Clinicopathological study of occult hepatitis B virus infection in hepatitis C virus-associated hepatocellular carcinoma

Clinical Significance and Remaining Issues of Anti-HBc Antibody and HBV Core-Related Antigen

Currently, hepatitis B virus (HBV) core antibody (anti-HBc antibody) and HBV core-related antigen (HBcrAg) are widely used as serum markers for diagnosis based on the HBV core region. This review focused on anti-HBc antibodies and HBcrAg and aimed to summarize the clinical significance of currently used assay systems and the issues involved. While anti-HBc is very significant for clinical diagnosis, the clinical significance of quantitative assay of anti-HBc antibody has been reevaluated with improvements in diagnostic performance, including its association with clinical stage and prediction of carcinogenesis and reactivation. In addition, concerning the new HBcrAg, a high-sensitivity assay method has recently been established, and its diagnostic significance, including the prediction of reactivation, is being reevaluated. On the other hand, the quantitative level of anti-HBc antibody expressed in different units among assay systems complicates the interpretation of the results. However, it is difficult to standardize assay systems as they vary in advantages, and caution is needed in interpreting the assay results. In conclusion, with the development of highly sensitive HBcrAg and anti-HBc antibody, a rapid and sensitive detection assay system has been developed and used in clinical practice. In the future, it is hoped that a global standard will be created based on the many clinical findings.

Prevalence of occult hepatitis B virus infection in Egypt: a systematic review with meta-analysis

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is a major public health problem. The clinical importance of OBI stems from the fact that it can be transmitted to healthy individuals at extremely low viral load levels. Additionally, immunosuppression has the potential to trigger viral replication, which can result in life-threatening liver decompensation. Despite several studies examining the prevalence of OBI, the pooled prevalence of OBI in Egypt remains unknown, particularly among blood donors and high-risk individuals, to whom intervention should be targeted.

METHODS

A comprehensive literature search of the following databases was conducted from inception to October 2022 using the following keywords: occult hepatitis B virus infection or occult HBV infection or OBI and Egypt in MEDLINE [PubMed], Scopus, Google Scholar, and Web of Science. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. I-squared and Cochran's Q were used to measure the heterogeneity between the studies, and based on the random effects model, results were reported as proportions (%) with a 95% confidence interval (CI). Analyses of subgroup analyses were conducted based on the target population. Sensitivity analyses were conducted using the leave-one-out approach to test the robustness of the results.

RESULTS

A total of 50 studies with 62 estimations of OBI were included, 19 in patients who were HBsAg-negative and anti-HBc-positive and 43 in patients who were HBsAg-negative. The highest prevalence (41%) was among multi-transfused patients according to  studies that report occult hepatitis B virus prevalence in an HBsAg-negative population, while the pooled prevalence of OBI among patients on hemodialysis, patients with chronic hepatitis C infection, patients with hepatocellular carcinoma (HCC), and patients with liver cirrhosis was 17%, 10%, 24%, and 13%, respectively. On the other hand, among studies that report OBI prevalence in HBsAg-negative and anti-HBc-positive individuals, the pooled prevalence of OBI among blood donors, patients with chronic hepatitis C infection, and patients with HCC was 12%, 15%, and 31%, respectively. Also, the majority of studies examining the genetic background of OBI have found that genotype D is the most prevalent.

CONCLUSION

 This study highlights the high prevalence in OBI among blood donors and high-risk populations in Egypt. The implementation of HBV nucleic acid amplification testing (NAT) may increase the safety of blood transfusions by excluding all HBV DNA-positive donations. However, the cost-effectiveness of these tests should be investigated.

