Real-world study of tenofovir disoproxil fumarate to prevent hepatitis B transmission in mothers with high viral load

Chronic Hepatitis B Infection: New Approaches towards Cure

Chronic hepatitis B virus (HBV) infection leads to the development of cirrhosis and hepatocellular carcinoma. Lifelong treatment with nucleotides/nucleoside antiviral agents is effective at suppressing HBV replication, however, adherence to daily therapy can be challenging. This review discusses recent advances in the development of long-acting formulations for HBV treatment and prevention, which could potentially improve adherence. Promising new compounds that target distinct steps of the virus life cycle are summarized. In addition to treatments that suppress viral replication, curative strategies are focused on the elimination of covalently closed circular DNA and the inactivation of the integrated viral DNA from infected hepatocytes. We highlight promising long-acting antivirals and genome editing strategies for the elimination or deactivation of persistent viral DNA products in development.

Current Therapy of Chronic Viral Hepatitis B, C and D

The majority of chronic viral hepatitis cases are induced via infection with the hepatitis B virus (HBV), hepatitis C virus (HCV), or hepatitis D virus (HDV). These patients are at increased risk for progressive liver disease leading to cirrhosis as well as hepatocellular carcinoma (HCC). HBV infection is well controlled by the currently available nucleosides as well as nucleotides, and the development of cirrhosis can be prevented. Additionally, it has been shown that HBV-induced liver fibrosis can regress during successful antiviral treatment; however, a "functional cure", i.e., loss of HBsAg, is a rare event when these drugs are used. Therefore, novel therapeutic strategies are aiming at the selective suppression of HBsAg levels in combination with immunostimulation. The development of directly acting antivirals (DAAs) has revolutionized HCV therapy, as almost all patients can be cured via this treatment. Additionally, DAA therapy has few, if any, side effects, and is generally well tolerated by patients. HDV remains the most challenging type of chronic viral hepatitis. Although novel therapeutic options have recently been approved, response rates are still less favorable compared to HBV and HCV. This review discusses current and future options for the treatment of chronic HBV, HCV, and HDV infection.

Effect of prophylactic antiviral intervention on T cell immunity in hepatitis B virus-infected pregnant women

BACKGROUND

Antiviral intervention in hepatitis B virus (HBV)-infected pregnant women can effectively reduce mother-to-child transmission. However, the immunological characteristics of pregnant women with chronic HBV infection and the effects of antiviral intervention during pregnancy on maternal immune response remain unknown. We aimed to investigate these effects by comparing mothers who received antiviral intervention during pregnancy with those who did not.

METHODS

Pregnant women positive for hepatitis B surface antigen and hepatitis B e-antigen (HBsAg⁺ HBeAg⁺) were enrolled at delivery, including 34 received prophylactic antiviral intervention during pregnancy (AVI mothers) and 15 did not (NAVI mothers). T lymphocyte phenotypes and functions were analysed using flow cytometry.

RESULTS

At delivery, maternal regulatory T cell (Treg) frequency in AVI mothers was significantly higher than that in NAVI mothers (P < 0.002), and CD4⁺ T cells in AVI mothers displayed a decreased ability to secrete IFN-γ (P = 0.005) and IL-21 (P = 0.043), but an increased ability to secrete IL-10 and IL-4 (P = 0.040 and P = 0.036), which represented a higher Treg frequency, enhanced Th2 response and suppressed Th1 response. Treg frequency among AVI mothers was correlated negatively with serum HBsAg and HBeAg levels. After delivery, the ability of CD4⁺ T cells or CD8⁺ T cells to secrete IFN-γ or IL-10 was similar and no significant difference in Treg frequency was found between the two groups.

CONCLUSIONS

Prophylactic antiviral intervention during pregnancy has an effect on T cell immunity in pregnant women, which was characterised by increased maternal Treg frequency, enhanced Th2 response and suppressed Th1 response at delivery.

The Use of Tenofovir Disoproxil Fumarate and Tenofovir Alafenamide for Preventing Vertical Transmission of Hepatitis B

BACKGROUND

Mother-to-child transmission (MTCT) of hepatitis B virus may occur in highly viremic mothers despite the infants receiving appropriate immunoprophylaxis. We aimed to review tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) data for preventing MTCT.

METHODS AND DATA SELECTION

We performed a systematic review between January 1, 2015 and December 31, 2021 on PUBMED, EMBASE, Cochrane, CNKI, and Wanfang databases. Data was extracted from randomized controlled trials or cohort studies in English or Chinese. The outcomes of interest included the efficacy and safety of TDF versus TAF or TDF/TAF versus placebo for preventing MTCT (PROSPERO registration: CRD42021256656).

