Serologic markers of hepatitis B virus infection

Atypical Hepatitis B Virus Serology Profile-Hepatitis B Surface Antigen-Positive/Hepatitis B Core Antibody-Negative-In Hepatitis B Virus/HIV Coinfected Individuals in Botswana

(1) Background: Hepatitis B core antibodies (anti-HBc) are a marker of hepatitis B virus (HBV) exposure; hence, a normal HBV serology profile is characterized by HBV surface antigen (HBsAg) and anti-HBc positivity. However, atypical HBV serologies occur, and we aimed to determine the prevalence of an atypical profile (HBsAg+/anti-HBc-) in a cohort of people with HIV-1 (PWH) in Botswana. (2) Methods: Plasma samples from an HIV-1 cohort in Botswana (2013-2018) were used. The samples were screened for HBsAg and anti-HBc. Next-generation sequencing was performed using the GridION platform. The Wilcoxon rank-sum test and Chi-squared tests were used for the comparison of continuous and categorical variables, respectively. (3) Results: HBsAg+/anti-HBc- prevalence was 13.7% (95% CI 10.1-18.4) (36/263). HBsAg+/anti-HBc- participants were significantly younger (p < 0.001), female (p = 0.02) and ART-naïve (p = 0.04) and had a detectable HIV viral load (p = 0.02). There was no statistically significant difference in the number of mutations observed in participants with HBsAg+/anti-HBc- vs. those with HBsAg+/anti-HBc+ serology. (4) Conclusions: We report a high HBsAg+/anti-HBc- atypical serology profile prevalence among PWH in Botswana. We caution against HBV-testing algorithms that consider only anti-HBc+ samples for HBsAg testing, as they are likely to underestimate HBV prevalence. Studies to elucidate the mechanisms and implications of this profile are warranted.

[Hepatitis B virus infection: Natural history, clinical manifestations and therapeutic approach]

Chronic hepatitis B infection remains a major public-health problem, with approximately 260 million world-wide cases of infection. Recent advances in the understanding of the natural history of chronic hepatitis B infection have led to progress in the care of infected patients. Sustained viral suppression is now possible for a majority of treated patients and is associated with a decrease in the morbidity and mortality attributable to cirrhosis and hepatocellular carcinoma. Complete cure is however not yet possible, due to the long-term persistence of viral DNA in hepatocytes of treated patients. Assessing the risk of viral reactivation in patients receiving immunosuppressive therapy is an increasingly frequent situation in clinical practice and its management is guided by both the patient's serological status and the potency of the immunosuppressive regimen. This review aims to present the clinical and biological presentations of chronic hepatitis B infection, the modalities of antiviral treatment, and how to assess the risk of viral reactivation in patients receiving immunosuppressive therapy.

Genetic diversity, viraemic and aminotransferases levels in chronic infected hepatitis B patients from Cameroon

Background

HBV infection annually accounts for 1 million deaths worldwide as a result of cirrhosis, liver failure, and hepatocellular carcinoma. In addition to varying responses to antiviral therapy, HBV genotypes have also been shown to be associated with different pattern of disease progression. Despite a high HBV prevalence of >8 %, very few studies have been carried out in Cameroon to determine the genotype distribution across the country. The aim of this study was to determine the prevalent genotypes, level of viraemia and correlate these parameters with liver enzymes known to be the most affordable and widely used biomarkers for monitoring disease progression in Cameroon.

Methods

This was a hospital-community based study in which 81 participants who had been previously diagnosed of HBV were recruited and screened for HIV, HCV (for exclusion) and HBsAg for confirmation. Fifty known negative cases for HIV, HBV and HCV were tested and recruited to be used as healthy controls. Viral load and genotyping was performed only for HBV-mono infected cases using the Abbott RealTime HBV automated m2000 system and INNO-LiPA HBV Genotyping assay respectively. Liver enzymes were measured by spectrophotometry on both hepatitis B positive and healthy control cases.

Results

The mean alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were significantly higher (p < 0.001) in HBV infected patients than “healthy controls”. Of the 81 HBV infected cases viral load was detected in 76 (93.8 %) with mean viral load of 120,807 IU/ml ± 440,159 SD. Mean viral load was significantly different in patients with abnormal AST and ALT when compared with patients who had normal ALT and AST. The identified genotypes in order of prevalence were A (47.4 %), E (39.5 %), C/E (3.9 %) A/C (2.6 %), A/E (2.6 %), B (1.3 %), A/B (1.3 %) and B/C (1.3 %).

Conclusion

Genotype E was significantly associated with higher mean viral load and mean AST levels. However, aminotransferase levels may not be a good marker for HBV disease progression as some patients could have normal levels but still present with very high viral loads and therefore, remain active HBV infection with possible high transmission.

