Acute hepatitis B viral infection in a patient with anti-HBs.

We report a patient with antibody to hepatitis B surface antigen (anti-HBs) but no antibodies to other hepatitis B virus components, who developed acute symptomatic type B hepatitis. The possible explanations for this unusual serological pattern are 1) the antibody-positive status, which developed against only a subdeterminant of hepatitis B surface antigen (HBsAg), arose naturally or as the result of cross-reaction with a variety of antigens; and 2) seroconversion to anti-HBs occurred in response to surface antigen of a mutant strain of hepatitis B virus (HBV). This anti-HBs positivity, in the absence of antibody to hepatitis B core antigen, does not provide natural immunization against HBV infection, and so is not protective. Individuals who are positive to anti-HBs antibody alone which is not elicited by HBV vaccine, should be vaccinated against possible HBV infection.     

Passively acquired antibody to hepatitis B surface antigen. Pitfall in evaluating immunity to hepatitis B viral infections

Antibody to hepatitis B surface antigen (anti-HBs) has been used clinically to indicate an immune response to hepatitis B virus (HBV) and a protection against reinfection with the virus. We describe a child with hemophilia who had high-titer IgG anti-HBs in his serum and who subsequently developed viral B hepatitis. The child had received a unit of fresh frozen plasma 17 days prior to the determination of anti-HBs. The fresh frozen plasma donor was later found to be anti-HBs positive. The patient's anti-HBs was most likely passively acquired and therefore did not signify immunity to HBV. Various tests, including hepatitis B surface antigen group-specific and subtype determinants, ratio units of anti-HBs, and antibody class, have been used to determine whether or not anti-HBs will confer immunity. Although these tests have been thought to accurately predict immune status against infection with HBV, our case shows this may not be true, especially in patients who have been recently transfused. Anti-HBs testing may be predictive of immunity to HBV in the absence of a source of passively acquired anti-HBs.     

Neutralization of hepatitis B virus infectivity by a murine monoclonal antibody: an experimental study in the chimpanzee

Two study chimpanzees were inoculated intravenously with approximately 1,000 chimpanzee infectious doses of hepatitis B virus (HBV), one with subtype adr and one with subtype ayw, each previously incubated with 0.1 ml of a murine monoclonal antibody (IgG 1(K) class) directed against a single epitope on hepatitis B surface antigen common to most or all HBV. Two control chimpanzees received identical doses of HBV not incubated with the murine anti-HBs. Neither study chimpanzee developed HBV infection during 12 months of follow-up as judged by normal serum aminotransferase activity, normal liver biopsies, and negative serological tests for HBV-associated antigens and antibodies. In contrast, both control chimpanzees became infected by HBV as evidenced by elevated serum aminotransferase activity, liver biopsy changes characteristic of viral hepatitis, and the appearance of hepatitis B surface antigen (HBsAg) in their sera. Both study chimpanzees were shown to be fully susceptible to infection with these same HBV inocula when challenged 15 months after the initial inoculations at a time when passively administered anti-HBs was no longer detectable. Prior to challenge with HBV, one of the two study chimpanzees received a second injection of the same volume of the murine monoclonal anti-HBs. The survival of this anti-HBs in serum was reduced from six weeks (after the initial injection) to approximately two weeks.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anti-idiotypic humoral and cellular responses to antibody to hepatitis B surface antigen in hepatitis B viral infections.

