The underlying mechanisms for the "simultaneous HBsAg and anti-HBs serological profile"

All-positive HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb in a patient with hepatitis B: A case report

RATIONALE

Mass vaccination, low cost of immunoglobulins, and new drugs led to the emergence of new, unusual patterns of hepatitis B serum markers. This study reported a rare case of hepatitis B with all 5 positive serum markers, including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb.

PATIENT CONCERNS

A 30-year-old female patient was admitted due to abnormal liver function. The 5 serum markers were all positive (+), including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb. After antiviral therapy, she was discharged with normal liver function and decreased hepatitis B virus-DNA levels, but all 5 serum markers were still positive. Regular follow-up was conducted every 3 months.

DIAGNOSES

Abnormal liver function.

INTERVENTIONS

The patient received antiviral treatment and liver protection therapy using entecavir dispersive tablet 0.5 mg po qd and glycyrrhizate diamine enteric capsule 150 mg po tid.

OUTCOMES

The patient's liver function was normal, hepatitis B virus-DNA continued to decline, and HBeAb turned negative at 6 months. After 9 and 12 months of follow-up, the results of hepatitis B markers in the patient were stable in HBsAg positive (+), HBeAb positive (+), and HBcAb positive (+).

LESSONS

The rare pattern of all 5 positive hepatitis B markers may occur in patients with chronic hepatitis B. Improvements can be achieved using first-line drugs and conventional treatment. Nevertheless, more attention should be paid to the patient's condition.

Anti-HBs Positivity Related to Past HBV Infection and Vaccination in Older Adults in Polish Population-Cohort-Based Study

BACKGROUND

In Poland, a national hepatitis B (HBV) immunization program was introduced for neonates in 1996, and between 2000 and 2011, those born from 1986 to 1995 were vaccinated. Little is known about vaccination rates among adults born before 1986. This study aimed to determine the frequency of anti-HBs seropositivity rates related to vaccination and past HBV infection in older Poles.

METHODS

The HBV serological status was analyzed in 5781 (96.6%) of the PolSenior2 population-based cohort (60+) by assessing serum seropositivity for HBs antigen, anti-HBs, and anti-HBc antibodies. The survey was performed in 2018-2019 and included medical and socio-economic questionnaires, anthropometric measurements, and comprehensive geriatric assessment.

RESULTS

Serological status implying past hepatitis B and serological profile consistent with anti-HBV vaccination corresponded to 15.2% (95% CI: 13.4-17.0) and 25.2% (95% CI: 23.4-27.0) prevalences, respectively. Female gender, living in a town or city, having better education, and suffering from coronary artery disease, or depression independently increased the rate of past hepatitis B. On the other hand, being 'white collar' and self-reliant, having the ability to use the Internet, and past surgical procedures in the last 5-year period were factors associated with a higher vaccination rate.

CONCLUSIONS

More than 15% of older adults in Poland present serological profiles suggesting past hepatitis B, and one-fourth anti-HBV vaccination. Being functionally independent, 'white collar', using the Internet, and having past surgical procedures are factors associated with a higher chance of being vaccinated. Nevertheless, a large group of older adults should be prophylactically vaccinated due to increased exposure to medical procedures.

Exchanges in the 'a' determinant of the hepatitis B virus surface antigen revisited

The hepatitis B virus surface antigen's (HBsAg) 'a' determinant comprises a sequence of amino acid residues located in the major hydrophilic region of the S protein, whose exchanges are closely associated with compromising the antigenicity and immunogenicity of that antigen. The HBsAg is generally present in the bloodstream of individuals with acute or chronic hepatitis B virus (HBV) infection. It is classically known as the HBV infection marker, and is therefore the first marker to be investigated in the laboratory in the clinical hypothesis of infection by this agent. One of the factors that compromises the HBsAg detection in the bloodstream by the assays adopted in serological screening in both clinical contexts is the loss of S protein antigenicity. This can occur due to mutations that emerge in the HBV genome regions that encode the S protein, especially for its immunodominant region - the 'a' determinant. These mutations can induce exchanges of amino acid residues in the S protein's primary structure, altering its tertiary structure and the antigenic conformation, which may not be recognized by anti-HBs antibodies, compromising the infection diagnosis. In addition, these exchanges can render ineffective the anti-HBs antibodies action acquired by vaccination, compromise the effectiveness of the chronically HBV infected patient's treatment, and also the HBsAg immunogenicity, by promoting its retention within the cell. In this review, the residues exchange that alter the S protein's structure is revisited, as well as the mechanisms that lead to the HBsAg antigenicity loss, and the clinical, laboratory and epidemiological consequences of this phenomenon.

Immune-Escape Mutations Are Prevalent among Patients with a Coexistence of HBsAg and Anti-HBs in a Tertiary Liver Center in the United States

The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, p = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.

Characteristics and clinical treatment outcomes of chronic hepatitis B children with coexistence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg

BACKGROUND

The coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) represents an uncommon serological pattern observed in patients with hepatitis B virus (HBV) infection, and its underlying mechanism and clinical significance have not been well established. The aim of this study was to investigate the association between this serological profile and clinical treatment outcomes in children with chronic hepatitis B (CHB).