Induced immunity against hepatitis B virus

Prevention of hepatitis B virus (HBV) infection with its consequent development of HBV chronic liver disease and hepatocellular carcinoma is a global mandatory goal. Fortunately, safe and effective HBV vaccines are currently available. Universal hepatitis B surface antigen HBV vaccination coverage is almost done. Growing knowledge based upon monitoring and surveillance of HBV vaccination programs has accumulated and the policy of booster vaccination has been evaluated. This review article provides an overview of the natural history of HBV infection, immune responses and the future of HBV infection. It also summarizes the updated sources, types and uses of HBV vaccines, whether in the preclinical phase or in the post-field vaccination.

The chimpanzee model for hepatitis B virus infection

Even before the discovery of hepatitis B virus (HBV), it was known that chimpanzees (Pan troglodytes) are susceptible to human hepatitis viruses. The chimpanzee is the only primate animal model for HBV infections. Much like HBV-infected human patients, chimpanzees can develop acute and chronic HBV infections and consequent hepatitis. Chimpanzees also develop a cellular immune response similar to that observed in humans. For these reasons, the chimpanzee has proven to be an invaluable model for investigations on HBV-driven disease pathogenesis and also the testing of novel antiviral therapies and prophylactic approaches.

Giving rituximab in patients with occult or resolved hepatitis B virus infection: are the current guidelines good enough?

INTRODUCTION

Hepatitis B virus (HBV) reactivation after 'resolved' infection can occur in the setting of immunosuppression, including iatrogenically induced by anti-CD20 antibodies. The presence of antibodies against the HBV core antigen (anti-HBc) is a marker of risk for this phenomenon. The risk of this occurring in patients with circulating HBV surface antigen (HBsAg) is well characterized, but is less well characterized in patients who are HBsAg negative.

AREAS COVERED

This article reviews the literature regarding HBV reactivation in the context of rituximab therapy. We have limited our review to HBsAg-negative patients, and clinical outcomes following HBV reactivation.

EXPERT OPINION

We have recommended prophylactic anti-viral therapy for all HBsAg-negative/anti-HBc-positive patients undergoing rituximab therapy in combination with other immunosuppressive therapy.

A drug safety evaluation of rituximab and risk of hepatitis B

INTRODUCTION

Rituximab is a widely prescribed anti-CD20 mAb for the treatment of CD20(+) B-cell non-Hodgkin Lymphoma and many other immune mediated conditions. There is a well-described association between rituximab containing chemo-immunotherapy treatment and reactivation of the hepatitis B virus (HBV). This review summarizes the current literature surrounding rituximab-associated HBV reactivation.

AREAS COVERED

Herein, we review the literature detailing the risk of HBV reactivation in inactive carriers and those with resolved hepatitis. The clinical presentation and management of HBV reactivation are also discussed along with a summary of clinical trials evaluating antiviral prophylaxis. Finally, clinical recommendations are detailed. Data from clinical trials, observational studies, reviews, and meta-analyses available in the Medline database were included in this narrative review.

EXPERT OPINION

Screening should be performed in all patients prior to the administration of any type of anti-CD20 mAb therapy. Among those with positive screening serology, testing for hepatitis B e antigen or viral load by polymerase chain reaction is appropriate. In those patients with detectable HBV DNA, the decision regarding the use of antiviral prophylaxis or observation should be individualized.

Impact of Pegylated Interferon-alfa-2a on Perforin Level in Patients With Chronic Hepatitis B; Preliminary Study

BACKGROUND

Chronic hepatitis B is one of the most common causes of cirrhosis and hepatocellular toxicity in many countries, including Iran. Cytotoxic T lymphocyte (CTL) and Natural killer (NK) cells are the two of main cell populations considered as cytotoxic cells. One of the distinct pathways CTL and NK cells exert cytotoxicity is perforin/granzyme. After the cytotoxic cell/target cell junction, perforin is released from granules by exocytosis. Once it is anchored, perforin forms cylindrical pores through which granzymes and granulysin enter and induce apoptosis.

OBJECTIVES

Large controlled trials have demonstrated the efficacy of PEG-IFN-α-2a in treatment of chronic hepatitis B. This study was aimed to examine whether the enhancement of cytotoxicity by PEG-IFN-α-2a is mainly due to the perforin pathway.

PATIENTS AND METHODS

This research work was performed on 50 patients and five healthy people. Patients with chronic hepatitis B were further subdivided into two groups: patients with inactive chronic hepatitis B (carriers, n = 30), and those with active chronic hepatitis B who were under treatment with PEG-IFN-alfa-2a (n = 20) for minimum six and maximum 12 months. Serum perforin level was measured using ELISA method (CUSABIO Company), HBV viral load was assessed using COBAS Taq-man, and we used Elecsys hepatitis B surface antigen (HBs Ag) II quantitative assay method for HBs Ag determination. HBeAg was evaluated by ELISA method, and AST and ALT were measured by routine laboratorymethods.

