, LdT, or TDF could lead to more favorable maternal/fetal outcomes, LdT seemed to show more potential in resolving certain infant- and maternal-related outcomes. More studies on the safety profile of such treatments are required.

Hepatitis B Virus Immunization and Neonatal Acquisition of Persistent Infection in England and Wales

Background

It is believed that between 2% and 5% of infants born to hepatitis B virus (HBV)-infected mothers at a high risk of perinatal transmission will become persistently infected despite immunization starting at birth. We investigated factors associated with breakthrough infections.

Methods

Sixty-nine samples from HBV-infected infants born between 2003 and 2015 were tested for HBV serological and molecular markers. Sequencing and epitope phenotyping were used to investigate alterations in hepatitis B surface antigen (HBsAg) sequence and antigenicity in infants and in mothers known to have transmitted and not to have transmitted virus to their infants.

Results

Vaccine/hepatitis B immune globulin uptake was complete in the majority of HBV-infected infants. A minority (8 [12%]) had detectable plasma antibody to HBsAg at 12 months. Twenty-five of 68 (37%) infants harbored a virus with amino acid changes in the HBsAg "a" determinant, of which 13 displayed altered HBsAg antigenicity. Viral load was 30-fold higher in maternal samples from those who transmitted.

Conclusions

Our data provide evidence to suggest that immune selection drives change at mother-infant transmission, resulting in the alteration of HBsAg antigenicity. These changes may play a role in immunization failure, but other factors including viral load may be more important. Continued monitoring of vaccine efficacy is essential.

Epidemiological trends and virological traits of hepatitis B virus infection in pregnant women and neonates

In infants, hepatitis B virus (HBV) infections are mainly acquired by mother-to-child transmission (MTCT). Current tests for the presence of HBV markers at birth can neither confirm nor exclude MTCT. The aim of this study was to find an early diagnostic marker of HBV MTCT. From 2011 to 2016, we studied a total of 5999 pregnant women who gave birth at our hospital in Shenzhen City, China. HBsAg-positive mothers and their offspring (n=386 pairs) were tested at birth for HBV markers, and 207 infants were followed up at 7-12 months after birth. The HBsAg-seropositive rate of the pregnant women was 12.5%. Additionally, 28.0%, 36.0%, 98.5% and 6.6% of umbilical cord (UC) blood samples of neonates were found to be positive for HBsAg, HBeAg, anti-HBc and HBV-DNA, respectively, whereas for neonatal femoral venous (FV) blood, the percentages were 16.2%, 38.0%, 98.8% and 2.6%, respectively. Mothers with high HBV DNA loads and those who were HBeAg positive were the most likely to have HBV-positive offspring. Immunoprophylaxis failed in five infants: the difference in median HBV DNA titer between UC blood from infants with and without HBV MTCT was statistically significant, and there was no significant difference in HBV DNA titer between UC blood and in peripheral blood of infants with HBV MTCT. In conclusion, we found that HBeAg positivity and high HBV loads are strong risk factors for MTCT of HBV and that the HBV DNA titer in the UC is a good predictor for HBV MTCT.

Safety and efficacy of telbivudine in late pregnancy to prevent mother-to-child transmission of hepatitis B virus: A multicenter prospective cohort study

Infection of hepatitis B virus (HBV) occurs in ~10% of infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg) after immunoprophylaxis. We aimed to evaluate the safety and efficacy of telbivudine used during late pregnancy for preventing mother-to-child transmission of HBV. We conducted a multicenter prospective cohort study in 5 hospitals from 2012 to 2014, which enrolled HBV-infected singleton pregnant women with positive HBeAg. By their choice, women were divided into therapy (telbivudine 600 mg/day, from gestation 28-32 weeks to 3-4 weeks postpartum) and control (no antiviral agent) groups. Infants received passive-active immunoprophylaxis and follow-up at the age of 7-14 months. Totally, 328 pregnant women were included: 149 in the telbivudine group and 179 in the control group. Baseline HBV DNA levels were similar in the 2 groups (7.43 vs 7.37 log₁₀ IU/mL, P = .711). At delivery, HBV DNA levels in the telbivudine and control groups were 3.80 and 7.26 log₁₀ IU/mL, respectively (P < .0001). Of the infants, 128 (85.9%) in the telbivudine group and 156 (87.2%) in the control group were followed up. No infant in the telbivudine group had chronic infection, while 2 (1.28%) infants in the control group did (P = .503). Three (2.34%) infants in the telbivudine group, but none in the control group, had severe congenital or developmental abnormalities (P = .090). The data indicate that telbivudine may block perinatal HBV transmission. However, larger studies are required to clarify whether anti-HBV therapy in pregnancy is associated with severe adverse effects in the foetuses and infants.

