Cutoff levels of immunoglobulin M antibody against viral core antigen for differentiation of acute, chronic, and past hepatitis B virus infections

Virus and viral components transmitted through surgical smoke; a silent danger in operating room: a systematic review

BACKGROUND

During surgical procedures, heat-generating devices are widely used producing surgical smoke (SS). Since the SS can transmit infectious viruses, this systematic review was designed to investigate the potential viruses transmitted through SS.

METHODS

PubMed, Scopus, Web of Science, ProQuest, and Embase databases, along with Cochran Library, and Google Scholar search engine were searched systematically (by April 21, 2024). No language, place, and time restrictions were considered. All studies evaluating the SS and virus transmission, and whole investigations regarding the viral infections transmitted through SS were totally considered inclusion criteria. Besides, non-original, qualitative, case reports, case series, letters to the editor, editorial, and review studies were excluded from the analysis. This study was conducted in accordance with the PRISMA 2020 statement.

RESULTS

Twenty-six eligible studies were selected and reviewed for data extraction. The results showed that the SS contains virus and associated components. Six types of viruses or viral components were identified in SS including papillomavirus (HPV, BPV), Human Immunodeficiency Virus (HIV), varicella zoster, Hepatitis B (HBV), SARS-CoV-2, and Oral poliovirus (OPV), which are spread to surgical team through smoke-producing devices.

CONCLUSIONS

Since the studies confirm the presence of viruses, and viral components in SS, the potential risk to the healthcare workers, especially in operating room (OR), seems possible. Thus, the adoption of protective strategies against SS is critical. Despite the use of personal protective equipment (PPE), these viruses could affect OR personnel in surgical procedures.

Serological patterns of hepatitis B virus infection among people living with HIV in Ibadan, Nigeria

Hepatitis B virus (HBV) is a leading cause of liver pathology, which has remained a serious public health challenge in spite of the availability of hepatitis B vaccine discovered about 40 years ago. People living with human immunodeficiency virus (PLHIV) are more at risk of hepatic problems as liver complications appear and progresses faster, owing to their immunocompromised status. This study seeks to determine HBV exposure, serological pattern, and HBV susceptibility among PLHIV. One hundred and fifty PLHIV were enrolled for the study. About 5 mL of blood was collected, processed, and tested for markers of hepatitis B virus: HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBc. Twenty-eight (18.7%) had at least one serological marker while 122 (81.3%) tested negative to all the markers. The prevalence of HBsAg in this study was 8.7%, anti-HBs prevalence was 10%, while HBeAg was 2.7%, anti-HBe 6.0%, and anti-HBc 6.7%. Higher HBsAg, HBeAg, and anti-HBc prevalence were observed among the male participants with 13.9%, 5.6%, and 13.9%, respectively, while the female participants had more anti-HBs and anti-HBe of 1.8% and 6.1%, respectively. Age group 51-60 years had the highest prevalence of HBsAg (17.7%), HBeAg (11.8%), and anti-HBe (11.8%) while age group 31-40 years had the highest prevalence of anti-HBs (14.8%) and anti-HBe (9.8%). This study revealed the different serologic patterns of HBV infection among PLHIV and that susceptibility to HBV infection among PLHIV is high.

Monitoring hepatitis B by using point-of-care testing: biomarkers, current technologies, and perspectives

Introduction: Liver diseases caused by hepatitis B virus (HBV) are pandemic infectious diseases that seriously endanger human health, conventional diagnosis methods can not meet the requirements in resource-limited areas. The point of acre detection methods can easily resolve those problems. Herein, we review the most recent advances in POC-based hepatitis B detection methods and present some recommendations for future development. It aims to provide ideas for future research.Areas covered: Epidemiological data on Hepatitis B, conventional diagnostic methods for hepatitis B detection, some latest point of care detection methods for hepatitis B detection and list out the recommendations for future development.Expert opinion: This manuscript summarized traditional biomarkers of different hepatitis B stages and recent-developed POCT platforms (including microfluidic platforms and lateral-flow strips) and discuss the challenges associated with their use. Some emerging biomarkers that can be used in hepatitis B diagnosis are also listed. This manuscript has certain guiding significance to the development of hepatitis B detection.

Case Report: Application of hepatitis B virus (HBV) deep sequencing to distinguish between acute and chronic infection

Deep sequencing of the full-length hepatitis B virus (HBV) genome provides the opportunity to determine the extent to which viral diversity, genotype, polymorphisms, insertions and deletions may influence presentation and outcomes of disease. Increasing experience with analysis of HBV genomic data opens up the potential for using these data to inform insights into pathophysiology of infection and to underpin decision making in clinical practice. We here set out to undertake whole genome HBV sequencing from an adult who presented acutely unwell with a new diagnosis of HBV infection, and tested positive for both HBV anti-core IgM and IgG, possibly representing either acute hepatitis B infection (AHB) or chronic hepatitis B with an acute reactivation (CHB-AR). The distinction between these two scenarios may be important in predicting prognosis and underpinning treatment decisions, but can be challenging based on routine laboratory tests. Through application of deep whole-genome sequencing we typed the isolate as genotype-D1, and identified several minority variants including G1764A and G1986A substitutions in the pre-core promoter and pre-core regions, which support CHB-AR rather than AHB. In the longer term, enhanced deep sequencing data for HBV may provide improved evidence to distinguish between acute and chronic infection, to predict outcomes and to stratify treatment.

Case Report: Application of hepatitis B virus (HBV) deep sequencing to distinguish between acute and chronic infection

Deep sequencing of the full-length hepatitis B virus (HBV) genome provides the opportunity to determine the extent to which viral diversity, genotype, polymorphisms, insertions and deletions may influence presentation and outcomes of disease. Increasing experience with analysis of HBV genomic data opens up the potential for using these data to inform insights into pathophysiology of infection and to underpin decision making in clinical practice. We here set out to undertake whole genome HBV sequencing from an adult who presented acutely unwell with a new diagnosis of HBV infection, and tested positive for both HBV anti-core IgM and IgG, possibly representing either acute hepatitis B infection (AHB) or chronic hepatitis B with an acute reactivation (CHB-AR). The distinction between these two scenarios may be important in predicting prognosis and underpinning treatment decisions, but can be challenging based on routine laboratory tests. Through application of deep whole-genome sequencing we typed the isolate as genotype-D1, and identified several minority variants including G1764A and G1986A substitutions in the pre-core promoter and pre-core regions, which support CHB-AR rather than AHB. In the longer term, enhanced deep sequencing data for HBV may provide improved evidence to distinguish between acute and chronic infection, to predict outcomes and to stratify treatment.

Serological profile of HBV infection among apparently healthy hospital attendees

Hepatitis B virus (HBV) infection has been rated 10th among the killer diseases. Occult HBV infection goes undetected with the widely used HBsAg screening in most hospital thereby encouraging progression into complications such as liver cirrhosis and hepatocellular carcinoma. This work therefore aimed at evaluating HBV serological profiles among the population of apparently healthy hospital attendees and their proportion of susceptibility to HBV infection. 239 participants were recruited for this study. Their blood samples were screened for the HBV markers - HBsAg, anti-HBs, HBeAg, anti-HBe, and anti-HBc. In conclusion, this work depicted various serological patterns of HBV infection among apparently healthy hospital attendees suggesting there are occult HBV infection and immune escape mutant in our population. It also showed that a huge number of the study population were susceptible to HBV infection.

