Cost-effectiveness of quantitative hepatitis B virus surface antigen testing in pregnancy in predicting vertical transmission risk

Role of HBsAg levels in guiding hepatitis B virus prophylaxis in pregnancy: Insights from a multi-ethnic cohort

Pregnant mothers with chronic hepatitis B infection (CHB) need peri-partum antiviral prophylaxis (PAP) to reduce the risk of mother-to-child-transmission. Currently, PAP is recommended in those with high viral load (VL) that is, HBV DNA >200,000 IU/mL. Quantitative hepatitis B surface antigen (qHBsAg) >10,000 IU/mL, a cut-off derived primarily from hepatitis B e-antigen (HBeAg) positive antenatal cohorts in Chinese populations, is advocated as a surrogate marker of VL for guiding PAP. We investigated the utility of qHBsAg to predict high-VL in a multi-ethnic urban cohort with CHB. A consecutive cohort of women with CHB was identified from Barts Health NHS Trust databases in the United Kingdom. We included women with paired HBV DNA and qHBsAg during pregnancy. Women already on antiviral at conception were excluded. A total of 769 pregnancies in 678 CHB pregnant mothers (median age 31 years-old, 8.6% HBeAg+) were included. At median gestational age of 15.3 weeks, HBV DNA was 336 (IQR 44-2998) IU/mL, with 65 (8.5%) being high-VL. Serum qHBsAg was most useful in Black/Black-British/Caribbean/African (AUROC 0.946) with 100% sensitivity and 80.6% specificity to predict high-VL; but it performed less well for other ethnicities: Asian (AUROC 0.877), White (AUROC 0.797) and mixed ethnicities (AUROC 0.742). In conclusion, for settings where healthcare resources are not limited, HBV DNA remains the optimal marker to identify highly viraemic pregnancies for guiding PAP. For resource-limited settings where the prevailing cost is treatment, serum qHBsAg can be used in Black/Black British/Caribbean/African sub-cohorts, but not for other ethnicities.

Predicting hepatitis B e Antigen seroconversion after pregnancy-The SydPregScore

BACKGROUND AND AIMS

Achieving Hepatitis B e antigen seroconversion (HBeAg SC) at an earlier age confers a better prognosis. We examined baseline and post-partum factors associated with HBeAg SC after pregnancy. We developed a tool, the SydPregScore, to estimate the likelihood of HBeAg SC in the years after pregnancy.

METHODS

A retrospective analysis of an HBeAg-positive pregnant cohort was conducted. Variables including baseline age, parity, alanine aminotransferase level, HBV viral load, quantitative HBsAg, use of antiviral therapy and post-partum flare were collected. Univariate and multivariate Cox regression analyses to determine predictors of HBeAg SC and develop a predictor score were performed.

RESULTS

We analysed HBeAg SC rates in 220 pregnancies to 149 HBeAg-positive women from 2006 to 2019. At baseline, their median age was 33 (IQR 29-37), ALT 23 U/L (IQR 17-33) and viral load 8 log₁₀ IU/mL (IQR 6.3-8.2 log₁₀ IU/mL). The majority (133/198, 67.2%) received short-course antiviral therapy to prevent mother-to-child transmission, and 109/192 (56.8%) had a post-partum flare. HBeAg SC occurred in 74/220 (33.6%) after pregnancy (median follow-up 814 days, IQR 405-1531). Multivariate analysis identified baseline viral load <8 log₁₀ IU/mL (HR 2.426 [1.224-4.809], p = .011), baseline ALT ≥2 ULN (HR 2.726 [1.299-5.721], p = .008) and age <35 (HR 2.859 [1.255-6.513], p = .012) to be positive predictors of HBeAg SC. The 'SydPreg Score' estimated the probability of HBeAg SC at 2000 days as 10%, 30%, 70% and 80% for 0, 1, 2, and 3 predictors respectively.

CONCLUSION

The SydPreg Score allows the prediction of HBeAg SC in the years after pregnancy. Even in those without elevated ALT, age <35 and viral load <8 log₁₀ IU/mL can identify women with a good chance of subsequent HBeAg SC. Those without a chance may benefit from viral suppression.

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.

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.

The relationship between hepatitis B virus serum DNA, RNA and quantitative hepatitis B surface antigen, and the predictive value for mother-to-child transmission: an observational cohort study

OBJECTIVE

To explore the relationships between hepatitis B virus (HBV) DNA, HBV RNA and hepatitis B surface antigen (HBsAg) and to evaluate their predictive value for mother-to-child transmission of HBV.

DESIGN

An observational cohort study.

SETTING

First Hospital of Jilin University.