RESULTS

Based on the results obtained serum perforin level in healthy group was 0.64 ng/mL, the mean of serum perforin level in inactive HBs Ag carriers was 2.63ng/mL, and 4.63 ng/mL in patients with active chronic hepatitis B under treatment with PEG-IFN-α-2a. The mean of serum perforin level in patients with and without virologic response to treatment were 5.45 ng/mL,and 3.4 ng/mL respectively. Finally in patients with virologic response and seroconverted serum perforin level was 7.23 ng/mL.

CONCLUSIONS

Based on our results higher perforin level in patients under treatment with PEG-IFN-α-2a, could be an indication of elevated cytotoxicity via perforin/granzyme pathway.

DNA prime-adenovirus boost immunization induces a vigorous and multifunctional T-cell response against hepadnaviral proteins in the mouse and woodchuck model

Induction of hepatitis B virus (HBV)-specific cytotoxic T cells by therapeutic immunization may be a strategy to treat chronic hepatitis B. In the HBV animal model, woodchucks, the application of DNA vaccine expressing woodchuck hepatitis virus (WHV) core antigen (WHcAg) in combination with antivirals led to the prolonged control of viral replication. However, it became clear that the use of more potent vaccines is required to overcome WHV persistence. Therefore, we asked whether stronger and more functional T-cell responses could be achieved using the modified vaccines and an optimized prime-boost vaccination regimen. We developed a new DNA plasmid (pCGWHc) and recombinant adenoviruses (AdVs) showing high expression levels of WHcAg. Mice vaccinated with the improved plasmid pCGWHc elicited a stronger WHcAg-specific CD8(+) T-cell response than with the previously used vaccines. Using multicolor flow cytometry and an in vivo cytotoxicity assay, we showed that immunization in a DNA prime-AdV boost regimen resulted in an even more vigorous and functional T-cell response than immunization with the new plasmid alone. Immunization of naïve woodchucks with pCGWHc plasmid or AdVs induced a significant WHcAg-specific degranulation response prior to the challenge, this response had not been previously detected. Consistently, this response led to a rapid control of infection after the challenge. Our results demonstrate that high antigen expression levels and the DNA prime-AdV boost immunization improved the T-cell response in mice and induced significant T-cell responses in woodchucks. Therefore, this new vaccination strategy may be a candidate for a therapeutic vaccine against chronic HBV infection.

Detection of Hepatitis B virus in serum and liver of chickens

Hepatitis B virus (HBV) is one of the most important human pathogens. Its existence in food animals could present a significant threat to public health. The objective of this study was to determine if HBV is present in serum and liver of chickens. A total of 129 serum samples from broiler chickens were collected for the detection of HBV antigens and antibodies, and 193 liver samples were tested for HBV DNA sequence by PCR and for the existence of HBV antigens by immunohistochemistry. The overall prevalence of HBsAg, anti-HBs, anti-HBc was 28.68%, 53.49%, 17.05%, respectively, whereas HBeAg, anti-HBe were barely detectable. Three serum samples were found to be positive for both HBsAg and HBeAg. Further analysis of these samples with transmission electron microscopy (TEM) revealed two morphologic particles with 20 nm and 40 nm in diameter, which were similar to small spherical and Danes particles of HBV. The viral DNA sequence identified in two of the chicken livers shared 92.2% of one known HBV strain and 97.9% nucleotide sequence of another HBV strain. Our results showed the existence of HBV in chickens. This would present a significant risk to people who work with live chickens or chicken products if HBV found in chicken could be confirmed to be the same as human HBV.

Review article: Hepatitis B and dialysis

The incidence of hepatitis B virus (HBV) infection in dialysis populations has declined over recent decades, largely because of improvements in infection control and widespread implementation of HBV vaccination. Regardless, outbreaks of infection continue to occur in dialysis units, and prevalence rates remain unacceptably high. For a variety of reasons, dialysis patients are at increased risk of acquiring HBV. They also demonstrate different disease manifestations compared with healthy individuals and are more likely to progress to chronic carriage. This paper will review the epidemiology, modes of transmission and diagnosis of HBV in this population. Prevention and treatment will be discussed, with a specific focus on strategies to improve vaccination response, new therapeutic options and selection of patients for therapy.