Patterns of serologic markers of hepatitis B virus infection and the risk of transmission among pregnant women in southwestern Nigeria

Hepatitis B virus (HBV) infection is a major health concern in developing countries that has a high morbidity and mortality rate. Vertical transmission of HBV from mother to child has been identified as a major factor leading to chronicity with attendant liver conditions, especially in poor socioeconomic settings. This study aims to evaluate the prevalence of serological HBV markers among pregnant women in Ibadan southwestern Nigeria and to determine the implications for perinatal HBV transmission. This study revealed the presence of varied HBV serological patterns of infection or immunity among pregnant women in Ibadan, Nigeria, and thus the risk of mother to child transmission.

The serological markers of acute infection with hepatitis A, B, C, D, E and G viruses revisited

Viral hepatitis is a liver infection caused by one of the six hepatitis viruses: hepatitis A, B, C, D, E, and G virus (HAV to HEV and HGV). These agents differ in their biological, immunological, pathological and epidemiological characteristics. They cause infections that, when symptomatic, lead to clinical manifestations and laboratory findings that are not specific to a particular virus, often making differential diagnosis difficult, especially when no knowledge is available regarding the patient's medical history or the epidemiological background. A number of acute-phase serological markers, such as anti-HAV, anti-HBc, anti-HDV and anti-HEV IgM antibodies, are able to provide a clear indication of an infection caused by HAV, HBV, HDV or HEV. Anti-HCV antibodies and HGV/RNA are used for the diagnosis of HCV and HGV infections. The importance of each of these markers will be reviewed, and different factors that can interfere with the diagnosis of acute infections caused by these viruses will be described.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Acute hepatitis B virus infection or acute exacerbation of chronic hepatitis B infection: the differential serological diagnosis

Acute exacerbations of chronic hepatitis B are common, and may even be the first presentation of hepatitis B virus (HBV) infection. Sometimes, patients involved in these scenarios may have mistaken diagnosis of acute hepatitis B. The reason for the confusion is that the two forms of infection manifestation resemble remarkably in clinical, biochemical, and serological features, such as apparent rapid onset of severe disease, advanced grades of encephalopathy, high aminotransferases and prolonged international normalized ratios (INRs), as well as positivity for HBsAg and for IgM anti-HBc antibodies and DNA detection. Therefore, these two entities cannot be distinguished easily without historical information of HBV-associated chronic infection or recent HBV exposure, information that is often inaccurate. Considering the different prognoses, treatment strategies, and the epidemiological impact in the public health context, the correct diagnosis is extremely important. Despite the lack of effective and reliable tests to differentiate between acute infection and acute exacerbation of chronic HBV infection, the expression and kinetic evaluation of viral markers present in the circulation of individuals infected, the observation of physical-chemical properties of specific antibodies, and the combination of these findings represent some strategies in serology that could assist in differentiating between the two entities, or at least in the guidance for the correct diagnosis.

Studies of nosocomial outbreaks of hepatitis B in nursing homes in Germany suggest a major role of hepatitis B e antigen expression in disease severity and progression

Hepatitis B virus (HBV) causes acute or chronic hepatitis B. Local outbreaks of HBV infections in skilled nursing facilities is a matter of growing concern in developed countries. Here, we investigated two outbreaks of hepatitis B that recently occurred in nursing homes in Germany. The outbreak at location A was associated with acute fulminant hepatitis with fatal outcome in several cases, while individuals infected at location B developed asymptomatic or mild hepatitis B. Sequence analysis of viruses involved in these outbreaks revealed different, but unique HBV strains for each location. Each of the strains produced high viremia of more than 10(9) virions/mL serum. We found that the mild course of hepatitis B at location B was caused by a circulating wild-type HBV genotype A2 strain, which is commonly found in Central Europe. Complete genome sequences of isolates obtained from infected patients revealed nearly 100% sequence identity at the nucleotide level as well as expression of HBV e protein (HBeAg), a known T cell tolerogen in the incubation or chronic phases of HBV infection. By contrast, the outbreak at location A was associated with an HBV genotype D2 variant that lacked HBeAg expression, suggesting that immunopathology and selection of specific HBV variants played a major role in the severe (or even fulminant) acute hepatitis observed at location A. Importantly, all patients were diagnosed with type 2 diabetes mellitus, a known risk factor for healthcare-associated transmission of HBV. The study leads us to suggest that, besides strict adherence to hygiene standards, additional efforts are required to reduce the risk of HBV transmission and fulminant disease progression in healthcare settings and nursing homes. In this context, a general screening for HBsAg and active hepatitis B vaccination should be considered for people living in nursing homes, especially for those with diagnosed diabetes or other predisposing factors for HBV transmission.

Total Hepatitis B Core Antigen Antibody, a Quantitative Non-Invasive Marker of Hepatitis B Virus Induced Liver Disease

Non invasive immunologic markers of virus-induced liver disease are unmet needs. We tested the clinical significance of quantitative total and IgM-anti-HBc in well characterized chronic-HBsAg-carriers. Sera (212) were obtained from 111 HBsAg-carriers followed-up for 52 months (28-216) during different phases of chronic-HBV-genotype-D-infection: 10 HBeAg-positive, 25 inactive-carriers (HBV-DNA≤2000IU/ml, ALT<30U/L), 66 HBeAg-negative-CHB-patients and 10 with HDV-super-infection. In 35 patients treated with Peg-IFN±nucleos(t)ide-analogues (NUCs) sera were obtained at baseline, end-of-therapy and week-24-off-therapy and in 22 treated with NUCs (for 60 months, 42-134m) at baseline and end-of-follow-up. HBsAg and IgM-anti-HBc were measured by Architect-assays (Abbott, USA); total-anti-HBc by double-antigen-sandwich-immune-assay (Wantai, China); HBV-DNA by COBAS-TaqMan (Roche, Germany). Total-anti-HBc were detectable in all sera with lower levels in HBsAg-carriers without CHB (immune-tolerant, inactive and HDV-superinfected, median 3.26, range 2.26-4.49 Log₁₀ IU/ml) versus untreated-CHB (median 4.68, range 2.76-5.54 Log₁₀ IU/ml), p<0.0001. IgM-anti-HBc positive using the chronic-hepatitis-cut-off" (0.130-S/CO) were positive in 102 of 212 sera (48.1%). Overall total-anti-HBc and IgM-anti-HBc correlated significantly (p<0.001, r=0.417). Total-anti-HBc declined significantly in CHB patients with response to Peg-IFN (p<0.001) and in NUC-treated patients (p<0.001); the lowest levels (median 2.68, range 2.12-3.08 Log₁₀ IU/ml) were found in long-term responders who cleared HBsAg subsequently. During spontaneous and therapy-induced fluctuations of CHB (remissions and reactivations) total- and IgM-anti-HBc correlated with ALT (p<0.001, r=0.351 and p=0.008, r=0.185 respectively). Total-anti-HBc qualifies as a useful marker of HBV-induced-liver-disease that might help to discriminate major phases of chronic HBV infection and to predict sustained response to antivirals.

