Reactivation of resolved hepatitis B virus infection with immune escape mutations after long-term corticosteroid therapy

Patterns of hepatitis b virus immune escape and pol/rt mutations across clinical cohorts of patients with genotypes a, e and occult hepatitis b infection in Nigeria: A multi-centre study

Hepatitis B virus (HBV) immune escape and Pol/RT mutations account for HBV immunoprophylactic, therapeutic, and diagnostic failure globally. Little is known about circulating HBV immune escape and Pol/RT mutants in Nigeria. This study focused on narrowing the knowledge gap of the pattern and prevalence of the HBV mutants across clinical cohorts of infected patients in southwestern Nigeria. Ninety-five enrollees were purposively recruited across clinical cohorts of HBV-infected patients with HBsAg or anti-HBc positive serological outcome and occult HBV infection. Total DNA was extracted from patients' sera. HBV S and Pol gene-specific nested PCR amplification was carried out. The amplicons were further sequenced for serotypic, genotypic, phylogenetic, and mutational analysis. HBV S and Pol genes were amplified in 60 (63.2%) and 19 (20%) of HBV isolates, respectively. All the sixty HBV S gene and 14 of 19 Pol gene sequences were exploitable. The ayw4 serotype was predominant (95%) while ayw1 serotype was identified in 5% of isolates. Genotype E predominates in 95% of sequences, while genotype A, sub-genotype A3 was observed in 5%. Prevalence of HBV IEMs in the "a" determinant region was 29%. Commonest HBV IEM was S113T followed by G145A and D144E. The Pol/RT mutations rtV214A and rtI163V among others were identified in this study. This study provided data on the occurrence of existing and new HBV IEMs and Pol gene mutations in Nigeria.

Analytical Performance of the Sysmex HISCL HBsAg Assay and Comparison with the Roche Elecsys HBsAg II Quant Assay in the Quantification of Hepatitis B Surface Antigen

Background and Objectives: This study aims to estimate the analytical performance of the Sysmex HISCL HBsAg assay and to assess the analytical correlation with the Roche Elecsys HBsAg II quant assay with clinical samples and the WHO International Standard (IS). Materials and Methods: The intra-assay precision, linearity, assay limitation, accuracy, and comparative evaluation of the HISCL HBsAg assay were estimated. Results: Extrapolating from the plot of the average total allowable error versus the reference value, an accuracy goal of 20% would be achieved around a limit of quantification (LoQ) of 0.014867 IU/mL. The percentage of biases for each level of the WHO IS measured by the two assays were less than 15%, except for the WHO 3rd IS, for which the HISCL HBsAg assay achieved a percentage of bias of 33%. In the comparative evaluation, Passing–Bablok regression analysis did not reveal any significant deviation from linearity between the two assays (y = −48.6998 + 1.9206x; p = 0.79 by the CUSUM test for linearity). The mean difference of the quantitative HBsAg level between the two assays was 1762.5 IU/mL in the Bland–Altman plot. Conclusions: The HISCL HBsAg assay, with a highly sensitive LoQ of 0.03 IU/mL, showed similar analytical performance in HBsAg quantification to the Elecsys HBsAg II quant assay and may be helpful in obtaining better diagnoses and therapeutic strategies for treating HBV infections.

Hepatitis B Virus Reactivation with Discontinuation of Nucleoside Analogue in Patients Who Received Allogeneic Hematopoietic Stem Cell Transplantation

Reactivation of hepatitis B virus (HBV) is known to occur frequently after hematopoietic stem cell transplantation (HSCT). The reactivation can be prevented by nucleos(t)ide analogue (NA), but it is unclear how long NA should be continued. Here, we report 3 cases of HBV reactivation with discontinuation of NA following the discontinuation of immunosuppressive therapies after HSCT. Three male patients aged 34, 59, and 54 years received allogeneic HSCT (allo-HSCT) for chronic myeloid leukemia, mixed phenotype acute leukemia, and myelodysplastic syndrome, respectively. Before HSCT, 2 patients were positive for hepatitis B surface antigen (HBsAg) and 1 patient was negative for HBsAg and positive for antibodies to hepatitis B core antigen. NA (lamivudine or entecavir) was started at the same time as HSCT and stopped after the discontinuation of immunosuppressive therapies. In all patients, the serum HBV DNA levels were increased after the discontinuation of NAs. Two of the three patients developed severe hepatitis with high levels of HBV DNA (7.5 and 7.4 log IU/mL, respectively). A patient without hepatitis was re-administered NA soon after the HBV DNA started to increase (3.3 log IU/mL). Interestingly, the 2 patients who developed hepatitis cleared HBsAg promptly after the recovery from hepatitis and they could stop NAs without the reversion of HBsAg. It was speculated that transplanted immune cells, which were naïve for HBV, react strongly with HBV antigens that were increased after the NA discontinuation. The discontinuation of NA after allo-HSCT is not recommended generally because strong hepatitis might be induced even after several years.

Case of hepatitis B virus reactivation after ibrutinib therapy in which the patient remained negative for hepatitis B surface antigens throughout the clinical course

A 71-year-old man was diagnosed with B-cell chronic lymphocytic leukemia. He was negative for hepatitis B surface antigen (HBsAg), positive for antibodies against the hepatitis B surface and core, and negative for hepatitis B virus (HBV)-DNA before starting chemotherapy. A total of 13 months after the initiation of ibrutinib (a Bruton's tyrosine kinase inhibitor), the patient's alanine aminotransferase levels suddenly increased to 427 U/L. As the level of serum HBV-DNA increased to 5.2 logIU/mL, a diagnosis of HBV reactivation was made, whereas the patient remained negative for HBsAg. The patient's serum alanine aminotransferase levels normalized after the initiation of entecavir at a dose of 1 mg/day. However, it took >1 year to achieve an undetectable level of HBV-DNA, even with an add-on therapy of tenofovir disoproxil fumarate. Interestingly, the patient remained negative for HBsAg throughout the clinical course owing to triple HBsAg escape mutations: Q101K, M133L, and G145A.