Motor development delay in offspring is associated with prenatal telbivudine exposure

Telbivudine is an orally nucleoside analog with potent and specific antihepatitis B virus (HBV) activity, and it has been reported to block mother-to-infant transmission. However, few studies have focused on the safety of prenatal exposure for offspring development.This is a prospective noninterventional study. Participants were enrolled during delivery through the Women's Hospital of Zhejiang University School of Medicine between January 2012 and September 2013. Neonate's umbilical cord arterial blood (UCAB) was collected after delivery. Hepatitis B virus DNA copy, HBV serology, alanine aminotransferase (ALT), creatine kinase (CK), creatinine (CRE), and blood urea nitrogen (BUN) were measured. The development of the offspring was evaluated by the Chinese Revision of Bayley Scales of Child Development (BSCD-CR) at 12 to 24 months old.Around 30 and 31 chronic hepatitis B mothers were recruited in untreated group (non-LdT group) and telbivudine-treatment group (LdT group), respectively, and 2 children (one in non-LdT group and 1 in LdT group) were lost in follow-up. Sixty-one normal women and their children were recruited as a normal control (control group). Compared with non-LdT group, telbivudine treatment effectively blocks HBV transmission from mother to infant. However, CK in UCAB was significantly increased in the LdT group. Moreover, children with prenatal telbivudine exposure showed lower level of serum creatinine than non-LdT group, reduction of psychomotor developmental index and increased risk of motor development delay.Prenatal telbivudine exposure is correlated with motor development delay in offspring.

Nucleoside/nucleotide analogues in the treatment of chronic hepatitis B infection during pregnancy: a systematic review

BACKGROUND

Women of childbearing age who have developed chronic hepatitis B (CHB) infection, especially HBeAg-positive highly viraemic pregnant women, are largely responsible for the familial transmission of the infection. Therefore, choosing the most effective and safest antiviral medications to manage pregnant CHB patients is of crucial importance.

MATERIALS AND METHODS

The PubMed and Scopus databases were searched through September 2017, for all the journal articles possessing original results regarding treatment of CHB pregnant women with any nucleos(t)ide analogue (NA) therapies, including lamivudine (LAM), adefovir (ADV), entecavir (ETV), telbivudine (LdT), and tenofovir (TDF).

RESULTS

After the primary search, 882 studies were recognized, and updating the searching results, 41 journal articles with original data were investigated, involving 3874 newborn infants from mothers with CHB, and their mothers completed follow-up until the delivery. The most important basic data and results regarding the efficacy of drugs, the rate of vertical transmission, safety issues associated with pairs of mothers and infants, median levels of HBV DNA, breastfeeding data, and rate of rate of vaccination success were collected. Moreover, possible key conclusion, recommendations, and learned lessons were discussed. Among the evaluated NAs, all LAM was efficient and safe. LdT was found to be very effective but had some safety concerns. In contrast, TDF had the advantages of both effectiveness and safety.

CONCLUSION

According to data in the literature, initiation of TDF at the trimester of pregnancy in combination with immunoprophylaxis to prevent mother-to-child transmission (MTCT) of CHB infection is strongly recommended as well as successful immunization of CHB pregnant women by anti-HBV vaccines.

The Ca2+/CaMKK2 axis mediates the telbivudine induced upregulation of creatine kinase: Implications for mechanism of antiviral nucleoside analogs' side effect

Telbivudine (LdT), a widely prescribed anti-hepatitis B virus (HBV) drug for the treatment of chronic Hepatitis B (CHB), causes adverse reactions ranging from creatine kinase (CK) elevation to myopathy. The purpose of this study was to explore the mechanism(s) of LdT induced CK elevation. The effects of LdT on mitochondrial morphology and proteins (TK2 and β-actin), oxidative stress, intracellular Ca²⁺ levels, Ca²⁺-related signaling pathway (CaMKK2/AMPK), and Ca²⁺-related biomarkers such as superoxide dismutase (SOD) and malondialdehyde (MDA) were assessed in human skeletal muscle cells (HSKMCs). The results showed that LdT induced a dose-dependent increase in CK activity in HSKMCs, without affecting mitochondrial morphology, and TK2 and β-actin protein levels, following 72 h of treatment. In addition, LdT increased Ca²⁺ production, ROS generation, MDA and lipid peroxide (LPO) levels, and activated the CaMKK2/AMPK signaling pathway. Moreover, these effects were attenuated by the BAPIA-AM (the calcium chelator). We also confirmed the presence of relevant markers (MDA, LPO, and SOD) in serum from CHB patients after LdT treatment, and found that CK was positively correlated with MDA and LPO, and negatively associated with SOD. These findings indicate that LdT induces CK elevation and oxidative stress associated with imbalance of intracellular Ca²⁺ in HSKMCs, suggesting that Ca²⁺/CaMKK2 axis imbalance may underlie human LdT-induced CK elevation. The present findings provide a solid basis for assessing the mechanism of drug-induced CK elevation, which can help develop new tools for the prevention and treatment of diseases associated with drug-induced CK elevation.

