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

Tenofovir alafenamide or tenofovir disoproxil fumarate in pregnancy to prevent HBV transmission: Maternal ALT trajectory and infant outcomes

BACKGROUND

The use of antiviral agents, specifically tenofovir disoproxil fumarate (TDF), in pregnant women to prevent mother-to-child HBV transmission is a key step towards hepatitis elimination. However, data on using tenofovir alafenamide (TAF) is insufficient. The frequent occurrence of postpartum ALT flares may impact the clinical implementation.

METHODS

The maternal and infant outcomes were compared in multi-centre trials of high viral load HBsAg/HBeAg+ pregnant women receiving TAF or TDF from the third trimester until 2 weeks postpartum with intensive follow-ups. To explore the dynamic pre- and postpartum changes in ALT levels, we used a group-based trajectory model for analysing data of 332 women from three prospective studies.

RESULTS

After treatment, the maternal HBV DNA levels significantly decreased from baseline to delivery: 7.87 ± 0.59 to 3.99 ± 1.07 Log10 IU/mL TAF (n = 78) and 8.30 ± 0.36 to 4.47 ± 0.86 Log10 IU/mL (TDF, n = 53), with viral load reductions of 3.87 versus 3.83 Log10 IU/mL. The HBsAg-positive rates among 12-month-old infants were 1.28% (1/78) versus 1.82% (1/55) respectively (p = 1.00). Of the TAF or TDF-treated mothers, 25.64% versus 16.98% experienced ALT > 2X ULN, and 11.54% versus 1.89% received extended antiviral treatment. Our model revealed four distinct ALT patterns: stable ALT (87.2%), moderate (8.0%) or marked (2.4%) postpartum flares, or prepartum elevations (2.4%).

CONCLUSIONS

TAF effectively reduces mother-to-child HBV transmission, but prophylaxis failure still occurred in few cases. Postpartum ALT flares are common in women receiving TAF or TDF during pregnancy. Approximately 12.8% of mothers may require extended postpartum antiviral treatment.

CLINICAL TRIAL NUMBER

NCT03695029 (ClinicalTrials.gov).

Staging and clinical characteristics of pregnant women with chronic hepatitis B virus infection: A retrospective cohort study from Nanjing, China

AIM

To investigate the immune status of Chinese chronic hepatitis B (CHB) pregnant women and their clinical characteristics.

METHODS

About 1544 CHB pregnant women without antiviral therapy from 2013 to 2018 were selected from the hospital records. The definition of immune status is based on American Association for the Study of Liver Diseases (AASLD) 2018 Hepatitis B Guidance, and those who did not meet any criteria of the immune status were referred to in the gray zones (GZ).

RESULTS

There were 284 patients in the immune-tolerance phase, 72 patients in the HBeAg-positive immune active phase, 553 patients in the inactive phase, 61 patients in the HBeAg-negative immune active phase. Of note, 574 (37.18%) patients did not fit into any of the above phases were defined as the GZ. Patients with elevated ALT had a higher rate of intrahepatic cholestasis of pregnancy (ICP). Mother to child HBV transmission was rare (only two cases) and occurred in mothers in the immune-tolerant phase.

CONCLUSIONS

Our data showed that more than one-third of CHB pregnant women were classified into the GZ. In standard stages, advanced age is associated with HBeAg-negative and a higher cesarean rate in the inactive phase. The incidence of ICP was higher in immune active phases, including GB and GD. The probability of mother-to-child transmission in gray zones is low.

Characterization of Hepatitis B Virus in Tenofovir-Treated and Untreated Chronically Infected Mothers and Their Immunoprophylaxis Failure Infants

BACKGROUND

Maternal tenofovir disoproxil fumarate (TDF) therapy during late pregnancy can reduce mother-to-infant transmission of hepatitis B virus (HBV). We investigated HBV mutations associated with maternal TDF therapy and their role in infant immunonophylaxis failure (IPF).

METHODS

Serum samples from untreated (n = 89) and TDF-treated (n = 68), highly viremic, chronically infected mothers and their infants were analyzed for HBV DNA by nested polymerase chain reaction (PCR) and direct sequencing.

RESULTS

At delivery, compared with untreated mothers, TDF-treated mothers had a lower HBV DNA titer and a higher frequency of basal core promoter (BCP) gene mutations, but they had similar frequencies in pre-S/S and pre-core/core mutations. The 14 mothers harboring surface "a" determinant mutants did not transmit the mutants to their immunized infants. Such mutants were found in 3 of 13 IPF infants; the 13 mothers had wild-type hepatitis B surface antigen (HBsAg). In univariable analysis, maternal HBV DNA titer (odds ratio [OR]: 1.54; 95% confidence intervals [CI]: 1.02-2.33; P = .039), genotype C (OR: 4.18; 95% CI: 1.28-13.62; P = .018) and pre-S1 wild-type sequence (OR: 6.33; 95% CI: 1.85-21.68; P = .003) at delivery were associated with infant IPF. Multivariable analyses showed that maternal genotype C (OR: 3.71; 95% CI: 1.11-12.36; P = .033) and pre-S1 wild-type (OR: 6.34; 95% CI: 1.79-22.44; P = .004) were associated with infant IPF independently of maternal viremia.