Spontaneous reactivation of hepatitis B virus with S gene mutations in an elderly patient with diabetic nephropathy

Generally, reactivation of hepatitis B virus (HBV) infection is induced by the administration of immunosuppressants or anticancer agents, but reactivation without such drugs has rarely been reported. Here we report an elder case with spontaneous reactivation of HBV replication accompanied by hepatitis B surface antigen (HBsAg) mutations. A 69-year-old man with a history of diabetes mellitus and chronic kidney disease (CKD) was found to be positive for HBsAg (0.072 IU/ml) in June 2018. In May 2019, marked hepatic dysfunction and increased HBsAg (2533.2 IU/ml) were observed when he visited the hospital due to diarrhea and worsening of CKD. At that time, hepatitis B surface antibody (HBsAb) was positive (268.9 mIU/ml) and HBV DNA was 6.0 log IU/ml. After treatment with entecavir, HBV DNA and HBsAg rapidly decreased. Full-genome HBV sequence analysis revealed that the patient was infected with HBV of subgenotype B1 and it had an "a" determinant mutation M133L in the S gene coding HBsAg. Notably, both HBsAg and HBsAb were positive at the time of HBV reactivation, suggesting that the HBV with these mutations escaped from neutralization by HBsAb. This case suggests that immune escape mutations could play an important role in spontaneous HBV reactivation.

Prevalence of infectious diseases in patients with autoimmune blistering diseases

A long-term immunosuppressive treatment can provoke latent infections. Autoimmune blistering diseases (AIBD) are mostly treated with systemic immunosuppressive agents. To prevent the reactivation or exacerbation of existing latent infections, patients must be screened for infectious diseases before immunosuppressive treatments are initiated. However, the prevalence of infectious diseases in AIBD remains to be elucidated. To evaluate the necessity of screening infectious diseases in AIBD, we retrospectively reviewed the clinical records of 215 patients at a single center with AIBD for hepatitis B virus (HBV), hepatitis C virus (HCV), Mycobacterium tuberculosis, Treponema pallidum, human T-cell leukemia virus type 1 (HTLV-1) and HIV infections. Approximately 40% of patients were infected with HBV. During systemic corticosteroid treatment, HBV DNA became positive in 3.4% of cases. Antibodies to HCV, interferon-γ release assays for M. tuberculosis and the T. pallidum latex agglutination test were positive in 0.6%, 6.6% and 1.2% cases, respectively. Neither HTLV-1 nor HIV infections were detected. In conclusion, checks for HBV and M. tuberculosis infections should be made before immunosuppressive treatments are started, because of the high prevalence of these potentially life-threatening infections. Other infections should be tested for depending on the patient's risk factors.

Immune-Escape Hepatitis B Virus Mutations Associated with Viral Reactivation upon Immunosuppression

Hepatitis B virus (HBV) reactivation occurs as a major complication of immunosuppressive therapy among persons who have recovered from acute hepatitis and those who have controlled chronic infection. Recent literature data emphasize the presence of a high degree of S gene variability in HBV isolates from patients who developed reactivation. In reactivated HBV, the most frequently detected mutations belong to the second loop of “a” determinant in HBsAg. These mutations were identified to be immune escape and responsible for vaccine- and diagnostic-escape phenomena. Their emergence clearly provides survival in the presence of a developed humoral immune response and is often associated with impaired serological diagnosis of HBV reactivation. The knowledge of their existence and roles can elucidate the process of reactivation and strongly highlights the importance of HBV DNA detection in monitoring all patients with a history of HBV infection who are undergoing immunosuppression. This review discusses the possible influence of the most frequently found immune-escape mutations on HBV reactivation.

Roles of Hepatitis B Virus Mutations in the Viral Reactivation after Immunosuppression Therapies

Reactivation of hepatitis B virus (HBV) is a major problem in patients receiving chemotherapy for malignant diseases or immunosuppression therapies. It has been thought that a reduction in the immune responses might result in the reactivation of HBV replication from covalently closed circular DNA (cccDNA) residing in hepatocytes. However, not only the host’s immune status, but also viral mutations have been reported to be associated with reactivation. Especially, several case reports about amino acid mutations in hepatitis B surface antigen (HBsAg) that escape from immune reactions have been reported, and recent reports showed that the frequencies of such mutations are higher than previously expected. In this review, we summarize the characteristics of viral mutations, including immune escape mutations in HBV-reactivated patients, and discuss their significance.

Horizontal Transmission of Hepatitis B Virus From Mother to Child Due to Immune Escape Despite Immunoprophylaxis

Hepatitis B virus (HBV) vaccination starting at birth is approximately 95% effective in preventing mother-to-child transmission to infants born to HBV-infected mothers. A higher risk of transmission is associated with birth to a highly viremic mother, often due to transplacental exposure, while later horizontal transmission is much less common, particularly following complete vaccination. This study reports a case of infection in an older child despite appropriate immunoprophylaxis starting at birth and an apparent protective immune response post-vaccination. Two immune escape mutations within the antigenic determinant of the surface antigen-coding region were observed in the child's dominant HBV sequence, whereas the maternal HBV variant lacked mutations at both sites. Ultra-deep sequencing confirmed the presence of 1 mutation at low levels within the maternal HBV quasispecies population, suggesting early exposure to the child followed by viral evolution resulting in immunoprophylaxis escape and chronic infection.