Hepatitis, epidemiology and liver function in hemophiliacs in Sweden

The epidemiology of viral hepatitis and liver function were studied in a retrospective survey of 69 patients with moderate and severe hemophilia A and B, and with severe von Willebrand's disease. Forty-nine patients were on prophylactic self-therapy and 20 on episodic treatment by medical personnel. Serologic markers of viral hepatitis (HBsAg, anti-HBs, anti-HBc, anti-HAV, and in some cases HBeAg and anti-HBe) and liver function tests (ASAT, ALAT, IgG) were followed for up to 12 years. There was a history of clinical hepatitis in 19%, and 96% showed some serologic evidence of exposure to hepatitis B virus. Only one patient was a HBsAg carrier. The prevalence of elevated ASAT and/or ALAT was 65% and the incidence 96%. In 68% of the patients there had been a transaminase elevation for more than 6 months. The clinical picture, serologic markers or liver function tests showed no significant difference between the types of hemophilia, amounts and modes of therapy, or age groups. The chronic hepatitis seen in our hemophiliacs seemed to be a slowly or non-progressive disease.

Immunopathology of hepatitis B virus infection

The interaction between immune responses and hepatitis B virus (HBV) is coordinated between innate and adaptive immunity. Anti-HBs antibodies protect the host by blocking the binding ability of HBV. Anti-HBc antibodies are detected with persistent HBV infection. The presence of anti-HBe antibodies is often associated with recovery from active diseases and is clinically used as a benchmark to assess response to treatment. Our studies have revealed that the anti-HBV immunoglobulins secreted are different in subclass patterns in different HBV infection status populations. These revelations may help to understand HBV escape and persistent infection and to develop strategies for prevention and therapeutic management of HBV infection.

[Prevalence of hepatitis B and D serological markers in the Parakanã, Apyterewa Indian Reservation, Pará State, Brazil]

In order to study the prevalence of hepatitis B (HBV) and D (HDV) viruses in the Parakanã Indians and to evaluate the impact of hepatitis B vaccination beginning there in 1995, 258 serum samples were analyzed in the year 2004 for hepatitis B and D serological markers using immunoenzymatic techniques; the results showed a moderate endemic pattern, with a total prevalence of HBV infection of 55.7% and 5.4% of virus carriers in the Apyterewa village and 49.5% with 1.1% of HBV carriers in the Xingu village; 31.4% of anti-HBs+ as an isolated marker in both villages and no detection of positive serological tests for HDV among HBV carriers. The laboratory analysis thus showed the presence of chronic HBV carriers, absence of HDV carriers, and an emerging vaccine profile among susceptibles, confirming the effectiveness and need to maintain vaccination, especially in the first year of life, and the need to implement effective epidemiological surveillance for early detection of HDV infection among HBV carriers.

Natural history of hepatitis B virus infection: an update for clinicians

Hepatitis B virus (HBV) is a common viral pathogen that causes a substantial health burden worldwide. Significant progress has been made in the past few decades in understanding the natural history of HBV infection. A dynamic balance between viral replication and host immune response is pivotal to the pathogenesis of liver disease. In immunocompetent adults, most HBV infections spontaneously resolve, whereas in most neonates and infants they become chronic. Those with chronic HBV may present in 1 of 4 phases of infection: (1) in a state of immune tolerance, (2) with hepatitis B e antigen (HBeAg)positive chronic hepatitis, (3) as an inactive hepatitis B surface antigen carrier, or (4) with HBeAg-negative chronic hepatitis. Of these, HBeAg-positive and HBeAg-negative chronic hepatitis may progress to cirrhosis and its long-term sequelae including hepatic decompensation and hepatocellular carcinoma. Several prognostic factors, such as serum HBV DNA concentrations, HBeAg status, serum aminotransferases, and certain HBV genotypes, have been identified to predict long-term outcome. These data emphasize the importance of monitoring all patients with chronic HBV infection to identify candidates for and select optimal timing of antiviral treatment, to recognize those at risk of complications, and to implement surveillance for early detection of hepatocellular carcinoma.

Natural History and Clinical Consequences of Hepatitis B Virus Infection

Despite the existence of Hepatitis B vaccination, hepatitis B virus (HBV) infection is still prevalent worldwide and accounts for significant morbidity and mortality. It is encouraging that majority of patients do recover from the acute infection, however, those that progress to chronic disease state is at great risk of developing complications such as hepatocellular carcinoma, cirrhosis and liver failure. Hepatitis B virus infection can be influenced by many factors such as host immune status, age at infection, and level of viral replication. The discovery about the existence of various genotypes and its association with different geographic distribution as well as the knowledge regarding mutant species has aid us in better understanding the nature of HBV infection and in delivering better care for patients. It is especially important to recognize those individuals with HBeAg-negative chronic HBV as they have a poorer prognosis compare with their counterparts, HBeAg-positive. Tremendous progress has been made over the years in understanding the behavior and clinical course of the disease; however, the natural history of HBV is complex and we still have much to explore and learn.