RESULTS

Data from forty-three studies (13 randomized controlled trials, 30 nonrandomized studies) were included in the review. All infants in the studies received appropriate immunoprophylaxis. Among 3656 highly viremic mothers treated with TDF, hepatitis B virus DNA suppression to the levels <200,000 IU/mL at delivery was achieved in 34% to 100% of mothers. MTCT rates were 0 to 5% and 2 to 83% in mothers treated with TDF and in those who received no treatment, respectively. Congenital malformation rates were 0 to 2.1% in the TDF groups, which did not differ from the nontreated groups. Similar findings were reported in 4 studies that enrolled 326 mothers for maternal TAF therapy, resulting in 0% of MTCT and 0% infant malformation. All studies observed that TDF or TAF maternal therapy reduced MTCT rates significantly without safety concerns when compared with untreated groups, except for 1 RCT that failed the therapeutic endpoint.

CONCLUSIONS

TDF is well established for preventing MTCT in highly viremic mothers, whereas TAF may become an option as data emerges.

Comparison of tenofovir disoproxil fumarate and telbivudine in preventing hepatitis B transmission in mothers with high viral load

OBJECTIVE

To add to the limited data that exist on the selection of drugs to prevent mother-to-child transmission (MTCT) of hepatitis B virus (HBV).

METHODS

This is a prospective cohort study that enrolled mothers with HBV-DNA ≥2 × 10⁵  IU/ml. All enrolled mothers received either tenofovir disoproxil fumarate (TDF) or telbivudine (LdT) to prevent HBV transmission.

RESULTS

A total of 270 mothers received TDF treatment and 275 mothers received LdT treatment. The predelivery decline in HBV-DNA in the TDF group was higher than the LdT group (3.92 ± 0.93 log IU/ml vs. 3.76 ± 0.94 log IU/ml, P = 0.043). In the primary analysis, the MTCT rate of the TDF group was comparable to that of the LdT group, both in the intention-to-treat analysis (1.5% [4/275] vs. 1.8% [5/273], P > 0.99) and the per-protocol analysis (0% in both groups, P > 0.99). The alanine aminotransferase elevation rates in the TDF group were lower than in the LdT group (17.3% vs. 27.4%, P = 0.005). Less anorexia and more arthralgia were observed in the LdT group than the TDF group.

CONCLUSIONS

TDF and LdT are both effective in preventing MTCT of HBV, but they may cause different adverse events. TDF is more effective in reducing HBV viral load and had fewer alanine aminotransferase abnormalities than LdT.

Tenofovir Alafenamide for Pregnant Chinese Women With Active Chronic Hepatitis B: A Multicenter Prospective Study

BACKGROUND & AIMS

Data on long-term tenofovir alafenamide (TAF) therapy for pregnant women with active chronic hepatitis B (CHB) (immune clearance and reactivation phases, currently and previously diagnosed) and their infants are lacking.

METHODS

Pregnant women with active CHB treated with TAF and tenofovir disoproxil fumarate (TDF) were enrolled in this multicenter prospective study, and infants received immunoprophylaxis. The primary outcomes were rates of adverse (safety) events in pregnant women and defects in infants and fetuses. The secondary outcomes were virologic responses in pregnant women, infants' safety, hepatitis B surface antigen (HBsAg) status, and growth conditions.

RESULTS

One hundred three and 104 pregnant women were enrolled and 102 and 104 infants were born in the TAF and TDF groups, respectively. In the TAF group, the mean age, gestational age, alanine aminotransferase level, and viral loads at treatment initiation were 29.3 years, 1.3 weeks, 122.2 U/L, and 5.1 log₁₀ IU/mL, respectively. TAF was well-tolerated, and the most common adverse event was nausea (29.1%) during a mean of 2 years of treatment. Notably, 1 (1.0%) TAF-treated pregnant woman underwent induced abortion due to noncausal fetal cleft lip and palate. No infants in either group had birth defects. In the TAF group, the hepatitis B e antigen seroconversion rate was 20.7% at postpartum month 6, infants had normal growth parameters, and no infants were positive for HBsAg at 7 months. The TDF group had comparable safety and effectiveness profiles.

CONCLUSIONS

TAF administered throughout or beginning in early pregnancy is generally safe and effective for pregnant women with active CHB and their infants.

New progress towards elimination of mother-to-child transmission of hepatitis B virus in China

Background

We conducted an evaluation on the potential data resources for the elimination of hepatitis B virus (HBV) mother-to-child transmission in China, so as to provide reference for WHO and other countries in the validation of HBV elimination of mother-to-child transmission (EMTCT) in a real-world large country setting.

