Prevalence of antibodies to hepatitis B core antigen and occult hepatitis B virus infections in Korean blood donors

Genetic diversity and occult hepatitis B infection in Africa: A comprehensive review

BACKGROUND

Occult hepatitis B infection (OBI) is a globally prevalent infection, with its frequency being influenced by the prevalence of hepatitis B virus (HBV) infection in a particular geographic region, including Africa. OBI can be transmitted through blood transfusions and organ transplants and has been linked to the development of hepatocellular carcinoma (HCC). The associated HBV genotype influences the infection.

AIM

To highlight the genetic diversity and prevalence of OBI in Africa.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and involved a comprehensive search on PubMed, Google Scholar, Science Direct, and African Journals Online for published studies on the prevalence and genetic diversity of OBI in Africa.

RESULTS

The synthesis included 83 articles, revealing that the prevalence of OBI varied between countries and population groups, with the highest prevalence being 90.9% in patients with hepatitis C virus infection and 38% in blood donors, indicating an increased risk of HBV transmission through blood transfusions. Cases of OBI reactivation have been reported following chemotherapy. Genotype D is the predominant, followed by genotypes A and E.

CONCLUSION

This review highlights the prevalence of OBI in Africa, which varies across countries and population groups. The study also demonstrates that genotype D is the most prevalent.

Protective Effect of Neonatal Hepatitis B Vaccine Against HBV Breakthrough Infection in Children with Leukemia: A Real-world Study

BACKGROUND AND AIMS

Hepatitis B vaccine is the most effective preventive measure against hepatitis B virus (HBV) infection. However, the risk of HBV breakthrough infection in fully immunized children (neonatal hepatitis B immunization) who receive immunosuppressive therapy and transfusion of blood components is not well characterized. In this real-world study, we aimed to investigate the immune protection conferred by neonatal hepatitis B vaccine in children with acute lymphoblastic leukemia (ALL) who were treated with immunosuppressive therapy and blood component transfusions.

METHODS

Children with ALL who had received all three doses of neonatal hepatitis B vaccine were included in this study. HBV seromarkers were detected before and after the initiation of immunosuppressive therapy.

RESULTS

A total of 1,011 children with ALL who were fully vaccinated against hepatitis B in infancy before the initiation of immunosuppressive therapy were eligible for inclusion. HBV infection was detected in four of 410 children (0.98%) with an HBsAg test after the initiation of immunosuppressive therapy. The median interval from treatment initiation was 19 months.

CONCLUSIONS

Three doses of neonatal hepatitis B vaccine conferred adequate protection. In endemic regions, there is a low risk of HBV breakthrough infection in fully immunized children with immunosuppressive therapy.

Estimates of the prevalence of occult HBV infection in Asia: a systematic review and meta-analysis

PURPOSE

Occult Hepatitis B virus infection (OBI) is of great significance to the transmission of Hepatitis B virus (HBV) and the evolution of the patient's clinical outcome. We conducted a systematic review and meta-analysis to estimate the prevalence of OBI in Asia.

METHODS

Literature search was conducted in PubMed, Cochrane Library database, Web of Science and Embase with the keywords of 'Hepatitis B virus', 'occult infection', 'prevalence'. 70 studies were included in the meta-analysis. Meta-analysis was performed using random-effects models to calculate the pooled prevalence of OBI and 95% confidence interval (CI). The data were analyzed in R 4.1.2.

RESULTS

The overall prevalence of OBI was 4% (95%CI: 0.03-0.06) in Asia. Subgroup analysis based on geographic region showed a prevalence of 3% (95%CI 0.02-0.06) in East Asia, 9% (95%CI 0.05-0.15) in West Asia, 3% (95%CI 0.01-0.11) in Southern Asia and 9% (95%CI 0.05-0.15) in Southeast Asia. Subgroup analysis demonstrated a prevalence of 1% (95%CI 0.00-0.02) in general population, 5% (95%CI: 0.03-0.08) in high-risk population, 9% (95%CI: 0.03-0.22) in the human immunodeficiency virus (HIV)-infected patient, 18% (95%CI: 0.09-0.32) in the hepatopathy patients.

CONCLUSION

Based on the meta-analysis of the prevalence of OBI in different populations, we concluded that the prevalence of OBI in the high-risk population, hepatopathy patients, and HIV-infected patients was higher than that in the general population. A systematic review showed that OBI was associated with disease progression and prognosis. Therefore, these populations should be routinely screened for OBI and promptly intervened to avoid promoting disease progression.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Presence of Hepatitis B Surface Antibody in Addition to Hepatitis B Core Antibody Confers Protection Against Hepatitis B Virus Infection in Hepatitis B Surface Antigen-negative Patients Undergoing Kidney Transplantation

BACKGROUND

The American Gastroenterological Association and European Association for the Study of the Liver recommend that hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (anti-HBc)-positive patients who receive immunosuppression should be monitored for hepatitis B virus (HBV) infection regardless of hepatitis B surface antibody (anti-HBs) status. However, anti-HBs may provide protection against infection. To investigate whether the presence of anti-HBs in addition to anti-HBc confers protection, we classified HBsAg(-) kidney transplantation (KT) patients into 4 groups according to anti-HBc and anti-HBs status, and compared the HBV infection rate between the anti-HBc(+)anti-HBs(+) group and the other 3 groups.

METHODS

In this single-center retrospective study, we classified 1959 patients into 4 groups: anti-HBc(-)anti-HBs(-) (n = 356), anti-HBc(-)anti-HBs(+) (n = 652), anti-HBc(+)anti-HBs(-) (n = 142), and anti-HBc(+)anti-HBs(+) (n = 809).

RESULTS

Hepatitis B virus infection was noted in 31 (1.6%) patients after KT. There was a significant difference in HBV infection rate between anti-HBc(+)anti-HBs(+) (1.2%) and anti-HBc(+)anti-HBs(-) (5.6%) (P < 0.001), but not between anti-HBc(+)anti-HBs(+) and anti-HBc(-)anti-HBs(-) (1.1%) or anti-HBc(-)anti-HBs(+) (1.4%). There was a significant difference in HBV infection rate according to anti-HBs titer, but no difference according to the donor viral profile. Hepatic failure occurred in 1 anti-HBc(+)anti-HBs(-) patient and 1 anti-HBc(+)anti-HBs(+) patient, both of whom died. Hepatocellular carcinoma was noted in 4 anti-HBc(-) patients, but not in anti-HBc(+) patients.

CONCLUSIONS

The presence of anti-HBs confers protection against HBV infection. We recommend monitoring for HBV infection after KT in HBsAg(-) anti-HBc(+) anti-HBs(-) patients, but not in HBsAg(-) anti-HBc(+) anti-HBs(+) patients.