Management of Chronic Hepatitis B in Pregnancy

Chronic hepatitis B virus (HBV) infection due to mother-to-child transmission during the perinatal period remains an important global health problem. Despite standard passive-active immunoprophylaxis with hepatitis B immunoglobulin and hepatitis B vaccine in neonates, up to 8.5% of newborns still acquire HBV infection. Thus, management of chronic HBV during pregnancy and strategies to prevent mother-to-child transmission are important steps in eradicating or reducing the global burden of chronic HBV infection. To date, the management of HBV infection in pregnancy still needs careful attention because of some controversial aspects, including the influence of pregnancy on the course of HBV replication, safety of antiviral prophylaxis with nucleus(t)ide analogs, postpartum flares of hepatitis after delivery, and the safety of breastfeeding. In this review, we highlight these important issues of preventive strategies in the perinatal period.

Prevention of Chronic Hepatitis B after 3 Decades of Escalating Vaccination Policy, China

China’s hepatitis B virus (HBV) prevention policy has been evaluated through nationally representative serologic surveys conducted in 1992 and 2006. We report results of a 2014 serologic survey and reanalysis of the 1992 and 2006 surveys in the context of program policy. The 2014 survey used a 2-stage sample strategy in which townships were selected from 160 longstanding, nationally representative, county-level disease surveillance points, and persons 1–29 years of age were invited to participate. The 2014 sample size was 31,713; the response rate was 83.3%. Compared with the 1992 pre–recombinant vaccine survey, HBV surface antigen prevalence declined 46% by 2006 and by 52% by 2014. Among children <5 years of age, the decline was 97%. China’s HBV prevention program, targeted toward interrupting perinatal transmission, has been highly successful and increasingly effective. However, this progress must be sustained for decades to come, and elimination of HBV transmission will require augmented strategies.

Chronic hepatitis B: a critical discussion

Telbivudine (LdT) is an antiviral agent currently used in the treatment of chronic hepatitis B virus, which was first approved by the US FDA in 2006. The safety of LdT is of great importance for patients that receive long-term treatment for this condition. It has been confirmed that patients treated with LdT have significantly elevated creatine kinase levels. However, the mechanism responsible for this adverse reaction is unclear. This review summarizes the current literature of the adverse reactions of LdT and the possible mechanisms that are involved in chronic hepatitis B infection. Thus, we aim to provide guidance on best practices in using LdT and to provide evidence of the possible mechanisms of LdT-associated adverse reactions.

Comprehensive review of telbivudine in pregnant women with chronic hepatitis B

AIM

To achieve an evidence-based conclusion regarding the safety and efficacy of telbivudine during pregnancy.

METHODS

A pooled analysis of data from a literature search reported 1739 pregnancy outcomes (1673 live births) from 1725 non-overlapping pregnant women treated with telbivudine. The prevalence of live birth defects (3.6/1000) was similar to that of the non-antiviral controls (3.0/1000) and not increased as compared with overall prevalence (14.5 to 60/1000). No target organ toxicity was identified. The prevalence of spontaneous abortion in pregnant women treated with telbivudine (4.2/1000) was not increased compared with the overall prevalence (16/1000). The mother-to-child transmission rate was significantly reduced in pregnant women treated with telbivudine (0.70%) compared to those treated with the non-antiviral controls (11.9%; P < 0.0001) or compared to the historical rates of hepatitis B virus (HBV)-infected population without antiviral treatment (10%-15%).

RESULTS

Cumulatively 489 pregnancy cases have been reported in the telbivudine pharmacovigilance database (with a cut-off date 31 August 2014), of those, 308 had known pregnancy outcomes with 249 cases of live births (239 cases of live birth without congenital anomaly and 10 cases of live birth with congenital anomaly). In the latest antiretroviral pregnancy registry report (1 January 1989 through 31 January 2015) of 27 patients exposed to telbivudine during pregnancy (18, 6 and 3 during first, second and third trimester, respectively) 19 live births were reported and there were no cases of birth defects reported.

CONCLUSION

Telbivudine treatment during pregnancy presents a favorable safety profile without increased rates of live birth defects, spontaneous abortion or elective termination, or fetal/neonatal toxicity. Exposure to telbivudine in the first, second and third trimester of pregnancy has been shown to significantly reduce the risk of HBV transmission from mother to child on the basis of standard immune prophylaxis procedure.

DNA polymerase inhibitors for treating hepatitis B: a safety evaluation

INTRODUCTION

Oral nucleoside/ nucleotide analogues (NAs) are currently the mainstay of treatment for patients with chronic hepatitis B virus (HBV) infection. They are generally safe to use. However, since their approval in the last decade and a half, the literature has reported adverse effects associated with the use of NA in HBV patients. A comprehensive review on the drug safety is lacking.

AREAS COVERED

Significant adverse effects associated with NA use in HBV patients including muscle toxicity, peripheral neuropathy, nephrotoxicity and lactic acidosis are discussed. The reported prevalence of each adverse effect, as well as their predictive factors, reversibility and their use in pregnancy and lactating mothers are covered in this review. Novel data regarding reno-protective effect of telbivudine are also discussed.

EXPERT OPINION

Use of NA in HBV is generally safe. Uncommon adverse effects can be minimized or detected early if clinicians exercise adequate precautions when using NA for at-risk populations with regular monitoring.