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

Clinical course of de novo hepatitis B infection after pediatric liver transplantation

The characteristics of hepatitis B virus (HBV) in vaccinated children who acquire de novo HBV infections after orthotopic liver transplantation (OLT) remain largely unknown. The aim of this study was to explore HBV mutants in pediatric OLT recipients with de novo HBV infections. In all, 50 recipients underwent OLT between December 1997 and October 2005, and they were regularly checked for HBV serum markers from November 2005 to April 2009. Before OLT, all were hepatitis B surface antigen (HBsAg)-negative and under the coverage of the universal infant HBV vaccination program. Those who became HBsAg-positive after OLT were diagnosed with de novo HBV infection. HBV viral loads and full-length genome sequencing were determined when the diagnosis of de novo HBV infection was established. Nine patients (9/50, 18%) acquired de novo HBV infections after OLT. None had graft loss or fulminant hepatitis. Five cleared HBsAg, and 4 of the 5 even recovered with antibody to hepatitis B surface antigen (anti-HBs) formation. The other 4 were persistently HBsAg-positive. Mutations in the major S gene (681 base pairs) were discovered in 8 (88.9%) of the de novo HBV-infected children. Six of them harbored mutations within the "a" determinant region (codons 124-147), whereas the other 2 had mutations outside this region. These 2 cleared HBsAg and recovered with anti-HBs formation. HBV DNA levels were not different between those who cleared HBsAg and those who did not. In conclusion, surface mutants are frequent among pediatric liver transplant recipients with de novo HBV infections, but their clinical relevance requires further study.

[Hepatitis B vaccination: a major player in the control of primary liver cancer]

In worst cases, chronic hepatitis B ultimately leads to primary liver cancer. Populations the more at risk to develop hepatocellular carcinoma (HCC), i.e. patients infected perinatally, reside essentially in Asia. A quarter of century after its introduction in medical practice, data coming from Eastern Asia demonstrate a strong impact of the vaccine on HCC incidence. Strikingly, universal immunization of Taiwanese newborns reduced fourfold pediatric HCC incidence. However, residual cases still appear though among children infected at birth by HBe antigen-carrying mothers. Epidemiologic models indicate that the continuation of universal vaccination policy will reduce chronic hepatitis B endemicity 50-fold in three generations. Recently, mutant forms of HBV potentially escaping to vaccine appeared as a potential consequence of large-scale vaccination. Finally, lack of early immunization of newborns in developing countries still represents a major limitation to the progresses against liver cancer.

Reactivation of hepatitis B with reappearance of hepatitis B surface antigen after chemotherapy and immunosuppression

BACKGROUND & AIMS

HBV infection may reactivate in the setting of immunosuppression, although the frequency and consequences of HBV reactivation are not well known. We report 6 patients who experienced loss of serologic markers of hepatitis B immunity and reappearance of HBsAg in the serum as a result of a variety of acquired immune deficiencies.

METHODS

Between 2000 and 2005, six patients with reactivation of hepatitis B were seen in consultation by the Liver Diseases Branch at the Clinical Center, National Institutes of Health. The course and outcome of these 6 patients were reviewed.

RESULTS

All 6 patients developed reappearance of HBsAg and evidence of active liver disease after stem cell transplantation (n = 4), immunosuppressive therapy (n = 1), or change in human immunodeficiency virus antiretroviral regimen (n = 1), despite having antibody to HBsAg (anti-HBs) or antibody to hepatitis B core antigen (anti-HBc) without HBsAg before. All 6 patients developed chronic hepatitis B, 2 patients transmitted hepatitis B to their spouses, and 1 patient developed cirrhosis. The diagnosis of hepatitis B reactivation was frequently missed or delayed and often required interruption of the therapy for the underlying condition. None of the patients received antiviral prophylaxis against HBV reactivation.

CONCLUSIONS

Serologic evidence of recovery from hepatitis B infection does not preclude its reactivation after immunosuppression. Screening for serologic evidence of hepatitis B and prophylaxis of those with positive results by using nucleoside analogue antiviral therapy should be provided to individuals in whom immunosuppressive therapy is planned.

Re-evaluation of anti-HBc non-reactive serum samples from patients with persistent hepatitis B infection by immune precipitation with labelled HBV core antigen

BACKGROUND

Core antigen (HBcAg) is the most immunogenic component of hepatitis B virus (HBV) and is believed to induce virtually always antibodies (anti-HBc) in immunocompetent infected persons. However, some chronically infected persons do not develop detectable anti-HBc.