A single-center, single-blind study to evaluate the clinical sensitivity, specificity, and agreement between Elecsys Anti-HBc II and Elecsys Anti-HBc in a Korean population

BACKGROUND

Anti-HBc IgG is almost always detected in hepatitis B virus (HBV)-infected individuals and persists in resolved infections. In certain cases, anti-HBc IgG is the only serological marker and anti-HBc-positive result generally means anti-HBc total positivity.

OBJECTIVES

To evaluate the clinical sensitivity and specificity of an investigational medical device, Elecsys Anti-HBc II, using samples from the Korean population. Agreement between Elecsys Anti-HBc II and its widely utilized predecessor Elecsys Anti-HBc was also evaluated.

STUDY DESIGN

Residual serum or plasma samples stored at below -20 °C without individual identifiers were used in this study. This study had 106 randomly selected HBV deoxyribonucleic acid (DNA)-positive samples used for evaluating clinical sensitivity. For clinical specificity, a total of 239 both HBV DNA and hepatitis B surface antigen-negative samples, which were anti-HBc-negative by Elecsys Anti-HBc, were used. Agreement between Elecsys Anti-HBc and Elecsys Anti-HBc II was evaluated in total 345 samples. The Architect Anti-HBc II was used as a confirmatory test regarding discrepancies between Elecsys Anti-HBc and Elecsys Anti-HBc II results.

RESULTS

The clinical sensitivity and specificity of Elecsys Anti-HBc II were found to be 99.06% and 100%, respectively. In total, 345 samples showed 100% agreement. Both positive and negative agreements were also 100%.

CONCLUSIONS

The clinical performance of Elecsys Anti-HBc II was confirmed as sufficient in Korean samples. Elecsys Anti-HBc II demonstrated an exceptional performance, exceeding the requirements of the Ministry of Food and Drug Safety and confirming its reliability as an in vitro diagnostic device for HBV diagnosis in Korea.

Incidence of hepatitis B virus infection in young Chinese blood donors born after mandatory implementation of neonatal hepatitis B vaccination nationwide

This study was carried out to determine the incidence of hepatitis B virus (HBV) infection in the young generation born after mandatory implementation of hepatitis B vaccination since 1992. Repeat blood donors born between 1992 and 1997 were enrolled, who gave blood at least twice during the past 3 years. Donors were tested for HBV infection markers of HBsAg, anti-HBc, anti-HBs and viral DNA by immunoassays (EIAs) and nucleic acid tests (NAT). A total of 14 937 pre-donation screening qualified young repeat donors aged 18-23 years were tested with 9 (0.06%) being HBsAg by EIA and 10 (1:1494) HBV DNA positive by Ultrio NAT (10.4 IU/mL), respectively. HBV DNA was further detected in 1:192 (9/1732) anti-HBc+ repeat donors with Ultrio Plus NAT (3.4 IU/mL). Most cases were identified as occult HBV infection (OBI). Of 14 937 repeat donors, 20.9% were anti-HBc+ positive, while approximately 50% of 12 024 repeat donors were anti-HBs negative or had levels <100 IU/L. HBsAg+ or OBI strains were classified as wild type of genotype B or genotype C. Incident HBV infection in repeat donors was approximately 1:18.5 person-years (1.1%/year) but significantly less frequent in donors with confirmed HBV vaccination (2.4%-3.3%) than those unsure of vaccination status (10.5%; P = .0023). Hepatitis B virus vaccination appears largely protective of HBV infection, but incidence of infections increases in young adults with mostly undetectable or low anti-HBs or occasionally high anti-HBs. A boost of hepatitis B vaccine for adolescents prior to age 18 years may reduce HBV infection, and implementation of more sensitive NAT in blood donation screening may improve HBV safety in blood transfusion.

Nonimmunity against hepatitis B virus infection in patients newly diagnosed with inflammatory bowel disease

Background/Aims

This study aimed to elucidate the prevalence of hepatitis B virus (HBV) serologic markers in Korean patients newly diagnosed with, but not yet treated for inflammatory bowel disease (IBD).

Methods

We prospectively enrolled 210 patients newly diagnosed with IBD (109 with ulcerative colitis and 101 with Crohn's disease). Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were measured and compared with those of 1,100 sex- and age-matched controls.

Results

The prevalence of chronic HBV infection (positive HBsAg, positive anti-HBc, and negative anti-HBs results) and past infection (negative HBsAg, positive anti-HBc, and positive or negative anti-HBs results) were not significantly different between the patients and controls (chronic HBV infection: IBD, 3.8% vs. control, 4.9%, P=0.596; past infection: IBD, 26.2% vs. control, 28.8%, P=0.625). The patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) for HBV infection than the controls (IBD, 41.5% vs. control, 22.4%; P=0.018). In the multivariate analysis, an age of <20 years (P=0.024) and symptom duration of ≥12 months before diagnosis (P=0.027) were identified as independent risk factors for nonimmunity against HBV infection.

Conclusions

The patients newly diagnosed with IBD were susceptible to HBV infection. The frequency of nonimmunity was high, especially in the patients aged <20 years and those with a longer duration of symptoms before diagnosis. Therefore, it is necessary to screen for HBV serologic markers and generate a detailed vaccination plan for patients newly diagnosed with IBD.

HBsAg-negative and anti-HBc-positive in eosinophilic granulomatosis with polyangiitis: a retrospective pilot study

We examined whether resolved hepatitis B virus (HBV) infection was associated with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), and affected AAV activity at diagnosis and prognosis during the follow-up. We reviewed the electronic medical records of 153 AAV patients, and included 91 hepatitis B surface antigen (HBsAg)-negative patients having results of both antibody to hepatitis B core antigen (anti-HBc) and surface antigen (anti-HBs). We collected clinical and laboratory data, Birmingham vasculitis activity score (BVAS) and five factor scores (FFS) at diagnosis and relapse rates during the follow-up. We divided patients into the two groups according to the presence of anti-HBc and compared variables between them in patients with AAV or those with each variant. The mean age and follow-up duration were 59.8 ± 15.2-year-old and 48.0 ± 47.5 months. Fifty patients (54.9%) had anti-HBc, and 61 patients (67.0%) had anti-HBs. Only thirty-six (39.6%) patients had ever experienced relapse after remission. There were no remarkable differences between HBsAg-negative AAV patients with and without anti-HBc. However, in eosinophilic granulomatosis with polyangiitis (EGPA) patients, patients with HBs-negative/anti-HBc-positive (resolved HBV infection) showed the higher initial mean BVAS and FFS (2009) than those without. Patients having anti-HBc exhibited significantly increased risk of relapse of EGPA than those having not (RR 16.0). Also, EGPA patients with HBs-negative/anti-HBc-positive showed meaningfully lower cumulative relapse-free survival rates than those without during the follow-up duration (p = 0.043). In conclusion, resolved HBV infection may importantly influence vasculitis activity at diagnosis and subsequently relapse after remission in EGPA patients.