Methods

We used the indicators set out in WHO Interim guidance for country validation of viral hepatitis elimination as the benchmark to evaluate the availability of data and progress against indicators for the elimination validation in China. We used descriptive analysis to illustrate the status of all indicators and parameters.

Results

According to the indicators which are recommended by WHO for HBV EMTCT validation, the national data in China are attainable, though not for HBV DNA testing for the HBsAg-positive mothers and their subsequent management. The remaining challenges for China are to consider how the national serosurvey might be conducted in future in the context of low HBV prevalence among children under 5 years; to collect systematically the programmatic impact data; to strengthen multi-sectoral collaboration among immunization, maternal and child health, hospital services, as well as other stakeholders.

Conclusion

The available data on HBV EMTCT are sufficient to support the validation of the elimination of HBV mother–to-child transmission in China.

Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission-A review of maternal and infant outcomes

Hepatitis B virus (HBV) is a global health problem. Vertical transmission of HBV from HBV surface antigen (HBsAg)-positive mothers to their infants is the most common cause of HBV infection worldwide. The use of passive-active immunoprophylaxis is >90% effective in reducing the risk of vertical transmission, but immunoprophylaxis failure can occur in infants born to mothers with high viraemia. Thus, it is recommended that pregnant women with HBV-DNA level >200 000 IU/ml receive nucleos(t)ide analogue (NA) treatment [i.e. tenofovir disoproxil fumarate (TDF), lamivudine or telbivudine] during third trimester to prevent infant immunoprophylaxis failure. TDF is recommended as the first-line therapy based on available data on efficacy, safety and resistance profile. However, maternal immunological reconstitution following parturition can increase immune-mediated flares to viral antigens that is potentially exacerbated following TDF withdrawal. In this article, we review available data on the efficacy and safety of TDF administration to prevent HBV mother-to-child transmission. We also discuss changes in maternal viral markers [i.e. HBV-DNA, HBV e antigen and HBsAg] and alanine aminotransferase during follow-up post-partum in mothers received NA to prevent HBV vertical transmission.

Antiviral Therapy for a Postpartum Flare in Women with Chronic HBV Infection Shortens the ALT Recovery Time and Reduces Hepatitis Re-Flare Rates within 4 years

BACKGROUND

Few studies explored whether anti-hepatitis B virus (HBV) therapy should be initiated during postpartum hepatitis flare.

AIM

This study aimed to analyze the effect of anti-HBV therapy on postpartum hepatitis flare and evaluate the prognosis within 4 years postpartum.

METHODS

This retrospective study enrolled hepatitis B surface antigen (HBsAg)-positive and hepatitis B e antigen (HBeAg)-positive pregnant women with HBV DNA ≥ 10⁶ IU/mL. A total of 152 pregnant women were included: 103 in the prophylactic anti-HBV therapy group (PT-G) and 49 in the non-prophylactic anti-HBV therapy group (NPT-G). The women with a postpartum flare were assigned to the anti-HBV therapy group (AT-G) and non-anti-HBV therapy group (NAT-G) to analyze the effect of postpartum anti-HBV therapy on hepatitis flare. Virological and biochemical parameters were assessed.

RESULTS

Taking postpartum 12 weeks as the cutoff point, the ALT recovered time for postpartum flare women is shorter in AT-G (n = 16, 42.1%) or PT-G (n = 23, 34.8%) than in NAT-G (n = 14, 23.0%; x ² = 4.067, P=0.044) or NPT-G (n = 4, 11.1%; x ² = 5.579, P=0.018). Taking postpartum 26 weeks as the cutoff point, the ALT recovered time is shorter in AT-G (n = 35, 57.3%) or PT-G (n = 44, 66.7%) than in NAT-G (n = 32, 84.2%; x ² = 7.707, P=0.006) or NPT-G (n = 16, 44.4%; x ² = 4.749, P=0.029). Postpartum flare recovery time was positively correlated with HBV DNA level at delivery [r = 0.223, P=0.025, 95%CI (0.022～0.41)]. The hepatitis re-flare rates within postpartum 4 years in AT-G (n = 3, 9.68%) is lower than that in NAT-G (n = 24, 45.4%; x ² = 14.003, P ≤ 0.001). The HBeAg, HBsAg, HBV DNA, and ALT level at postpartum 4 years in AT-G were lower than that in NAT-G (P < 0.001).

CONCLUSION

Anti-HBV therapy for postpartum hepatitis flare of women with chronic HBV could shorten the ALT recovery time and reduce hepatitis re-flare rates within 4 years of postpartum.

The role of tenofovir disoproxil fumarate for preventing vertical transmission of hepatitis B

Background

Since immunoprophylaxis failure can occur if maternal serum hepatitis B virus (HBV) DNA levels are >200,000 IU/ml, tenofovir disoproxil fumarate (TDF) therapy has been investigated for preventing mother to child transmission (PMTCT).