In order to investigate regulatory significance of humoral and cellular responses to the idiotypic (Id) determinants on the antibody to hepatitis B surface antigen (anti-HBs), they were studied in acute hepatitis B and in chronic HBV infection. The results were compared with humoral and cellular responses of the same patients to hepatitis B surface antigen (HBsAg). In acute hepatitis B, the responses to HBsAg, were delayed until 3-4 weeks after the onset of clinical symptoms. However, the leucocyte migration inhibition (LMI) and the lymphocyte transformation (LTT) responses to affinity purified anti-HBs were found to be evolved very early in the course of acute hepatitis B, though anti-Id antibodies were absent. The majority of chronic HBV carriers showed a poor humoral and cellular response to HBsAg. Ten out of 38 chronic carriers showed anti-Id antibodies which recognized a major cross-reactive idiotype (CRI) on the anti-HBs molecule. Twenty-five out of 38 chronic carriers also showed LMI response to the Id determinants on the anti-HBs. LMI response induced by anti-HBs could be blocked by a specific Balb/c anti-Id antibody which also recognized the CRI. Thus, in both acute and chronic HBV infections, the anti-Id humoral and cellular responses correlated with poor humoral and cellular responses to HBsAg, indicating regulatory significance.     

Acute hepatitis B virus infection with simultaneous high HBsAg and high anti-HBs signals in a previously HBV vaccinated HIV-1 positive patient

We present a case of a clinical manifest hepatitis B virus infection and a potentially misleading HBV serological profile in an HIV-1 positive patient despite previous HBV vaccination. The patient presented with an acute hepatitis B and there was no indication of chronic HBV infection or the presence of a mutation in the ‘a’ determinant. Remarkably, simultaneously with high HBV surface antigen and HBV viral load, high anti-HBs antibodies were present. If, due to previous HBV vaccination only anti-HBs was tested in this patient, the result of the high anti-HBs antibodies could be very misleading and offering a false sense of security. Our findings contribute to the ongoing discussion on how to assess HBV specific immunological memory and determining the role of HBV booster vaccinations in immunocompromised individuals.     

Detection of a hepatitis B surface antigen variant emerging in a patient with chronic lymphocytic leukaemia treated with fludarabine

Fludarabine is used widely for the treatment of chronic lymphocytic leukaemia, but not as yet implicated in the emergence of hepatitis B surface antigen (HBsAg) variants following hepatitis B virus (HBV) reactivation. Such a variant was detected in a 78-year-old female who was HBsAg(-)/anti-HBc(+)/anti-HBs(+)/anti-HBe(+), and with normal ALT levels, who developed HBV reactivation after fludarabine treatment. She had high HBV-DNA levels, and became positive for HBeAg, in the absence of detectable HBsAg. HBV-DNA was extracted from serum and the HBsAg encoding region of the genome was amplified by PCR, followed by cloning and sequencing. The HBV strain appeared to be subtype adw, but had higher nucleotide homology with ayw than adw isolates, supported further by phylogenetic tree analysis. Amino-acid sequence comparisons over the alpha determinant region revealed the following substitutions: C124N, G130R, and N146S. There were also unique substitutions outside the alpha determinant. All these mutations appeared to have a profound effect on the antigenicity of this region, which resulted in failure to detect HBsAg by commercially available diagnostic assays. It is concluded that a surface variant emerged in an HBsAg(-)/anti-HBs(+) patient with chronic lymphocytic leukaemia following fludarabine treatment, with an unprecedented number of amino-acid substitutions in the alpha determinant region of HBsAg, including a subtype switch.     

Immunogenicity in chimpanzees of experimental hepatitis B vaccines prepared from intact hepatitis B virus,purified polypeptides,or polypeptide micelles

The immunogenicity of three experimental hepatitis B vaccines was evaluated in chimpanzees. Although no antibody to hepatitis B surface antigen (anti-HBs) was detected in two chimpanzees that received an aqueous polypeptide vaccine subcutaneously, a strong anti-HBs response was observed two and ten weeks, respectively, following challenge with hepatitis B virus. Inoculation of two additional chimpanzees with a micellar preparation of these polypeptides by the intravenous route resulted in anti-HBs production in one of the chimpanzees. Two chimpanzees inoculated subcutaneously with an aqueous vaccine of formalin-inactivated intact hepatitis B virus developed anti-HBs in low titers, but the development of antibody to the hepatitis B core antigen following challenge inoculations suggested that subclinical HBV infections may have occurred despite prior vaccination.     