CONCLUSIONS

Along with high maternal HBV DNA titer at delivery, maternal genotype C and pre-S1 wild-type sequence were potential risk factors for infant IPF, although BCP mutations were not. The offspring of pregnant women harboring "a" determinant mutants as major strains seemed to be protected by immunoprophylaxis.

CLINICAL TRIALS REGISTRATION

NCT01312012.

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.

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.

Kinetics of hepatitis B surface antigen in pregnant women with and without tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent mother-to-infant transmission in highly viremic HBV-infected women. Data on hepatitis B surface antigen (HBsAg) levels in pregnant women are lacking. We aimed to investigate prepartum and postpartum HBsAg kinetics and its correlation with HBV DNA in pregnant women. HBV-infected mothers with HBV DNA ≥7.5 log₁₀  IU/ml were tested for HBsAg and HBV DNA from baseline to 6 months postpartum. Of the 186 pregnant women with comparable baseline HBsAg and HBV DNA, 101 received TDF from the third trimester until 1 month postpartum. At delivery, TDF group had mildly lower HBsAg (4.32 ± 0.47 vs. 4.54 ± 0.35 log₁₀  IU/ml, p = .0004) and markedly lower HBV DNA (4.26 ± 0.97 vs. 8.11 ± 0.70 log₁₀  IU/ml, p < .0001) than the control group. In the TDF group, mean reduction of HBsAg and HBV DNA from baseline to delivery were 0.22 ± 0.38 and 3.96 ± 0.93 log₁₀  IU/ml. HBsAg reduction had a positive correlation (r = .309; p = .0017) with HBV DNA reduction, and was predictive of HBV DNA reduction ≥3 log₁₀  IU/ml (area under the receiver operating characteristic curve, 0.67; 95% confidence interval, 0.50-0.82). At 6 months postpartum, TDF and control group had comparable HBsAg and HBV DNA. In conclusion, HBsAg decreased slightly at delivery in pregnant women receiving TDF. For monitoring the effect of antiviral therapy during pregnancy, HBV DNA is a better marker than HBsAg. Our data provided valuable information regarding monitoring HBV-infected pregnant women using antiviral therapy.

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.

The Importance of Hepatitis B Antigen Screening in Pregnancy

In the United States, pregnant women are screened for hepatitis B antigen because of the significant risk of perinatal vertical transmission of hepatitis to the fetus. It is important that the maternal hepatitis B antigen screen is documented in the medical record to ensure appropriate prophylaxis for the neonate. The purpose of this column is to discuss the pathophysiology of hepatitis B, as well as the screening process and prophylaxis for the neonate.

Clinical characteristics and efficacy evaluation of antiviral therapy in pregnant women with chronic hepatitis B virus infection

BACKGROUND

During pregnancy, decreased maternal liver blood supply and increased load metabolism make woman susceptible to hepatitis attack. Severe cases often develop liver failure, leading to coagulation mechanism abnormality, bleeding and infection, fetal distress, premature delivery, stillbirth, etc. Therefore, high attention to the treatment and management of pregnant women with chronic hepatitis B virus (HBV) infection is the key to reducing the mother-to-child transmission of HBV, representing an important issue of concern for clinical medical personnel. Therefore, the early diagnosis and treatment of hepatitis attack during pregnancy are particularly important.

AIM

To observe the clinical characteristics of HBV in pregnant women and evaluate the efficacy of antiviral therapy.

METHODS

A total of 180 pregnant women with chronic HBV infection who visited Yuyao Maternal and Child Health Center of Zhejiang Province from February 2017 to June 2019 were selected as study subjects. Liver function was tested every 4 to 12 wk during pregnancy, and HBV serum markers were checked to determine whether there was hepatitis attack during pregnancy. For those with a definite diagnosis, tibivudine was given orally at a dose of 600 mg once per day. The clinical characteristics, alanine aminotransferase (ALT), HBV serum markers, and HBV DNA changes in pregnant women with chronic HBV infection were recorded. ALT recovery rate, HBV DNA and hepatitis B e antigen (HBeAg) negative conversion rate, and HBeAg seroconversion rate after antiviral treatment at different time points during pregnancy were also recorded.

RESULTS

Of the 180 pregnant women with chronic HBV infection included in this study, 48 (26.67%) had hepatitis attacks during pregnancy. The average age was 32.3 ± 2.4 years. The duration of hepatitis attacks ranged from 6 to 34 wk, with an average of 20.3 ± 7.8 wk. The mean value of ALT was 224.95 ± 19.6 U/L. Compared with pregnant women without hepatitis attack during pregnancy, ALT and HBV DNA changes were significant (P < 0.05), and hepatitis B surface antigen and HBeAg quantification were significantly reduced (P < 0.05). For hepatitis attacks during pregnancy, with the extension of treatment time, ALT recovery rate, HBV DNA negative conversion rate, HBeAg negative conversion rate, and HBeAg seroconversion rate had varying degrees of rise. Especially at 36 wk after treatment, the ALT recovery rate was 100.0%, HBV DNA negative conversion rate was 72.92%, HBeAg negative conversion rate was 41.67%, and HBeAg seroconversion rate was 37.5%, which were significantly higher than those at 6 wk, 12 wk, and 24 wk of treatment (P < 0.05).