Methods

A literature search for maternal TDF therapy for PMTCT between 1/1/2015 and 7/1/21 on PUBMED, EMBASE, Cochrane, CNKI, and Wanfang databases was performed. Data from RCTs in English or Chinese were extracted and reviewed. The outcomes of interest included the efficacy and safety of TDF versus placebo for PMTCT.

Results

Among 11 RCTs identified from the databases, the risk-of-bias was low. All studies demonstrated that maternal TDF therapy initiated from the second or third trimester for highly viremic chronic hepatitis B mothers is highly effective and safe in the PMTCT of HBV, except one RCT performed in Thailand which showed no therapeutic advantage on TDF treatment versus placebo for PMTCT (0% vs 3% transmission). Recent emerging data suggest that maternal TDF therapy initiated at the 2nd or early 3rd trimester in mothers with HBV DNA >200,000 IU/ml achieved viremic control before delivery. In the 4-year long follow-up study for maternal TDF therapy, there were no impacts on infants’ physical growth, psychological or mental development, and bone mineral density after fetal exposure to TDF. In the light of updated efficacy and safety data from RCTs, an algorithm was proposed. The approaches in resource-limit areas were discussed.

Conclusions

TDF is safe for both mothers and infants as the preferred therapy for PMTCT in highly viremic mothers. TDF should be initiated at the second or early third trimester in the combination of the appropriate infants’ immunoprophylaxis.

Long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil in China

OBJECTIVE

The physical and neuromental development of infants remains uncertain after fetal exposure to tenofovir disoproxil fumarate (TDF) for the prevention of mother-to-child transmission of HBV. We aimed to investigate the safety of TDF therapy during the third trimester of pregnancy.

DESIGN

Infants from a previous randomised controlled trial were recruited for our long-term follow-up (LTFU) study. Mothers with chronic hepatitis B were randomised to receive TDF therapy or no treatment during the third trimester. Infants' physical growth or malformation, bone mineral density (BMD) and neurodevelopment, as assessed using Bayley-III assessment, were examined at 192 weeks of age.

RESULTS

Of 180 eligible infants, 176/180 (98%) were enrolled and 145/176 (82%) completed the LTFU (control group: 75; TDF-treated group: 70). In the TDF-treated group, the mean duration of fetal exposure to TDF was 8.57±0.53 weeks. Congenital malformation rates were similar between the two groups at week 192. The mean body weight of boys in the control and TDF-treated groups was significantly higher (19.84±3.46 kg vs. 18.47±2.34 kg; p=0.03) and within the normal range (18.48±2.35 kg vs. 17.80±2.50 kg; p=0.07), respectively, when compared with the national standard. Other prespecified outcomes (head circumference, height, BMD, and cognitive, motor, social-emotional, and adaptive behaviour measurements) were all comparable between the groups.

CONCLUSION

Infants with fetal exposure to TDF had normal physical growth, BMD and neurodevelopment at week 192. Our findings provide evidence on the long-term safety of infants after fetal exposure to maternal TDF therapy for preventing hepatitis B transmission.

TRIAL REGISTRATION NUMBER

NCT01488526.

UK guideline for the use of HIV post-exposure prophylaxis 2021

We present the updated British Association for Sexual Health and HIV (BASHH) guidelines for post-exposure prophylaxis (PEP) to HIV following sexual exposures, occupational exposures and other nonoccupational exposures in the community. This serves as an update to the 2015 BASHH guideline on PEP following sexual exposures and the 2008 Expert Advisory Group on AIDS guidelines on HIV PEP. We aim to provide evidence-based guidance on best clinical practice in the provision, monitoring and support of PEP for the prevention of HIV acquisition following sexual, occupational and other nonoccupational exposures in the community. The guideline covers when to prescribe PEP, what antiretroviral agents to use and how to manage PEP. This includes (i) evidence of PEP efficacy; (ii) evidence relating to individual-level efficacy of antiretroviral therapy to prevent the sexual transmission of HIV; (iii) data on the detectable (transmissible) prevalence of HIV in specific populations; (iv) risk of HIV transmission following different types of sexual and occupational exposure; (v) baseline risk assessment; (vi) drug regimens and dosing schedules; (vii) monitoring PEP; (viii) baseline and follow-up blood-borne virus testing; (ix) the role of PEP within broader HIV prevention strategies, for example, HIV pre-exposure prophylaxis (PrEP). The guideline also covers special scenarios such as PEP in pregnancy, breastfeeding and chronic hepatitis B virus infection, and when PEP should be considered in people using HIV PrEP. The guidelines are aimed at clinical professionals directly involved in PEP provision and other stakeholders in the field. A proforma to assist PEP consultations is included. A public consultation process was undertaken prior to finalizing the recommendations.

