Effects of antiviral therapy and drug withdrawal on postpartum hepatitis in pregnant women with chronic HBV infection

Chinese clinical practice guidelines for the prevention and treatment of mother-to-child transmission of hepatitis B virus (version 2024)

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International Practice Guidelines Registry Platform (PREPARE-2023CN171).

Chinese Clinical Practice Guidelines for the Prevention and Treatment of Mother-to-child Transmission of Hepatitis B Virus (Version 2024)

The Chinese Clinical Practice Guidelines for the Prevention and Treatment of Mother-to-child Transmission of Hepatitis B Virus, developed by the Chinese Society of Infectious Diseases of the Chinese Medical Association in 2019, serves as a valuable reference for standardizing the prevention of mother-to-child transmission in China. As new evidence continues to emerge, it is essential to update these guidelines regularly to optimize clinical practice and research. To this end, the Infectious Disease Physician Branch of the Chinese Medical Doctor Association and the Chinese Society of Infectious Diseases of the Chinese Medical Association, in collaboration with multidisciplinary experts, have updated the guidelines based on the latest domestic and international research advancements and clinical practices, providing up-to-date guidance for clinicians and maternal and child healthcare workers.

Postpartum hepatitis flares in mothers with chronic hepatitis B infection

Postpartum elevation of alanine aminotransferase (ALT) in mothers with chronic hepatitis B (CHB) presents a significant clinical challenge. However, the existing literature demonstrates inconsistencies regarding its incidence and predictors in mothers infected with the hepatitis B virus (HBV). Recent advancements in antiviral prophylaxis against mother-to-child transmission of HBV and postpartum cessation of antiviral therapy further complicate this issue. Our literature review, spanning PubMed, and two Chinese-language databases (CNKI and Wanfang) from 1 January 2000 to 31 December 2023 aimed to consolidate and analyse available data on the frequency and severity of postpartum ALT flares, identify risk factors, and propose a management algorithm. Data from 23 eligible studies involving 8,077 pregnant women revealed an overall incidence of postpartum ALT elevation: 25.7% for mild cases, 4.4% for moderate cases, and 1.7% for severe cases. In the subgroup of mothers who were HBeAg-positive and on antiviral prophylaxis for preventing mother-to-child transmission, postpartum intermediate and severe ALT elevations were reported with pooled rates of 5.9% and 0.8%, respectively. Importantly, none resulted in mortality or necessitated liver transplantation. Identified risk factors for postpartum ALT flares in mothers with CHB included HBV DNA levels, ALT levels during pregnancy, postpartum cessation of antiviral treatment, and HBeAg status. By leveraging this evidence and recent data on predictors of intermediate or severe postpartum ALT flares, we propose a risk-stratified algorithm for managing postpartum ALT elevation and selecting therapy in mothers with CHB, tailoring different approaches for treatment-naive vs treatment-experienced populations. These recommendations aim to provide guidance for clinical decision-making and enhance patient outcomes.

Chinese Clinical Practice Guidelines for the Prevention and Treatment of Mother-to-Child Transmission of Hepatitis B Virus (Version 2024)

The Chinese Clinical Practice Guidelines for the prevention and treatment of mother-to-child transmission of hepatitis B virus, developed by the Chinese Society of Infectious Diseases of the Chinese Medical Association in 2019, serves as a valuable reference for standardizing the process of preventing mother-to-child transmission in China. As new evidence emerges, it is crucial that timely and regular updates are made to the clinical practice guidelines so as to optimize guidance for clinical practice and research. To this end, the Infectious Disease Physician Branch of Chinese Medical Doctor Association and the Chinese Society of Infectious Diseases of Chinese Medical Association, in collaboration with multidisciplinary experts, have updated the guidelines based on the latest domestic and international research advancements and clinical practice, in order to provide guidance and reference for clinicians and maternal and child healthcare workers.

Immediate postpartum cessation of tenofovir did not increase risk of virological or clinical relapse in highly viremic pregnant mothers with chronic hepatitis B infection

Background & Aims

Peripartum prophylaxis (PP) with tenofovir disoproxil fumarate (TDF) is the standard of care to prevent mother-to-child transmission of chronic hepatitis B (CHB) infection in mothers who are highly viremic. We investigated the maternal and infant outcomes in a large Chinese cohort of TDF-treated CHB pregnant participants.

Methods

In this prospective study, treatment-naive mothers with CHB and highly viremic (HBV DNA ≥200,000 IU/ml) but without cirrhosis were treated with TDF at 24-28 weeks of pregnancy. In accordance with Chinese CHB guidelines, TDF was stopped at delivery or ≥4 weeks postpartum. Serum HBV DNA and alanine aminotransferase were monitored every 6-8 weeks to determine virological relapse (VR). Infants received standard neonatal immunization, and HBV serology was checked at 7-12 months of age.

Results

Among 330 participants recruited (median age 30, 82.7% HBeAg+, median HBV DNA 7.82 log IU/ml), TDF was stopped at delivery in 66.4% and at ≥4 weeks in 33.6%. VR was observed in 98.3%, among which 11.6% were retreated with TDF. Timing of TDF cessation did not alter the risk of VR (99.0 vs. 96.9%), clinical relapse (19.5 vs. 14.3%), or retreatment (12.6 vs. 10.1%) (all p > 0.05). A similar proportion of patients developed alanine aminotransferase flare five times (1.1 vs. 2.1%; p = 0.464) and 10 times (0.5 vs. 0%; p = 0.669) above the upper limit of normal (ULN) in the early withdrawal and late withdrawal groups, respectively. No infants developed HBsAg-positivity.

