Novel HBsAg mutations correlate with hepatocellular carcinoma, hamper HBsAg secretion and promote cell proliferation in vitro

Mutations in the HBV PreS/S gene related to hepatocellular carcinoma in Vietnamese chronic HBV-infected patients

Background

Chronic hepatitis B virus (CHB) infection is a major health problem and leading cause of hepatocellular carcinoma (HCC) worldwide. Several point and deletion mutations on the PreS/S gene have been intensively considered associated with HCC. This study aimed to describe the characteristics of HBV PreS/S mutations in Vietnamese CHB-infected patients and their association with HCC.

Methods

This cross-sectional study was conducted from 02/2020 to 03/2021, recruited Vietnamese CHB-infected patients with HBV-DNA >3 log₁₀-copies/mL and successful PreS/S gene sequencing. Mutations were detected by direct Sanger sequencing.

Results

247 CHB-infected patients were recruited, characterized by 68.8% males, 54.7% HBV genotype B, 57.5% HBeAg positive, 23.1% fibrosis score ≥F3 and 19.8% HCC. 61.8% amino acid replacements were detected throughout the PreS1/PreS2/S genes. The most common point-mutations included N/H51Y/T/S/Q/P (30.4%), V68T/S/I (44.9%), T/N87S/T/P (46.2%) on PreS1 gene; T125S/N/P (30.8%), I150T (42.5%) on PreS2 gene; S53L (37.7%), A184V/G (39.3%), S210K/N/R/S (39.3%) on S gene. The rates of case(s) with any point-mutation on the Major Hydrophylic Region (MHR) and the "a" determinant region were 63.6% and 39.7%, respectively. Most of S point-mutations were presented with low rates such as T47A/E/V/K (9.3%), P120S/T (8.5%), G145R (2%). On multivariable analysis, males (OR = 4.51, 95%CI 1.78–11.4, p = 0.001), age≥40 (OR = 5.5, 95%CI 2.06–14.68, p = 0.001), W4P/R/Y on PreS1 (OR = 11.56, 95%CI 1.99–67.05, p = 0.006) and 4 S point-mutations as: T47A/E/V/K (OR = 3.67, 95%CI 1.19–11.29, p = 0.023), P120S/T (OR = 3.38, 95%CI 1.09–10.49, p = 0.035), S174N (OR = 29.73, 95%CI 2.12–417.07, p = 0.012), P203R (OR = 8.45, 95%CI 1.43–50.06, p = 0.019) were associated with HCC.

Conclusions

We detected 61% amino acid changes on PreS/S regions in Vietnamese CHB patients. One point-mutation at amino acid 4 on PreS1 gene and 4 point-mutations at amino acids 47, 120, 174, and 203 on S gene were associated with HCC. Further investigations are recommended to further clarify the relationship and interaction between mutations in HBV genome and HCC progression.

State of the art treatment of hepatitis B virus hepatocellular carcinoma and the role of hepatitis B surface antigen post-liver transplantation and resection

Chronic hepatitis B virus (HBV) infection is the major aetiology of hepatocellular carcinoma (HCC). The optimal goal of therapy, hepatitis B surface antigen (HBsAg) loss and anti-HBs production, is achieved rarely and HBsAg-associated HCC risk is well recognized. Here we review the role of HBsAg in HCC, the link between HBsAg and HCC recurrence post-liver transplantation or resection, and the implications for therapy. HBV-associated carcinogenesis is a multifactorial process. The observation that HBV-related HCC can occur in the absence of cirrhosis is compatible with a direct oncogenic effect of the virus, which may occur via multiple mechanisms, including those mediated by both mutated and unmutated HBsAg. HCC recurrence in HBsAg-positive patients post-liver transplantation has been reported in 10%-15% of patients and is likely to be because of expansion of residual HCC tumour cell populations containing integrated HBV DNA, which expand and independently replicate HBV, leading to the recurrence of both HCC and HBV. The direct role of HBsAg in HCC recurrence post-liver resection is less clear. Cirrhosis is the most important risk factor for HCC development, and precancerous cirrhotic liver remains after resection, with the potential to undergo malignant transformation regardless of the existence of HBV-derived oncogenic drivers. The role of HBsAg in the development of HCC and its recurrence post-surgical intervention has multiple implications for therapy and suggests a potential role for immunotherapy in the future management of HCC, in particular post-liver transplantation. Use of hepatitis B immunoglobulins that target HBsAg directly, alongside immune-oncology therapies, may be relevant in this setting.