METHODS

This retrospective cohort study included 372 treatment-naïve CHB children from the Hunan Children's Hospital. The participants were categorized into HBsAb-positive group and HBsAb-negative group. The associations between HBsAb positive status to clinical outcomes were assessed using Cox proportional hazard regression. Receiver operating characteristic curve was conducted to evaluate the prediction ability in HBsAg loss.

RESULTS

The coexistence of HBsAg and HBsAb accounted for 23.39% (87/372) of the participants. The crude incidence rates of HBsAg loss, hepatitis B e antigen (HBeAg) clearance, and HBV-DNA undetectability were higher in the HBsAb-positive group compared with the HBsAb-negative group (37.46 vs. 17.37, 49.51 vs. 28.66, 92.11 vs. 66.54 per 100 person-years, respectively, all P < 0.05). The Cox regression analysis revealed a significant association between this serological profile and an increased likelihood of HBsAg loss (HR = 1.78, P = 0.001), and HBeAg clearance (HR = 1.78, P = 0.001). In addition, a combination of HBsAb ≥ 0.84 log10 IU/L and age ≤ 5 years can help identify patients likely to achieve HBsAg loss after antiviral therapy, with an AUC of 0.71.

CONCLUSIONS

Children who are positive for both HBsAg and HBsAb demonstrate a higher probability of favorable outcomes after antiviral treatment. Thus, children with HBsAb-positive CHB should be actively treated to achieve functional cure.

Seroprevalence of Hepatitis A, B and C Among a Sample of Refugees in Egypt: An Exploratory Survey

BACKGROUND

Estimating the prevalence of infectious diseases, including viral hepatitis, among refugees is important for evaluating their health needs and predicting the burden on the health system of the host country. This study aimed at estimating the seroprevalence of viral hepatitis among refugees in Egypt.

METHODS

This cross-sectional study involved a heterogeneous group of 501 refugees. Enzyme-linked immunosorbent assays were used to detect IgG antibodies against hepatitis A virus (HAV), B virus (HBV) surface antigen (anti-HBsAg), C virus (HCV), and HBV surface antigen (HBsAg).

RESULTS

Anti-HAV was the most prevalent marker (n = 482, 96.2%), followed by anti-HBs (n = 142, 28.3%) and HBsAg (n = 21, 4.2%), while only four refugees (0.8%) had positive anti-HCV IgG. Anti-HBs was higher in males (p < 0.05). Older refugees and non-working subjects had significantly higher seropositive rates of anti-HAV (p = 0.051 and p = 0.023, respectively), while students and those below 15 years of age had higher rates of anti-HBs (p < 0.05). Positive HBsAg results were associated with history of hepatitis (p < 0.001). Obese participants were more likely to be positive for HBsAg (p = 0.025) and anti-HBs (p < 0.05). Sudanese refugees had significantly higher rates of anti-HAV antibodies (p = 0.049), while Yemini refugees had significantly higher rates for HBsAg (p = 0.019) positivity. Residents of Dakahlia had significantly higher rates of anti-HAV (p = 0.008) and anti-HBs (p < 0.05). None of the studied risk factors was significantly associated with anti-HCV.

CONCLUSION

Refugees in Egypt have poor immunity against HBV with intermediate to high HBV and low HCV prevalence rates. Despite that 65% of refugees received the HAV vaccine, almost all had IgG anti-HAV, denoting previous infection.

Bio-nanogate manipulation on electrode surface as an electrochemical immunosensing strategy for detecting anti-hepatitis B surface antigen

The diagnosis of hepatitis B virus (HBV) and monitoring of the vaccination efficiency against HBV require real-time analysis. The presence of antibody against hepatitis B virus surface antigen (anti-HBsAg) as a result of HBV infection and/or immunization may indicate individual immune status towards HBV. This study investigated the ability of a bio-nanogate-based displacement immunosensing strategy in detecting anti-HBsAg antibody, via nonspecific-binding between polyamidoamine dendrimers encapsulated gold nanoparticles (PAMAM-Au) and the 'antigenic determinant' region (aD) of HBsAg. For this purpose, maltose binding protein harbouring the aD region (MBP-aD) was synthesized as a bioreceptor and immobilized on the screen-printed carbon electrode (SPCE). Following that, PAMAM-Au was deposited on MBP-aD, forming the 'gate' and was used as a monitoring agent. Under optimal conditions, the high specificity of anti-HBsAg antibody towards MBP-aD displaced PAMAM-Au causing the decrement of anodic peak in differential pulse voltammetry (DPV) analysis. The signal changes were proportionally related to the concentration of anti-HBsAg antibody, in a range of 1 - 1000 mIU/mL with a limit of detection (LOD) of 2.5 mIU/mL. The results also showed high specificity and selectivity of the immunosensor platform in detecting anti-HBsAg antibody both in spiked buffer and human serum samples.

The Impact of HBV Quasispecies Features on Immune Status in HBsAg+/HBsAb+ Patients With HBV Genotype C Using Next-Generation Sequencing

Background

This study aimed to explore the molecular mechanism of the coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) serological pattern via intensive characterization of HBV s gene in both chronic hepatitis B (CHB) and hepatocellular carcinoma (HCC) patients.

Method

A total of 73 HBsAg+/HBsAb+ patients (CHB = 36, HCC = 37) and 96 HBsAg+/HBsAb− patients (CHB = 47, HCC = 49) were enrolled from 13 medical centers in China. The sequence features were elaborated based on the combination of next-generation sequencing (NGS) and multidimensional bioinformatics analysis.