OBJECTIVE

A more sensitive assay for anti-HBc was to be developed and used to re-evaluate a cohort of chronically HBV infected persons without detectable anti-HBc.

STUDY DESIGN

Among 3309 serum samples which had been tested by commercially available (microparticle) enzyme immune assay (M/EIA) 34 samples from 22 patients were identified having reacted positive for HBsAg and negative for anti-HBc. Nine of these patients had immunosuppression or HIV coinfection, 13 patients were immunocompetent, 5 of them were perinatally infected. Anti-HBc was re-tested for in an immune precipitation (IP) assay using (32)P-labelled recombinant HBcAg as reagent and anti-human-IgG-coated magnetic beads as separation system for immunecomplexes containing HBcAg. Specificity was controlled for by competition with unlabelled HBcAg.

RESULTS

27 serum samples from the 22 patients could be retested. IP was positive in 7 MEIA negative sera, unspecific positive in 4 and negative in 16. Using 5 anti-HBe positive control sera, we found IP to be 1.8-fold (1.3-2.9) more sensitive than MEIA, but IP was 6.5-fold (5.8-7.4) more sensitive with 4 anti-HBe negative, anti-HBc positive sera.

CONCLUSION

IP allowed specific detection of anti-HBc in about 25% of MEIA negative chronic HBV patients. The majority of these seem to produce no or very little anti-HBc, however.

Retrospective and prospective studies of hepatitis B virus reactivation in malignant lymphoma with occult HBV carrier

BACKGROUND

In surface antigen of hepatitis B virus (HBsAg)-positive carrier for anticancer treatment of malignant lymphoma, it is well recognized that reactivation of hepatitis B virus (HBV) occasionally occurs. However, there have been only a few studies of HBV reactivation in serum HBsAg-negative and hepatitis B core antigen (HBcAb)-positive occult HBV carriers. We looked at both retrospective and prospective studies to determine the prevalence, clinical course and risk factor of HBV reactivation during chemotherapy in lymphoma patients.

PATIENTS AND METHODS

Forty-eight of 127 (37.8%) lymphoma patients were HBsAg negative and HBcAb positive, and 24 of these patients were then given liver function tests and HBsAg tests monthly and serum HBV DNA every 3 months.

RESULTS

HBV reactivation was observed in two patients (4.1%) who had received intensive chemotherapy including steroid and rituximab. Immediate administration of entecavir therapy after elevation of HBV DNA level was conducted, and this resulted in reduction of it and improvement of liver function test.

CONCLUSIONS

Rituximab plus steroid-containing regimens may increase the risk of HBV reactivation in HBsAg-negative and HBcAb-positive lymphoma patients. More ambitious prospective studies are required to establish clinically useful or cost-effective follow-up methods for control of HBV reactivation in lymphoma patients with occult HBV infection.

Identification of low HBV-DNA levels by nucleic acid amplification test (NAT) in blood donors

OBJECTIVE

To evaluate the presence of HBV-DNA in 22,765 consecutive blood donors, who donated blood in the period from January 2006 to August 2007 at a transfusion centre in Lazio, a region in central Italy with low HBV endemicity.

METHODS

Each donation was individually tested using immunoenzymatic assays and nucleic acid amplification technologies (NAT). Samples that were reactive to generic NAT, Procleix Ultrio Assay were tested for HBV-DNA, HCV-RNA and HIV1-RNA by Discriminatory Procleix Ultrio NAT Assay. In samples that were reactive to generic NAT and negative for HBsAg, HCV-RNA and HIV1-RNA, HBV-DNA was further tested using Cobas TaqMan and an in-house nested PCR following an ultracentrifugation step. Sequence analysis confirmed HBV-DNA positivity.

RESULTS

Generic NAT identified 31 (0.13%) reactive sera. HBV-DNA discriminatory NAT identified 15 positive sera; HBsAg was positive in 12 sera. Of the 5 generic NAT-reactive/discriminatory NAT-negative/HBsAg-negative sera and of the 3 HBsAg-negative/HBV-DNA discriminatory NAT-positive sera, 7 were positive to Cobas TaqMan or the in-house PCR after ultracentrifugation. The overall HBV-DNA positivity was 0.083% [19 of 22,765 donors: 12 HBsAg-positive (HBV-DNA range 10(2)-10(4) IU/mL), 7 HBsAg-negative/anti-HBc positive (HBV-DNA< 6 IU/mL)].