Fatal liver failure with the emergence of hepatitis B surface antigen variants with multiple stop mutations after discontinuation of lamivudine therapy

Treatment of chronic hepatitis B virus (HBV) infection with lamivudine is effective and well-tolerated. However, discontinuation of the treatment is associated frequently with acute exacerbation of liver diseases. A patient suffering from acute liver failure after discontinuation of lamivudine treatment is described. The patient was treated with lamivudine for 4 months and ceased the treatment without consulting. After receiving lamivudine, the patient developed anti-HBs and became negative for hepatitis B surface antigens (HBsAg). However, HBV DNA reappeared to a level of 6.47 x 10(5) copies/ml. The patient died due to acute liver failure. Sequencing of HBV isolates revealed that mutations including G145R and stop codons occurred within the HBsAg coding region. In conclusion, HBV replication resumed after the uncontrolled cessation of lamivudine treatment in this patient and may have triggered the process leading to liver failure. Anti-HBs antibody appeared and may be the selective force for the emergence of HBV mutants.     

The clinical relevance of the antibody to hepatitis B core antigen (anti-HBc): A review

The antibody against the core component of the Dane particle (anti-HBc) is generally detected in the sera of individuals with acute type B hepatitis and in chronic HBsAg carriers. While the serological demonstration of HBsAg with or without anti-HBc indicates continued replication of viral antigens, the co-occurrence of anti-HBs and anti-HBc is considered a marker of recent HBV replication. The demonstration of anti-HBc in the absence of HBsAg and anti-HBs is in agreement with at least four different states of HBV infection. As this pattern indicates persistent HBV infection in some cases and recovery from an acute type B hepatitis in others, current efforts focus on further characterization of this pattern, using additional test methods such as anti-HBe and anti-HBc of the IgM class.     

Diagnosis of type B hepatitis

Since 1965, when Blumberg discovered the Australia antigen, the hepatitis B surface antigen (HBsAg), the research on viral hepatitis has rapidly progressed. The identification of specific hepatitis B associated antigens and antibodies in blood, and liver tissue, together with the improvement of detection systems, have enhanced our knowledge about the mechanism of liver injury and the natural history of hepatitis B virus (HBV) infection. Now it has been recognized that HBV has no direct cytopathic effect on hepatocytes and that hepatocyte necrosis is associated with the virus induced immunological reaction of the host. From the reaction, there are two types of HBV infection, i.e., transient (acute) and persistent (chronic) infection. In addition to the conventional measurements, such as HBsAg, anti-HBs, anti-HBc, HBeAg, anti-HBe and anti-IgM HBc, recently pre S1, pre S2 antigen/antibody systems and polymerized human albumin receptor and antibody have been developed. The significance of the detection of these antigen/antibody systems was discussed. On the other hand, to determine the presence of HBV, the state of HBV replication or the infectivity directly, HBV associated DNA polymerase and HBVDNA should have been detected. (Very recently, the polymerase chain reaction method has been introduced to detect very small amounts of HBVDNA). In this presentation, the change of these viral markers in various cases was shown, and especially emphasized was anti-IgM HBc in acute hepatitis and HBeAg/Ab status in chronic liver disease. Lastly, the present state of Interferon therapy for type B chronic hepatitis was mentioned.     

Evaluation of a reduced dose of hepatitis B vaccine administered intradermally

Intradermal inoculation of hepatitis B vaccine (HBsAg subtype adw) caused no side effects, but the vaccine was less immunogenic than following intramuscular administration. Intradermal inoculation does not, therefore, offer a major advantage to the generally used intramuscular immunization. A single multisite intradermal administration of a reduced dose of vaccine did not result in a more rapid seroconversion compared to intramuscular inoculation. Although the antibody levels were similar after two intradermal or intradermal or intramuscular injections given 1 month apart, the booster (third injection) at 6 months resulted in anti-HBs levels that were about 10 times higher following intramuscular inoculation as compared to intradermal. All persons immunized developed anti-HBs. The levels of anti-HBs (a and w) were about 30-40% of the total anti-HBs, and the proportion did not change significantly during the course of immunization. Cross-protection against all HBV strains is thus also assured after intradermal administration of vaccine containing only one HBsAg subtype (adw). A skin reaction was elicited only in a small proportion of anti-HBs-positive individuals, and the reaction correlated roughly with the immune responses.     