Results

The 16 high-frequency missense mutations, changes of stop codon mutation, clustering, and random forest models based on quasispecies features demonstrated the significant discrepancy power between HBsAg+/HBsAb+ and HBsAg+/HBsAb− in CHB and HCC, respectively. The immunogenicity for cytotoxic T lymphocyte (CTL) epitope Se and antigenicity for the major hydrophilic region (MHR) were both reduced in HBsAg+/HBsAb+ patients (CTL Se: p < 0.0001; MHR: p = 0.0216). Different mutation patterns were observed between HBsAg+/HBsAb+ patients with CHB and with HCC. Especially, mutations in antigenic epitopes, such as I126S in CHB and I126T in HCC, could impact the conformational structure and alter the antigenicity/immunogenicity of HBsAg.

Conclusion

Based on NGS and bioinformatics analysis, this study indicates for the first time that point mutations and quasispecies diversities of HBV s gene could alter the MHR antigenicity and CTL Se immunogenicity and could contribute to the concurrent HBsAg+/HBsAb+ with different features in HCC and CHB. Our findings might renew the understanding of this special serological profile and benefit the clinical management in HBV-related diseases.

Controversies in Treating Chronic Hepatitis B Virus Infection: Discordant Serologic Results

Despite effective vaccines and approved therapeutic agents, hepatitis B virus (HBV) remains a prevalent global health problem. Current guidelines rely on a combination of serologic, virological, and biochemical markers to identify the phase in the natural history of chronic HBV infection. Discordant serologic results can occur, which may lead to misclassification. Commonly encountered results that differ from the typical profiles seen in chronic HBV infection are described. For each scenario, the frequency of occurrence, possible explanations, and recommendations for clinical management are discussed. Recognition of discordant serologic findings is crucial for optimal clinical decision.

Prevalence of Hepatitis B Virus Infection Markers among Patients of the Ibn Sina University Hospital Center (Rabat, Morocco)

INTRODUCTION

Viral hepatitis B is a global scourge affecting millions of people worldwide. In Morocco, hepatitis B is considered a public health problem, and available data converge to consider Morocco as a country with intermediate endemicity. In the present study, we have planned to evaluate the HBV prevalence in Morocco on a large scale and to assess the prevalence of different serological markers for better management of this infection in Morocco.

METHODS

This study was conducted on 18,877 patients referring to the Ibn Sina University Hospital Center of Rabat, Morocco. HBV serological markers including HBsAg, HBsAb, HBeAg, HBeAb, and total HBcAb were assessed by immune-enzymatic assays. The quantification of HBV DNA was performed by real-time PCR.

RESULTS

The overall prevalence of positive cases for HBsAg, HBsAb, and total HBcAb was 2.47%, 27.66%, and 21.2%, respectively. From 141 patients with an isolated HBcAb serological profile (HBcAb+/HBsAb-/HBsAg-), HBV DNA was detected in 10 patients, representing a rate of 7.09%. In the present study, up to 95.78% of HBV chronic carriers were negative for HBeAg.

CONCLUSION

This study highlights a higher prevalence of HBsAg in the hospital-based population than the general population reported previously in Morocco and a very low HBV immunization coverage. Of particular interest, detectable HBV DNA levels in isolated HBcAb patients show that exclusive HBsAg screening cannot eliminate the risk of HBV transmission in certain cases. Many efforts are then mandatory to promote serological testing and increase the vaccination rate to limit viral dissemination for better management of this disease in Morocco.

Paradoxical HBsAg and anti-HBs coexistence among Chronic HBV Infections: Causes and Consequences

Hepatitis B surface antigen (HBsAg) and Hepatitis B surface antibody (anti-HBs) were reported simultaneously among Hepatitis B virus (HBV) infections. HBsAg is a specific indicator of acute or chronic HBV infections, while anti-HBs is a protective antibody reflecting the recovery and immunity of hosts. HBsAg and anti-HBs coexist during seroconversion and then form immune complex, which is rare detected in clinical cases. However, with the promotion of vaccination and the application of various antiviral drugs, along with the rapid development of medical technology, the coexistence of HBsAg and anti-HBs has become more prevalent. Mutations in the viral genomes, immune status and genetic factors of hosts may contribute to the coexistence. Novel HBsAg assays, with higher sensitivity and ability to detect mutations or immune complexes, can also yield HBsAg/anti-HBs coexistence. The discovery of coexistence has shattered the idea of traditional serological patterns and raised questions about the effectiveness of vaccines. Worth noting is that HBsAg/anti-HBs double positivity is strongly associated with progressive liver diseases, especially hepatocellular carcinoma. In conclusion, viral mutations, host factors, and methodology impacts can all lead to the coexistence of HBsAg and anti-HBs. This coexistence is not an indicator of improvement, as an increased risk of adverse clinical outcomes still exists.

Characteristics of amino acid substitutions within the "a" determinant region of hepatitis B virus in chronically infected patients with coexisting HBsAg and anti-HBs

OBJECTIVES

Simultaneous positivity for both hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) is an atypical serological profile in chronic hepatitis B (CHB) patients. The exact mechanisms underlying the uncommon profile remains unclear. The aim of this study was to analyze the characteristics of amino acid substitutions within the "a" determinant region in a large cohort of CHB patients with coexistence of HBsAg and anti-HBs.