Acute exacerbation of chronic hepatitis B: the dilemma of differentiation from acute viral hepatitis B

Exacerbations of chronic hepatitis B are common in endemic countries. Acute exacerbation of chronic hepatitis B virus (CHB-AE) causing derangement of liver functions may be seen in a flare of HBV in immune clearance phase or as a reactivation of HBV in patients with inactive or resolved HBV infection. While reactivation of HBV is usually seen in HBsAg positive patients, it is being increasingly recognized in patients with apparently resolved HBV infection who do not have HBsAg in serum but have IgG antibody to core antigen (anti-HBc) in the serum, especially so in patients on chemotherapy, immunosuppressive therapy or undergoing hematopoietic stem cell transplantation. In an icteric patient who is HBsAg positive, it may be difficult to differentiate CHB-AE from acute viral hepatitis B (AVH-B). Both may have similar clinical presentation and even IgM anti-HBc, the traditional diagnostic marker of AVH-B, may also appear at the time of exacerbation of CHB. The differentiation between CHB-AE and AVH-B is important not only for prognostication but also because management strategies are different. Most cases of AVH-B will resolve on their own, HBsAg clearance is achieved spontaneously in 90-95% of adults and treatment is rarely indicated except in the few with severe/fulminant disease. In contrast, in CHB-AE, the onset of jaundice may lead to decompensation of liver disease and treatment is warranted. The mechanisms of acute exacerbation and the differentiating features between AVH-B and CHB-AE are reviewed.

Molecular epidemiology and clinical characteristics of hepatitis B identified through the French mandatory notification system

BACKGROUND & AIMS

Strains responsible for acute hepatitis B infections (AHB) in France have not been characterized. This study was first designed to analyze the molecular epidemiology of AHB and second to describe the differences between AHB and chronic hepatitis B (CHB) exacerbations.

METHODS

This prospective study was based on the French mandatory notification system for AHB. 147 samples corresponding to declared cases were shipped to a central laboratory for classification as AHB or CHB according to the level of anti-HBc IgM and anti-HBc avidity.

RESULTS

Based on biological marker values and file examination, 75 cases (59%) were classified as AHB. Independently of the acute or chronic status, genotype A (57%), D (22%) and E (14%) were the most prevalent and no phylogenetic clustering was observed among HBV sequences (n=68). Precore or basal core-promoter variants were not particularly associated with disease severity but were more prevalent in CHB. No antiviral resistant strains or immune-escape HBsAg was observed. HBV viral loads in AHB or CHB were comparable but with opposite distributions. ALT levels reached 10 times the upper normal value in 94% of AHB but only in 24% of CHB.

CONCLUSIONS

After rigorous classification, no major difference at the genetic level was found between HBV strains isolated from AHB and CHB. Absence of potentially deleterious variant detection is reassuring. When based upon HBsAg and anti-HBc IgM determination, AHB notification may falsely include more than 40% CHB, leading to an important risk of bias in national surveillance programs of AHB.

Medical virology of hepatitis B: how it began and where we are now

Infection with hepatitis B virus (HBV) may lead to acute or chronic hepatitis. HBV infections were previously much more frequent but there are still 240 million chronic HBV carriers today and ca. 620,000 die per year from the late sequelae liver cirrhosis or hepatocellular carcinoma. Hepatitis B was recognized as a disease in ancient times, but its etiologic agent was only recently identified. The first clue in unraveling this mystery was the discovery of an enigmatic serum protein named Australia antigen 50 years ago by Baruch Blumberg. Some years later this was recognized to be the HBV surface antigen (HBsAg). Detection of HBsAg allowed for the first time screening of inapparently infected blood donors for a dangerous pathogen. The need to diagnose clinically silent HBV infections was a strong driving force in the development of modern virus diagnostics. HBsAg was the first infection marker to be assayed with a highly sensitive radio immune assay. HBV itself was among the first viruses to be detected by assay of its DNA genome and IgM antibodies against the HBV core antigen were the first to be selectively detected by the anti-μ capture assay. The cloning and sequencing of the HBV genome in 1978 paved the way to understand the viral life cycle, and allowed development of efficient vaccines and drugs. Today’s hepatitis B vaccine was the first vaccine produced by gene technology. Among the problems that still remain today are the inability to achieve a complete cure of chronic HBV infections, the recognition of occult HBV infections, their potential reactivation and the incomplete protection against escape mutants and heterologous HBV genotypes by HBV vaccines.

Management of acute hepatitis B and reactivation of hepatitis B

The natural course of hepatitis B virus infection and the resulting hepatic injury is determined by the degree of virus replication and the intensity of host immune response. Upon exposure to hepatitis B virus (HBV), individuals with a vigorous and broad immune response develop acute self-limited infection, which may result in acute hepatitis. However, with stringent testing for HBV and universal precautions, acute HBV is rather rare. Reactivation of HBV most often presents as acute hepatitis B (AVH-B) and clinically, it is difficult to differentiate AVH-B from reactivation of chronic hepatitis B (CHB) and it requires a high index of suspicion. In the presence of high HBV DNA (>2 × 10(4) IU/ml) underlying liver disease should be investigated by liver biopsy, endoscopy and/or imaging. The degree of liver failure often depends on the severity of acute insult and the stage of underlying chronic liver disease. Mutations in the HBV genome, immunosuppressive therapy and viral or drug induced injury are common causes of reactivation. As most patients with AVH-B resolve the infection spontaneously, antiviral therapy is not indicated in them. However, the use of a potent oral nucleoside(tide) analogue is necessary as soon as possible in patients with CHB reactivation. Liver transplantation should be considered in patients who develop liver failure secondary to severe acute exacerbation. If this is not feasible, supportive therapy with the addition of granulocyte colony stimulating factor (GCSF) therapy could be beneficial.

Core mutations in patients with acute episodes of chronic HBV infection are associated with the emergence of new immune recognition sites and the development of high IgM anti-HBc index values

Acute exacerbations in HBeAg negative patients with chronic hepatitis B virus (HBV) infection are invariably associated with concurrent increases in the index of IgM class antibodies against the core protein (anti-HBc) of the virus. This study aimed to investigate whether this was related to the clearance of variants from the quasispecies pool and the appearance of new ones, with aminoacid substitutions in well recognized B-cell epitopes. In this study, 5 HBeAg negative patients (A to E) with 13 sequential serum samples (A1-A2, B1-B2-B3, C1-C2, D1-D2-D3, E1-E2-E3) were investigated after amplification of the entire core encoding region followed by cloning/sequencing studies. The sequences at different time points were compared with those from a single HBeAg positive patient with no apparent acute exacerbations. The results from sequence comparison showed that virus variants emerged in all (A2, B3, C2, D3, E2, and E3) but two (B2 and D2) subsequent sera with amino-acid substitutions affecting B-cell epitopes. It is concluded that the rise in the values of IgM anti-HBc may be attributed to the alteration of the antigenic epitopes leading to new antibody production in the majority of the cases. However, it appears that increases in IgM anti-HBc indexes in a few cases may relate to other possible mechanisms which are discussed.

What is the role of serology for the study of chronic hepatitis B virus infection in the age of molecular biology?