Conclusions

PP-TDF and neonatal immunization were highly effective in preventing mother-to-child transmission of HBV in mothers who are highly viremic. Timing of cessation of PP-TDF did not affect the risk of VR or retreatment.

Impact and Implications

In pregnant mothers with chronic hepatitis B infection who are started on peripartum tenofovir to prevent mother-to-child-transmission (MTCT), the optimal timing for antiviral withdrawal during the postpartum period remains unknown. This prospective study demonstrates that stopping tenofovir immediately at delivery, compared with longer treatment duration of tenofovir, did not lead to an increased risk of virological relapse, retreatment, or transmission of the virus to the baby. Shortening the duration of peripartum antiviral prophylaxis from 12 weeks to immediately after delivery can be considered. The immediate withdrawal of peripartum tenofovir, combined with standard neonatal immunization schemes, is 100% effective in preventing MTCT among pregnant mothers with CHB who are highly viremic, with a high rate of vaccine response in infants.

Effects of hepatitis B virus infection and strategies for preventing mother-to-child transmission on maternal and fetal T-cell immunity

One of the most common routes of chronic hepatitis B virus (HBV) infection is mother-to-child transmission (MTCT). Approximately 6.4 million children under the age of five have chronic HBV infections worldwide. HBV DNA high level, HBeAg positivity, placental barrier failure, and immaturity of the fetal immune are the possible causes of chronic HBV infection. The passive-active immune program for children, which consists of the hepatitis B vaccine and hepatitis B immunoglobulin, and antiviral therapy for pregnant women who have a high HBV DNA load (greater than 2 × 105 IU/ml), are currently two of the most important ways to prevent the transmission of HBV from mother to child. Unfortunately, some infants still have chronic HBV infections. Some studies have also found that some supplementation during pregnancy can increase cytokine levels and then affect the level of HBsAb in infants. For example, IL-4 can mediate the beneficial effect on infants' HBsAb levels when maternal folic acid supplementation. In addition, new research has indicated that HBV infection in the mother may also be linked to unfavorable outcomes such as gestational diabetes mellitus, intrahepatic cholestasis of pregnancy, and premature rupture of membranes. The changes in the immune environment during pregnancy and the hepatotropic nature of HBV may be the main reasons for the adverse maternal outcomes. It is interesting to note that after delivery, the women who had a chronic HBV infection may spontaneously achieve HBeAg seroconversion and HBsAg seroclearance. The maternal and fetal T-cell immunity in HBV infection is important because adaptive immune responses, especially virus-specific CD8 T-cell responses, are largely responsible for viral clearance and disease pathogenesis during HBV infection. Meanwhile, HBV humoral and T-cell responses are important for the durability of protection after fetal vaccination. This article reviews the literature on immunological characteristics of chronic HBV-infected patients during pregnancy and postpartum, blocking mother-to-child transmissions and related immune mechanisms, hoping to provide new insights for the prevention of HBV MTCT and antiviral intervention during pregnancy and postpartum.

Postpartum hepatitis and host immunity in pregnant women with chronic HBV infection

In order to develop immune tolerant to the fetal, maternal immune system will have some modification comparing to the time before pregnancy. Immune tolerance starts and develops at the maternal placental interface. In innate immunity, decidual natural killer (dNK) cells, macrophages and dendritic cells play a key role in immue tolerance. In adaptive immunity, a moderate increase of number and immune inhibition function of regulatory T cells (Treg) are essential for immune tolerance. The trophoblast cells and immune cells expressing indoleamine 2,3-dioxygenase (IDO), the trophoblast cells expressing HLA-G, and Th1/Th2 shifting to Th2 dominant and Th17/Treg shifting to Treg domiant are in favor of maternal fetal immune tolerance. Steroids (estrogen and progesterone) and human chorionic gonadotropin (HCG) also participate in immune tolerance by inducing Treg cells or upregulating immunosuppressive cytokines. Most of the patients with chronic HBV infection are in the "HBV immune tolerance period" before pregnancy, and the liver disease is relatively stable during pregnancy. In chronic HBV infection women, after delivery, the relative immunosuppression in vivo is reversed, and Th1 is dominant in Th1/Th2 and Th17 is dominant in Th17/Treg balance. After delivery, the number of Treg decrease and NK cells increase in quantity and cytotoxicity in peripheral blood. Liver NK cells may cause liver inflammation through a non-antigen specific mechanism. After delivery, the number of CD8+ T cells will increase and HBV specific T cell response recovers from the disfunction in pregnancy. Under the background of postpartum inflammation, the rapid decrease of cortisol after delivery, and especially the enhancement of HBV specific T cell response induced by HBV DNA and cytokines, are the main reasons for postpartum hepatitis. HBeAg positive, especially HBeAg<700 S/CO, and HBV DNA>3-5Log10IU/ml are risk factors for postpartum hepatitis. Antiviral treatment in late pregnancy can reduce the incidence of mother to child transmission (MTCT) in chronic HBV infection women. Chronic HBV infection women have hepatitis both during pregnancy and more often in 12 weeks postpartum. It is generally agreed that postpartum hepatitis is mild symptoms and self-limited. Delaying drug withdrawal to 48 weeks can increase the seroconversion rate of HBeAg in delivery women with elevated alanine aminotransferase (ALT) in pregnancy.