METHODS

In total 8687 CHB patients, of which 505 had coexisting HBsAg and anti-HBs, were enrolled in this study. Mutations within the "a" determinant region in 131 HBsAg+/anti-HBs+ patients and 150 age and gender matched HBsAg+/anti-HBs- patients were determined by direct sequencing and the characteristics of amino acid substitutions were analyzed.

RESULTS

The prevalence of coexistence of HBsAg and anti-HBs in the CHB patients was 5.81%. Compared to the control subjects, there were more amino acid substitutions in HBsAg+/anti-HBs+ patients (30.5% vs. 12.7%, P<0.001), especially within the first loop of the "a" determinant region. The most frequent amino acid substitution was located at position s126 and the predominant substitution was sI126T in HBsAg+/anti-HBs+ patients with genotype C. The frequency of additional N-glycosylation sites in HBsAg+/anti-HBs+ patients and the control subjects was 3.8% and 0.6%, respectively.

CONCLUSIONS

The accumulation and diversity of amino acid variations within "a" determinant region might contribute to the coexistence of HBsAg and anti-HBs. These findings extend understanding of the genetic mechanism of this atypical serological profile in CHB patients.

Analysis of HBsAg mutations in the 25 years after the implementation of the hepatitis B vaccination plan in China

Since 1992, China has promoted hepatitis B vaccination. Concurrently, during this period, increasing use of immunoglobulins and nucleoside analogues might have exerted selective pressure on the hepatitis B virus (HBV) S gene, driving mutations in the HBsAg and changed the subtype. Using the National Center for Biotechnology Information database, we obtained gene sequence information for HBV strains from China and analysed changes in HBsAg subtypes and substitution mutations in HBsAg in 5-year intervals over 25 years to identify potential challenges to the prevention and treatment of hepatitis B. Most HBV sequences from China were genotype C (1996/2833, 70.46%) or B (706/2833, 24.92%). During the implementation of hepatitis B vaccination (recombinant hepatitis B vaccine was subgenotype A2 and HBsAg subtype adw2), the proportion of subtypes ayw1 and adw3 in genotype B and ayw2 in genotype C increased over the programme period. The overall mutation rate in HBsAg tended to decrease for genotype B, whereas, for genotype C, the rate increased gradually and then decreased slightly. Moreover, the mutation rate at some HBsAg amino acid sites (such as sG145 of genotype B and sG130 and sK141 of genotype C) is gradually increasing. HBV strains with internal stop codons of HBsAg (e.g., sC69*) and additional N-glycosylation (e.g., sG130N) mutations should be studied extensively to prevent them from becoming dominant circulating strains. The development of HBV vaccines and antiviral immunoglobulins and use of antiviral drugs may require making corresponding changes.

Long-term outcomes of HBsAg/anti-HBs double-positive versus HBsAg single-positive patients with chronic hepatitis B

The coexistence of HBsAg and anti-HBs has been reported in some chronic hepatitis B patients; however, the long-term outcomes of this serological profile have not been elucidated. We aimed to evaluate the long-term outcomes of HBsAg/anti-HBs double-positive chronic hepatitis B patients. Chronic hepatitis B patients who underwent baseline abdominal ultrasonography and follow-up (HBsAg/anti-HBs assessment and abdominal ultrasonography) at our healthcare center were included. The "coexistence group" included patients positive for both HBsAg and anti-HBs and the "control group" included patients positive for only HBsAg during follow-up. The outcomes were hepatocellular carcinoma (HCC) incidence, HBsAg seroclearance and overall mortality. Kaplan-Meier and Cox proportional hazard regression analyses were performed. Of the 2,341 eligible patients, 166 (7.1%) were in the coexistence group. The total follow-up duration was 5.4 years. The coexistence group had a 3.08-fold higher risk of HCC than the control group [hazard ratio (HR) 3.08, 95% confidence interval(CI) 1.26-7.55, P = 0.014] in multivariate analysis. The coexistence group had more HBsAg seroclearance than the control group (HR 1.43, 95% CI 1.01-2.03, P = 0.046). However, overall mortality did not significantly differ between the 2 groups. The coexistence group is heterogeneous and includes subjects with unfavorable outcomes (incidence of HCC) and favorable outcomes (more HBsAg seroclearance).

Coexistence of low levels of HBsAg and high levels of anti-HBs may increase risk of hepatocellular carcinoma in chronic hepatitis B patients with high HBV load

OBJECTIVE

The clinical significance of coexistence of HBsAg/anti-HBs in chronic hepatitis B (CHB) patients remains controversial. This study was aimed to assess the association of this serological pattern with hepatocellular carcinoma (HCC) in patients with CHB.

METHODS

In this cross-section study, 206 CHB patients with coexistence of HBsAg/anti-HBs and 206 CHB patients with HBsAg alone were included to evaluate the risk of HCC development by logistic regression analysis. In addition, a retrospective cohort of 260 patients with CHB was recruited to estimate the cumulative incidence of HCC by Kaplan-Meier analysis.