To assess quantitative serology in chronic hepatitis B virus (HBV) infection, testing by novel immunoassays has been carried out on 202 specimens from untreated patients and in 83 samples from 10 patients with chronic hepatitis B treated with lamivudine. Serum samples were assayed for quantitative HBsAg, in comparison with quantitative HBV-DNA, and for anti-HBc IgM and the avidity index (AI) of total anti-HBc antibodies. The AI was high (mean: 0.93 +/- 0.19) in all groups, confirming the consistency of this procedure in chronic HBV infections. A low-level positivity (2-28 Paul-Ehrlich units/ml) for IgM anti-HBc was detectable both in HBeAg-positive and in HBeAg-negative untreated chronic hepatitis cases (mean S/CO values by the Abbott Architect assay: 0.51 +/- 0.12 and 0.48 +/- 0.10, respectively; correlation between assays: r = 0.685), while treated patients (mean: 0.20 +/- 0.15) and inactive carriers (mean: 0.17 +/- 0.21), were generally negative for IgM. The levels of HBsAg (IU/ml) showed a weak correlation with HBV-DNA (IU/ml). A difference in HBsAg levels was found between inactive carriers (1,935 +/- 2,887 IU/ml) and chronic hepatitis B cases, either treated (5,199 +/- 9,259 IU/ml) or untreated (14,596 +/- 15,227 IU/ml). Pre-treatment levels of HBsAg in patients undergoing lamivudine treatment were correlated with a sustained response to therapy over 13-33 months (mean: 27.3) of follow-up: mean HBsAg values were 1,576 + 1,487 IU/ml in five responders and 6,063 + 5,142 in five nonresponders or breakthrough responders (P < 0.05). The availability of standardized quantitative immunoassays for HBsAg and anti-HBc IgM may be considered in addition to quantitative HBV-DNA in the staging and monitoring of chronic HBV infection.

Performance characteristics of microparticle enzyme and chemiluminescence immunoassays for measurement of anti-HBc immunoglobulin M in sera of patients with HBeAg-negative chronic hepatitis B virus infection

The IMx, AxSym, and Architect immunoglobulin M anti-HBc assay systems for detecting hepatitis B virus e antigen-negative chronic hepatitis B virus infection were compared. Despite good intra- and interassay coefficients of variation, significantly different values and low correlation (overestimation by AxSym and underestimation by Architect) were observed. Association and cutoff values for distinguishing patients with viral replication should be established for all methods.

Quantitative analysis of HBsAg, IgM anti-HBc and anti-HBc avidity in acute and chronic hepatitis B

BACKGROUND AND OBJECTIVES

We evaluated hepatitis B virus (HBV) serological markers by novel, quantitative immunoassays in order to study their behaviours and possible role in the various phases of HBV infection.

STUDY DESIGN

The quantitative determination of HBsAg and anti-HBc/IgM by chemiluminescent immunoassays (Abbott Architect) and the calculation of anti-HBc avidity index have been carried out on repository specimens from patients with acute or chronic hepatitis B.

RESULTS

In acute hepatitis the levels of HBsAg were generally >10,000 UI/mL and decreased sharply in the recovery phase. In 35 anti-HBe-positive chronic hepatitis cases HBsAg levels were generally lower than 10,000 UI/mL (mean: 2655), whereas in five HBeAg-positive chronic hepatitis patients the mean value was 78,756 UI/mL and 90% of specimens exceeded 10,000 UI/mL. The lowest values (mean: 1029 IU/mL) were found in the seven patients with minimal hepatic damage. IgM anti-HBc antibodies were positive in all acute cases and in 68/207 samples (32.85%) from patients with chronic hepatitis, with significantly lower levels (average sample/cutoff (S/CO) ratio: 2.95 in chronic cases versus 25.96 in acute cases; p<0.005). A S/CO value of 10 for anti-HBc IgM had a 100% negative predictive value and a 99.13% positive predictive value for acute hepatitis B. The study of anti-HBc avidity by an experimental procedure showed that an avidity index (AI) threshold of 0.7 had a good efficacy to discriminate the cases of chronic hepatitis, among whom only 2 specimens out of 193 (1.04%) had an AI<0.7.

CONCLUSION

The quantitative determination of HBsAg, anti-HBc/IgM and anti-HBc avidity provides additional information and may be useful in the differential diagnosis of acute and chronic HBV infections and in the follow-up of chronically infected patients.

Higher cut-off index value of immunoglobulin M antibody to hepatitis B core antigen in Taiwanese patients with hepatitis B

BACKGROUND

The cut-off index value of immunoglobulin M (IgM) antibody to hepatitis B core antigen (anti-HBc; AxSYM CORE-M, Abbott) for diagnosing acute hepatitis B is 1.2. A high false-positive rate of IgM anti-HBc was observed in acute flare-ups of chronic hepatitis B in Taiwanese patients. Thus the purpose of the present paper was to study the optimal index value of IgM anti-HBc in Taiwanese subjects.

METHODS

The peak index values of 42 IgM anti-HBc-positive patients were collected. There were 20 acute hepatitis B patients and 22 patients with chronic hepatitis B with acute flare. The biochemical, virological, and serological data were obtained.

RESULTS

There were significant differences in mean age (36 vs 47 years, P = 0.01), serum alanine aminotransferase level (2042 U/L vs 1193 U/L, P = 0.02) and peak index value of IgM anti-HBc (2.9 vs 1.5, P < 0.01) between patients with acute hepatitis B and those with acute flare of chronic hepatitis B. Eleven (50%) of 22 patients with chronic hepatitis B with acute flare had index value of >1.2. The optimal cut-off index value to differentiate acute hepatitis B from chronic hepatitis B with acute flare was 2.4-2.5, with a sensitivity of 90% and specificity of 90%.

CONCLUSIONS

The cut-off index value of IgM anti-HBc to differentiate acute hepatitis B from chronic hepatitis B with acute flare among Taiwanese patients should be set at 2.4-2.5 instead of 0.8-1.2.

Outbreak of hepatitis B in a nursing home associated with capillary blood sampling

In 2001, two residents of a nursing home in Lower Saxony, Germany, were diagnosed with acute hepatitis B virus (HBV) infection. A systematic contact investigation of 188 residents yielded 19 confirmed or probable cases of acute or recent HBV infection and three persistent asymptomatic HBsAg carriers. Sequence analysis revealed that one carrier had high viraemia (109 genomes/ml), HBV genotype A2, and the same S gene and/or X gene sequence as 16 acutely infected persons. An unmatched case-control study was conducted with the 17 cases that had sequence identity together with 26 controls. The strongest association was found for treatment by a particular general practitioner (GP) (OR > 11, P < 0.001) and blood sampling for glucose monitoring on a particular day by the GP's staff (OR 13.6, P < 0.001, adjusted OR 8.5, P = 0.017). Control measures were implemented. Serological controls after 6 and 18 months revealed that the outbreak was brought under control.

Poor response to 18-month lamivudine monotherapy in chronic hepatitis B patients with IgM anti-HBc and acute exacerbation

BACKGROUND

Appearance of immunoglobulin class M antibody against hepatitis B core antigen is a predictor of beneficial response to interferon-alpha therapy in chronic hepatitis B patients, but its relationship with the efficacy of lamivudine therapy remains unclear.

AIM

To investigate the outcome of lamivudine therapy in chronic hepatitis B patients with immunoglobulin class M antibody against hepatitis B core antigen and acute exacerbation.

