Efficacy and safety of tenofovir disoproxil fumarate in pregnancy for the prevention of vertical transmission of HBV infection

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Antiviral therapy in chronic hepatitis B viral infection during pregnancy: A systematic review and meta-analysis

Perinatal or mother-to-child transmission (MTCT) of hepatitis B virus (HBV) remains the major risk factor for chronic HBV infection worldwide. In addition to hepatitis B immune globulin and vaccination, oral antiviral therapies in highly viremic mothers can further decrease MTCT of HBV. We conducted a systematic review and meta-analysis to synthesize the evidence on the efficacy and maternal and fetal safety of antiviral therapy during pregnancy. A protocol was developed by the American Association for the Study of Liver Diseases guideline writing committee. We searched multiple databases for controlled studies that enrolled pregnant women with chronic HBV infection treated with antiviral therapy. Outcomes of interest were reduction of MTCT and adverse outcomes to mothers and newborns. Study selection and data extraction were done by pairs of independent reviewers. We included 26 studies that enrolled 3622 pregnant women. Antiviral therapy reduced MTCT, as defined by infant hepatitis B surface antigen seropositivity (risk ratio = 0.3, 95% confidence interval 0.2-0.4) or infant HBV DNA seropositivity (risk ratio = 0.3, 95% confidence interval 0.2-0.5) at 6-12 months. No significant differences were found in the congenital malformation rate, prematurity rate, and Apgar scores. Compared to control, lamivudine or telbivudine improved maternal HBV DNA suppression at delivery and during 4-8 weeks' postpartum follow-up. Tenofovir showed improvement in HBV DNA suppression at delivery. No significant differences were found in postpartum hemorrhage, cesarean section, and elevated creatinine kinase rates.

CONCLUSIONS

Antiviral therapy improves HBV suppression and reduces MTCT in women with chronic HBV infection with high viral load compared to the use of hepatitis B immunoglobulin and vaccination alone; the use of telbivudine, lamivudine, and tenofovir appears to be safe in pregnancy with no increased adverse maternal or fetal outcome.

Clinical course of 161 untreated and tenofovir-treated chronic hepatitis B pregnant patients in a low hepatitis B virus endemic region

Hepatitis B immunoprophylaxis failure is linked to high maternal viraemia. There is limited North American data on hepatitis B outcomes in pregnancy. Pregnant hepatitis B carriers were enrolled January 2011-December 2014 and offered tenofovir in the 3rd trimester if hepatitis B virus (HBV)-DNA was >7-log IU/mL. Outcomes were determined in treated vs untreated patients. In total, 161 women with 169 pregnancies (one twin, 170 infants; median age 32 years), 18% (29/161) HBeAg+ and median HBV-DNA 2.51 log IU/mL (IQR 1.66-3.65; range 0.8-8.1) were studied. 14.3% (23/161) received tenofovir due to high viral load (16/23, median 74 days, IQR 59-110) or due to liver disease (7/23). In 10/16 treated due to high viraemia, with confirmed adherence, follow-up HBV-DNA showed a 5.49 log decline (P = 0.003). In treatment naïve mothers, median alanine aminotransferase (ALT) increased from 17 IU/L (IQR 12-24) to 29 (IQR 18-36) post-partum (P = 1.5e-7). In seven highly viraemic mothers who declined therapy (HBV-DNA >8-log IU/mL); median ALT increased ~3X from baseline (P < 0.01). 26% (44/169) had Caesarean section with no difference in treated vs untreated subjects. No tenofovir-treated mothers had renal dysfunction. Data were available on 167/170 infants; in 50.8% (85/167) who completed immunoprophylaxis, 98.8% (84/85, including 12 exposed to tenofovir in utero) were HBV immune. One infant born to an HBeAg+ mother with HBV-DNA >8-log IU/mL failed immunoprophylaxis. In this prospective Canadian cohort study, most untreated mothers experienced mild HBV flares. Tenofovir in pregnancy is well tolerated and reduces viral load prior to parturition.

Evaluation of hepatitis B virus transmission and antiviral therapy among hepatitis B surface antigen-positive pregnant women

AIM

The aim of the present study was to assess the potential risk of hepatitis B virus (HBV) vertical transmission among Turkish parturient women and to evaluate the efficacy and safety of antiviral agents.

MATERIAL AND METHODS

Data were collected retrospectively from 114 HBV-infected pregnant women and their infants in eight health institutions in Turkey.