Use of supplemental anti-HBc testing of donors showing non-discriminating reactive results in multiplex nucleic acid testing

BACKGROUND AND OBJECTIVES

The Korean Red Cross began nucleic acid amplification testing (NAT) for HIV and HCV in February 2005, and added HBV NAT beginning in June 2012. The current NAT system utilizes a multiplex assay for simultaneous detection of HBV DNA, HCV RNA and HIV-1 RNA. For samples that are reactive in the multiplex assay, we do specific tests for each virus. However, there have been cases of non-discriminated reactive (NDR) results which appear to be the result of non-specific reactions or cross-contamination, although some cases are considered to arise from the presence of low levels of HBV DNA due to occult hepatitis B infection.

MATERIALS AND METHODS

We examined the incidence of NDR results in previous donations of some NAT-reactive donors. Additionally, for those donors with NDR results, we performed an HBV core antibody (anti-HBc) assay.

RESULTS

From November 2015 to March 2016, there were 408 NAT-reactive donors. Of these, nineteen HBV NAT-reactive donors showed a history of NDR results in the past donations. Seven donors showed NDR results more than once. Of 771 NDR donors, 362 (47·0%) were anti-HBc reactive.

CONCLUSION

The NDR donors had a substantially higher rate of anti-HBc reactivity than other blood donors indicating that some with anti-HBc reactivity represent donors with occult HBV. Therefore, the incorporation of an anti-HBc testing for NDR donors could improve blood safety testing for the Korean Red Cross.

Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia

OBJECTIVES

To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.

METHODS

A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.  

RESULTS

Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E. 

CONCLUSION

The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.

Occult Hepatitis Infection in Transfusion Medicine: Screening Policy and Assessment of Current Use of Anti-HBc Testing

HBV still represents a global risk factor in transfusion medicine. The residual risk of HBV is not limited to pre-seroconversion window period but it extends to donors with occult HBV infection (OBI) characterized by the presence of HBV DNA in liver and by the absence of the virus surface antigen. Each country developed an appropriate blood screening policy according to local HBV prevalence, yields of infectious units per different screening methods and cost-effectiveness. We underline the need of maintaining a high level of attention for OBI carrier identification in all blood banks worldwide where the screening procedures are generally based on a combination of both serological markers and nucleic acid amplification test. In this context, markers such as hepatitis B surface antibodies and hepatitis B core antibodies (anti-HBc) might be useful, although the use of this latter is highly debated and still controversial. Our aim is to give an overview on the relevant diagnostic approaches for the routine screening for HBV focusing on the feasibility of anti-HBc testing as precautionary measure in preventing OBI transmission worldwide. In our tailored algorithm, the loss of about 1% of 'anti-HBc only' donors, does not significantly affect the blood supply while improving recipient safety.

Hepatitis B reactivation in occult viral carriers undergoing hematopoietic stem cell transplantation: A prospective study

Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative, antibody to hepatitis B core antigen (anti-HBc)-positive patients after allogeneic hematopoietic stem cell transplantation (HSCT) has not been prospectively studied. HBsAg-negative, anti-HBc-positive patients with undetectable HBV DNA undergoing allogeneic HSCT were prospectively monitored every 4 weeks. The primary endpoint was HBV reactivation, defined as detectable HBV DNA (≥10 IU/mL). Secondary endpoints included overall survival, HBsAg positivity, and changes in liver biochemistry and antibody to HBsAg levels. Among 297 allogeneic HSCT recipients, 85 (28.7%) were HBsAg-negative, anti-HBc-positive, of whom 62 were recruited and monitored for a median of 48 (4-104) weeks. The 2-year cumulative HBV DNA detectability rate was 40.8%, occurring at a median of 44 (8-100) weeks. Multivariate analysis showed that age ≥50 years (P = 0.004, hazard ratio = 8.2) and chronic graft-versus-host disease (P = 0.010, hazard ratio = 5.3) were significantly associated with HBV reactivation. Other clinical parameters, including baseline antibody to HBsAg status, serial changes in antibody to HBsAg levels, and donor serology, were not associated with HBV reactivation. Patients <50 years old and without chronic graft-versus-host disease, compared with the remaining patient cohort, had a significantly lower 2-year cumulative HBV reactivation rate (5.6% versus 65.0%, P = 0.004). Entecavir successfully suppressed HBV DNA to undetectable levels, with no cases developing biochemical hepatitis.

CONCLUSION

HBsAg-negative, anti-HBc-positive patients had a high rate of HBV reactivation after allogeneic HSCT, with determinants of HBV reactivation including age ≥50 years and chronic graft-versus-host disease; treatment strategies based on these parameters may prevent HBV reactivation and subsequent complications. (ClinicalTrials.gov identifier NCT01481649.) (Hepatology 2017;65:1451-1461).

Association of Hepatitis B Core-Related Antigen With Hepatitis B Virus Reactivation in Occult Viral Carriers Undergoing High-Risk Immunosuppressive Therapy

OBJECTIVES

Hepatitis B core-related antigen (HBcrAg) is a novel serum marker that correlates with intrahepatic hepatitis B virus (HBV) activity. Its association with HBV reactivation in hepatitis B surface antigen (HBsAg)-negative antibody to hepatitis B core antigen (anti-HBc)-positive patients undergoing high-risk immunosuppressive therapy is undefined.

METHODS

HBcrAg was measured in HBsAg-negative, anti-HBc-positive Asian patients with undetectable HBV DNA, who participated in two prospective studies investigating HBV reactivation during rituximab-containing chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). Patients were monitored every 4 weeks for up to 2 years, with entecavir started when HBV reactivation, defined as HBV DNA ≥10 IU ml^-1, developed.

RESULTS

One hundred and twenty-four HBsAg-negative, anti-HBc-positive patients (rituximab, N=62; allogeneic HSCT, N=62) with a median follow-up of 64 weeks (range: 4-104 weeks) were studied. HBV reactivation occurred in 31 patients, with a 2-year cumulative reactivation rate of 40.4%. Serum HBcrAg was detected in 43 (34.7%) patients. Baseline HBcrAg positivity was significantly associated with HBV reactivation (P=0.004, hazard ratio (HR): 2.94, 95% confidence interval (95% CI): 1.43-6.07). HBcrAg-positive patients had a significantly higher 2-year HBV reactivation rate than HBcrAg-negative patients (71.8 vs. 31%, P=0.002). In the rituximab cohort, the HRs for positive HBcrAg and negative antibody to HBsAg for HBV reactivation were 3.65 and 2.84, respectively (P=0.011, 95% CI: 1.35-9.86 and P=0.032, 95% CI: 1.10-7.37, respectively).