POPULATION

HBsAg-positive and hepatitis B e antigen (HBeAg) -positive pregnant women were recruited.

METHODS

Blood samples were collected from mothers before delivery, and HBV infection of infants was evaluated at 7 months of age.

RESULTS

Overall, 268 mothers and 271 infants were enrolled. HBV DNA and HBsAg levels were correlated (r_s  = 0.699; P < 0.001), and HBV DNA (r_s  = 0.500; P < 0.001) and HBsAg (r_s  = 0.372; P < 0.001) were both correlated with HBV RNA. The areas under the curve for HBV DNA, HBsAg and HBV RNA for prediction of infection were 0.69 (95% CI 0.57-0.82), 0.63 (95% CI 0.51-0.76) and 0.65 (95% CI 0.52-0.78), respectively. Higher HBV DNA (odds ratio [OR] 4.77, 95% CI 1.44-15.86), higher HBsAg (OR 4.13, 95% CI 1.12-15.25) and higher HBV RNA (OR 3.19, 95% CI 1.09-9.32) were risk factors for HBV infection. Analysis of the HBV DNA-RNA-HBsAg Score revealed that it was an independent predictive factor for mother-to-child transmission (the OR of Score 3 was 8.81, 95% CI 2.79-27.82).

CONCLUSION

HBV DNA, HBV RNA and HBsAg were correlated in HBeAg-positive pregnant women. HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. We should pay special attention to pregnant women with high levels of all three markers.

TWEETABLE ABSTRACT

HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. Special attention should be given to pregnant women with high levels of all three markers (HBV DNA, HBV RNA and HBsAg).

Viral hepatitis and pregnancy

The management of viral hepatitis in the setting of pregnancy requires special consideration. There are five liver-specific viruses (hepatitis A, B, C, D, E), each with unique epidemiology, tendency to chronicity, risk of liver complications and response to antiviral therapies. In the setting of pregnancy, the liver health of the mother, the influence of pregnancy on the clinical course of the viral infection and the effect of the virus or liver disease on the developing infant must be considered. Although all hepatitis viruses can harm the mother and the child, the greatest risk to maternal health and subsequently the fetus is seen with acute hepatitis A virus or hepatitis E virus infection during pregnancy. By contrast, the primary risks for hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus are related to the severity of the underlying liver disease in the mother and the risk of mother-to-child transmission (MTCT) for HBV and HCV. The prevention of MTCT is key to reducing the global burden of chronic viral hepatitis, and prevention strategies must take into consideration local health-care and socioeconomic challenges. This Review presents the epidemiology of acute and chronic viral hepatitis infection in pregnancy, the effect of pregnancy on the course of viral infection and, conversely, the influence of the viral infection on maternal and infant outcomes, including MTCT.

Hepatitis B - Vertical transmission and the prevention of mother-to-child transmission

Hepatitis B virus (HBV) infection is the commonest cause of chronic hepatitis, with an estimated global prevalence of 3.5%, and which leads to significant morbidity and mortality. Mother-to-child transmission (MTCT) during pregnancy is the leading form of transmission in endemic populations, and its interruption is thus crucial as the initial step in the elimination of HBV infection, notwithstanding the availability of potent antiviral medications. The risk of MTCT is dramatically reduced by timely neonatal HBV vaccination and the administration of hepatitis B immunoglobulin after birth in high-risk infants. Maternal HBV DNA quantification during pregnancy allows the assessment of the risk of newborn immunoprophylaxis failure (IF). Maternal antiviral treatment in highly viremic women can reduce the risk of IF. However, the optimal HBV DNA cutoff level for the initiation of antiviral treatment remains to be determined.

Hepatitis B and Pregnancy: Virologic and Immunologic Characteristics

The hepatitis B virus (HBV) is an important human pathogen. Unvaccinated infants infected through mother-to-child transmission (MTCT) are at >95% risk of developing serum hepatitis B surface antigen-positive chronic hepatitis B (CHB). Despite complete passive-active HBV immunoprophylaxis, approximately 10% of infants born to mothers who are highly viremic develop CHB, and thus maternal treatment with nucleos(t)ide analogs (tenofovir disoproxil fumarate, lamivudine, or telbivudine) is recommended in the third trimester of pregnancy to reduce MTCT risk. Viral rebound usually occurs after stopping treatment and, in the context of maternal immunologic reconstitution postpartum, can also precipitate host immune-mediated hepatic (biochemical) flares. In this article, we review the epidemiology of HBV MTCT, discuss management and potential mechanisms of HBV vertical transmission, and highlight recent studies on virologic and immunologic aspects of hepatitis B in pregnancy and postpartum.