CONCLUSIONS

For blood transfusion safety, the significance of the finding of very low HBV-DNA levels should be further investigated. Our data indicate that in areas with a low HBV endemicity, single NAT assays may not always identify blood donations with very low HBV-DNA levels.

[Hepatitis B virus reactivation during chlorambucil and prednisolone treatment in an HBsAg-negative and anti-HBs-positive patient with B-cell chronic lymphocytic leukemia]

It is generally accepted that seroconversion of hepatitis B virus (HBV) surface antigen (HBsAg) to an antibody to HBsAg (anti-HBs) indicates clearance of HBV. Here we report a case of severe hepatitis that manifested during chemotherapy in a female patient with chronic lymphocytic leukemia (CLL) who had been initially seronegative for HBsAg and seropositive for anti-HBs. The patient received chlorambucil and prednisolone for the treatment of CLL. After 6 months the serum levels of aminotransferases were increased, and HBsAg and HBV DNA were present in serum. Lamivudine was administered immediately after confirming the HBV reactivation, which considerably improved jaundice and aminotransferase levels after 3 weeks. The patient was able to resume the chemotherapy whilst continuing lamivudine treatment. This case report highlights the need for physicians to be aware of the potential risk of HBV reactivation even in an HBsAg-negative person but with detectable anti-HBc and/or anti-HBs, underscoring the need for future studies that explore the role of antiviral prophylaxis in this setting.

Molecular characterization of a variant virus that caused de novo hepatitis B without elevation of hepatitis B surface antigen after chemotherapy with rituximab

Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative patients following treatment with rituximab has been reported increasingly. The aim of this study was to investigate the molecular mechanisms underlying HBV reactivation in an HBsAg-negative patient. HBV was reactivated in a 75-year-old man following chemotherapy with rituximab, without elevation of HBsAg. The patient's full-length HBV genome was cloned and the entire sequence was determined. Transfection studies were performed in vitro using recombinant wild-type HBV (wild-type), the patient's HBV (patient), and two chimeric HBV constructs, in which the preS/S region of the patient and wild-type virus had been exchanged with one another. Secreted HBsAg and intra- and extra-cellular HBV DNA were measured. The number of amino acid substitutions in HBV from this patient was much higher than in previous reports of HBV mutants, such as occult HBV and vaccine escape HBV mutants. Levels of HBsAg and HBV DNA production in vitro were significantly lower in the patient compared to wild-type transfections. From analyses of the chimeric constructs, the altered preS/S region was responsible mainly for this impairment. These results show that highly mutated HBV can reactivate after chemotherapy with rituximab, despite an unusually large number of mutations, resulting in impaired viral replication in vitro. Severe immune suppression, probably caused by rituximab, may permit reactivation of highly mutated HBV. These findings have important clinical implications for the prevention and management of HBV reactivation and may explain partially the mechanism of recent, unusual cases of HBV reactivation.

Hepatitis B caused by a hepatitis B surface antigen escape mutant

Amino acid substitutions within the S gene involving the major antigenic a determinant of the hepatitis B virus (HBV) surface antigen (HBsAg) have been detected in cases of failure of immunization against the virus. Our report showed development of clinical hepatitis in presence of antibody to HBsAg in a healthy individual. A single amino acid substitution (G145R) within the a determinant of the HBsAg was determined by sequencing of the isolated HBV strain. Lamivudine treatment efficiently cleared the peripheral HBV DNA, HBsAg, and hepatitis B e antigen. In conclusion, the immune escape mutant in the S gene can cause hepatitis despite pre-existing naturally acquired immunity.

Detection and characterization of hepatitis B virus of anti-hepatitis B core antigen-reactive blood donors in Quebec with an in-house nucleic acid testing assay

BACKGROUND

Hepatitis B virus (HBV) infection can be detected in blood donations by many serologic markers. Since the introduction of routine anti-hepatitis B core antigen (HBc) donor screening at Héma-Québec in April 2003, a large number of donors have been deferred on the basis of reactive anti-HBc test results. The objective of this study was to evaluate the correlation between the anti-HBc-reactive donations and the detection of HBV DNA with an in-house nucleic acid testing (NAT) assay.

STUDY DESIGN AND METHODS

The in-house HBV NAT assay is a conventional polymerase chain reaction amplifying part of the viral S gene. From October 2004 to November 2005, a total of 1169 anti-HBc-reactive donations were tested with this in-house assay. The results were correlated with hepatitis B surface antigen (HBsAg) and anti-HBs markers. HBV DNA-positive samples were further investigated by DNA sequencing.