CONCLUSIONS

Serum HBcrAg positivity is a significant risk factor of HBV reactivation in HBsAg-negative, anti-HBc-positive patients undergoing high-risk immunosuppressive therapy and can potentially have a role in identifying patients who will best benefit from prophylactic nucleoside analogue treatment.

Update on occult hepatitis B virus infection

The event of mutations in the surface antigen gene of hepatitis B virus (HBV) results in undetectable hepatitis B surface antigen with positive/negative anti-hepatitis B core (anti-HBc) antibody status in serum and this phenomenon is named occult hepatitis B infection (OBI). The presence of anti-HBc antibody in serum is an important key for OBI tracking, although about 20% of OBI cases are negative for anti-HBc antibody. The diagnosis of OBI is mainly based on polymerase chain reaction (PCR) and real-time PCR assays. However, real-time PCR is a more reliable method than PCR. OBI is a great issue for the public health problem and a challenge for the clinical entity worldwide. The persistence of OBI may lead to the development of cirrhosis and hepatocellular carcinoma. With regard to OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for: (1) patients with a previous history of chronic or acute HBV infection; (2) patients co-infected with hepatitis C virus/human immunodeficiency virus; (3) patients undergoing chemotherapy or anti-CD20 therapy; (4) recipients of organ transplant; (5) blood donors; (6) organ transplant donors; (7) thalassemia and hemophilia patients; (8) health care workers; (9) patients with liver related disease (cryptogenic); (10) hemodialysis patients; (11) patients undergoing lamivudine or interferon therapy; and (12) children in time of HBV vaccination especially in highly endemic areas of HBV. Active HBV vaccination should be implemented for the close relatives of patients who are negative for OBI markers. Thus, the goal of this review is to evaluate the rate of OBI with a focus on status of high risk groups in different regions of the world.

Clinical characteristics and potential aetiologies of non-B non-C hepatocellular carcinoma in hepatitis B virus endemic area

BACKGROUND & AIMS

We investigated potential aetiologies, clinical characteristics and prognosis of non-B non-C (NBNC) hepatocellular carcinoma (HCC) patients in hepatitis B virus (HBV) endemic area, according to potential causes such as previous HBV exposure, chronic alcohol intake and metabolic syndrome.

PATIENTS AND METHODS

Among 4690 HCC patients treated at Asan Medical Center between 2007 and 2009, 523 were newly diagnosed with NBNC HCC, and their medical records and survival data were analyzed retrospectively.

RESULTS

Among 321 NBNC HCC patients whose hepatitis B core antibody (anti-HBc) test results were available, 81.0%, 37.1% and 15.5% had anti-HBc positivity, chronic alcohol intake and metabolic syndrome respectively. One-hundred and fifty-two patients (47.4%) had previous exposure to HBV without chronic alcohol intake or metabolic syndrome. Hepatitis B surface antibody (anti-HBs) was positive in 48.0% of the 523 NBNC HCC patients, which was much lower than that in general Korean population, and 52.3% of anti-HBc-positive NBNC HCC patients were negative for anti-HBs. Anti-HBc-negative alcoholic patients presented with more advanced cirrhosis with Child-Pugh class B/C liver function than anti-HBc-positive patients (P = 0.002). In multivariate analysis, baseline liver function, alpha-foetoprotein levels and tumour stage were significant prognostic factors and aetiology did not affect patient survival.

CONCLUSIONS

Prior HBV infection could be a potential aetiology in over 40% of NBNC HCC patients in HBV endemic area. Positivity for anti-HBc and negativity for anti-HBs may be a serologic surrogate marker for occult HBV infection in these area. The prognosis of NBNC HCC was determined by tumour stage and underlying liver function.

Molecular and serological detection of occult hepatitis B virus among healthy hepatitis B surface antigen-negative blood donors in Malaysia

BACKGROUND

Occult hepatitis B infections are becoming a major global threat, but the available data on its prevalence in various parts of the world are often divergent.

OBJECTIVE

This study aimed to detect occult hepatitis B virus in hepatitis B surface antigen-negative serum using anti-HBc as a marker of previous infection.

PATIENT AND METHODS

A total of 1000 randomly selected hepatitis B surface antigen-negative sera from blood donors were tested for hepatitis B core antibody and hepatitis B surface antibody using an ELISA and nested polymerase chain reaction was done using primers specific to the surface gene (S-gene).

RESULTS

Of the 1000 samples 55 (5.5%) were found to be reactive, of which 87.3% (48/55) were positive for hepatitis B surface antibody, indicating immunity as a result of previous infection however, that does not exclude active infection with escaped mutant HBV. Nested PCR results showed the presence of hepatitis B viral DNA in all the 55 samples that were positive for core protein, which is in agreement with the hepatitis B surface antibody result.

CONCLUSION

This study reveals the 5.5% prevalence of occult hepatitis B among Malaysian blood donors as well as the reliability of using hepatitis B core antibody in screening for occult hepatitis B infection in low endemic, low socioeconomic settings.

Quantification of Transfusion Recipients at Risk of Receiving Hepatitis B Virus-Contaminated Blood Components: A Korean Study

Although there are lots of studies about the risk for the hepatitis B virus infection such as the residual risk for donated blood, there is no research on the risk of HBV infection, from the viewpoint of recipients in Korea. Using the data about HBsAg status of donated blood in 2008 and 2009, the distribution of blood components from the claim data of health insurance in 2009, the distribution of HBsAg and HBsAb of recipients, and some assumptions, we quantified the number of recipients in Korea that might be expected to receive HBV-contaminated blood components, as a proxy index for HBV infection by transfusion in 2009. Of the 376,211 recipients, the number who might be expected to receive blood components with HBV in 2009 was 23.2 (95 % CI 13.6, 36.8) in the basic model, 43.2 (95 % CI 25.4, 68.7) in extended model I, 55.2 (95 % CI 32.5, 87.7) in extended model II and 101.6 (95 % CI 59.8, 161.4) in extended model III. The number of HBV-positive samples per 100,000 transfused units was 0.6 in the basic model (95 % CI 0.3, 0.9), 1.1 in extended model I (95 % CI 0.6, 1.8), 1.4 in extended model II (95 % CI 0.8, 2.2), and 2.6 in extended model III (95 % CI 1.5, 4.1). This study showed that a few recipients might receive HBV-contaminated blood component by transfusion. These results could be used as a scientific evidence for health policy on HBV transfusion infection.

Genetic variation of occult hepatitis B virus infection

Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant "α" determinant of S protein are "hot spots" that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.