Changes in serologic markers of hepatitis B following autologous hematopoietic stem cell transplantation.

Korea is an endemic area for hepatitis B virus (HBV) infection. Reactivation of HBV is a well-recognized complication in patients with chronic HBV infection undergoing cytotoxic or immunosuppressive therapy, and there are some reports of hepatitis B reverse seroconversion after HSCT. This study evaluated changes in HBV serology after HSCT. We reviewed the medical records of 141 patients who had available HBV serologic data after autologous HSCT. Patient information was retrospectively collected from the BMT database. Before transplantation, 12 patients were positive for hepatitis B surface antigen (HBsAg) and received lamivudine prophylaxis. There was 1 case of reactivation of HBV among these patients. One hundred twenty-nine patients were negative for HBsAg before HSCT, of whom 110 were positive and 19 were negative for hepatitis B surface antibody (anti-HBs). Sixty-two of the 110 patients who were positive for anti-HBs were also positive for hepatitis B core antibody (anti-HBc). Eight patients were negative for anti-HBs and anti-HBc. Seven patients who were initially negative for HBsAg were identified as positive after HSCT, and 5 of those 7 patients developed acute hepatitis, thus indicating reverse seroconversion. Univariate analysis showed that reverse seroconversions were observed more frequently with multiple myeloma than another disease (P = .005; relative risk, 11.854; 95% confidence interval, 1.381-101.770). Other factors, such as age, sex, and presence of HBcAb before HSCT, had no statistically significant affect on reverse seroconversion. In conclusion, reverse seroconversion of HBV is not a rare complication of autologous HSCT, and the risk of reverse seroconversion after treatment is a serious concern due to possible complications arising from patients' suppressed immune systems.     

Acute self-limiting hepatitis B after immunoprophylaxis failure in an infant.

The occurrence of acute hepatitis after failure of immunoprophylaxis in cases of mother-to-infant transmission of hepatitis B virus (HBV) is uncommon. Because immunoprophylaxis failure is caused by the emergence of an "a" determinant escape mutant, the infants usually become HBV carriers. To evaluate whether mutations in the S gene coding for the surface protein that contains the "a" determinant are associated with acute hepatitis after immunoprophylaxis failure, HBV DNA of an infant in with acute hepatitis developed with seroconversion to anti-HBs antibodies at 12 months of age despite administration of anti-hepatitis B immunoglobulin and hepatitis B vaccine was analyzed. The S gene from HBV DNA isolated from the serum of the infant at 12, 19, and 27 months of age was cloned and sequenced. Mutations affecting amino acid residues in the first loop within the "a" determinant (codons 124-147) were found at 12 months of age. Moreover, a novel deletion mutant, with a 1-bp deletion at nucleotide 449 of the S gene, was found at 19 and 27 months of age. This deletion resulted in a frame shift and it introduced a stop codon (TAG) at codon 176. Because the open reading frame of the S gene is completely overlapped by the polymerase gene, mutations in the S gene may affect the polymerase gene. Based on this case, this study suggests that the observed frame-shift mutation in the S gene might affect the polymerase protein and induce prompt suppression of viral replication.     