Occult hepatitis B in blood donation centers

Occult hepatitis B (OHB) is characterized by the presence of hepatitis B virus (HBV) DNA in the blood of individuals who test negative for the hepatitis B surface antigen (HBsAg). OHB in blood donors can lead to HBV transmission through transfusions, yet the prevalence of OHB in Basrah, Iraq, is unknown. This study aimed to determine the prevalence of OHB in blood donation centers in Basrah and investigate the immune response to HBV in OHB-positive donors. We recruited 450 blood donors and categorized them into four groups based on HBV markers: the HBsAg-negative/HBsAb-negative/HBcAb-positive group, the recovery group (HBsAg-negative/HBsAb-positive/HBcAb-positive), the patient group (HBsAg-positive/HBsAb-negative/HBcAb-positive), and the apparently healthy group (negative for all HBV markers). We measured levels of IgG, IgM, complement components (C3 and C4), ALT, AST, and serum ALP in OHB-positive donors. Of the 450 donors, 97 (21.6%) were OHB-positive. IgG levels were significantly higher than IgM levels in OHB-positive donors. Healthy and HBsAg-negative/HBsAb-positive donors had significantly lower C3 levels than patients. IgG levels were significantly higher than IgM in both the patient and recovery groups. C3 levels were higher than C4 levels in all groups. The serum ALP level was significantly higher in the patient group. OHB prevalence in Basrah blood donors is high, indicating the potential for HBV transmission. OHB-positive donors showed an immune response to HBV. Our study provides insights into OHB prevalence and immune response in Basrah, with implications for diagnostic and therapeutic approaches in blood donation centers.

Occult Hepatitis B Virus Infection: An Update

Occult hepatitis B virus (HBV) infection (OBI) refers to a condition in which replication-competent viral DNA is present in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing negative for the HBV surface antigen (HBsAg). In this peculiar phase of HBV infection, the covalently closed circular DNA (cccDNA) is in a low state of replication. Many advances have been made in clarifying the mechanisms involved in such a suppression of viral activity, which seems to be mainly related to the host's immune control and epigenetic factors. OBI is diffused worldwide, but its prevalence is highly variable among patient populations. This depends on different geographic areas, risk factors for parenteral infections, and assays used for HBsAg and HBV DNA detection. OBI has an impact in several clinical contexts: (a) it can be transmitted, causing a classic form of hepatitis B, through blood transfusion or liver transplantation; (b) it may reactivate in the case of immunosuppression, leading to the possible development of even fulminant hepatitis; (c) it may accelerate the progression of chronic liver disease due to different causes toward cirrhosis; (d) it maintains the pro-oncogenic properties of the "overt" infection, favoring the development of hepatocellular carcinoma.

What is the clinical impact of occult HBV infections and anti-HBc positivity in patients with chronic hepatitis C?

Occult hepatitis B infection (OBI) is defined by the persistence of the hepatitis B virus (HBV) genome in the liver of individuals testing negative for hepatitis B surface antigen (HBsAg). Hepatitis B core antibody (anti-HBc) is the serological marker that indicates HBV exposure. The impact of anti-HBc and OBI on patients with chronic hepatitis C remains unclear. The aim of the present study was to determine the prevalence of anti-HBc and OBI and to evaluate their impact on the clinical and pathological outcomes of patients with chronic hepatitis C. The study included 59 HBsAg-negative chronic hepatitis C patients who underwent a liver parenchymal biopsy. The presence of HBV DNA was investigated using an in-house nested PCR method. OBI was detected in 16 (27.1%) of the 59 cases and also in 10 (62.5%) of 22 (37.3%) anti-HBc-positive patients. None of the patients had positive serum HBV DNA. OBI was associated with the presence of anti-HBV antibodies (p<0.05). There was also an association between anti-HBc positivity and the activity grades and fibrosis stages of the liver and also a prevalence of liver steatosis (p<0.05). Positive anti-HBc results may predict OBI and also be associated with the progression of liver injury in HBsAg-negative patients with chronic hepatitis C. Therefore, it is suggested that patients with chronic hepatitis C should be screened for anti-HBc positivity, and anti-HBc-positive patients should be carefully evaluated for disease progression. This article is protected by copyright. All rights reserved.