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.

Alteration of the Immune Microenvironment in HBsAg and HBeAg Dual-Positive Pregnant Women Presenting a High HBV Viral Load

Purpose

The aim of this study was to compare the differences in the immune microenvironment between HBV-infected pregnant women with a high HBV viral load and healthy pregnant women, with an emphasis on T cell subset alteration.

Patients and Methods

We compared the differences of cellular and molecular signatures between HBV-infected and healthy pregnant women by performing single-cell RNA and T cell receptor sequencing of peripheral blood mononuclear cells from 51,836 women in the mid-trimester pregnancy stage. Specific trajectories of the different T clusters throughout the course of T cell differentiation were investigated. Flow cytometry was used to validate the proportion of different T cell subtypes.

Results

We identified nine cellular subtypes and found an increased proportion of effector/memory CD8+ T cells in HBV-infected pregnant women. Both CD4+ and CD8+ effector/memory T cells in HBV-related samples expressed higher levels of metallothionein (MT)-related genes (MT2A, MTIE, MTIF, MTIX), metal ion pathways, and multiple inflammatory responses. Among CD8+ T cell clusters, we identified a particular subset of effector/memory CD8+ T cells (CD8-cluster 2) with MTs as the top-ranking genes, which may be enriched in HBV-related samples. These cells showed an increased clonal expansion in HBV infection. Moreover, we found more active immune responses, according to cellular interaction patterns, between immune cell subsets in HBV-infected samples.

Conclusion

This study shows significant differences between HBV-infected and healthy samples, including cell clusters, dominant gene sets, T cell function, clonal expansion, and V/J gene usage of T cell clonotypes, and identifies a distinct CD8+ T cell cluster with immune-active and antiviral properties. These findings pave the way for a deeper understanding of the impact of HBV infection on the immune microenvironment during pregnancy.

Advances in treatment and prevention of hepatitis B

Chronic hepatitis B (CHB) continues to contribute to worldwide morbidity and mortality significantly. Scientists, clinicians, pharmaceutical companies, and health organizations have dedicated substantial Intellectual and monetary resources to finding a cure, increasing immunization rates, and reducing the global burden of CHB. National and international health-related organizations including the center for disease control, the national institute of health, the American Association for the study of liver disease (AASLD), The European association for the study of the Liver (EASL), The Asia Pacific association for the study of the Liver (APASL) and the world health organization release periodic recommendations for disease prevention and treatment. Our review of the most recent guidelines by EASL, AASLD, APASL, and Taiwan Association for the Study of the Liver revealed that an overwhelming majority of cited studies were published before 2018. We reviewed Hepatitis B-related literature published 2018 onwards to identify recent developments and current barriers that will likely direct future efforts towards eradicating hepatitis B. The breakthrough in our understanding of the hepatitis B virus life cycle and resulting drug development is encouraging with significant room for further progress. Data from high-risk populations, most vulnerable to the devastating effects of hepatitis B infection and reactivation remain sparse. Utilization of systems approach, optimization of experimental models, identification and validation of next-generation biomarkers, and precise modulation of the human immune response will be critical for future innovation. Within the foreseeable future, new treatments will likely complement conventional therapies rather than replace them. Most Importantly, pragmatic management of CHB related population health challenges must be prioritized to produce real-world results.

Tenofovir Alafenamide to Prevent Perinatal Hepatitis B Transmission: A Multicenter, Prospective, Observational Study

BACKGROUND

Few safety and effectiveness results have been published regarding the administration of tenofovir alafenamide fumarate (TAF) during pregnancy for the prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV).

METHODS

In this multicenter prospective observational study, pregnant women with HBV DNA levels higher than 200,000 IU/ml who received TAF or tenofovir disoproxil fumarate (TDF) from gestational weeks 24-35 to delivery were 1:1 enrolled and followed until postpartum month 6. Infants received immunoprophylaxis. The primary endpoint was the safety of mothers and infants. The secondary endpoint was the hepatitis B surface antigen (HBsAg)-positive rate at 7 months for infants.

RESULTS

In total, 116 and 116 mothers were enrolled, and 117 and 116 infants were born, in the TAF and TDF groups, respectively. TAF was well tolerated during a mean treatment duration of 11.0 weeks. The most common maternal adverse event was nausea (19.0%). One (0.9%), 3 (2.6%), and 9 (7.8%) mothers had abnormal alanine aminotransferase levels at delivery and at postpartum months 3 and 6, respectively. The TDF group had safety profiles that were comparable to those of the TAF group. No infants had birth defects in either group. The infants' physical and neurological development at birth and at 7 months in the TAF group were comparable with those in the TDF group. The HBsAg positive rate was 0% at 7 months in all 233 infants.