RESULTS

The serological pattern of coexistence of HBsAg/anti-HBs, with high levels of ("High") HBsAg/low levels of ("Low") anti-HBs, were considered as independent risk factors for HCC. In particular, patients with "High" HBsAg/"High" anti-HBs [odds ratio (OR), 4.295; 95% confidence interval (CI), 1.104-16.699; p = 0.035] and "Low" HBsAg/ "High" anti-HBs (OR, 3.207; 95%CI, 1.299-7.919; p = 0.012) exhibited significantly higher risk for HCC development. However, only "Low" HBsAg /"High" anti-HBs might increase risk of HCC in CHB patients with high HBV load (logrank p < 0.001) in our cohort study.

CONCLUSION

The coexistence of "Low" HBsAg /"High" anti-HBs might increase the risk of HCC development in CHB patients with high HBV load, which reflected that the long-term interaction between immune response and virus might lead to the development of HCC. The identification of the patients with poor prognosis will help clinicians to refine the therapeutic decisions and individualize follow-up strategies.

Identified OAS3 gene variants associated with coexistence of HBsAg and anti-HBs in chronic HBV infection

The underlying mechanism of coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antigen antibody (anti-HBs) is still controversial. To identify the host genetic factors related to this unusual clinical phenomenon, a two-stage study was conducted in the Chinese Han population. In the first stage, we performed a case-control (1:1) age- and gender-matched study of 101 cases with concurrent HBsAg and anti-HBs and 102 controls with negative HBsAg and positive anti-HBs using whole exome sequencing. In the second validation stage, we directly sequence the 16 exons on the OAS3 gene in two dependent cohorts of 48 cases and 200 controls. Although, in the first stage, a genome-wide association study of 58,563 polymorphism variants in 101 cases and 102 controls found no significant loci (P-value ≤ .05/58563), and neither locus achieved a conservative genome-wide significance threshold (P-value ≤ 5e-08), gene-based burden analysis showed that OAS3 gene rare variants were associated with the coexistence of HBsAg and anti-HBs. (P-value = 4.127e-06 ≤ 0.05/6994). A total of 16 rare variants were screened out from 21 cases and 3 controls. In the second validation stage, one case with a stop-gained rare variant was identified. Fisher's exact test of all 149 cases and 302 controls showed that the rare coding sequence mutations were more frequent in cases vs controls (P-value = 7.299e-09, OR = 17.27, 95% CI [5.01-58.72]). Protein-coding rare variations on the OAS3 gene are associated with the coexistence of HBsAg and anti-HBs in patients with chronic HBV infection in Chinese Han population.

Mutations within the major hydrophilic region (MHR) of Hepatitis B virus from individuals with simultaneous HBsAg and anti-HBs in Guangzhou, Southern China

The mechanism of the coexistence of HBsAg and anti-HBs is still unclear. This study investigated the variations located in the major hydrophilic region (MHR) of HBV from individuals with simultaneous HBsAg and anti-HBs in Guangzhou, southern China. Among 4455 samples analyzed, 179 (4.02%) patients were discovered with both HBsAg and anti-HBs. Finally, 44 individuals with concurrent HBsAg and anti-HBs (defined as group I), and 88 patients with positive HBsAg and negative anti-HBs (defined as group II, served as control) were enrolled in the study. The number of residue changes per 100 residues within the MHR in group I was 7.1 times more frequent than group II (P < 0.001) and was discovered mostly in the MHR1 (aa99-119) (P < 0.001). Two or more residue changes in the MHR were discovered in 15 patients (34.1%) of group I, but were found in only one (1.1%) patient of group II (P < 0.001). The most common variants in group I were at positions s101Q, s133M, s126T/I, s131T, s145G, s120P, and s129Q. In addition, sQ101 K, sT131N, and sM133L were more frequently discovered in group I with significant difference (P < 0.05). In chronic hepatitis B (CHB) patients, the simultaneous of HBsAg and anti-HBs were accompanied with an increase of MHR variants, and suggested that the HBsAg mutants were selected by naturally acquired anti-HBs during chronic carriage.

Patients with Coexistence of Circulating Hepatitis B Surface Antigen and Its Antibody May Have a Strong Predisposition to Virus Reactivation During Immunosuppressive Therapy: A Hypothesis

Hepatitis B virus (HBV) reactivation is a well-recognized complication in patients who undergo immunosuppressive drug therapy. Although the recommendation of antiviral prophylaxis made by the American Gastroenterological Association in 2015 focuses on the risk stratification of different immunosuppressive drugs, risk factors for HBV reactivation are also worth identifying in clinical practice. Recent studies have shown that the uncommon serological pattern of coexistent circulating HBV surface antigen (HBsAg) and its antibody (anti-HBs) was associated with double mutations (A1762T/G1764A) in the basal core promoter (BCP) region of the HBV genome, which is critical for HBV replication. Here, we depicted rheumatoid arthritis (RA) patients with coexistent HBsAg and anti-HBs in our medical center, who developed HBV reactivation during immunosuppressive drug therapy. DNA sequencing analysis of the HBV genome revealed triple mutations (A1762T, G1764A, and T1753V) in the BCP region, which could further enhance the ability of HBV replication. Hence, a novel hypothesis is advanced for the first time that patients with coexistent HBsAg and anti-HBs may have a strong predisposition to HBV reactivation due to specific BCP mutations. This hypothesis would, if correct, justify the concurrent detection of HBsAg and anti-HBs in HBV screening in patients with rheumatic diseases and quickly recognize patients with high risk of HBV reactivation. Further controlled studies are needed to confirm this hypothesis.