Hepatitis B Core Antibody Positivity Associated with Increased Risk of Liver Cancer in Patients with Chronic Hepatitis C: Analysis of a Large Patient Cohort in Hawai'i

Chronic hepatitis C infection is a major cause of liver cancer in the United States. Hawai'i's incidence of liver cancer consistently ranks among the highest in the US, due in part to the high prevalence of hepatitis B in the state. To better understand the factors associated with liver cancer among patients in Hawai'i with hepatitis C virus (HCV) infection, the patient database of Kaiser Permanente's Hawai'i region was used to identify a cohort of 3198 patients with a history of chronic HCV infection, of whom 159 (5%) were diagnosed with liver cancer between the years 2004-2020. Multiple logistic regression was used to identify factors independently associated with liver cancer. Male sex (AOR 2.02, 95% CI 1.34-3.06), Asian race (AOR 1.78, 1.16 - 2.74) and hepatitis B core antibody (HBCAB) positivity (AOR 1.76, 95% CI 1.25 - 2.49) emerged as independent predictors of liver cancer among patients with chronic HCV infection. A history of diabetes (AOR 1.56, 1.07 - 2.27) and older age at the time of HCV diagnosis (AOR 1.19, 1.09-1.29) also emerged as significant associations. HBCAB-positive individuals did not differ significantly from those who were HBCAB-negative in regards to demographics or 5-year survival rate. In this cohort of patients with chronic HCV, a positive HBCAB without evidence of active hepatitis B infection was associated with 1.76 increased odds of liver cancer compared to those with negative HBCAB. This finding may have important implications for screening algorithms among individuals with hepatitis C infection.

Occult hepatitis B infection and hepatocellular carcinoma: Epidemiology, virology, hepatocarcinogenesis and clinical significance

Occult hepatitis B infection (OBI) refers to a condition where replication-competent HBV DNA is present in the liver, with or without HBV DNA in the blood, in individuals with serum HBsAg negativity assessed by currently available assays. The episomal covalently closed circular DNA (cccDNA) in OBI is in a low replicative state. Viral gene expression is mediated by epigenetic control of HBV transcription, including the HBV CpG island methylation pathway and post-translational modification of cccDNA-bound histone, with a different pattern from patients with chronic HBV infection. The prevalence of OBI varies tremendously across patient populations owing to numerous factors, such as geographic location, assay characteristics, host immune response, coinfection with other viruses, and vaccination status. Apart from the risk of viral reactivation upon immunosuppression and the risk of transmission of HBV, OBI has been implicated in hepatocellular carcinoma (HCC) development in patients with chronic HCV infection, those with cryptogenic or known liver disease, and in patients with HBsAg seroclearance after chronic HBV infection. An increasing number of prospective studies and meta-analyses have reported a higher incidence of HCC in patients with HCV and OBI, as well as more advanced tumour histological grades and earlier age of HCC diagnosis, compared with patients without OBI. The proposed pathogenetic mechanisms of OBI-related HCC include the influence of HBV DNA integration on the hepatocyte cell cycle, the production of pro-oncogenic proteins (HBx protein and mutated surface proteins), and persistent low-grade necroinflammation (contributing to the development of fibrosis and cirrhosis). There remain uncertainties about exactly how, and in what order, these mechanisms drive the development of tumours in patients with OBI.

Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development

INTRODUCTION

The sexually transmitted infections (STIs) caused by viruses including human T cell leukemia virus type-1 (HTLV-1), human immunodeficiency virus-1 (HIV-1), human simplex virus-2 (HSV-2), hepatitis C virus (HCV), hepatitis B virus (HBV), and human papillomavirus (HPV) are major public health issues. These infections can cause cancer or result in long-term health problems. Due to high prevalence of STIs, a safe and effective vaccine is required to overcome these fatal viruses.