METHODS

Chronic hepatitis B patients with acute exacerbation receiving a national-wide therapeutic trial of 18-month lamivudine monotherapy were enrolled for the analysis. Four consecutive seronegative patients were recruited as individual matching controls of one positive subject. Immunoglobulin class M antibody against hepatitis B core antigen in serum was assayed monthly by an automated microparticle enzyme immunoassay.

RESULTS

Fifteen (8.9%) of 167 chronic hepatitis B patients with acute exacerbation were seropositive for IgM anti-HBc. Thus 60 seronegative patients were consecutively recruited as control group. At the end of therapy, two (13.3%) of the 15 seropositive patients achieved a sustained response, significantly lower than 26 (43.3%) of the control group.

CONCLUSIONS

Appearance of immunoglobulin class M antibody against hepatitis B core antigen in chronic hepatitis B patients with acute exacerbation is a predictor of poor response to lamivudine monotherapy. This is clinically relevant to the decision-making in treating chronic hepatitis B patients with acute exacerbation.

Virological profiles in hepatitis B virus inactive carriers: monthly evaluation in 1-year follow-up study

STUDY SUBJECT: We longitudinally evaluated the virological behaviour and the hepatitis B virus (HBV) genomic variability in inactive HBV surface antigen (HBsAg) chronic carriers.

PATIENTS AND METHODS

Fourteen HBsAg-positive healthy workers (13 inactive carriers and 1 with active HBV infection) were followed up for 12 months by monthly evaluation of aminotransferase, HBV DNA, and IgM anti HBV core antigen (IgM anti-HBc) values. Moreover, HBV serum isolates from each case were amplified, cloned and sequenced to evaluate the presence of the potentially clinical relevant core-promoter and precore mutations. The same technical procedures were used to examine the S gene of isolates from 3 randomly selected inactive carriers and the patients with active HBV infections.

RESULTS

Aminotransferase values were constantly normal in all cases. Viremia levels appear to fluctuate widely over time in each individual case, although the HBV DNA remained below 2 x 10(4) copies/ml in all samples. Only four serum samples from two inactive carriers had IgM anti-HBc values higher than the specific cut-off limit of the assay. Either wild type or core-promoter/precore HBV variants or a mixture of them were detected in the inactive carriers. S gene nucleotide homology among the clones from the three inactive carriers and the subject with active infection was 98.9%, 98.3%, 98.1% and 98.2%, respectively.

CONCLUSIONS

The degree of suppression of HBV replication in inactive carriers is variable over time, and the entity and quality of HBV variability is comparable between active and inactive carriers.

Hepatitis B virus core antigen binds and activates naive human B cells in vivo: studies with a human PBL-NOD/SCID mouse model

The hepatitis B virus (HBV) core (HBc) antigen (HBcAg) is a highly immunogenic subviral particle. Studies with mice have shown that HBcAg can bind and activate B cells in a T-cell-independent fashion. By using a human peripheral blood leukocyte (hu-PBL)-Nod/LtSz-Prkdc(scid)/Prkdc(scid) (NOD/SCID) mouse model, we show here that HBcAg also activates human B cells in vivo in a T-cell-independent way. HBcAg was capable of inducing the secretion of HBcAg-binding human immunoglobulin M (IgM) in naive human B cells derived from adult human and neonatal (cord blood) donors when these hu-PBL were transferred directly into the spleens of optimally conditioned NOD/SCID mice. No such responses were found in chimeric mice that were given hu-PBL plus HBV e antigen or hu-PBL plus phosphate-buffered saline. In addition, HBcAg activated purified human B cells to produce anti-HBc IgM in the chimeric mice, thus providing evidence that HBcAg behaves as a T-cell-independent antigen in humans. However, HBcAg-activated hu-PBL from naive donors were unable to switch from IgM to IgG production, even after a booster dose of HBcAg. Production of HBcAg-specific IgG could only be induced when hu-PBL from subjects who had recovered from or had an ongoing chronic HBV infection were transferred into NOD/SCID mice. Our data suggest that humans also have a population of naive B cells that can bind HBcAg and is subsequently activated to produce HBcAg-binding IgM.

Semiquantitative assessment of IgM antibody to hepatitis B core antigen and prediction of the severity of chronic hepatitis B

Controversial results have been reported concerning the correlation between serum levels of IgM antibodies to hepatitis B core antigen (IgM HBcAb) and the histological activity of chronic hepatitis B. In this study, paired serum samples and liver biopsies were collected from 200 consecutive chronic hepatitis B patients (mean age 39.2 +/- 0.8 years; M:F 154:46; 41 hepatitis B e antigen (HBeAg) positive) and tested for IgM HBcAb using a semiquantitative highly sensitive assay (IMx CORE-M(R)). The severity of liver disease was assessed by the Ishak score, grading the necroinflammatory activity (by using the histology activity index, HAI) and staging the fibrosis. The index values of IgM HBcAb were significantly different among patients with mild (HAI < or = 6), moderate (HAI 7-12) and severe (HAI > or = 13) necroinflammatory activity but the stage of fibrosis was unrelated to the IgM HBcAb. According to the index value of IgM HBcAb, we selected three groups of patients: Group A included 36 patients with an index value below 0.200; Group B, 99 patients with an index value between 0.200 and 0.500; and Group C, 65 patients with an index value over 0.500. The mean HAI grading in Group A was 5.3 +/- 0.4, in Group B it was 7.4 +/- 0.3 and in Group C it was 8.9 +/- 0.4 (f = 16.5, P < 0.0001). A mild HAI grading was observed in 77.8% of Group A, in 47.5% of Group B and in 23.1% of Group C patients; conversely, severe grading was detected in 0% of Group A, in 11.1% of Group B and in 18.5% of Group C patients (P < 0.0001). An index value of IgM HBcAb below 0.200 was 75% predictive of a mild necroinflammatory activity (29% sensitivity and 91.6% specificity) and ruled out a severe activity. Therefore, the quantitative assessment of IgM HBcAb appears to be a useful clinical tool in the prediction of the necroinflammatory activity of chronic hepatitis B. A serum index value of IgM HBcAb consistently below 0.200 could be considered a surrogate marker of remission of hepatitis B virus-induced liver disease.

Relevance of inapparent coinfection by hepatitis B virus in alpha interferon-treated patients with hepatitis C virus chronic hepatitis

The aim of the study was to investigate whether an "inapparent" coinfection by hepatitis B virus (HBV) in anti-HCV-positive chronic liver disease patients may influence interferon (IFN) response. Fourteen anti-HCV-positive, hepatitis B surface antigen (HBsAg)-negative but serum HBV-DNA-positive patients and 111 anti-HCV-positive, HBsAg-negative, and HBV-DNA-negative patients with chronic hepatitis were treated with 3 MU of recombinant alpha-2a IFN 3/week for 1.2 months. Serum HBV-DNA and HCV-RNA were determined before treatment, after 6-12 months, and at the time of alanine aminotransferase (ALT) flare-up by HBV polymerase chain reaction (PCR) and HCV PCR, respectively. IgM anti-HBc were tested using the IMx Core-M assay (Abbott Laboratories, North Chicago, IL). By the end of treatment, ALT values had become normal in 4/14 HBV-DNA-positive patients (28%), but all "responders" (4/4) relapsed. IgM anti-HBc was detected both before treatment and during ALT elevation in three patients and only during ALT relapse in another three. In the remaining 111 patients, a biochemical response to IFN treatment was observed in 54% and relapse of ALT values in 47%. "Inapparent" HBV/HCV coinfection may be implicated in cases of resistance to IFN. HBV replication and HBV-related liver damage may persist in patients in whom HCV replication was inhibited by current doses of IFN, as suggested also by the presence of IgM anti-HBc in some cases. Further studies will show the effect of different treatment schedules. HBV-DNA and/or IgM anti-HBc detection with very sensitive methods may be important both as a prognostic factor and as a tool for better understanding of intervirus relationships and mechanisms involved in multiple hepatitis virus infections.