Hepatitis B virus reactivation associated with antirheumatic therapy: Risk and prophylaxis recommendations

Accompanying the increased use of biological and non-biological antirheumatic drugs, a greater number of cases of hepatitis B virus (HBV) reactivation have been reported in inactive hepatitis B surface antigen (HBsAg) carriers and also in HBsAg-negative patients who have resolved HBV infection. The prevalence of resolved infection varies in rheumatic disease patients, ranging from 7.3% to 66%. Through an electronic search of the PubMed database, we found that among 712 patients with resolved infection in 17 observational cohort studies, 12 experienced HBV reactivation (1.7%) during biological antirheumatic therapy. Reactivation rates were 2.4% for etanercept therapy, 0.6% for adalimumab, 0% for infliximab, 8.6% for tocilizumab, and 3.3% for rituximab. Regarding non-biological antirheumatic drugs, HBV reactivation was observed in 10 out of 327 patients with resolved infection from five cohort studies (3.2%). Most of these patients received steroids concomitantly. Outcomes were favorable in rheumatic disease patients. A number of recommendations have been established, but most of the supporting evidence was derived from the oncology and transplantation fields. Compared with patients in these fields, rheumatic disease patients continue treatment with multiple immunosuppressants for longer periods. Optimal frequency and duration of HBV-DNA monitoring and reliable markers for discontinuation of nucleoside analogues should be clarified for rheumatic disease patients with resolved HBV infection.

Occult hepatitis B virus infection and blood transfusion

Transfusion-transmitted infections including hepatitis B virus (HBV) have been a major concern in transfusion medicine. Implementation of HBV nucleic acid testing (NAT) has revealed occult HBV infection (OBI) in blood donors. In the mid-1980s, hepatitis B core antibody (HBc) testing was introduced to screen blood donors in HBV non-endemic countries to prevent transmission of non-A and non-B hepatitis. That test remains in use for preventing of potential transmission of HBV from hepatitis B surface antigen (HBsAg)-negative blood donors, even though anti-hepatitis C virus tests have been introduced. Studies of anti-HBc-positive donors have revealed an HBV DNA positivity rate of 0%-15%. As of 2012, 30 countries have implemented HBV NAT. The prevalence of OBI in blood donors was estimated to be 8.55 per 1 million donations, according to a 2008 international survey. OBI is transmissible by blood transfusion. The clinical outcome of occult HBV transmission primarily depends on recipient immune status and the number of HBV DNA copies present in the blood products. The presence of donor anti-HBs reduces the risk of HBV infection by approximately five-fold. The risk of HBV transmission may be lower in endemic areas than in non-endemic areas, because most recipients have already been exposed to HBV. Blood safety for HBV, including OBI, has substantially improved, but the possibility for OBI transmission remains.

Naturally occurring hepatitis B virus surface antigen mutant variants in Malaysian blood donors and vaccinees

Hepatitis B virus surface mutants are of enormous importance because they are capable of escaping detection by serology and can infect both vaccinated and unvaccinated populations, thus putting the whole population at risk. This study aimed to detect and characterise hepatitis B-escaped mutants among blood donors and vaccinees. One thousand serum samples were collected for this study from blood donors and vaccinees. Hepatitis B surface antigen, antibodies and core antibodies were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. DNA detection was performed via nested polymerase chain reaction (PCR), and the S gene was sequenced and analysed using bioinformatics. Of the 1,000 samples that were screened, 5.5 % (55/1,000) were found to be HBsAg-negative and anti-HBc- and HBV DNA-positive. All 55 isolates were found to belong to genotype B. Several mutations were found across all the sequences from synonymous and non-synonymous mutations, with the most nucleotide mutations occurring at position 342, where adenine was replaced by guanine, and cytosine at position 46 was replaced by adenine in 96.4 % and 98 % of the isolates, respectively. Mutation at position 16 of the amino acid sequence was found to be common to all the Malaysian isolates, with 85.7 % of the mutations occurring outside the major hydrophilic region. This study revealed a prevalence of 5.5 % for hepatitis B-escaped mutations among blood donors and vaccinated undergraduates, with the most common mutation being found at position 16, where glutamine was substituted with lysine.

Viral hepatitis and liver cancer in Korea: an epidemiological perspective

In the past, hepatitis B virus (HBV) infection was endemic in the general Korean population. The association of HBV infection with the occurrence of liver cancer has been well demonstrated in several epidemiologic studies. While the mortality rates of liver cancer in Korea have decreased steadily over the last decade, the presence of hepatitis B surface antigen (HBsAg) in mothers remains high at 3-4%, and 25.5% of these HBsAg positive mothers are positive for hepatitis B e antigen (HBeAg). HBV infection caused almost a quarter of hepatocellular carcinoma (HCC) cases and one-third of deaths from HCC. These aspects of HBV infection prompted the Korean government to create a vaccination program against HBV in the early 1980s. In 1995, the Communicable Disease Prevention Act (CDPA) was reformed, and the government increased the number of HBV vaccines in the National Immunization Program (NIP), driving the vaccination rate up to 95%. In 2000, the National Health Insurance Act (NHIA) was enacted, which provided increased resources for the prevention of perinatal HBV infection. Then in 2002, the Korean government, in conjunction with the Korean Medical Association (KMA), launched an HBV perinatal transmission prevention program. The prevalence of HBsAg in children had been high (4-5%) in the early 1980s, but had dropped to below 1% in 1995, and finally reached 0.2% in 2006 after the NIP had been implemented. After the success of the NIP, Korea finally obtained its first certification of achievement from the Western Pacific Regional Office of the World Health Organization (WPRO-WHO) for reaching its goal for HBV control. An age-period-cohort analysis showed a significant reduction in the liver cancer mortality rate in children and adolescents after the NIP had been implemented. In addition to its vaccination efforts, Korea launched the National Cancer Screening Program (NCSP) for 5 leading sites of cancer, including the liver, in 1999. As a consequence of this program, the 5-year liver cancer survival rate increased from 13.2% (1996-2000) to 23.3% (2003-2008). The development of both the primary and secondary prevention for liver cancer including HBV immunization and cancer screening has been of critical importance.

Hepatitis B reactivation in patients with previous hepatitis B virus exposure undergoing rituximab-containing chemotherapy for lymphoma: a prospective study

PURPOSE

Patterns of hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg) -negative, antihepatitis B core antigen antibody (anti-HBc) -positive patients with lymphoma receiving rituximab-containing chemotherapy have not been well described.

PATIENTS AND METHODS

HBsAg-negative, anti-HBc-positive Chinese patients with undetectable serum HBV DNA (< 10 IU/mL), diagnosed with hematologic malignancies and receiving rituximab-containing chemotherapy, were prospectively monitored every 4 weeks for up to 2 years. Entecavir was started when HBV reactivation (defined as detectable HBV DNA) was encountered.