Virus safety of human blood, plasma, and derived products

The reconstitution of blood and its components is hampered by factors of compatibility, availability, and the risk of transmission of infectious diseases. Protozoal agents such as plasmodium malariae and trypanosoma cruzi are only regionally relevant. Bacterial transmissions are easy to prevent and treat. Antibody, antigen, and nucleic acid screening have been implemented to prevent transmission of blood-borne viruses. Transfusion-relevant viruses include hepatitis B and C virus (HBV and HCV), human immunodeficiency virus (HIV), human T leukemia virus (HTLV-I), and in certain circumstances, parvovirus B19, hepatitis A virus (HAV), and cytomegalovirus (CMV). Of great concern is the possible transmission of prion protein causing transmissible spongiform encephalopathy. Of future interest will be whether other viruses such as Nipah and Hendra virus are blood-borne and whether viruses such as TT, SEN, and GBV-C are involved in diseases or their progression, while not causing hepatitis.

Expression of an enzymatically active polymerase of human hepatitis B virus in an coupled transcription-translation system

Genome replication of hepadnavirus proceeds by reverse transcription from a viral pregenomic RNA template by a virally encoded polymerase that possesses protein-priming, reverse transcriptase, DNA polymerase, and RNase H activities. Characterization of this enzyme has been hampered by failure to purify an active enzyme from virions and difficulties in expressing an active polymerase in heterologous systems. In this study, we constructed human hepatitis B virus polymerase cDNA under the control of a phage T7 promoter and expressed it in a rabbit reticulocyte lysate-coupled transcription-translation system. In vitro site-directed mutagenesis confirmed that the recombinant polymerase cDNA produced three products: a full-length protein (approximately 94 kDa), an internally initiated protein (approximately 81 kDa), and an N-terminal protein (approximately 40 kDa). The in vitro expressed polymerase possessed protein priming activity, as demonstrated by 32P-dGTP-labeling of the full size polymerase and the N-terminal portion of the molecule in an in vitro priming assay. The polymerase also exhibited polymerization activity, as detected in an in vitro polymerase assay by incorporation of radionucleotides into acid-precipitable polynucleotides and by synthesis of human hepatitis B virus (HBV) specific DNA with product lengths between 100 and 500 nucleotides. In addition, the polymerase was found to use an RNA sequence bearing HBV DR1/epsilon stem-loop motif as a template for DNA synthesis. Both the protein-priming and the reverse transcription activities of this recombinant polymerase are dependent on the RNA fragment containing the HBV DR1/epsilon stem-loop sequence known to be required for the polymerase activities. The in vitro systems used in this study will be applicable to further functional and biochemical studies of this enzyme.

Antibody-directed complement-mediated cytotoxicity to hepatocytes from patients with chronic hepatitis B

The susceptibility of hepatocytes from patients with chronic hepatitis B to complement-dependent cytotoxicity mediated by heterologous antibodies to hepatitis B virus core (anti-HBc) and surface (anti-HBs) antigens and to hepatic asialoglycoprotein receptor was examined using a microcytotoxicity assay. The anti-HBc-induced cytotoxicity was found to be markedly enhanced against hepatocytes isolated from patients with chronic active hepatitis (72.6 +/- 9.5% (mean +/- s.e.m.); n = 6) over that against hepatocytes from individuals with chronic persistent hepatitis or inactive liver cirrhosis (40.6 +/- 18.6%; n = 4) (P = 0.019). Overall, values of the anti-HBc-directed cytotoxicity were higher in patients positive for HBcAg in hepatocytes and seropositive for hepatitis B virus e antigen (HBeAg). Hepatocytotoxicity was also exerted by anti-HBs and anti-asialoglycoprotein receptor antibodies in the presence of complement, but it was not seemingly related to disease activity. These results indicate that hepatitis B virus core and surface antigens and asialoglycoprotein receptor at the hepatocyte surface can be recognized by antibodies, and raise the possibility that complement-dependent cytolysis may contribute to the injury of hepatitis B virus-infected hepatocytes. The data also suggest that liver cells of patients with severe chronic hepatitis might be more susceptible to anti-HBc antibody-directed complement-mediated cytotoxicity than those with inactive liver histology.

[Methodological considerations in the interpretation of serologic screening for hepatitis B virus among blood donors]

Between October 1988 and February 1989, 1,033 voluntary first-time blood donors were screened for hepatitis B infection in five blood banks in Goiâna, Central Brazil. The survey was part of a major study designed to estimate seroprevalence of HBsAg and anti-HBs and to discuss methodological issues related to prevalence estimation based on data from blood banks. Donors were interviewed and blood samples were collected and tested for HBsAg and anti-HBs by ELISA tests. Prevalences of 1.9% and 10.9% were obtained for HBsAg and anti-HBs, respectively, and no statistical difference was found between the sexes. Prevalence of anti-HBs increased with age (X2 for trend = 7.9 p = 0.004). The positive predictive value and sensitivity of history of jaundice or hepatitis reported in the interview in detecting seropositives were 13.6% and 2.2%, respectively. The methodological issues, including internal and external validity of HBV prevalence estimated among blood donors are discussed. The potential usefulness of blood banks as a source of morbidity information for surveillance for Hepatitis B virus infection is stressed.