AREAS COVERED

This review includes a comprehensive overview of the literatures relevant to vaccine development against the sexually transmitted viruses (STVs) using PubMed and Sciencedirect electronic search engines. Herein, we discuss the efforts directed toward development of effective vaccines using different laboratory animal models including mice, guinea pig or non-human primates in preclinical trials, and human in clinical trials with different phases.

EXPERT OPINION

There is no effective FDA approved vaccine against the sexually transmitted viruses (STVs) except for HBV and HPV as prophylactic vaccines. Many attempts are underway to develop vaccines against these viruses. There are several approaches for improving prophylactic or therapeutic vaccines such as heterologous prime/boost immunization, delivery system, administration route, adjuvants, etc. In this line, further studies can be helpful for understanding the immunobiology of STVs in human. Moreover, development of more relevant animal models is a worthy goal to induce effective immune responses in humans.

Pathological characterization of occult hepatitis B virus infection in hepatitis C virus-associated or non-alcoholic steatohepatitis-related hepatocellular carcinoma

Occult hepatitis B virus (HBV) infection, by definition, is a state in which infection with this virus does not manifest with the conventional diagnostic laboratory criteria reserved for the obvious form of HBV infection. As a result, occult HBV infection is commonly a surprise finding discovered accidently during the evaluation of other apparent liver diseases, such as hepatitis C virus (HCV) infection or non-alcoholic fatty liver disease and, more importantly, their evolution into life-threatening hepatocellular carcinoma. As infection with HCV and occult HBV is rarely considered when assessing these more obvious conditions, and in an attempt to offer a better understanding of this phenomenon, this study attempted to shed some light onto the uniqueness of occult HBV infection by addressing the natural history of HBV and HCV infections, as well as non-alcoholic fatty liver disease. This was carried out by taking into account the exclusive integration process undertaken by the HBV genome into infected host hepatocytes, with consideration given to conditions which afford reactivation of the occult infection and stress on the molecular mechanisms that underlie occult HBV infection. Finally, the clinical outcome of occult HBV infection and its relation to hepatocellular carcinoma is analyzed.

Comparison of clinical features and outcomes between HBV-related and non-B non-C hepatocellular carcinoma

Objective

To evaluate the difference between hepatitis B virus related hepatocellular carcinoma (HBV-HCC) and non-HBV non-HCV hepatocellular carcinoma (NBNC-HCC) patients based on clinical features and prognosis.

Methods

A total of 175 patients with HCC were enrolled. Patients’ characteristics were extracted from medical records. Among them, 107 patients were positive for HBsAg and negative for HCV-Ab while 68 patients were negative for HBsAg and HCV-Ab.

Results

The patients in the NBNC-HCC group were significantly older than those in the HBV-HCC group (P = 0.045). Moreover, vascular invasion was found in 23.4% of HBV-HCC patients, which was significantly higher than that in the NBNC-HCC patients with 10.3% (P = 0.029). Kaplan-Meier analysis revealed that HBV-HCC patients had significantly worse outcomes in terms of overall survival (P = 0.036). Compared with the NBNC-HCC patients, the HBV-HCC patients had a significantly worse disease-free survival (P = 0.0018). The multivariate analysis results indicated that TNM stage (HR = 1.541, 95%CI 1.072–2.412, P = 0.002) and HBV infection (HR = 1.087, 95%CI 1.012–1.655, P = 0.042) were independent risk variables for overall survival. While vascular invasion (HR = 1.562, 95%CI 1.013–2.815, P = 0.042) and HBV infection (HR = 1.650, 95%CI 1.017–2.676, P = 0.037) were independent risk factors associated with disease-free survival.

Conclusion

Our data revealed that HBV-HCC is more common in young males with vascular invasion, while NBNC-HCC occurs mostly in elderly patients, and overall survival rate is significantly better than that of HBV-HCC. Our study therefore provides evidence that patients with HBV-HCC require closer follow-up due to their poor prognosis.