RESULTS

The baseline characteristics of the women were: mean age, 28.3 ± 5.2 years; alanine aminotransferase, 57.4 ± 139.0 U/L; aspartate aminotransferase, 56.6 ± 150.0 U/L; and HBV DNA, 8.3 × 10(7) ± 2.6 × 10(8) copies/mL. Family history of HBV infection was detected in 53.5% (n = 61). In total, 60 (52.6%) pregnant women received tenofovir (60.0%), lamivudine (33.3%) or telbivudine (6.7%) therapy at the median gestational age of 22.2 ± 8.5 (1-36) weeks. All infants were vaccinated and hepatitis B immune globulin was administered, with 81 of them (71.1%) available for follow-up. After completion of HBV vaccination course, 71 (87.7%) infants had protective anti-HBs levels, three (3.7%) were hepatitis B surface antigen-positive, and seven (8.6%) were hepatitis B surface antigen-negative with nonprotective anti-HBs levels. Five of the infants had low gestational birthweight but no other birth defects were observed.

CONCLUSION

According to our results, viral load may not be the only effecting factor for transmission of HBV to children of infected mothers. Pregnant women with high viral load should be followed-up closely during pregnancy. They should begin to take tenofovir or telbivudine, which are category B drugs for pregnancy, at the beginning of the third trimester at the latest. We need new treatment strategies; and close follow-up of mothers and children is another important issue.

Efficacy of maternal tenofovir disoproxil fumarate in interrupting mother-to-infant transmission of hepatitis B virus

The efficacy and safety of maternal tenofovir disoproxil fumarate (TDF) in reducing mother-to-infant hepatitis B virus (HBV) transmissions is not clearly understood. We conducted a prospective, multicenter trial and enrolled 118 hepatitis B surface antigen (HBsAg)- and hepatitis B e antigen-positive pregnant women with HBV DNA ≥7.5 log10 IU/mL. The mothers received no medication (control group, n = 56, HBV DNA 8.22 ± 0.39 log10 IU/mL) or TDF 300 mg daily (TDF group, n = 62, HBV DNA 8.18 ± 0.47 log10 IU/mL) from 30-32 weeks of gestation until 1 month postpartum. Primary outcome was infant HBsAg at 6 months old. At delivery, the TDF group had lower maternal HBV DNA levels (4.29 ± 0.93 versus 8.10 ± 0.56 log10 IU/mL, P < 0.0001). Of the 121/123 newborns, the TDF group had lower rates of HBV DNA positivity at birth (6.15% versus 31.48%, P = 0.0003) and HBsAg positivity at 6 months old (1.54% versus 10.71%, P = 0.0481). Multivariate analysis revealed that the TDF group had lower risk (odds ratio = 0.10, P = 0.0434) and amniocentesis was associated with higher risk (odds ratio 6.82, P = 0.0220) of infant HBsAg positivity. The TDF group had less incidence of maternal alanine aminotransferase (ALT) levels above two times the upper limit of normal for ≥3 months (3.23% versus 14.29%, P = 0.0455), a lesser extent of postpartum elevations of ALT (P = 0.007), and a lower rate of ALT over five times the upper limit of normal (1.64% versus 14.29%, P = 0.0135) at 2 months postpartum. Maternal creatinine and creatinine kinase levels, rates of congenital anomaly, premature birth, and growth parameters in infants were comparable in both groups. At 12 months, one TDF-group child newly developed HBsAg positivity, presumably due to postnatal infection and inefficient humoral responses to vaccines.

CONCLUSIONS

Treatment with TDF for highly viremic mothers decreased infant HBV DNA at birth and infant HBsAg positivity at 6 months and ameliorated maternal ALT elevations. (Hepatology 2015;62:375-386.

Efficacy of tenofovir disoproxil fumarate to prevent vertical transmission in mothers with lamivudine-resistant HBV

BACKGROUND

In China, women with chronic HBV infection and who are of childbearing age receive lamivudine at an early age. Thus, viral resistance becomes a challenge for intervention to prevent mother-to-infant transmission. We prospectively assessed the efficacy of tenofovir in pregnant women with lamivudine-resistant HBV.

METHODS

Chronic HBV-infected mothers resistant to lamivudine were enrolled. Tenofovir was administrated at gestation weeks 24 or 28. Virological and biochemical parameters were assessed. All infants received combined immunoprophylaxis and were followed for 1 year.

RESULTS

Of the 48 mothers enrolled, 21 started tenofovir therapy at gestation week 24 and 27 started at week 28. Tenofovir resulted in an HBV DNA decline of 5.23 ± 1.68 log10 IU/ml at delivery. The group starting therapy at week 24 exhibited a more rapid viral inhibition (P<0.001) and more significant HBV DNA load decline (5.89 ± 1.66 versus 4.72 ± 1.55; P=0.019) than the group starting at week 28. At delivery, all mothers had a viral titre <10(6) IU/ml, 76.2% from the week 24 starting group displayed virus <10(4) IU/ml, and 52.4% showed undetectable virus at delivery, much higher than the week 28 starting group (29.6%), although there was no statistically significant difference in viral levels at delivery between the two groups. Congenital abnormalities and neonatal growth were comparable to the normal population. No case of perinatal transmission was diagnosed.