Hepatitis C virus infection of salivary gland epithelial cells. Lack of evidence

BACKGROUND

Hepatitis C virus genome (HCV-RNA) has been detected in whole salivary gland tissue of chronically infected patients. However, contamination of the tissue by plasma or blood cells was not excluded by the previous reports.

AIMS

To assess whether HCV infects the salivary gland epithelial cells in patients with chronic HCV liver disease.

METHODS

Twenty unselected patients with chronic active hepatitis (11 cases) or active cirrhosis (nine cases) were examined. Serum and saliva samples were obtained from all patients, 12 of whom (seven, chronic active hepatitis; five, active cirrhosis) underwent salivary gland biopsy. PCR for HCV-RNA was performed on RNA extracted from serum, saliva and salivary gland epithelial cells collected by isokinetic gradient separation after trypsin digestion of whole salivary gland tissue. Saliva samples were also examined for the presence of secretory IgA anti-HCV by gel chromatography and ELISA testing.

RESULTS

HCV-RNA was detected in all sera with titers ranging from 5.42 x 10(5) genome equivalents/ml to 123.2 x 10(5) genome equivalents/ml. Thirteen patients were infected with genotype 1b, four patients had genotype 1a, two patients had genotype 2a and one patient was unclassifiable. Low titer HCV-RNA (<2 x 10(5) genome equivalents/ml) was detected in 3/20 saliva samples (15%) from highly viremic patients infected with 1b genotype. RNA extracted from salivary gland epithelial cells consistently tested negative for HCV-RNA. In addition, all saliva specimens tested negative for secretory-IgA (S-IgA) anti-HCV, even after a 10-fold concentration of the samples.

CONCLUSIONS

There was no evidence that HCV infects the salivary gland epithelial cells in our viremic patients with HCV chronic liver disease. Low level HCV-RNA in saliva is most probably due to virus spillover from blood.

Are alanine aminotransferase, hepatitis B virus DNA or IgM antibody to hepatitis B core antigen serum levels predictors of histological grading in chronic hepatitis B?

Paired sera and liver biopsies from 105 patients with chronic hepatitis B virus infection (34 HBeAg positive and 71 anti-HBe positive) were studied to investigate the relation between the degree of histological activity and alanine aminotransferase (ALT), hepatitis B virus DNA (HBV-DNA) or IgM antibody to hepatitis B core antigen (IgM anti-HBc) levels. ALT levels were significantly higher in patients with piecemeal necrosis (155 +/- 124 vs 75 +/- 42, p = 0.0017), but there were no differences in the ALT values of patients with or without intralobular necrosis. ALT values were within normal range in 29% of 31 patients without versus 15% of 65 with piecemeal necrosis (p = 0.19). Serum HBV-DNA levels were not related to the grade of lobular or portal/periportal activity in HBeAg-positive patients. Anti-HBe-positive subjects with piecemeal necrosis had higher HBV-DNA levels (34 +/- 93 vs 4 +/- 6, p = 0.01). IgM anti-HBc indexes were significantly higher in patients with intralobular necrosis (0.635 +/- 0.600 vs 0.356 +/- 0.367, p = 0.0005) or piecemeal necrosis (0.671 +/- 0.633 vs 0.321 +/- 0.219, p = 0.0002). In summary, since serum IgM anti-HBc-IMx indexes can reflect the grade of histological activity, the quantitative assessment of this antibody could be useful for non-invasive monitoring of hepatocellular damage in chronic hepatitis B.

Differential diagnosis of acute HBsAg positive hepatitis using IgM anti-HBc by a rapid, fully automated microparticle enzyme immunoassay

BACKGROUND/AIMS

We determined the diagnostic significance of IgM anti-HBc by a rapid, fully automated microparticle enzyme immunoassay (IMx CORE-M) in acute HBsAg positive hepatitis.

METHODS

We studied prospectively for at least 6 months 100 patients with acute self-limited hepatitis B (group A) and 40 patients with acute hepatitis superimposed on histologically confirmed chronic hepatitis B (group B). On admission, all patients in group A were positive and those in group B were negative for IgM anti-HBc by a commercially available enzyme immunoassay.

RESULTS

Based on the assay criteria, the rates of IMx CORE-M (> 1.2) positive serum samples on admission, 4, 12 and 24 weeks later were: in group A: 100%, 95%, 72%, 44% and in group B: 20%, 27.5%, 17.5%, and 15%, respectively. Misclassification was observed in 20-27.5% of the acute on chronic hepatitis B cases. However, the mean IMx CORE-M index value was found to be significantly higher in group A during the whole follow-up. In particular, on admission the mean IMx CORE-M index value was 2.504 +/- 0.435 (range: 1.508-3.482) in group A and 0.747 +/- 0.346 (range: 0.062-1.384) in group B (p < 0.001). Discriminant function analysis showed that the cutoff level between the two groups for IMxCORE-M index on admission was 1.5. Four to 12 weeks from admission, in the group with acute on chronic hepatitis B cases, 13 patients with HDV and/or HCV superinfection had significantly lower IMx-CORE M index values compared with 27 patients with acute hepatitis due to exacerbation of chronic hepatitis B.

CONCLUSIONS

IMx CORE-M appears to be an accurate diagnostic test to differentiate acute from acute on chronic HBsAg positive hepatitis, but the cut-off level seems to be higher (1.5 instead of 1.2).

Quantitative analysis of IgM anti-HBc in chronic hepatitis B patients using a new "gray-zone" for the evaluation of "borderline" values

BACKGROUND/METHODS

In order to define the clinical significance of borderline levels of IgM anti-HBc in chronic hepatitis B patients, we followed up 89 untreated hepatitis B patients (19 HBeAg pos and 70 anti-HBe pos) for 1 year, with monthly monitoring of IgM anti-HBc using a highly sensitive quantitative microparticle enzyme immunoassay (IMx CORE-M, Abbott). As a control group we used 304 healthy subjects: 150 HBsAg negative and anti-HBc/anti-HBs positive, and 154 without markers of HBV infection. The statistical analysis performed by Receiver Operating Characteristic curve indicated the 100% sensitivity cut-off at 0.081 IMx index and 100% specificity cut-off at 0.358 IMx index.

RESULTS

We could define the range of a chronic hepatitis B "gray-zone" between 0.100 [80.6% specificity (95% CI, 76.2%-85%), 96.6% sensitivity (95% CI, 92.8%-100%)] and 0.200 [95.7% specificity (95% CI, 93.4%-98%) and 78.7% sensitivity (95% CI, 70.2%-87.2%)] of the IgM anti-HBc-IMx index. In fact, none of the chronic hepatitis B patients had IgM anti-HBc-IMx values persistently below 0.100 during the follow-up, whereas 57.3% had values persistently higher than 0.200. In 38.2%, IgM anti-HBc values occasionally fell within the "gray-zone" limits. In the remaining four patients (4.4%), the results overlapped the "gray-zone" values.