Additional N-glycosylation mutation in the major hydrophilic region of hepatitis B virus S gene is a risk indicator for hepatocellular carcinoma occurrence in patients with coexistence of HBsAg/anti-HBs

The study aimed to determine the association of additional N-glycosylation mutations in the major hydrophilic region (MHR) of hepatitis B virus (HBV) S gene with hepatocellular carcinoma (HCC) occurrence in HBsAg/anti-HBs coexistent patients. A total of 288 HBsAg/anti-HBs coexistent patients and 490 single HBsAg-positive patients were enrolled, including 193 with HCC, 433 with chronic hepatitis B (CHB), and 152 with acute-on-chronic liver failure (ACLF). The HBV S genes were amplified from serum and sequenced. The frequency of additional N-glycosylation mutations was significantly higher in HCC patients (12.37%) than in CHB patients (4.39%) and ACLF patients (2.63%). The frequency escalated by an order of single HBsAg-positive non-HCC (1.61%), single HBsAg-positive HCC (5.98%), HBsAg/anti-HBs coexistent non-HCC (8.01%), and HBsAg/anti-HBs coexistent HCC (22.36%). Twelve kinds of mutations/mutation patterns were detected, five of which have not been reported. Multivariate analysis showed that age > 40 years [OR, 3.005; 95% CI, 1.177−7.674; P = 0.021], alpha-fetoprotein > 10 ng/mL [OR, 4.718; 95% CI, 2.406−9.251; P <0.001], cirrhosis [OR, 6.844; 95% CI, 2.773−16.891, P < 0.001], Hepatitis B e antigen negativity [OR, 2.218; 95% CI, 4.335, P = 0.020], and additional N-glycosylation mutation [OR, 2.831; 95% CI, 1.157−6.929; P = 0.023] were independent risk factors for HCC in HBsAg/anti-HBs coexistent patients. Dynamical analysis showed that the additional N-glycosylation mutations existed 1-4 years prior to HCC occurrence in eight of 18 patients observed. In conclusion, the dditional N-glycosylation mutations together with HBsAg/anti-HBs coexistence might serve as a predictive indicator for HCC occurrence in chronic HBV-infected patients.

Evolution of full-length genomes of HBV quasispecies in sera of patients with a coexistence of HBsAg and anti-HBs antibodies

Although the evolutionary changes of viral quasispecies are correlated to the pathological status of a disease, little is known in the coexistence of hepatitis B surface antigen (HBsAg) and antibodies to these antigens (anti-HBs). To examine evolutionary changes in hepatitis B virus (HBV) and their relationship to the coexistence of HBsAg and anti-HBs antibodies, HBV genomes in patients with a coexistence of HBsAg and anti-HBs antibodies (experimental group) and HBsAg positive without anti-HBs (control group) were assessed. Our results showed that quasispecies diversity was significantly higher in the experimental group for large HBsAg (LHBsAg), middle HBsAg (MHBsAg), and HBsAg genes. LHBsAg harbored dN/dS values eight times higher in the experimental group; however, the mean dN/dS ratios in genes HbxAg, Pol and PreC/C of the experimental patients had an opposite trend. Phylogenetic trees in the experimental group were more complex than the control group. More positive selection sites, mutations and deletions were observed in the experimental group in specific regions. Furthermore, several amino acid variants in epitopes were potentially associated with the immune evasion. In conclusion, cumulative evolutionary changes in HBV genome that facilitate immune evasion provide insights into the genetic mechanism of a coexistence of HBsAg and anti-HBs antibodies.

Mutation in the S gene a determinant of the hepatitis B virus associated with concomitant HBsAg and anti-HBs in a population in Northeastern Brazil

Mutations in the a determinant of S gene may develop co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in the serum of infected hepatitis B virus (HBV) individuals. Mutations in this region may change the antigenicity of HBsAg, which in turn, lead to escape of neutralizing action of anti-HBs antibodies. This study identified individuals with concomitant HBsAg and anti-HBs serological markers in individuals of Maranhão, Northeastern Brazil. Samples from a population-based study were evaluated for HBsAg, anti-HBs, and anti-HBc, and those that tested positive for simultaneous HBsAg and anti-HBs were submitted to HBV DNA quantification and S gene characterization by Sanger sequencing. Mutations were investigated in the a determinant located in major hydrophilic region (MHR) of the S gene. Among 3,984 samples analyzed, 92 (2.3%) were positive for HBsAg and three had the atypical HBsAg and anti-HBs-positive profile (3.26%). The frequency of HBsAg and anti-HBs co-existence was similar to previous studies. Only one individual harbored mutation in the S gene a determinant associated with this profile. Little is known about this phenomenon; however, studies as ours may contribute for future enlightenment of this important issue. J. Med. Virol. 89:458-462, 2017. © 2016 Wiley Periodicals, Inc.