CONCLUSION

Antiviral prophylaxis with TAF was determined to be generally safe for both mothers and infants and reduced the MTCT rate to 0%.

Efficacy and safety of tenofovir alafenamide fumarate for preventing mother-to-child transmission of hepatitis B virus: a national cohort study

BACKGROUND

Data on tenofovir alafenamide fumarate (TAF) for preventing mother-to-child transmission of hepatitis B virus (HBV) are lacking.

AIMS

To investigate the efficacy and safety of TAF therapy for preventing hepatitis B mother-to-child transmission.

METHODS

Mothers with chronic HBV infection, positive for hepatitis B e-antigen and with HBV DNA >200 000 IU/mL received TAF for preventing mother-to-child transmission were enrolled retrospectively from multiple centres with data collection on mother-infant dyads up to postpartum week 24-28. Primary measurements were the mother-to-child transmission rate and infants' malformation rate. Secondary assessments included maternal HBV DNA reduction at delivery, and maternal or infant adverse events during follow up.

RESULTS

Among 71 mothers enrolled, the mean (±SD) age was 30.3 (±2.2) years. TAF was initiated during the second or third trimester and continued to delivery with a mean (±SD) duration of 12.8 (±4.0) weeks. At delivery, 85.9% (61/71) of the mothers achieved HBV DNA <200 000 IU/L. Seventy-three infants (two sets of twins) were born from mothers treated with TAF and none had congenital defects or malformations. All infants received HBV immunoglobulin and vaccine at birth with additional HBV vaccinations at one and six months. At age 24-28 weeks, all infants had negative hepatitis B surface antigen and undetectable levels of HBV DNA (<100 IU/mL). Body weight, height, and head circumferences were comparable to national standards for physical development. No severe adverse effects were reported in either mothers or infants.

CONCLUSIONS

TAF for highly viraemic mothers effectively prevented mother-to-child transmission of hepatitis B. There were no safety concerns for either mothers or infants with 24-28 weeks of follow up.

Tenofovir for prevention of mother to child transmission of hepatitis B in migrant women in a resource-limited setting on the Thailand-Myanmar border: a commentary on challenges of implementation

BACKGROUND

The aim of this manuscript is to highlight challenges in the implementation of maternal tenofovir disoproxil fumarate (tenofovir) for prevention of mother to child transmission (PMTCT) of hepatitis B virus (HBV) in resource limited setting. Current preventive strategies in resource-limited settings fail mainly due to prohibitive costs of hepatitis B immunoglobulin (HBIG) and a high proportion of homebirths, meaning both HBIG and hepatitis B birth dose vaccine are not given. A new strategy for PMTCT without the necessity of HBIG, could be daily tenofovir commenced early in gestation. Implementation challenges to early tenofovir for PMTCT can provide insight to elimination strategies of HBV as the burden of disease is high in resource-limited settings.

METHODS

Challenges encountered during implementation of a study of tenofovir for PMTCT before 20 weeks gestation in rural and resource-limited areas on the Thailand-Myanmar border were identified informally from trial study logbooks and formally from comments from patients and staff at monthly visits. ClinicalTrials.gov Identifier: NCT02995005.

MAIN BODY

During implementation 171 pregnant women were hepatitis B surface antigen (HBsAg) positive by point of-care test over 19 months (May-2018 until Dec-2019). In this resource-limited setting where historically no clinic has provided tenofovir for PMTCT of HBV, information provided by staff resulted in a high uptake of study screening (95.5% (84/88) when offered to pregnant women. False positive point-of-care rapid tests hinder a test and treat policy for HBV and development of improved rapid tests that include HBeAg and/or HBV DNA would increase efficiency. Integrated care of HBV to antenatal care, transport assistance and local agreements to facilitate access, could increase healthcare at this critical stage of the life course. As safe storage of medication in households in resource-limited setting may not be ideal, interactive counseling about this must be a routine part of care.

CONCLUSION

Despite challenges, results from the study to date suggest tenofovir can be offered to HBV-infected women in resource-limited settings before 20 weeks gestation with a high uptake of screening, high drug accountability and follow-up, with provision of transportation support. This commentary has highlighted practical implementation issues with suggestions for strategies that support the objective of PMTCT and the World Health Organization goal of HBV elimination by 2030.