RESULTS

Among 260 patients receiving rituximab-containing chemotherapy, 63 patients (24.2%) who were HBsAg negative and anti-HBc positive underwent follow-up for a median of 70 weeks (range, 6 to 104 weeks). The 2-year cumulative rate of HBV reactivation was 41.5%, occurring at a median of 23 weeks (range, 4 to 100 weeks) after rituximab treatment. The median HBV DNA level at reactivation was 43 IU/mL (range, 14 to 920 IU/mL). A baseline undetectable antibody to HBsAg (anti-HBs; < 10 mIU/mL) was the only significant risk factor that was positively associated with HBV reactivation (hazard ratio, 3.51; 95% CI, 1.37 to 8.98; P = .009). Patients with negative baseline anti-HBs, compared with those with positive anti-HBs, had a significantly higher 2-year cumulative rate of HBV reactivation (68.3% v 34.4%; P = .012). At HBV reactivation, all patients had normal ALT, and all patients but one were HBsAg negative. Entecavir successfully controlled HBV reactivation in all patients.

CONCLUSION

A high rate of HBV reactivation was observed in HBsAg-negative, anti-HBc-positive patients undergoing rituximab-containing chemotherapy, with the risk of reactivation significantly higher in anti-HBs-negative patients. Periodic HBV DNA monitoring was an effective strategy in preventing HBV-related complications.

[Occult hepatitis B virus infection: transmission and reactivation]

Occult HBV infection (OBI) is defined as presence of HBV DNA in the liver tissue in patients with serologically undetectable HBsAg. There are differences in virologic and serological profiles of OBI. Majority of OBI are positive for anti-HBs and/or anti-HBc and minor portion are negative for all HBV markers. However, there are no HBV mutations in the surface and its regulatory regions. HBV infection persists by the presence of covalently closed circular DNA (cccDNA) within the infected hepatocytes, which serves as a reservoir for future infection. OBI increases the risk of HBV transmission through transfusion, hemodialysis, and organ transplantation. Therefore effective measures should be employed to screen OBI. Antiviral therapy is needed in HBsAg-negative transplant patients who are anti-HBc positive to prevent the recurrence of HBV infection. Since HBV replication is strongly suppressed by immune surveillance system in OBI patients, immunosuppression results in massive HBV replication. This leads to acute hepatitis and sometimes mortality when immune surveillance is recovered after stopping immunosuppressive drugs/anticancer chemotherapy. Therefore, narrow surveillance is required to recognize the viral reactivation and start antiviral agents during immunosuppressive therapy/anticancer chemotherapy in patients with OBI.

Hepatitis B virus nucleic acid amplification testing of Australian blood donors highlights the complexity of confirming occult hepatitis B virus infection

BACKGROUND

We present an analysis of the first 2 years of hepatitis B virus (HBV) nucleic acid testing (NAT) of the Australian donor population.

STUDY DESIGN AND METHODS

Between July 5, 2010, and July 4, 2012, all blood donations were screened for HBV DNA and hepatitis B surface antigen (HBsAg). Donors who tested HBsAg negative but HBV NAT positive were assessed as occult hepatitis B infections (OBI) if reactive for antibodies to HBV core antigen (anti-HBc). Donors who were anti-HBc reactive but with nonrepeatable or nondiscriminated NAT results were assessed as HBV inconclusive pending follow-up testing.

RESULTS

During the study period a total of 2,673,521 donations were screened for HBV. Forty-two chronic OBI infections (5.55/100,000 donors) were identified compared to eight acute serologic window period infections (1.06/100,000 donors). Of the 42 OBI cases, 23 (54.8%) were detected the first time they were screened for HBV DNA while 19 (45.2%) gave one or more HBV NAT-nonreactive results before detection. Of 68 donors initially assessed as HBV inconclusive and available for follow-up, 10 later confirmed as OBI cases while 51 were NAT nonreactive but remained anti-HBc reactive and OBI could not be excluded.

CONCLUSION

This study demonstrated a substantially higher prevalence of OBI compared to acute serologic window period HBV infections in Australian blood donors. Follow-up testing of OBI cases indicates that HBV DNA is often only intermittently detectable in OBI, highlighting the importance of including anti-HBc to optimize the HBV testing algorithm.

Significance of screening antibodies to hepatitis B virus core antigen among Syrian blood donors

BACKGROUND

Hepatitis B virus (HBV) transmission via hepatitis B surface antigen (HBsAg)-negative blood donors has been reported. While many countries have implemented screening antibodies to hepatitis B core antigen (anti-HBc) to further enhance transfusion safety, HBsAg is still the only obligatory HBV screening test of blood donors in Syria.

OBJECTIVE

To evaluate the significance of screening anti-HBc to reduce the risk of transfusion transmitted HBV infection in Syria.

METHODS/MATERIALS

A cohort cross-sectional prospective study included 1939 healthy blood donors assigned at the blood transfusion center of Damascus University. All donors were tested for HBsAg and anti-HBc. HBsAg-negative, anti-HBc-positive sera were further tested quantitatively for antibodies to hepatitis B surface antigen (anti-HBs) and 'anti-HBc alone' sera were considered for HBV quantitative real time polymerase chain reaction (qPCR).

RESULTS

Among 1913 HBsAg-negative donors, 215 (11·2%) were anti-HBc-positive including 125 anti-HBs high-positive and 59 anti-HBs low-positive donors. The remaining 31 donors were 'anti-HBc alone', five of which were HBV DNA-positive.

CONCLUSION

Our results suggest including anti-HBc as an additional screening test for blood donors in Syria to reduce the risk of HBV transmission. As the most cost-effective measure, anti-HBc-positive donors should be tested quantitatively for anti-HBs and only donors with no or low (<100 IU L(-1) ) anti-HBs should be deferred.

Decrease in hepatitis B prevalence among blood donors in Central-West Brazil

Background

The aim of the present study was to estimate hepatitis B virus seroprevalence among first-time blood donors in the city of Campo Grande, Mato Grosso do Sul State, in the central-western region of Brazil.

Findings

A retrospective analysis of first-time voluntary blood donor records, from January 2010 to December 2010, was conducted at the Hematology Center of Mato Grosso do Sul. The prevalence of the HBsAg and anti-HBc serological markers and their respective 95% confidence intervals were calculated. Chi-square analysis was performed between the seroprevalence previously found in 2001 and the one determined by the current study. Results were considered statistically significant if p < 0.05. Among 8,840 subjects, 269 (3.04%, 95% CI: 2.7-3.4) were positive for HBV markers. The prevalence rate of HBsAg was 0.19% (95% CI: 0.1-0.3) and anti-HBc alone was 2.85% (95% CI: 2.5-3.2).