Quantitative Hepatitis B Surface Antigen Predicts Hepatitis B Transmission in Infants Born to e Antigen-positive Mothers

GOALS

This study aimed to explore whether quantitative surface antigen [hepatitis B surface antigen (HBsAg)] can be used as a surrogate marker of hepatitis B virus (HBV) DNA to predict hepatitis B transmission before the first hepatitis vaccine dose in infants born to hepatitis B e antigen (HBeAg)-positive pregnant women.

BACKGROUND

Currently, HBV transmission persistently occurs worldwide, especially in infants born to e antigen (HBeAg)-positive highly viremic mothers. However, due to high cost, the extensive use of viral load testing to identify these high-risk mothers is limited.

MATERIALS AND METHODS

In total of 275 HBeAg-positive pregnant women paired with 280 infants were enrolled in this study. Quantitative HBsAg and HBV DNA levels were measured in the third trimester. Spearman rank correlation was used to assess the correlation between HBsAg levels and viral load, and multivariate logistic regression to identify factors related to HBV transmission in infants.

RESULTS

Among 280 infants included, 15 (5.4%) infants were infected with HBV. In this study, we observed that quantitative HBsAg was positively correlated with maternal viral load (r=0.70, P<0.001) and highly predicted HBV transmission in infants born to HBeAg-positive mothers with area under the curve of 0.76 (95% confidence interval, 0.71-0.81). The optimum threshold HBsAg levels above 4.6 log10 IU/mL to predict HBV transmission in infants had a sensitivity of 80.0%, specificity of 67.9%.

CONCLUSIONS

Quantitative HBsAg could be used as a surrogate marker of HBV DNA levels to predict hepatitis B transmission occurring before the injection of first-dose vaccine in infants born to e antigen-positive mothers.

Presence of Precore (C)/C Promoter Mutants in Peripheral Blood Mononuclear Cells of Chronic Hepatitis B (CHB) Carriers During Pregnancy Does Not Correlate with Increased Risk of Liver Disease in 4 Years of Follow-Up

PURPOSE

HBV precore (PC) and basal core promoter (BCP) mutants are associated with liver disease severity, yet have been suggested to protect against HBV vertical transmission. HBV within peripheral blood mononuclear cells (PBMC) has been reported in association with intrauterine HBV infection. We analyzed HBV replication status in PBMC and PC/BCP mutants in PBMC from pregnant chronic hepatitis B (CHB) patients.

METHODS

Pregnant CHB carriers were assessed for HBeAg, HBV-DNA, ALT in second-third trimester and liver stiffness measurement (LSM) postpartum. HBV-DNA, HBV-cccDNA, and HBV-mRNA were tested in PBMC by in-house PCR. BCP/PC variants were determined by Sanger sequencing and analyzed using MEGA7.

RESULTS

In 37 CHB pregnant carriers, median age 32 years, 53% Asian, median ALT 19 versus 26 U/L, median HBV-DNA 2.6 versus 8.1 logIU/mL (untreated vs. treated), eight HBeAg⁺, with genotype 10%A, 29%B, 21%C, 10%D, 19%E, eight received tenofovir in pregnancy to reduce vertical transmission risk. HBV-DNA was detected in ~ 55% (25/45) PBMC, and PC/BCP mutations were found in 36% (9/25) and 4% (1/25), respectively. All infants received HBV immunoprophylaxis and tested HBV surface antigen negative at 9-12 months of age. During a median 4 years (IQR 3-5), follow-up all mothers showed normal LSM, with no significant change in ALT, HBeAg status, or HBV-DNA levels compared to baseline in untreated CHB carriers.

CONCLUSION

In this multiethnic cohort of pregnant CHB carriers, HBV replicative intermediates and PC/BCP mutants were found in significant proportion of PBMC, but were not associated with increased risk of HBV immunoprophylaxis failure or liver disease severity over long-term follow-up.

Use of HBsAg quantification in the natural history and treatment of chronic hepatitis B

In patients with chronic hepatitis B (CHB) infection, it is important to monitor the natural history, assess treatment response, and predict the risk of liver-related complications. Quantification of serum hepatitis B surface antigen (HBsAg) has gained wide interests since the last decade. It is secreted from hepatocytes in both hepatitis B e antigen (HBeAg)-positive and HBeAg-negative phases of the disease, and can be transcribed and translated from different sources of viral genome [ccc DNA or integrated hepatitis B virus (HBV) DNA]. In untreated patients, it declines slowly through the natural course and remains stable for a long time after HBeAg seroconversion. In patients treated with nucleos(t)ide analogues (NA), it also declines very slowly, even though serum hepatitis B DNA has been rendered negative. Low serum HBsAg may predict either spontaneous or treatment-induced HBsAg seroclearance, and potentially selects out HBeAg-negative patients who can safely stop NA. High serum HBsAg is associated with high risk of hepatocellular carcinoma in untreated population, and predicts treatment failure in patients receiving pegylated interferon. These potential roles of HBsAg quantification are applicable to selected populations only. There is also a need for novel markers to study the effect of emerging antiviral therapies targeting various parts of the HBV cycle to reflect their distinct mechanistic effects. Several agents measuring HBsAg levels have shown rapid and significant decline. Ongoing studies are required to demonstrate the sustainability of HBsAg suppression by these novel agents.