Eliminating mother-to-child transmission of HBV: progress and challenges in China

China has the world's largest burden of hepatitis B virus (HBV) infection, but the country has made considerable progress in preventing its mother-to-child transmission (MTCT) in the past three decades. This feat is made possible due to the high coverage of birth-dose hepatitis B vaccine (HepB, > 95%), hepatitis B surface antigen (HBsAg) screening for pregnant women ( > 99%), and hepatitis B immunoglobulin plus HepB for newborns whose mothers are HBsAg positive ( > 99%). Studies on the optimal antiviral treatment regimen for pregnant women with high HBV-DNA load have also been conducted. However, China still faces challenges in eliminating MTCT of HBV. The overall HBsAg prevalence among pregnant women is considered an intermediate endemic. The prevalence of HBsAg among pregnant women from remote, rural, or ethnic minority areas is higher than that of the national level because of limited health resources and public health education for HBV. The coverage for maternal and child healthcare and immunization services should be improved, especially in western regions. Integration of current services to prevent MTCTof HBV with other relevant health services can increase the acceptability, efficiency, and coverage of these services, particularly in remote areas and ethnic minority areas. By doing so, progress toward key milestones and targets to eliminate hepatitis B as the main public health threat by 2030 can be achieved.

Present and Future Therapies for Chronic Hepatitis B

Chronic hepatitis B (CHB) remains the leading cause of liver-related morbidity and mortality across the world. If left untreated, approximately one-third of these patients will progress to severe end-stage liver diseases including liver failure, cirrhosis, and hepatocellular carcinoma (HCC). High level of serum HBV DNA is strongly associated with the development of liver failure, cirrhosis, and HCC. Therefore, antiviral therapy is crucial for the clinical management of CHB. Current antiviral drugs including nucleoside/nucleotide analogues (NAs) and interferon-α (IFN-α) can suppress HBV replication and reduce the progression of liver disease, thus improving the long-term outcomes of CHB patients. This chapter will discuss the standard and optimization antiviral therapies in treatment-naïve and treatment-experienced patients, as well as in the special populations. The up-to-date advances in the development of new anti-HBV agents will be also discussed. With the combination of the current antiviral drugs and the newly developed antiviral agents targeting the different steps of the viral life cycle or the newly developed agents modulating the host immune responses, the ultimate eradication of HBV will be achieved in the future.

Early Start Of Tenofovir Treatment Achieves Better Viral Suppression In Pregnant Women With A High HBV Viral Load: A Real-World Prospective Study

Purpose

To investigate whether tenofovir disoproxil fumarate (TDF) treatment that started from the second trimester had an advantage over TDF treatment that started from the third trimester.

Patients and methods

Twenty 35-year-old pregnant women with hepatitis B virus (HBV) DNA >2×106 IU/mL were prospectively enrolled in this study. All participants were divided into two subgroups: the second trimester group who started TDF treatment at 24-27 weeks and the third trimester group who started TDF treatment at 28-30 weeks. The primary outcome was the change in serum HBV DNA level from baseline to delivery. Each parameter was tested every 4 weeks from TDF initiation to 3 months postpartum.

Results

There were 80 pregnant women in the second trimester group and 49 pregnant women in the third trimester group. The decline in HBV DNA from baseline to delivery was more obvious in the second trimester group (4.8±1.2 log10 IU/mL) than that in the third trimester group (4.3±1.1 log10 IU/mL, p=0.041). The downward shift of haemoglobin (HB) from baseline to delivery was greater in the second trimester group (10.6±10.7 g/L) than in the third trimester group (6.3±12.3 g/L, p=0.041). The decline in HBV DNA from baseline to delivery was linearly related to the start of TDF treatment from the second trimester (β=0.50 and 95% CI: 0.26-0.75, p<0.001). There were no significant differences between the two groups regarding HBV serologic markers and safety indicators.

Conclusion

Starting TDF treatment from the second trimester achieved better viral suppression than starting TDF treatment from the third trimester in highly viraemic pregnant women without increasing additional adverse reactions. HB level needed frequent monitoring during treatment to avoid anaemia.

Registry number

Clinical Trial No. NCT02719808.

Abnormal IL-10 levels were related to alanine aminotransferase abnormalities during postpartum in HBeAg positive women with chronic hepatitis B