[Seroprevalence and risk factors for hepatitis B virus infection by AgHBs and anti-HBs markers in prisoners and prime blood donors]

Two cross-sectional surveys on hepatitis B virus (HBV) infection were carried out among 1,033 volunteer first-time blood donors in five blood banks (3 private, 2 public) and among 201 prisoners in the Penitentiary Center of Industrial Activity, in Goiania, Central Brazil, between June 1988 and February 1989. Those surveys were part of a major study designed to estimate seroprevalence of HBsAg and anti-HBsAg markers by ELISA test, and to study risk factors associated with seropositivity. The presence of any serum marker was considered as previous exposure to HBV. A standard questionnaire was applied to both populations to evaluate previous blood transfusion, number of sexual partners, homo/bisexual activity, history of sexually transmitted diseases, drug abusers, use of parenteral medicine, acupuncture, tattooing and VDRL seropositivity. Seroprevalence varied from 12.8% to 26.4% in blood donors and prisoners, respectively, (p less than 0.05) and increased with age (X2 trend=14.0 p less than 0.05%). Prisoners had higher percentages of all risk factors investigated than blood donors, with the exception of number of sexual partners. Among all risk factors studied, age, imprisonment and tattooing were statistically associated with seropositivity, even after multivariate analysis controlling for age and reclusion. The paper discusses the methodologic issues related to this epidemiologic investigation.

A new bioassay for terbinafine

A simple, sensitive and specific agar diffusion bioassay for the antifungal agent terbinafine is described. Using a strain of Aspergillus flavus as the test organism, terbinafine at concentrations ranging from 0.2 microgram/ml to 6.4 micrograms/ml could be measured in serum.

Hepatitis B serology--help in interpretation

This review discusses the serologic markers of hepatitis B virus (HBV) infection. Interpretation of various serologic profiles is provided, and the importance of maternal screening for interruption of perinatal transmission of HBV infection is stressed.

Absence of maternal antibodies to hepatitis B core antigen and HBV vertical transmission: one case of infection notwithstanding passive-active prophylaxis

We report the case of a newborn of an HBsAg carrier mother who was infected by vertical transmission and developed a subclinical hepatitis B at four months of age, notwithstanding the passive-active prophylaxis performed right after birth. The mother's HBV marker status was: HBsAg positive, HBeAg positive, anti-HBc IgM positive at low titer, anti-HBc IgG negative, anti-HBs negative, anti-HBe negative. It is assumed that the absence of anti-HBC antibodies might have favoured, perhaps in utero, the HBV infection whose antigenic expression was subsequently delayed by HBIg administered at birth. These findings suggest that the positivity for anti-HBc IgM must be considered an additional marker of maternal infectivity especially in the absence of anti-HBc IgG antibodies.

Frequency and significance of concurrent hepatitis B surface antigen and antibody in acute and chronic hepatitis B

Of 228 consecutive hepatitis B surface antigen (HBsAg)-positive patients who had simultaneous hepatitis B surface antibody (anti-HBs) determinations, HBsAg and anti-HBs were found concurrently in 73 (32%). Concurrence was found with greater frequency in patients with chronic active hepatitis than in those with acute hepatitis (36/57 vs 13/38, p less than 0.02). Patients with chronic active hepatitis had concurrent markers more commonly than those with chronic persistent hepatitis or asymptomatic carrier state (36/57 vs. 24/133, p less than 0.001). No major risk factors were identified. Hepatitis B e antigen was detected more frequently in patients with concurrence (68% vs. 42%, p less than 0.01). Subtyping was possible in 30 patients with chronic infection, including 18 with chronic active hepatitis, 7 with chronic persistent hepatitis, and 5 with a carrier state. In 25 patients, HBsAg subtype ad was found with antibody to subdeterminant y and in four instances, HBsAg subtype ay was found with antibody to subdeterminant d. Only 1 patient had homotypic HBsAg and anti-HBs. Of 38 patients who had successive determinations, concurrence was constant in 29. In 9 others, anti-HBs was detected intermittently and the heterotypia of the recurrent antibody remained constant. Antibody to hepatitis delta-virus was not detected. We conclude that concurrent HBsAg and anti-HBs are found frequently in acute and chronic hepatitis B. The markers are commonly heterotypic in chronic disease. The presence of heterotypic markers is not associated with specific risk factors or delta-infection. Concurrence is associated with evidence of viral replication and features of active inflammation.