CONCLUSIONS

These results suggest that the use of a chronic hepatitis B "gray-zone" for values of quantitative IgM anti-HBc assays helps to distinguish "true healthy carriers" from asymptomatic chronic anti-HBe positive hepatitis B patients who have been shown to have temporary remissions of liver disease and frequently undetectable serum HBV-DNA.

Significance of anti-hepatitis C virus core IgM antibodies in patients with chronic hepatitis C

Antihepatitis C virus (HCV) IgM antibodies were found in patients with both acute and chronic hepatitis C. The aims of the study were to determine the significance, in terms of liver disease and virological parameters, of anti-HCV core IgM antibodies in the serum of patients with chronic hepatitis C, and the possible relationship between the presence of these antibodies before treatment and biochemical and virological responses to interferon therapy. Sixty-one patients with chronic hepatitis C were studied. Tests for serum anti-HCV core IgM antibodies were carried out before treatment. The patients received 3 mega units of interferon alpha-2a subcutaneously thrice weekly for at least 3 months (6 months when alanine aminotransferase activity was normal at month 3). A biochemical response to interferon therapy was defined as normal alanine aminotransferase activity at the end of treatment (month 6: biochemical response) and 6 months later (month 12: sustained biochemical response). A sustained virological response was defined as serum HCV RNA negativity by a polymerase chain reaction-based detection method (PCR) in patients with normal alanine aminotransferase at month 12. Anti-HCV core IgM antibodies were detected in 28 of the 61 patients (46%). The prevalence of these antibodies was significantly higher in patients infected with HCV genotype 1 (including subtypes 1a and 1b) than in patients infected with other genotypes (including 2a and 3a) (57% vs. 17%; P < 0.01). No significant difference was found between IgM-positive and IgM-negative patients as regards the mean age, sex ratio, serum alanine aminotransferase and gamma-glutamyl transpeptidase activities, the prevalence of cirrhosis in liver biopsy specimens, detection of HCV RNA by PCR, and quantitation by branched DNA assay. At month 6 of interferon therapy, normal alanine aminotransferase activity was significantly more frequent in IgM-negative than in IgM-positive patients (52% vs. 21%, respectively; P < 0.02). At month 12, normal alanine aminotransferase activity and PCR negativity were significantly more frequent in IgM-negative than in IgM-positive patients (18% vs. 0%, P < 0.04). It is concluded that anti-HCV core IgM antibodies in serum are significantly more frequent in patients infected by HCV type 1 than by other types. This suggests that their overall prevalence in patients with chronic hepatitis C in industrialized countries, where HCV type 1 accounts for the majority of infections, would be of the order of 50%, that anti-HCV core IgM antibodies are not associated with characteristic features of liver disease, and that their presence before treatment is associated with a failure of interferon alpha therapy to clear the virus.

The fluctuations of hepatitis C virus RNA and IgM anti-HCV (core) serum levels correlate with those of alanine aminotransferases during the hepatitis relapses of patients treated with interferon

Variations in the serum levels of hepatitis C virus (HCV) RNA. IgM antibody against the HCV 'core' structural protein (c22) and alanine amino-transferase (ALT) were measured in 23 patients with chronic hepatitis C who underwent therapy with interferon-alpha 2a (IFN alpha 2a). Low pretreatment levels of viraemia and undetectable IgM anti-core were significantly associated with a long-term response to treatment. In patients with hepatitis relapses after the end of treatment, HCV RNA levels increased before or at the same time as ALT in 29 out of 34 cases (85%). ALT flares occurred before or simultaneously with IgM anti-core elevations in 18 out of 20 cases (90%). Therefore, post-treatment hepatitis C exacerbations show the same sequence of events seen as in hepatitis B exacerbations (increases of viraemia followed by those of ALT and IgM anti-'core'). These findings underscore the diagnostic and prognostic usefulness of monitoring anti-HCV-positive patients with quantitative assays for HCV markers.

Semiquantitative anti-HBc IgM detection in children with chronic hepatitis B: a long-term follow-up study

Serum anti-HBc IgM titres were monitored monthly by a semiquantitative method in 14 children with HBeAg positive chronic hepatitis B followed up for 18-65 months. All patients, but one, were treated with alfa-interferon (IFN) at different times. On the whole, 12 flare-up episodes were observed and 7 patients cleared HBV-DNA and seroconverted to anti-HBe. Seroconversion occurred only in patients with pretreatment anti-HBc IgM index greater than 0.15 and serum HBV-DNA concentration below 100 pg/ml; the pretreatment alanine aminotransferase (ALT) value was not predictive of response. Combining anti-HBc IgM results and serum HBV-DNA levels observed during the pre-IFN period allowed a precise identification of patients who were likely to respond to IFN therapy. Patients who seroconverted to anti-HBe showed a progressive reduction in serum anti-HBc IgM titres within 6 months. Interestingly, one child, in whom HBV-DNA reappeared and who reconverted to HBeAg 7 months after treatment, showed no anti-HBc IgM decrease after the transient clearance of HBV-DNA and anti-HBe seroconversion. Semiquantitative anti-HBc IgM detection is a useful tool in the decision making process for children with chronic hepatitis B.

Development and retrospective evaluation of Hepaxpert-I: a routinely-used expert system for interpretive analysis of hepatitis A and B serologic findings

Hepaxpert-I is an expert system that interprets the results of routine serologic tests for infection with hepatitis A or B virus. The tests measure antibody to the hepatitis A virus (anti-HAV), IgM antibody to the hepatitis A virus (IgM anti-HAV), hepatitis A virus (HAV) in the stool, hepatitis B surface antigen (HBsAg) and antibody (anti-HBs), antibody to hepatitis B core antigen (anti-HBc and IgM anti-HBc), and hepatitis B envelope antigen (HBeAg) and antibody (anti-HBe). The knowledge base of Hepaxpert-I contains 13 If-Then rules for hepatitis A and 106 If-Then rules for hepatitis B serology. Formally, knowledge acquisition was done by forming a partition of each of the two sets of possible serologic finding patterns that contain patterns of serologic test results, 64 for hepatitis A and 4096 for hepatitis B, respectively. After entering an input pattern of serologic test results in Hepaxpert-I, a rule pattern matching algorithm based on indexing is internally employed as efficient access method for providing the respective interpretive text. Since 1 September 1989, Hepaxpert-I has been routinely applied at the Hepatitis Serology Laboratory of the 2nd Department of Gastroenterology and Hepatology at the University of Vienna Medical School (Vienna General Hospital). Beforehand, a retrospective evaluation of the expert system based on 23,368 hepatitis A and 24,071 hepatitis B serology requests was carried out.

Distinguishing between acute and symptomatic chronic hepatitis B virus infection

BACKGROUND/AIMS

Differentiating between an acute hepatitis B (AH-B) infection and an acute exacerbation of a chronic hepatitis B (CH-B) infection can present a problem for the clinician. The only current serological method of distinguishing between acute and symptomatic chronic hepatitis B virus (HBV) infection is the immunoglobulin M antibody to hepatitis B core antigen (anti-HBc) assay, which can be problematic. Therefore, in an attempt to better distinguish between acute and chronic HBV infection, sera from 26 patients with AH-B and 53 patients with CH-B were compared in a variety of experimental immunoassays.