Hepatitis B virus DNA integration as a novel biomarker of hepatitis B virus-mediated pathogenetic properties and a barrier to the current strategies for hepatitis B virus cure

Chronic infection with Hepatitis B Virus (HBV) is a major cause of liver-related morbidity and mortality worldwide. HBV-DNA integration into the human genome is recognized as a frequent event occurring during the early phases of HBV infection and characterizing the entire course of HBV natural history. The development of refined molecular biology technologies sheds new light on the functional implications of HBV-DNA integration into the human genome, including its role in the progression of HBV-related pathogenesis and in triggering the establishment of pro-oncogenic mechanisms, promoting the development of hepatocellular carcinoma. The present review provides an updated and comprehensive overview of the current body of knowledge on HBV-DNA integration, focusing on the molecular mechanisms underlying HBV-DNA integration and its occurrence throughout the different phases characterizing the natural history of HBV infection. Furthermore, here we discuss the main clinical implications of HBV integration as a biomarker of HBV-related pathogenesis, particularly in reference to hepatocarcinogenesis, and how integration may act as a barrier to the achievement of HBV cure with current and novel antiviral therapies. Overall, a more refined insight into the mechanisms and functionality of HBV integration is paramount, since it can potentially inform the design of ad hoc diagnostic tools with the ability to reveal HBV integration events perturbating relevant intracellular pathways and for identifying novel therapeutic strategies targeting alterations directly related to HBV integration.

Clinical, Pathological and Genetic Characteristics of Pediatric Hepatocellular Carcinoma Associated with Hepatitis B Virus Infection

Introduction

Hepatocellular carcinoma (HCC) remains the major challenge in the management of patients with hepatitis B virus (HBV) infection. To date, limited studies have been done on pediatric HBV-associated HCC specifically.

Methods

Pediatric patients younger than 16 years with HBV-associated HCC were included in the study. HBV integration detection was performed using a high-throughput viral integration detection (HIVID) method.

Results

Among the 13 included pediatric patients, boys predominated (10, 76.9%). The median age at diagnosis of HCC was 13 years and the youngest age was 6 years. Nine patients had initially seronegative hepatitis B e antigen (HBeAg) and 4 had seropositive HBeAg. All patients had cirrhosis and elevated alpha-fetoprotein. Splenomegaly was present in all patients. Intrahepatic HBsAg was not detected in any tumor tissues from 5 patients who underwent biopsy or excision, while it was positive in all matched non-tumor tissues. In the tumor and matched non-tumor tissues from 3 individuals, HBV integration was identified except in the neoplastic specimen from 1 patient. Integration into the reported genes associated with hepatocarcinogenesis was not found in the tumor tissues from the 3 patients.

Discussion

Hypervigilance for HCC development is required in HBeAg-negative cirrhotic children. The findings based on the immunohistochemical and genetic results expand the knowledge of pediatric HCC development.

Prophylaxis of Hepatitis B Virus (HBV) Re-Infection in Liver Transplantation: Is the Reappearance of Hepatitis B Surface Antigen (HBsAg) Significant?

The recurrence of hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) was in the past a primary cause of organ loss or mortality. Currently, post-OLT prophylaxis with anti-HBs immunoglobulins plus a nucleos(t)ide analogue has virtually abolished the risk of re-infection. Some studies have proposed to simplify prophylaxis by discontinuing immunoglobulins while continuing the analogue alone.