Clinical and Virological Characteristics of Chronic Hepatitis B Patients with Coexistence of HBsAg and Anti-HBs

Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) comprises an atypical serological profile in patients with chronic hepatitis B virus (HBV) infection. In this study, in total 94 patients with coexisting HBsAg and anti-HBs and 94 age- and sex-matched patients with positive HBsAg were characterized by quantitatively measuring HBsAg and HBV DNA, sequencing large S genes, and observing clinical features. Compared with common hepatitis B patients, the patients with coexisting HBsAg and anti-HBs had lower HBsAg and HBV DNA levels. These two groups had similar rate of pre-S deletion mutations. However, in patients with coexisting HBsAg and anti-HBs, more amino acid substitutions in the a determinant of S gene were observed in HBV genotype C, but not in genotype B. Fourteen patients with coexisting HBsAg and anti-HBs were followed up for an average of 15.5 months. There were no significant changes in the levels of HBsAg, anti-HBs, HBV DNA and ALT over the follow-up period. Compared with the baseline sequences, amino acid substitutions in the MHR of HBsAg occurred in 14.3% (2/14) patients. In conclusion, coexistence of HBsAg and anti-HBs may be associated with higher frequency of mutations in the a determinant of HBV genotype C.

Sequence analysis of the HBV S protein in Chinese patients with coexisting HBsAg and anti-HBs antibodies

The coexistence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in patients with hepatitis B virus (HBV) infection has been discovered and explained for several decades, but debate still exists. This study was to explore the relationship between this special serological pattern and mutations in S gene region. Fifteen patients with coexisting HBsAg and anti-HBs were selected as the experimental group, and 27 patients with HBsAg positive only were selected as the control group. The S gene region was amplified and sequenced. No significant differences were observed between the two groups with regard to age, gender, alanine aminotransferase level, HBsAg titer, genotype, and HBV DNA level. The patients from the two groups were infected with HBV of the genotype B and C. Compared with the control group, the experimental group showed a higher variability in amino acid within the N-terminal region and the MHR, especially the "a" determinant. The most frequent change in patients from the experimental group was located at positions s126. The coexistence of HBsAg and anti-HBs might be associated with the increased amino acid mutations in the "a" determinant. Further studies should be performed to determine the clinical implication of this serological pattern, including the binding of anti-HBs to HBsAg, escape from immune system, and efficacy of antiviral therapy.

Molecular mechanisms underlying HBsAg negativity in occult HBV infection

Although genomic detection is considered the gold standard test on HBV infection identification, the HBsAg investigation is still the most frequent clinical laboratory request to diagnose HBV infection in activity. However, the non-detection of HBsAg in the bloodstream of chronic or acutely infected individuals has been a phenomenon often observed in clinical practice, despite the high sensitivity and specificity of screening assays standardized commercially and adopted in routine. The expansion of knowledge about the hepatitis B virus biology (replication/life cycle, genetic variability/mutability/heterogeneity), their biochemical and immunological properties (antigenicity and immunogenicity), in turn, has allowed to elucidate some mechanisms that may explain the occurrence of this phenomenon. Therefore, the negativity for HBsAg during the acute or chronic infection course may become a fragile or at least questionable result. This manuscript discusses some mechanisms that could explain the negativity for HBsAg in a serological profile of individuals with HBV infection in activity, or factors that could compromise its detection in the bloodstream during HBV infection.

Coexistence of circulating HBsAg and anti-HBs antibodies in chronic hepatitis B carriers is not a simple analytical artifact and does not influence HBsAg quantification

BACKGROUND

Presence at the same time of HBsAg and anti-HBs antibodies (HBsAg/Ab) is an entity sometimes encountered in chronic hepatitis B (CHB) carriers.

OBJECTIVES

This study was designed to characterize such serological profiles and to assess the reliability of serological marker quantification by three commercially available assays in this setting.

STUDY DESIGN

Among 2578 CHB identified patients, 129 (5%) had an HBsAg/Ab profile as determined by Abbott Architect. After exclusion of co-infections (HIV, HCV, HDV), HBV reactivation or HBIg treatment, 101 samples from 62 patients were tested for HBsAg and anti-HBs quantification using Architect, DiaSorin Liaison-XL and Roche Modular-Cobas. Influence of genotype and HBsAg variants was studied in 31 samples with HBV replication.

RESULTS

HBsAg detection was confirmed with the 3 techniques for 98% (n = 99) of the samples while the HBsAg/Ab profile was concordant between all techniques for 65% of them. The overall correlation between the 3 HBsAg quantification techniques was good (R(2): 0.94-0.97). The median HBsAg concentration was comparable for the 99 samples whatever the used technique but a bias of -0.11 and 0.02 log IU/mL were noticed for DiaSorin and Roche compared to Abbott, respectively. Anti-HBs quantifications were poorly correlated between techniques with major discrepancies observed. Genotype and substitutions within the "a" determinant showed an impact on HBsAg quantification.

CONCLUSIONS

The double HBsAg/Ab profile is not an analytical artifact and is confirmed on all commercially available techniques. While such profile does not influence HBsAg quantification, differences of HBsAg quantification were noticed according to HBV genotype or HBsAg variant.

Experimental HBsAg/anti-HBs complex assay for prediction of HBeAg loss in chronic hepatitis B patients treated with pegylated interferon and adefovir

BACKGROUND

We studied whether hepatitis B surface antigen (HBsAg)/anti-HBs immune complex levels in chronic hepatitis B (CHB) patients receiving antiviral therapy could be used as a response marker at baseline (BL) or early during treatment to predict treatment outcome.