CONCLUSION

Hepatitis attacks in pregnant women with chronic HBV infection usually occur in the second trimester.

Accuracy of HBeAg to identify pregnant women at risk of transmitting hepatitis B virus to their neonates: a systematic review and meta-analysis

BACKGROUND

Prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) involves neonatal immunoprophylaxis, with a birth dose of hepatitis B vaccine and immune globulin, and provision of peripartum antiviral prophylaxis in highly viraemic women. However, access to assays to quantify HBV DNA levels remains inadequate in resource-poor settings. This study was commissioned by WHO and aimed to identify the HBV DNA threshold for MTCT, to assess the sensitivity and specificity of hepatitis B e antigen (HBeAg) testing to identify pregnant women with HBV DNA levels above this threshold, and to predict MTCT of HBV infection on the basis of HBeAg testing.

METHODS

For this systematic review and meta-analysis, we searched the PubMed, EMBASE, Scopus, CENTRAL, CNKI, and Wanfang databases for studies of pregnant women with chronic HBV infection without concurrent antiviral therapy, published between Jan 1, 2000, and April 3, 2019. Studies were eligible for inclusion if MTCT in mother-child pairs could be stratified by different levels of maternal HBV DNA during pregnancy, if maternal HBeAg status could be stratified by HBV DNA level, and if the MTCT status of infants could be stratified by maternal HBeAg status during pregnancy. Studies that selected pregnant women on the basis of HBeAg serostatus or HBV DNA levels were excluded. Aggregate data were extracted from eligible studies by use of a pre-piloted form; study authors were contacted to clarify any uncertainties about potential duplication or if crucial information was missing. To pool sensitivities and specificities of maternal HBeAg to identify highly viraemic women and to predict MTCT events, we used the DerSimonian-Laird bivariate random effects model. This study is registered with PROSPERO, CRD42019138227.

FINDINGS

Of 9007 articles identified, 67 articles (comprising 66 studies) met the inclusion criteria. The risk of MTCT despite infant immunoprophylaxis was negligible (0·04%, 95% CI 0·00-0·25) below a maternal HBV DNA level of 5·30 log₁₀ IU/mL (200 000 IU/mL) and increased above this threshold. The pooled sensitivity of HBeAg testing to identify HBV DNA levels of 5·30 log₁₀ IU/mL or greater in pregnant women was 88·2% (83·9-91·5) and pooled specificity was 92·6% (90·0-94·5). The pooled sensitivity of HBeAg testing in predicting MTCT of HBV infection despite infant immunoprophylaxis was 99·5% (95% CI 91·7-100) and pooled specificity was 62·2% (55·2-68·7).

INTERPRETATION

Maternal HBV DNA of 5·30 log₁₀ IU/mL or greater appears to be the optimal threshold for MTCT of HBV infection despite infant immunoprophylaxis. HBeAg is accurate to identify women with HBV DNA levels above this threshold and has high sensitivity to predict cases of immunoprophylaxis failure. In areas where HBV DNA assays are unavailable, HBeAg can be used as an alternative to assess eligibility for antiviral prophylaxis.

FUNDING

World Health Organization.

Elimination of Mother-to-Infant Transmission of Hepatitis B Virus: 35 Years of Experience

Chronic hepatitis B viral (HBV) infection remains a major health threat, especially in high-prevalence areas. Most infants infected by mother-to-infant HBV transmission become chronic carriers. In Taiwan, many important preventive interventions have been implemented to block the perinatal transmission of HBV in the past 35 years. The first nationwide universal HBV vaccination program was launched in Taiwan in July 1984. The three-dose HBV vaccine completion rate reached 98.1% in 2018. The prevalence of Hepatitis B surface antigen (HBsAg) decreased from 9.8% in pre-vaccinated period in 1984 to 0.5% in the vaccinated cohort in 2014. The incidence of hepatocellular carcinoma in children aged 6-9 years significantly declined from 0.52 to 0.13 per 100,000 children born before and after 1984, respectively. Furthermore, we have performed a maternal HBV screening program during pregnancy since 1984, with the screening rate peaked at 93% in 2012. The HBsAg- and HBeAg-seropositive rate in pregnant women declined from 13.4% and 6.4% in 1984-1985 to 5.9% and 1.0% in 2016, respectively. To closely control perinatal HBV infection, we have administered hepatitis B immunoglobulin immediately after birth and checked the serum level of HBsAg and anti-HBs in high-risk babies born to HBsAg-seropositive mothers, irrespective of their HBeAg status, since July 2019. We have also adopted short-term antiviral treatments such as tenofovir 300 mg daily in the third trimester for highly viremic mothers and reduced the perinatal infection rates from 10.7 to 1.5%. Through all these efforts, we expect to meet the global goal of eliminating HBV infection by 2030.

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.