RESULTS

All HBsAg-positive samples were detected by the NAT assay. Overall, 38 (3.25%) of anti-HBc-positive samples were found to be positive for the presence of HBV DNA. Of these 38, a total of 12 donations with a low level of HBV DNA were HBsAg-negative. The sequencing results clearly showed various genotypes and subtypes within a same genotype.

CONCLUSION

The 3.25 percent HBV DNA positivity rate among the anti-HBc-reactive donations and more particularly the low level of HBV DNA observed in occult donations underline the importance of the use of a sensitive assay to detect HBV DNA in conjunction with other markers. The HBV genetic diversity found in our donor population reflects the province demographics, particularly in the Montreal area where most of the positive donors were from.

Deficiencies in the standardization and sensitivity of diagnostic tests for hepatitis B virus

The patterns of hepatitis B virus (HBV) markers described in textbooks apply to acute and chronic infection with wild-type HBV. Deviations from these patterns occur in the very early phase, in low-level (or occult) infection and under immunosuppression. Variability may originate from the virus, the host or the test kits. In order to obtain a reliable diagnosis under these conditions, tests for all three markers of HBV infection have to be applied: HBsAg, HBV DNA and anti-HBc. All tests should be as sensitive as feasible, but even then occult infection may be missed. Reliable detection of occult or mutated HBV is particularly important in blood and organ donors and in patients before or with immunosuppression.

Multicenter study of a new fully automated HBsAg screening assay with enhanced sensitivity for the detection of HBV mutants

In a multicenter study a new, fully automated Roche Diagnostics Elecsys HBsAg II screening assay with improved sensitivity to HBsAg mutant detection was compared to well-established HBsAg tests: AxSYM HBsAg V2 (Abbott), Architect HBsAg (Abbott), Advia Centaur HBsAg (Bayer) Enzygnost HBsAg 5.0 (Dade-Behring), and Vitros Eci HBsAg (Ortho). A total of 16 seroconversion panels, samples of 60 HBsAg native mutants, and 31 HBsAg recombinant mutants, dilution series of NIBSC and PEI standards, 156 HBV positive samples comprising genotypes A to G, 686 preselected HBsAg positive samples from different stages of infection, 3,593 samples from daily routine, and 6,360 unselected blood donations were tested to evaluate the analytical and clinical sensitivity, the detection of mutants, and the specificity of the new assay. Elecsys HBsAg II showed a statistically significant better sensitivity in seroconversion panels to the compared tests. Fifty-seven out of 60 native mutants and all recombinant mutants were found positive. Among 156 HBV samples with different genotypes and 696 preselected HBsAg positive samples Elecsys HBsAg II achieved a sensitivity of 100%. The lower detection limit for NIBSC standard was calculated to be 0.025 IU/ml and for the PEI standards ad and ay it was <0.001 and <0.005 U/ml, respectively. Within 2,724 daily routine specimens and 6.360 unselected blood donations Elecsys HBsAg II showed a specificity of 99.97 and 99.88%, respectively. In conclusion the new Elecsys HBsAg II shows a high sensitivity for the detection of all stages of HBV infection and HBsAg mutants paired together with a high specificity in blood donors, daily routine samples, and potentially interfering sera.

Permanent loss of anti-HBc after reactivation of hepatitis B virus infection in an anti-HBs and anti-HBc-positive patient after allogeneic stem cell transplantation

BACKGROUND

Reactivation of a hepatitis B virus (HBV) infection after transplantation is associated with a high morbidity and mortality. HBV infections generally result in anti-HBc persisting lifelong.

CASE REPORT

A 44-year-old female presented 10 years after allogeneic stem cell transplantation with a chronic hepatitis B. The infection was reactivated from a resolved (anti-HBs and anti-HBc positive) HBV infection acquired some years prior to transplantation. Interestingly, she lost all antibodies to HBV including anti-HBc and is upto now anti-HBc negative. The sequence of the surface and the core gene did not reveal any escape mutations. Thus, the loss of anti-HBc might suggest an immunotolerance of the donor's immune system against HBcAg.

CONCLUSION

This data illustrate that an HBV infection might be reactivated despite high anti-HBs levels prior to transplantation. Furthermore, this is the first patient in which a complete loss of anti-HBc could be documented. Moreover, since anti-HBc is often used as a screening marker for HBV it should be kept in mind that anti-HBc negative patients with high viremic HBV infection may occur.