METHODS

An experimental array-based assay (immunological multi-parameter chip technology [IMPACT]; Roche Diagnostics, Penzberg, Germany) served to determine HBsAg, anti-HBs and complex levels. We tested a panel of serum samples of 40 hepatitis B e antigen (HBeAg)-positive and 44 HBeAg-negative patients who received pegylated interferon and adefovir for 48 weeks.

RESULTS

HBsAg loss occurred in 4 of 40 HBeAg-positive and 4 of 44 HBeAg-negative patients. A total of 14 of 40 HBeAg-positive patients lost HBeAg and 12 of them formed anti-HBe. At BL, complexes were present in 83 (99%) patients, whereas free anti-HBs levels were detectable in 5 patients. Complex levels at BL and week 12 were higher in HBeAg-positive patients with HBeAg loss, compared to patients who retained HBeAg (P=0.002 and P=0.005, respectively). Receiver operating characteristic analysis for HBeAg loss in HBeAg-positive patients at BL and week 12 showed area-under-the-curve values of 0.79 (P=0.002) and 0.82 (P=0.003) for complex levels. We found no correlation in either HBeAg-positive or -negative patients between complex levels and HBsAg loss.

CONCLUSIONS

We demonstrated for the first time that before and during treatment HBsAg/anti-HBs immune complex levels can predict HBeAg loss in HBeAg-positive CHB patients treated with pegylated interferon and adefovir. Complexes were present in almost all patients at BL and were higher in patients who lost HBeAg. In conclusion, determining HBsAg/anti-HBs immune complex levels before and early during treatment could aid in selecting CHB patients with an optimal chance to achieve HBeAg loss.

Coexistence of hepatitis B surface antigen and antibody to hepatitis B surface may increase the risk of hepatocellular carcinoma in chronic hepatitis B virus infection: a retrospective cohort study

The simultaneous detection of hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface (anti-HBs) is unusual in chronic hepatitis B virus (HBV) infection, but may be related with more advanced liver diseases. This retrospective long-term cohort study was aimed to investigate whether coexistence of HBsAg and anti-HBs may increase the risk of hepatocellular carcinoma (HCC) in chronic HBV infection. A total of 1,042 non-HCC patients were recruited and followed up for a median 4.3 years (range 1.0-22 years). Univariate and multivariate analyses were performed to identify the risk factors for HCC development. The prevalence of coexistence of HBsAg and anti-HBs was 7.0% (73/1,042). In univariate analysis, the 5-, 10-, and 15-year cumulative incidences of HCC were significantly higher in coexistence group than in HBsAg only group (12.7%, 23.4%, 69.4% vs. 4.9%, 13%, 20.6%, respectively; P = 0.008). In multivariate analysis, coexistence of HBsAg and anti-HBs [Hazard ratio (HR), 2.001; 95% confidence interval (CI), 1.023-3.912; P = 0.043] as well as male gender [HR, 1.898; 95% CI, 0.31-0.896; P = 0.018], age over 40 years [HR, 14.56; 95% CI, 4.499-47.08; P = 0.0001], and cirrhosis [HR, 7.995; 95% CI, 4.756-13.439; P = 0.0001] was identified as the independent factor for HCC development. Also, the cumulative incidence of HCC increased in proportion to the number of the risk factors. In conclusion, coexistence of HBsAg and anti-HBs may increase independently the risk of HCC development in chronic HBV infection. Therefore, consideration of HCC development is required in patients with coexistence of HBsAg and anti-HBs.

Atypical serological profiles in hepatitis B virus infection

During hepatitis B virus (HBV) infection, at least four antigen-antibody systems are observed: HBsAg and anti-HBs; preS antigen and anti-preS antibody; HBcAg and anti-HBc; and HBeAg and anti-HBe. Through the examination of these antigen-antibody systems, hepatitis B infection is diagnosed and the course of the disorder may be observed. Although the serologic findings that allow both the diagnosis of HBV infection as well as assessing of its clinical course are already well established, the dynamics of viral proteins expression and of the antibodies production may vary during the infection natural course. This causes the HBV infection to be occasionally associated with the presence of uncommon serological profiles, which could lead to doubts in the interpretation of results or suspicion of a serological result being incorrect. This paper is dedicated to the discussion of some of these profiles and their significance.

Molecular analysis of hepatitis B virus (HBV) in an HIV co-infected patient with reactivation of occult HBV infection following discontinuation of lamivudine-including antiretroviral therapy

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is characterized by HBV DNA persistence even though the pattern of serological markers indicates an otherwise resolved HBV infection. Although OBI is usually clinically silent, immunocompromised patients may experience reactivation of the liver disease.

CASE PRESENTATION

We report the case of an individual with human immunodeficiency virus (HIV) infection and anti-HBV core antibody positivity, who experienced severe HBV reactivation after discontinuation of lamivudine-including antiretroviral therapy (ART). HBV sequencing analysis showed a hepatitis B surface antigen escape mutant whose presence in an earlier sample excluded reinfection. Molecular sequencing showed some differences between two isolates collected at a 9-year interval, indicating HBV evolution. Resumption of ART containing an emtricitabine/tenofovir combination allowed control of plasma HBV DNA, which fell to undetectable levels.

CONCLUSION

This case stresses the ability of HBV to evolve continuously, even during occult infection, and the effectiveness of ART in controlling OBI reactivation in HIV-infected individuals.