Overlapping gene mutations of hepatitis B virus in a chronic hepatitis B patient with hepatitis B surface antigen loss during lamivudine therapy

Disappearance of hepatitis B surface antigens (HBsAg) in chronic hepatitis B usually indicates clearance of hepatitis B virus (HBV) infection. However, false HBsAg negativity with mutations in pre-S2 and 'a' determinant has been reported. It is also known that YMDD mutations decrease the production of HBV and escape detection of serum HBsAg. Here, we report overlapping gene mutations in a patient with HBsAg loss during the lamivudine therapy. After 36 months of lamivudine therapy in a 44-yrold Korean chronic hepatitis B patient, serum HBsAg turned negative while HBV DNA remained positive by a DNA probe method. Nucleotide sequence of serum HBV DNA was compared with the HBV genotype C subtype adr registered in NCBI AF 286594. Deletion of nucleotides 23 to 55 (amino acids 12 to 22) was identified in the pre-S2 region. Sequencing of the 'a' determinant revealed amino acid substitutions as I126S, T131N, M133T, and S136Y. Methionine of rtM204 in the P gene was substituted for isoleucine indicating YIDD mutation (rtM204I). We identified a HBV mutant composed of pre-S2 deletions and 'a' determinant substitutions with YMDD mutation. Our result suggests that false HBsAg negativity can be induced by combination of overlapping gene mutations during the lamivudine therapy.     

Detection of hepatitis B surface antigen (HBsAg) in peripheral blood mononuclear cells of patients with acute and chronic active hepatitis B

Seventy five patients with acute and chronic active hepatitis (CAH) were studied by indirect immunofluorescence with monoclonal antibodies for the presence of hepatitis B surface antigen (HBsAg) on peripheral blood mononuclear cells (PBMC). The viral surface antigen was detected in the PBMC of all the patients with hepatitis B virus (HBV)-induced CAH and in acute patients with more than 2 months of evolution. No HBsAg was detected in the samples obtained from 12 normal controls or from 14 non-A, non-B CAH patients. Analysis of PBMC subsets revealed that HBsAg was present in non-T cells; dual fluorescence studies showed HBsAg on surface Ig-positive lymphocytes. The binding of anti-HBs monoclonal antibodies was higher than that of a goat anti-HBs serum, and the highest reactivity was observed with an antibody against the pre-S(2)-region sequence. Both HBsAg and hepatitis B core antigen (HBcAg) were also detected in lysates of PBMC by dot blot analysis.     

Lack of genetic restriction by a potential anti-idiotype vaccine for type B viral hepatitis

Anti-idiotype (anti-Id) reagents that bear an internal image capable of mimicking hepatitis B surface antigen (HBsAg) were used to induce an antibody to HBsAg (anti-HBs) response in both rabbits and chimpanzees. The anti-idiotype induced antibody response produced in rabbits recognized HBsAg determinants associated with the induction of protective immunity against hepatitis B virus (HBV). Attesting further to the specificity was the binding of the rabbit anti-idiotype to the anti-idiotype induced anti-HBs containing sera. Our findings suggest that genetic restrictions associated with the induction of an interspecies immune response may not be a limitation of anti-idiotype based vaccines. In addition, anti-idiotype immunization also produced an anti-HBs in chimpanzees, a species susceptible to infection with human HBV. These data demonstrate that internal-image-bearing anti-idiotype reagents can induce an immune response across species barriers. Additionally, the reagents represent a viable alternative approach to vaccination against agents such as hepatitis B virus that cause human disease.     

A hepatitis B virus variant found in the sera of immunised children induces a conformational change in the HBsAg "a" determinant.

The emergence of variants in the outer envelope proteins of hepatitis B virus (HBV) are found among individuals vaccinated against HBV and asymptomatic carriers of the infection. For example, children in The Gambia vaccinated against hepatitis B may show serological evidence of breakthrough infections, particularly if anti-HBs antibodies induced by the vaccine are low in titre. A single-point mutation at nucleotide 421 of the S gene is associated with such breakthrough infections. In the present study, the antigenicity of variant HBV S protein expressed as HBsAg particles in a vaccinia virus expression system has been characterised using a panel of monoclonal antibodies directed against linear and conformational determinations of the S protein. A cellular ELISA procedure using expressed antigen in Vero cells revealed differences in reactivity using four of the six antibodies that had been raised against the adw subtype of HBV and recognise conformational epitopes in the a determinant. In two instances, an enhanced reactivity for the variant antigen was found, confirming that point mutations in the a determinant of the S protein between residues 139 and 147 may result in significant changes in conformation. These findings also demonstrate that there are distinct antigenic differences between the vaccine strains of HBsAg/ adw subtype and the predominant HBsAg subtype circulating in West Africa. The implications of this work are that serodiagnosis of HBV infections may be unreliable in populations where there is a possibility of variant HBV infections emerging in the face of increasing herd immunity to HBV as a result of vaccination, particularly using monoclonal antibody-based diagnostic tests. Such variants may play a role in the maintenance of HBV infections in endemic regions.     