Alanine transaminase (ALT) abnormalities are common in chronic hepatitis B (CHB) carriers during postpartum period. Disturbances in cytokines are considered to be associated with hepatitis Flares. There are limited data on cytokines changes in HBeAg positive patients with ALT abnormalities.This is an observational study. Pregnant patients with hepatitis B e-antigen (HBeAg) positive were enrolled from January 2014 to September 2018. Patients were assigned into three groups based on ALT levels in postpartum 6 to 8 weeks: ALT in normal range, ALT in 1 to 2-fold upper limits of normal (ULN) and ALT >2-fold ULN. Serum cytokines, ratios of regulatory T cells, and the concentration of cortisol were collected and compared among the three groups.Of the 135 mothers enrolled, 80.7% (109/135) completed the postpartum 6-week study. 13.8% (15/109) patients had postpartum ALT higher than 2ULN, 27.5% (30/109) patients had ALT in 1 to 2ULN and 58.7% (64/109) patients had ALT in normal range. Compared to control group, patients with ALT >2ULN had a higher IL-10 level (P < .05). No differences of IL-10 levels were found in the comparison of other inter comparison among three groups. No differences were found in the levels of other collected serum cytokines, cortisol, and regulatory T cells among three groups. On multivariate analysis, abnormal IL-10 level was independent risk factor for postpartum ALT elevating >2ULN. At the same time, the incidence of postpartum ALT elevated >2ULN were higher in patients with abnormal elevation IL-10 level than in patients with normal IL-10 level (14/68 vs 1/41, P = .008).CHB patients with postpartum ALT abnormalities show higher IL-10 level and postpartum ALT abnormalities were mainly occurred in patients with abnormal IL-10 level. IL-10 may be an underlying predictor and treatment target of hepatitis B, and further studies are needed.

Decreased neonatal hepatitis B virus (HBV) viremia by maternal tenofovir treatment predicts reduced chronic HBV infection in children born to highly viremic mothers

BACKGROUND

Maternal anti-viral treatment prevents mother-to-infant transmission of hepatitis B virus (HBV), but the role of neonatal viremia on subsequent HBV infection is not clear.

AIMS

To investigate the effect of maternal anti-viral treatment on neonatal serum HBV DNA and hepatitis B surface antigen (HBsAg) in infants born to highly viremic mothers and the roles of neonatal markers in predicting chronic HBV infection in children.

METHODS

Serum HBV DNA and HBsAg were tested in children. Of the 201 pregnant mothers, 110 received tenofovir during the third trimester. Chronic infection in children was defined by HBsAg seropositivity at 6 or 12 months lasting more than 6 months.

RESULTS

The maternal HBV viral loads from baseline to delivery were 8.25 ± 0.48 to 4.29 ± 0.98 log₁₀  IU/mL; and 8.29 ± 0.49 to 8.12 ± 0.68 log₁₀  IU/mL in the tenofovir and control group respectively. Of the 208 children, those in the tenofovir group had a lower rate of neonatal HBV DNA seropositivity at birth (5.22% vs 30.11%, P < 0.0001) and HBsAg seropositivity at 6 months (1.74% vs 11.83%, P = 0.003) and 12 months (1.74% vs 10.75%, P = 0.007). In a first multivariate analysis, maternal HBV DNA level at delivery (odds ratio = 1.70, P = 0.0172) and neonatal HBsAg positivity (odds ratio = 19.37, P < 0.0001) were significantly associated with children's chronic HBV infection. In a second model, neonatal HBV DNA positivity was a strong independent influence variable (odds ratio = 61.89, P = 0.0002).

CONCLUSIONS

Maternal tenofovir therapy decreased maternal viral load and neonatal viremia. Positive neonatal HBV DNA was highly correlated with chronic HBV infection in children. Clinical Trial Identifier: NCT01312012.

Telbivudine Treatment during Late Pregnancy Prevents Mother-to-Child Transmission of Hepatitis B Virus: A Retrospective Study

PURPOSE

To investigate the efficacy of telbivudine (LdT) in blocking mother-to-child transmission (MTCT) of hepatitis B virus (HBV) during late pregnancy.

METHODS

A total of 651 pregnant women aged 18-40 in Nantong Third People's Hospital and Hospital affiliated to Nantong University with positive hepatitis B surface antigen (HBsAg) and HBV DNA were enrolled between January 2011 and December 2015. Patients with HBV DNA≥10⁶ copies/mL (n=251) received LdT during late pregnancy according to the patients' will, while 136 high viral patients with HBV DNA≥10⁶ copies/mL who did not take LdT therapy and 268 low viral patients with HBV DNA<10⁶ copies/mL served as the controls.

RESULTS

At 7 months and 1 year postpartum, the basal HBV DNA serum level of treated patients declined significantly (P<0.001), while no obvious decline was observed in the untreated high viraemic controls (P<0.05) and untreated low viraemic controls (P<0.05). Only 1 infant (0.4%) in LdT group was HBsAg positive at 7 months, while 14 (5.2%) were in the untreated low viraemic controls (P<0.001) and 15 (11.0%) were in untreated high viraemic controls (P<0.001).

CONCLUSION

For pregnant women with HBV DNA≥10⁶ copies/mL, the use of LdT during late pregnancy could effectively reduce the MTCT rate of HBV.