CONCLUSIONS

This investigation clarifies the efficacy of tenofovir for reducing vertical transmission of HBV in mothers with lamivudine-resistant HBV and demonstrates that tenofovir is well-tolerated in the second and third trimesters.

Global elimination of mother-to-child transmission of hepatitis B: revisiting the current strategy

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a major route of HBV transmission worldwide despite an existing immunoprophylaxis regimen. The implementation of immunoprophylaxis has been challenging, especially in low-income and middle-income countries, where MTCT is common, because of difficulty obtaining and delivering the monovalent HBV vaccine and the HBV immunoglobulin. Global control of the HBV epidemic will need improved prevention of MTCT. We discuss research gaps that hinder development of new options for the elimination of MTCT as well as policy changes that may help the current vaccine-based strategy to live up to its full potential. We propose that decreasing hepatitis B viral concentrations before delivery, along with HBV vaccine use, could provide an alternative strategy that would decrease MTCT of HBV.

Hepatitis B virus infection in children

For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate.

[Prophylaxis of mother-to-infant transmission of hepatitis B virus]

Hepatitis B virus (HBV) infection is a worldwide health problem and mother-to-infant (or vertical) transmission is the main source of chronic infection in Asian countries. Administration of HBV vaccine to the infant at birth, with or without concurrent specific immunoglobulin, efficiently prevents such transmission (efficacy>90%). In France, testing Ag HBs is mandatory during pregnancy in all pregnant women. Infants born to Ag HBs-positive mothers should receive the first injection of vaccine and one injection of specific immunoglobulins at birth. Vaccination should thereafter be completed according to a three-injection protocol (at 1 and 6 months) or a four-injection protocol in case of prematurity. Failure of immunoprophylaxis can be observed when the viral load is very high in the mother during pregnancy (HBV-DNA levels>200,000 IU/mL). In such women, antiviral therapy with analogs (lamivudine, telbivudine, or tenofovir) during the third trimester of pregnancy and 1 month post-partum, in association with accurate immunoprophylaxis, may prevent vertical transmission. The optimal cut-off value of maternal viral load for antiviral therapy in late pregnancy and post-partum to prevent vertical transmission is still under debate.

Missed opportunities: Peripartum hepatic failure in a Chinese immigrant

Hepatitis B surface antigen (HBsAg) positivity presents unique management challenges in pregnancy. We present the case of a 26-year-old HBsAg-positive woman who presented at 35 weeks gestational age with nausea, vomiting, and abdominal pain with markedly elevated liver enzymes. An elevated alpha feto-protein on antenatal screening had been misconstrued as fetal in origin. Magnetic resonance imaging and liver biopsy confirmed hepatocellular carcinoma. She died of fulminant hepatic failure two weeks after emergent delivery. This case highlights the importance of adequate evaluation and management of pregnant patients testing positive for HBsAg on routine antenatal testing.

Vertical transmission of hepatitis B virus: challenges and solutions

More than 240 million people worldwide are chronically infected with hepatitis B virus (HBV). Mother-to-child transmission remains the most important mechanism of infection in countries with a high prevalence of HBV. Universal screening of all pregnant women, at-birth prophylaxis with specific anti-HBV immune globulin, as well as HBV vaccination for newborns of infected mothers are effective in reducing the risk of vertical transmission. However, in cases of a high viral load and hepatitis B e antigen positivity, there is a residual risk of HBV transmission to the newborn despite prophylaxis. This review focuses on the above-indicated strategies and on the efficacy and safety of antiviral drugs administered during the third trimester of pregnancy.

Prevention of mother-to-child transmission of hepatitis B virus and hepatitis C virus

About 240 million people worldwide are chronically infected with hepatitis B virus (HBV). Vertical transmission is the most important mechanism of infection persistence in endemic areas. About 150 million people worldwide are chronically infected with hepatitis C virus (HCV). Mother-to-child transmission of HCV, which occurs in 3-10% of cases, is the leading route of infection in childhood. This review focuses on strategies to reduce the vertical transmission of HBV and HCV. The at-birth prophylaxis of newborns of HBV-infected mothers with specific immunoglobulin and vaccine plus administration of antivirals (tenofovir or telbivudine) in the third trimester of pregnancy (in case of high maternal viral load) greatly reduces the risk of transmission. In contrast, currently there is no drug able to reduce the vertical transmission of HCV infection. We discuss the possibility of reducing mother-to-child HCV transmission using newly available antivirals or antivirals in the pipeline for the treatment of hepatitis C.