Conclusions

There was no statistically significant difference regarding gender. However, an important association was observed between HBV infection and older age (p < 0.01). The seroprevalence of HBV infection in first-time blood donors diminished from 2001 to 2010 (p < 0.01). Such decrease suggests an improvement in the recruitment of safe donors, the positive impact of vaccination programs and the decreasing of HBV infection prevalence in the general population.

Hepatitis B viral DNA among HBs antigen negative healthy blood donors

BACKGROUND

Presence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission.

OBJECTIVES

The aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center during 2011.

PATIENTS AND METHODS

1000 serum specimens negative for HBsAg, HCV antibody and HIV antibody were collected from healthy blood donors and tested for HBcAb. Presence of hepatitis B viral DNA was checked in HBcAb positive samples by nested PCR with two sets of primers to amplify part of HBV S gene.

RESULTS

There were 64 women and 936 men in the population under study. The mean ± SD age of the donors was 38 ± 11 years. 80 out of 1000 samples (8%) were found to be positive for HBcAb. HBV DNA was detected in 50% of HBcAb positive specimens. The mean ± SD age of donors without HBV DNA was 37.7 ± 10.5 years and for donors with HBV DNA was 40.9 ± 11.2 years (P = 0.05).

CONCLUSIONS

OBI was prevalent among 50% of HBcAb positive healthy blood donors. The frequency of positive HBcAb among healthy HBsAg negative blood donors was comparable to previous studies reported from Iran. On the other hand, the frequency of HBV DNA in HBsAg negative blood donors was higher than previous reports.

Prevalence, risk factors, and impact of isolated antibody to hepatitis B core antigen and occult hepatitis B virus infection in HIV-1-infected pregnant women

BACKGROUND

Prevalence and risk factors for isolated antibody to hepatitis B core antigen (anti-HBc) and occult hepatitis B virus (HBV) infection are not well known in human immunodeficiency virus type 1 (HIV-1)-infected pregnant women. It is unclear if women with occult infections are at risk of transmitting HBV to their infants.

METHODS

HIV-1-infected and HBV surface antigen (HBsAg)-negative pregnant women were tested for antibody to HBsAg (anti-HBs) and anti-HBc using enzyme immunoassay. Women with isolated anti-HBc were assessed for occult HBV infection, defined as HBV DNA levels >15 IU/mL, using the Abbott RealTime HBV DNA assay. Infants born to women with isolated anti-HBc and detectable HBV DNA were tested at 4 months of age for HBV DNA. Logistic regression analysis was used to identify factors associated with isolated anti-HBc and occult HBV infection.

RESULTS

Among 1812 HIV-infected pregnant women, 1682 were HBsAg negative. Fourteen percent (95% confidence interval [CI], 12%-15%) of HBsAg-negative women had an isolated anti-HBc that was independently associated with low CD4 count, age >35 years, birth in northern Thailand, and positive anti-hepatitis C virus serology. Occult HBV infection was identified in 24% (95% CI, 18%-30%) of women with isolated anti-HBc, representing 2.6% (95% CI, 1.9%-3.5%) of HIV-1-infected pregnant women, and was inversely associated with HIV RNA levels. None of the women with isolated anti-HBc and occult HBV infection transmitted HBV to their infants.

CONCLUSIONS

HIV-1-infected pregnant women with isolated anti-HBc and occult HBV infection have very low HBV DNA levels and are thus at very low risk to transmit HBV to their infants.

The prevalence of the hepatitis B core antibody and the occult hepatitis B infection among voluntary blood donors in chennai, India

INTRODUCTION

The infection with the Hepatitis B Virus (HBV) is a global health problem which affects 2 billion people worldwide. In India, the prevalence of the Hepatitis B infection is 4% in the general population. The prevalence of the HBV infection in voluntary blood donors is 1-3%. It has been reported that the viraemia continues even after the clinical recovery from the acute HBV infection. Some blood donors who were negative for the surface antigen but positive for the core antibody have been reported to transmit HBV, leading to acute hepatitis. This study was done to determine the seroprevalence of the hepatitis B core antibody in voluntary blood donors in Chennai, India.

MATERIALS AND METHOD

This prospective study was conducted in our department during 2008-2009. A total of 9100 donor samples were screened for the Hepatitis B surface antigen and the Hepatitis B core antibody (IgM and IgG) by ELISA. The samples which were positive for the core antibody were subjected to Real-time PCR for the Hepatitis B DNA detection.

RESULTS

Among the 9100 donors, 911 (10.01%) donors were positive for the core antibody. The Hepatitis B Surface antigen was positive in 199 (2.18%) donors. Among the 911 donors who were positive for the core antibody, 820 (90.01%) donors were negative for the HBsAg and 2 donors were positive for Hepatitis B DNA.

CONCLUSION

If a routine screening of the sera for the core antibody is not done, the low-level HBV viraemia may not be identified. The absence of the surface antigen in the blood of apparently healthy individuals may not be sufficient to ensure the lack of the circulating virus.

Hepatitis B-positive donors in renal transplantation: increasing the deceased donor pool

It is reasonable to transplant HbsAg-positive kidneys into recipients who are themselves hepatitis B surface antigen (HbsAg) positive with appropriate antiviral treatment after transplantation. Although there are limited data regarding the hepatitis B virus (HBV) transmission risk following transplantation of kidneys from HbsAg-positive donors into HBV-immune recipients, current literature suggests that the risk of chronic infection in the recipient can be prevented by using antiviral agents or by boosting protective anti-HBs titers. The risk of chronic HBV infection following transplantation of kidneys from HbsAg-positive donors for HBV-naive recipients is high but can be minimized by administering lifelong antiviral therapy. Such a policy could be considered in an urgent situation. The most cost-effective antiviral prophylaxis strategy is lifelong lamivudine. Kidneys from HBsAg neg/anti-HBcore pos recipients are associated with a low rate of chronic HBV infection in the recipient and therefore can no longer be regarded as marginal donors. Booster vaccination to achieve protective HBV immunity or lifelong lamivudine therapy should prevent posttransplant HBV infection. Hence, we believe that strategies allowing transplantation of kidneys from donors with HBV can be undertaken safely with careful selection and matching of donors and recipients increasing access to kidney transplantation.

Prevalence and clinical significance of occult hepatitis B virus infection among renal transplant recipients in Korea

BACKGROUND

Occult hepatitis B infection (OBI) is the presence of hepatitis B virus (HBV) DNA in serum or hepatic tissue without detectable hepatitis B surface antigen (HBsAg) in serum. Kidney disease patients in the post-renal transplantation period are in a specific situation as a result of the high pre-transplantational risk of HBV infection and post-transplantational immunosuppression. We studied the pre-transplantational prevalence and post-transplantational influence of OBI on kidney transplantation patients.