Acute hepatitis B caused by a vaccine-escape HBV strain in vaccinated subject: Sequence analysis and therapeutic strategy

HBV vaccine contains the ‘a’ determinant region, the major immune-target of antibodies (anti-HBs). Failure of immunization may be caused by vaccine-induced or spontaneous ‘a’ determinant surface gene mutants. Here, we evaluate the possible lack of protection by HBV vaccine, describing the case of an acute hepatitis B diagnosed in a 55-year-old Caucasian male unpaid blood donor, vaccinated against HBV. Sequencing data for preS–S region revealed multiple point mutations. Of all the substitutions found, Q129H, located in the “a” determinant region of HBsAg, can alter antigenicity, leading to mutants. This mutant may cause vaccine failure especially when associated with high viremia of infecting source.     

Reactivation of an occult hepatitis B virus escape mutant in an anti-HBs positive, anti-HBc negative lymphoma patient.

BACKGROUND: Hepatitis B virus (HBV) often persists after resolution, but its replication is suppressed by antiviral T cells. Immunosuppressive treatment may lead to viral reactivation and severe hepatitis. Early antiviral therapy prevents reactivation but some occult HBV infections are not easily detectable. RESULTS: Here we describe a patient with a progressive non-Hodgkin lymphoma who had probably not been vaccinated against HBV and, before immunosuppression, showed antibodies (anti-HBs) against the viral surface antigen (HBsAg) as the only possible marker of occult HBV infection. Under immunosuppression he developed viremia (>10(8)copies/mL). The virus exhibited three S gene mutations (L109R, C137W, G145R) which led to false negative HBsAg results and diminished binding of vaccine-induced anti-HBs. CONCLUSIONS: Reliable screening and monitoring of severely immunosuppressed patients for HBV should include, in addition to anti-HBc and HBsAg, anti-HBs and sensitive HBV DNA assays. Furthermore, active vaccination or hepatitis B immune globulin may not protect against such mutants.     

Low-dose vaccination against hepatitis B in children: one-year follow-up

Six hundred forty-three children, negative for markers of hepatitis B virus (HBV) infections, were given three X 2-micrograms doses of Merck, Sharp and Dohme (MSD) plasma derived hepatitis B vaccine (H-B-Vax) at monthly intervals. Twelve months after the first dose of vaccine, antibody to hepatitis B surface antigen (anti-HBs) was detected in 89% of children by radioimmunoassay (RIA) and in 83% by enzyme immunoassay (EIA). Seroconversion rates and anti-HBs titres were significantly greater in 1-4-year-olds than in older children (p less than 0.01). Eighteen children with no anti-HBs or other markers of HBV at this time were given 10 micrograms of vaccine and tested one month later. Seventeen developed anti-HBs, 12 at levels consistent with an anamnestic response. Forty-nine HBV-marker-negative children seroconverted for antibody to hepatitis B core antigen (anti-HBc) in the 8-month period before or the 12-month period following vaccination. Forty-six of these children were positive for anti-HBs, and one has been confirmed as a chronic carrier of hepatitis B surface antigen (HBsAg). Three cases of clinical hepatitis B in children have been seen in the community since the vaccination programme began. Two of these were amongst the estimated 5% of children who were not vaccinated. The third was in a vaccinee and occurred 4 1/2 months after the last dose of vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)