Infectious hepatitis in dialysis patients

Infectious hepatitis is a major problem for patients with end-stage renal disease and for staff caring for these patients. Initially hepatitis B was the major cause of hepatitis in dialysis patients and staff. Patients had a tendency to develop chronic hepatitis or become chronic carriers of the virus while staff either developed typical acute hepatitis or a primary antibody response. The discovery of the hepatitis B surface antigen (HBsAg), the screening of transfused blood for HBsAg, and the institution of infection control measures including isolation techniques have resulted in a remarkable decrease in the incidence of this disease. Nonetheless, the problem of infectious hepatitis continues as non-A, non-B hepatitis has become more commonplace among dialysis patients. Unfortunately, no viral markers have been discovered, and blood products remain the major vehicle of transmission. The institution of infection control measures similar to those used to control hepatitis B has probably been effective in controlling the spread of this disease. It is hoped that the discovery of the etiologic agent(s), with the eventual goal of screening blood products and the development of a vaccine, will lead to full control of this disorder.

Clinical significance of concurrent hepatitis B surface antigen and antibody positivity

Over a period of 30 months, 64 patients with concurrently positive hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) were identified at two institutions. When all assays were considered, 23.9% of HBsAg-positive individuals exhibited anti-HBs. Both persistent HBsAg/anti-HBs positivity and variable changes in antigen or antibody status were observed among the 36 patients with follow-up beyond six months. When compared to a control group, these patients did not exhibit differences in risk factors for acquiring hepatitis B or in clinical and histological diagnoses. Concurrent HBsAg and anti-HBs was present at detection in 25 patients, while antibody appeared in the remaining 11 subjects. Subsequently, it was undetectable in seven of these 36 patients; no clinical changes occurred at the time of acquisition or loss of the antibody. The titer of the antibody was below 10 mIU/ml in 75% of these individuals. In 10 patients, the subtype of HBsAg was ad, while the anti-HBs was anti-y. Concurrent HBsAg and anti-HBs is a pattern frequently observed throughout the spectrum of hepatitis B-related events. The heterotypic antibody in these patients is of a low titer, and its appearance or disappearance is not associated with changes in the clinical course; simultaneous HBsAg/anti-HBs positivity does not appear to reflect a distinct clinical entity.

Hepatitis B virus in Gizan, Saudi Arabia

The enzyme-linked immunosorbent assay (ELISA) was used to study the prevalence rates for hepatitis B virus surface antigen (HBsAg), antibody to surface antigen (anti-HBs), and antibody to core antigen (anti-HBc) in 724 voluntary donors, students, pregnant women and those seeking treatment for minor ailments in the Gizan area of Saudi Arabia. Tests for hepatitis B e antigen (HBeAg) and e antibody (anti-HBe) were made in HBsAg positive sera. There was serological evidence of an existing or earlier infection in 337 Saudis (46.5%), of whom 12.7% were HBsAg carriers, 25.4% were positive for anti-HBs, and 8.4% were positive only for anti-HBc. The percentage of HBsAg carriers was 19.9% and 9.3% in males and females, respectively (p less than 0.001). The evidence of existing or earlier infection in males (58.7%) was significantly higher than in females (38.7%) (p less than 0.001), with no intersex difference in anti-HBs or anti-HBc. No difference was observed in the positivity of either of the markers, alone or together, between the cord blood and the female population in the child-bearing age of 20-39 years. Corresponding to the values in other age groups, there was an overall fall in the number of HBsAg carriers during adolescence as well as in 20-39-year-old females. Among the HBsAg carriers, there was no significant difference between the two sexes for HBeAg and anti-HBe positivity. The HBsAg carrier rate of 19.9% in males is consistent with the high male dominant prevalence of hepatocellular carcinoma in the Gizan area.(ABSTRACT TRUNCATED AT 250 WORDS)

Immune disorders of the gastrointestinal tract and liver

Immune disorders of the gastrointestinal tract and hepatobiliary systems comprise a diverse group of illnesses which share in common certain overlapping and yet distinctive expressions of cellular and humoral immunity. As is evident from material contained in this article, controversy and disparate results frequently characterize the study of immune mechanisms in a given disease process. Nonetheless, advances in quantitation of specific immunocyte function and phenotypic expression have greatly facilitated the depth of understanding of the immune process related to these disorders. Challenges for future clinical investigation of these disorders are to characterize cell-specific target antigens to which immunologic attack is directed and to unravel the immunogenetic mechanisms that trigger and direct immune-mediated injury to host tissues. It is anticipated that continued investigation of immune disorders of the gastrointestinal tract and liver will clarify pathogenetic mechanisms and thus permit formulation of rational and effective therapies.

Evidence for limited humoral immunoglobulin M antibody response to hepatitis B core antigen during acute and chronic hepatitis B virus infections

The periods of persisting immunoglobulin M class antibodies to hepatitis B core antigen in 28 patients with acute hepatitis B infections and in 134 patients with chronic hepatitis B infections were studied by using an enzyme-linked immunosorbent assay and an indirect immunofluorescence technique. We showed that the clearance of antibodies to hepatitis B core antigen is independent of the degree of viremia in both forms of hepatitis.