This review analysed the available studies, focusing on the recurrence of HBsAg in serum and its biological effects. In all, 16 studies were retrieved, mainly observational or retrospective, each enrolling 14 to 80 patients. Our review of the literature found that HBsAg re-appeared in 0% to 24% of the patients, generally with HBV DNA undetectable in plasma. One study measured HBsAg using a new ultra-sensitive method, which could allow a reappraisal of the incidence of recurrence. This review discusses the role of HBV surface proteins in inducing hepatocellular carcinoma, particularly when mutations in the C-terminal occur that induce stop-codons that cause defects of secretion and retention of truncated protein S, resulting in direct cell toxicity and cancer. The data on the suspension of immunoglobulins in the prophylaxis regimes of post-transplant re infection do not appear sufficiently robust for an extensive and safe application in clinical practice.

Hepatitis B virus pre-S/S variants in liver diseases

Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis (CH), liver cirrhosis (LC), and hepatocellular carcinoma (HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus (HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.

Personalized subcutaneous administration of hepatitis B surface antibodies without nucleos(t)ide analogs for patients at risk of renal failure after liver transplantation: a prospective single center cohort study

Currently, nucleos(t)ide analogs (NAs) in monotherapy are favored as prophylaxis against hepatitis B recurrence after liver transplantation. However, in patients at risk of renal failure, renal safety of NAs is of concern. We investigated the safety and efficacy of subcutaneous (SC) hepatitis B immunoglobulins (HBIG) in monotherapy. This is a single-arm prospective trial in patients transplanted >1 year. We included 43 Caucasian patients. The majority was treated with calcineurin inhibitors, and several patients had other risk factors for renal impairment as well: diabetes mellitus (n = 10/43), arterial hypertension (n = 11/43), and hyperlipidemia (=10/43). At inclusion, 42% (n = 18) had chronic kidney disease ≥ grade 3a. All patients were switched from IV HBIG with or without NAs to SC HBIG without NAs. After one year, the targeted titer was lowered to ≥150 IU/l in patients with low risk of recurrence. Mean follow-up time was 36 ± 5 months. None of the patients had a relapse of HBsAg or HBV DNA. The treatment was well tolerated, safe and the renal function remained unchanged both in patients with (n = 18) or without (n = 25) renal impairment at baseline. The mean HBsAb titer could be decreased from 343 ± 163 to 199 ± 81 IU/l in the low-risk group (n = 17) and 218 ± 71 IU/l in the high-risk group (n = 26). In 86% (n = 37) doses, reductions were possible, which significantly lowered the cost of treatment. SC HBIG without NAs had a 100% success rate in the long-term prevention of HBsAg and HBV DNA reappearance, without deterioration of renal function.

IL-18 polymorphisms contribute to hepatitis B virus-related cirrhosis and hepatocellular carcinoma susceptibility in Chinese population: a case-control study

IL-18 polymorphisms influence the transcriptional activity of the IL-18 gene and associated with various diseases. However, their relationships with hepatitis B virus-related liver diseases had not reached a consensus. So we conducted this case-control study with a view to clarifying the association. We included four groups: healthy controls, chronic hepatitis B virus (CHB) carriers, liver cirrhosis (LC) and hepatocellular carcinoma (HCC) groups with each group of 250 persons. Odd ratios (ORs) and 95% confidence intervals (95%CIs) with or without adjustment were calculated. Haplotype analysis was also performed. The results showed people carrying rs187238 CG genotype had a lower risk of LC (CG vs. CC: OR = 0.59, 95%CI = 0.38–0.91, P = 0.02), while GG genotype carriers had a higher risk of HCC (GG vs. CC+CG: OR = 4.73, 95%CI = 1.01–22.1, P = 0.03) than those with CC and CG genotypes in healthy group. Rs187238 GG genotype increased the risk from CHB to LC status (GG vs. CC: OR = 4.81, 95%CI = 1.03–22.6; GG vs. CC+CG: OR = 4.73, 95%CI = 1.01–22.1), meanwhile the trend also existed by controlling confounding factors (GG vs. CC: OR = 6.25, 95%CI = 1.09–35.8; GG vs. CC+CG: OR = 5.91, 95%CI = 1.04–33.7). Haplotype Crs187238Trs1946518 moderately decreased the risk of CHB carriers developing into HCC (OR = 0.69, 95%CI = 0.50–0.96, P = 0.03) after adjustment. In conclusion, IL-18 rs187238 GG genotype may increase the risk of HCC in healthy population and the risk of LC in CHB carriers.