Observation of the effect of the pregnancy complicated with the hepatitis B infection on the lying-in women and neonates

Objective

To investigate the effect of pregnancy complicated with the hepatitis B infection on the pregnancy outcome, immunological factors and the subgroup of lymphocytes in neonates.

Methods

Subjects admitting to this hospital between January 1, 2016 and January 1, 2018 in this study were divided into two groups according to the hepatitis B infection, i.e. the observation group (infection) and the control group (healthy), with 60 subjects in each group. Pregnancy complications and the neonatal complications were all recorded, and furthermore, the subgroups of lymphocytes and the levels of immunoglobin in the umbilical cord blood were measured.

Results

The incidence rates of the premature rupture of fetal membranes, premature delivery, postpartum hemorrhage and pregnancy-induced hypertension syndrome in the observation group were all higher than those in the control group, and the differences had statistical significance. In the observation group, the incidence rates of the neonatal distress and asphyxia, and the levels of neonatal CD3^＋, CD4^＋, CD19^＋, IgA and IgM varied significantly from those in the control group, and the differences showed statistical significance. However, no significant differences were identified in comparison of the incidence rate of the cesarean delivery, neonatal deformity, neonatal death, or levels of neonatal CD8⁺ and IgG.

Conclusion

During pregnancy, complications of hepatitis B infection results in the increases in the incidence rates of the premature rupture of fetal membranes and neonatal asphyxia, with influences on the levels of immunological factors and lymphocyte subgroups in the umbilical cord blood.

Long-Term Follow-up and Quantitative Hepatitis B Surface Antigen Monitoring in North American Chronic HBV Carriers

INTRODUCTION

Quantitative hepatitis B surface antigen (qHBsAg) combined with HBV DNA may be useful for predicting chronic hepatitis B (CHB) activity and nucleoside analogue (NA) response.

MATERIAL AND METHODS

In this retrospective cohort study we evaluated qHBsAg levels according to CHB disease phase and among patients on treatment. Random effect logistic regression analysis was used to analyze qHBsAg change with time in the NA-treated cohort.

RESULTS

545 CHB carriers [56% M, median age 48 y (IQR 38-59), 73% Asian] had qHBsAg testing. In the untreated group (44%), 8% were classified as immune tolerant, 10% immune clearance, 40% inactive, and 43% had HBeAg- CHB and the median HBsAg levels were 4.6 (IQR 3.4-4.9), 4.0 (IQR 3.4-4.5), 2.9 (IQR 1.4-3.8), and 3.2 log IU/mL (IQR 2.6-4.0), respectively; p < 0.001. In the NA-treated group (28% entecavir, 68% tenofovir, 4% lamivudine), no significant change in qHBsAg levels occured with time. However, 19% of patients on long-term NA had sustained qHBsAg < 2 log10 IU/mL.

CONCLUSION

qHBsAg titers were associated with CHB phase and remained stable in those on long-term NA. A significant number of treated patients had low-level qHBsAg, of which some may be eligible for treatment discontinuation without risk of flare.

Review of Laboratory Tests used in Monitoring Hepatitis B Response to Pegylated Interferon and Nucleos(t)ide Analog Therapy

There are only two currently approved classes of hepatitis B virus (HBV) antiviral agents, pegylated interferon (Peg-IFN), and nucleos(t)ide analogs (NAs) for chronic HBV infection. Although Peg-IFN is used for a finite 48-week duration and offers a greater chance of sustained off-treatment virological response, it is poorly tolerated and can only be offered to selected patients. The NAs are well tolerated but require prolonged therapy due to risk of relapse with treatment cessation. There is evolving data that novel virological assays (e.g., quantitative hepatitis B surface antigen, quantitative hepatitis B core antigen, quantitative antibody to core protein) in combination with hepatitis B genotype and more sensitive HBV DNA polymerase chain reaction (PCR) assays may be useful to predict response to IFN as well as off-treatment NA durability. Utilization of these clinical laboratory tests may be important given the development of novel anti-HBV therapies, hoping to achieve a cure for chronic hepatitis B infection.