The HBV HBX gene expressed in E. coli is recognised by sera from hepatitis patients

We have cloned the X gene (HBx) and the HBc antigen (HBc Ag) gene of human hepatitis B virus (HBV) in Escherichia coli as fusion products with beta-galactosidase. Both HBV genes are expressed in E. coli strain CSR 603. Expression is detected by u.v. irradiation of the bacteria, metabolic labelling and electrophoresis of the labelled extracts on SDS-polyacrylamide gels. The HBc Ag protein produced in bacteria can be recognised by anti-HBc sera and peptides derived from the protein are also recognised by anti-HBe sera. The HBx protein is recognised by some, but not all, sera which are anti-HBe positive. HBx Ag is also recognised by a woodchuck antibody similar to anti-HBe (anti-WHe). These results constitute the first proof that the open reading frame X is a true viral gene and is expressed during HBV (and WHV) infection and that an HBx/anti-HBx system, which may have important biological implications, can exist in parallel with the classic HBe/anti-HBe system.

Hepatitis B viral nucleotide sequences in non-A, non-B or hepatitis B virus-related chronic liver disease

The presence of serological markers of hepatitis B virus (HBV) infection and of hepatocellular HBV DNA were investigated in 19 HBsAg-negative patients with clinically and histologically significant chronic liver disease. Four cases negative for antibodies to HBsAg (anti-HBs), to the core antigen (anti-HBc), and to the e antigen (anti-HBe) were classified as non-A, non-B hepatitis. The remainder, positive for one or more of the three antibodies, were classified as hepatitis B. Histologic diagnosis was chronic active hepatitis in five, chronic persistent hepatitis in 11, micronodular cirrhosis in two, and fatty liver in one patient. The DNA extracted from limited amounts of liver biopsies, without cleavage by restriction endonucleases, was analyzed by the Southern blot technique for the presence of episomal HBV DNA. Autoradiographs showed a single band of less than 4.0 kilobase (kb) corresponding to the monomeric form of HBV DNA in five patients, several bands of larger forms (4.0 to 18.0 kb) in three patients, both the monomeric and the larger forms in eight patients, and no HBV DNA in three patients. While HBV DNA was detected in the hepatocellular DNA of six patients who underwent splenectomy, hybridization was negative with the DNA extracted from their spleens. The episomal viral DNA larger than 4.0 kb may represent concatemeric forms or free oligomers which could not be distinguished from rearranged and/or integrated viral DNA in the limited analyses of the hepatocellular DNA hydrolyzed with HindIII or EcoRI. Our observations suggest the presence of HBV-like agents in the liver of serologically HBsAg-negative patients with chronic liver disease.

Hepatitis B e-antigen titres for evaluating infectivity during hepatitis B virus infection

By means of an ELISA the level of hepatitis B e-antigen (HBeAg) titre was determined in 51 patients with acute and 123 patients with persistent hepatitis B virus (HBV) infection. We also investigated 120 sera of these patients for infectivity by detecting HBV-specific DNA polymerase (DNA-P). Additional determination of the HBeAg titre revealed that the detection of HBeAg at a dilution of at least 1:50 correlates with the detection of DNA-P in 95% of cases, while in sera with an HBeAg titre of 1:25 or less DNA-P is only detectable in up to 5% of cases. Since the detection of DNA-P indicates high infectivity, certain titres of HBeAg can be employed to differentiate three different degrees of infectivity: (1) Sera without HBeAg show no or only little infectivity; (2) sera containing HBeAg greater than or equal to 1:50 are highly infectious; (3) HBeAg titres up to 1:25 indicate a medium degree of infectivity. These three markers for different degrees of infectivity were applied to study the course of infectivity during acute and persistent forms of HBV infection. In acute hepatitis B the period for the elimination of HBeAg is independent of the HBeAg titre in the first serum sample. In all cases the elimination of HBeAg in acute hepatitis B did not exceed 4 months. Patients with persistent HBV infection and an initial HBeAg titre greater than or equal to 1:50 remained at this high degree of infectivity for at least 18-30 months in 70% of cases. Only 30% of this collective showed a decrease in infectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of preexisting antibody against hepatitis B surface antigen to prevent subsequent hepatitis B infection

We studied a patient who developed acute hepatitis B virus (HBV) infection despite the presence of preexisting antibody to the surface antigen of HBV (anti-HBs). Anti-HBs has been reported to consist primarily of antibody against the common a determinant of HBV. Antibody directed against this major determinant appears to confer protection against HBV, regardless of the subtype. Our patient was shown to have had preexisting anti-HBs of anti-d but not anti-a specificity. She subsequently developed non-A, non-B viral hepatitis followed by an episode of acute hepatitis B after exposure to HBV of the ayw subtype.