METHODS

Experimental assays have been designed to detect free antibody to hepatitis B e antigen (anti-HBe), hepatitis B e antigen (HBeAg)/anti-HBe immune complexes (ICs), and hepatitis B surface antigens (HBsAg)/antibody to hepatitis B surface antigen (anti-HBs) in the presence of excess antigen. An additional assay was developed to detect a novel anti-HBc specificity, designated antibody to woodchuck hepatitis virus (anti-HBcW), which cross-reacts with the core antigen of the woodchuck hepatitis virus.

RESULTS

Sera from patients with CH-B showed significantly higher levels of free anti-HBe, HBeAg/anti-HBe ICs, and HBsAg/anti-HBs ICs compared with AH-B patient sera. Furthermore, patients with CH-B consistently produced high titer anti-HBcW, whereas patients with AH-B produced little or no anti-HBcW antibody.

CONCLUSIONS

The serology of AH-B infection and symptomatic CH-B infection can be distinguished using a variety of experimental immunoassays in addition to the immunoglobulin M anti-HBc assay.

Quantitative assessment of serum IgM anti-HBc in the natural course and during interferon treatment of chronic hepatitis B virus infection

Serum IgM anti-HBc was determined in 135 chronic HBsAg carriers with various categories of histological activity on liver biopsy and hepatitis B serological profile. Thirty-three patients were treated with interferon-alpha to investigate the correlation between serum IgM anti-HBc with histological activity and viral replication, to evaluate the usefulness of pretreatment IgM anti-HBc as a predictor of a successful response to interferon-alpha and to examine the IgM anti-HBc response during this treatment. All 53 patients with chronic active hepatitis with either wild-type (n = 42) or precore mutant variant HBV infection (n = 11) had an IgM anti-HBc index greater than 0.300 compared with 7.4% (2 of 27) of the chronic HBsAg/HBeAg-positive carriers with chronic persistent hepatitis, 10% (3 of 30) of the anti-HBe-positive asymptomatic carriers and none of the 25 patients with hepatitis D virus-positive chronic active hepatitis (p < 0.0001). Pretreatment IgM anti-HBc index was greater than 0.300 in 82.4% (14 of 17) of HBeAg/HBV DNA-positive patients who seroconverted after interferon-alpha treatment compared with 25% (4 of 16) of the patients who did not seroconvert (p = 0.0013), whereas an elevated pretreatment AST was present in only 52.9% (9 of 17) of responders and in 37.5% (6 of 16) of nonresponders (p = 0.42). Serial testing of IgM anti-HBc in these 33 patients during interferon-alpha treatment showed a significant rise in IgM anti-HBc in all responders, which followed the AST flare-up but preceded the time of the HBeAg to anti-HBe seroconversion.(ABSTRACT TRUNCATED AT 250 WORDS)

Immune recognition of linear antigenic regions within the hepatitis B pre-C and C-gene translation products using synthetic peptides

The antibody recognition of linear regions within the amino acid (aa) sequence of hepatitis B (HB) core antigen (HBcAg), e antigen (HBeAg), and pre-C region was investigated in 46 patients infected with hepatitis B virus (HBV), and one immunized rabbit. Peptide analogues were synthesized to cover the complete product of the C-gene, including the pre-C region using various synthetic methods. Two carriers of hepatitis B surface antigen (HBsAg) with anti-HBe, recognized pin-bound decapeptides covering amino acid (aa) 76-83 of HBc/eAg, and the most essential residues were found to be Asp78, Pro79, Arg82, and Asp83. Pre-C peptides were recognized by IgG1 or IgG3 in sera from two out of ten cases with acute HB, in four out of twelve sera from HBeAg-positive carriers of HBsAg, and in two out of twelve sera from anti-HBe-positive carriers of HBsAg. Two sera from the cases of acute HB showed strong reactivity of the IgG3 isotype with HBc/eAg peptides 61-85. Five of the sera from HBeAg-positive carriers of HBsAg were weakly reactive with peptides 41-60, 61-85, 121-140, and/or 141-160. Eight of the sera from anti-HBe-positive carriers of HBsAg recognized aa 121-140 of HBc/e with IgG1, IgG3, and/or IgG4 isotypes. IgG from one immunized rabbit recognized peptides 1-20, 61-85, and 71-90, and the T-cells recognized peptides 1-20 and 71-90. Thus, human and rabbit antibodies recognize linear antigenic regions within the pre-C, and within regions 1-20, 41-60, 61-85, 121-140, and 141-160 of HBcAg.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring the natural course and response to therapy of chronic hepatitis B with an automated semi-quantitative assay for IgM anti-HBc

The clinical significance of a semi-quantitative microparticle enzyme immunoassay (IMx Core-M, Abbott) was evaluated for detection of IgM-class antibodies against the hepatitis B core antigen (IgM anti-HBc) in 136 hepatitis B surface antigen (HBsAg) positive individuals (96 chronic HBV carriers, 20 patients with chronic HBV-HDV infections and 20 patients with acute hepatitis B) and 50 HBV-negative controls. Baseline and follow-up sera (4-11 samples) were analysed from 79 carriers with chronic hepatitis B, 44 of whom were treated with interferon. IMx indexes above 3,000 were found in 95% of the acute hepatitis B patients and above 0.300 in 91.5% of patients with ongoing chronic hepatitis B. IMx indexes between 0.200 and 0.300 were observed in (a) patients with recent HBeAg to anti-HBe seronconversion (6-12 months) and normal serum ALT levels, (b) patients immuno-tolerant to HBV infection and without liver disease despite high levels of viremia, and (c) patients with anti-HBe-positive chronic hepatitis B during 7-13-month intervals of asymptomatic carriage between episodes of disease reactivation. IMx indexes below 0.200 were detected in all HBV-negative individuals and healthy HBV carriers, in 14 (70%) of 20 chronic hepatitis D patients and in all but 1 of 22 interferon-treated patients with histological remission of liver disease, 5-12 months after clearance of viremia and normalization of serum ALT levels. In contrast, IMx indexes remained above 0.200 in all patients with hepatitis B reactivation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic significance of antibodies to hepatitis B virus polymerase in acutely and chronically HBV-infected individuals

The prevalence and time course of the occurrence of antibodies to the hepatitis B virus polymerase (anti-HBpol) were investigated in acutely and in chronically HBV-infected individuals by using recombinant HBpol protein for Western blot analysis. One group consisted of 19 patients who were acutely infected and recovered completely. Five of these patients (26%, 69 serum samples examined) exhibited anti-HBpol. Among those anti-HBpol positive patients, recovery from the disease was combined with a complete loss of this antibody. In contrast, in a second group of 15 individuals who developed chronic hepatitis B, 13 (87%, 102 serum samples examined) had anti-HBpol during the acute phase of the disease. The difference between the anti-HBpol prevalence rates of the two patient groups is statistically significant (Exact Fisher test, P < .002), implying that the occurrence of anti-HBpol may be indicative of a potential chronic course of hepatitis B. Remarkably, anti-HBpol was found in one case of a clinically suspected hepatitis B in which no other serological HBV parameters were found. This serum sample was positive in HBV PCR, supporting a possible diagnostic value of anti-HBpol.