METHODS

We investigated pre-transplantational serum samples of 217 HBsAg-negative patients of post-renal transplant status for the presence of HBV DNA by real-time quantitative polymerase chain reaction. Serologic markers for HBV and hepatitis C virus (HCV) infection as well as liver enzymes were analyzed.

RESULTS

We detected HBV DNA in 2.3% (5/217) of HBsAg-negative patients, and the median HBV DNA titer was 33.15 copies/ml (range 30.6-144.6 copies/ml). Among the 5 OBI patients, 2 had hepatitis B surface antibodies (anti-HBs) and 1 had hepatitis B core antibodies (anti-HBc IgG). None of the patients with OBI were co-infected with HCV. There was no evidence of reactivation of OBI during the 36-month (range 27-63 months) follow-up monitoring period after transplantation, in spite of immune suppression to prevent rejection.

CONCLUSIONS

The prevalence of occult HBV in the setting of renal transplantation was higher than that in the general population of Korea, and no reactivation of hepatitis B was observed in patients with OBI in the post-renal transplantation period.

Seroprevalence of hepatitis B e antigen (HBe antigen) and B core antibodies (IgG anti-HBcore and IgM anti-HBcore) among hepatitis B surface antigen positive blood donors at a Tertiary Centre in Nigeria

Background

Hepatitis B virus (HBV) is a common cause of liver disease throughout the world. HBV is transmitted through blood and other body fluids, including semen and saliva. Chronic replication of HBV virons is characterized by persistence circulation of HBsAg, HBeAg and HBV DNA; usually with anti-HBc and occasionally with anti-HBs. Aim: To determine the prevalence of HBeAg, IgG anti-HBcore and IgM anti-HBcore amongst HBsAg positive blood donors. These parameters are reflective of transmissibility and active hepatitis B infection. A cross sectional study was carried out at the blood donor clinics of Lagos State University Teaching Hospital Ikeja and Lagos University Teaching Hospital Idiaraba. A total of 267 donors were recruited to determine HBe antigen, IgG and IgM anti-HBcore antibodies amongst hepatitis BsAg positive donors. Five milliliters of blood was collected from those who tested positive to HBsAg screen during donation. The sera were subjected to enzyme linked immunosorbent assay (ELISA). Pearson chi-squared test was used for the analytical assessment.

Findings

A total number of 267 HBsAg positive blood donors were studied. A seroprevalence of 8.2% (22 of 267) HBeAg was obtained, 4 of 267 (1.5%) were indeterminate while 241 (90.3%) tested negative. Only 27 out of 267 donors (10.1%) tested positive to IgM anti-HBcore, 234(87.6%) tested negative, while 6(2.2%) were indeterminate. A higher percentage of 60.7% (162 of 267) tested positive to IgG anti-HBcore, while 39.3% (105 of 267) tested negative.

Conclusion

There is a low seroprevalence rate of HBeAg-positive chronic hepatitis and relatively high IgG anti-HBcore and IgM anti-HBcore rates in South West Nigeria.

Evidence of serologic activity in chronic hepatitis B after surface antigen (HBsAg) seroclearance documented by conventional HBsAg assay

BACKGROUND

Possible serologic activity after hepatitis B surface antigen (HBsAg) seroclearance documented by conventional assays in chronic hepatitis B (CHB) has not been thoroughly investigated.

METHODS

We determined the levels of serum hepatitis B virus (HBV) DNA, hepatitis B core-related antigen (HBcrAg), and linearized HBsAg (CLEIA prototype) in 329 CHB patients (72.0% male) after HBsAg seroclearance was documented by a conventional HBsAg assay.

RESULTS

The median interval between presentation and HBsAg seroclearance was 69.4 months. The median age at HBsAg seroclearance was 50 years. Assays for serum HBV DNA, HBcrAg, and linearized HBsAg were performed at a median time interval of 11.2 months after HBsAg loss. Linearized HBsAg and HBcrAg were detectable in 85 (25.8%) and 69 (21%) patients, respectively, and one or both serologic markers were detectable in 133 patients (40.4%). Serum HBV DNA was detectable in only 7 patients (2.1%). There was no correlation between linearized HBsAg and HBcrAg levels (r = 0.095, p = 0.924). The incidences of detectable linearized HBsAg and HBcrAg did not differ between patient samples taken at 6-12 and >12 months after HBsAg seroclearance (p = 0.146 and 0.079, respectively). Among patients with detectable serologic markers, median levels of linearized HBsAg (p = 0.581) and HBcrAg (p = 0.951) did not significantly change with time after HBsAg seroclearance.

CONCLUSION

Using novel HBcrAg and linearized HBsAg assays, viral serologic activity after HBsAg seroclearance was demonstrated in more than 40% of CHB patients. These tests have potential applications in diagnosing and prognosticating CHB patients with HBsAg seroclearance.

Hepatitis B virus in transfusion medicine: still a problem?

Hepatitis B virus (HBV) has probably evolved with humans for nearly 35,000 years. HBV diversified into 9 genotypes (A-I) presenting specific features directing epidemiology, clinical expression and testing. Genotypes E and C are more infectious and carry higher risk of chronicity and cancer. HBsAg blood screening implemented 40 years ago enormously decreased the risk of transfusion transmission but the remaining risk requires extremely sensitive nucleic acid testing (NAT) to be removed. Limitations of the host immune system, the impact of immunodeficiency and the mechanisms utilised for viral persistence were recently identified. HBV replication produces excess HBsAg and infectious and defective viral particles but screening assays for HBsAg or viral particles alone do not allow fully efficient detection, making necessary screening for both. The host immune system fails to completely control the virus that escapes and persists unrecognized at very low levels or as immuno-selected variants. Variants may not be identified by assays, explaining false negative results. Specific mutations may affect post-transcriptional mechanisms including HBV RNA splicing. Asymptomatic HBV infected blood donors are at risk of long-term complications through mechanisms to be understood for appropriate counselling. Infectivity of occult HBV infection (OBI) by transfusion appears low, anti-HBc (anti-core antigen) only being more infectious than anti-HBs (anti-S protein) positive units.

Challenges in hepatitis B detection among blood donors

PURPOSE OF REVIEW

The availability of hepatitis B virus (HBV) nucleic acid testing (NAT) for donor blood screening led to its implementation in low prevalence and high prevalence countries. Genomic detection was a substantial addition to HBV surface protein (HBsAg) screening by detecting window period infections and 'occult' HBV infections (OBIs), characterized by undetectable HBsAg, low viral load and presence of serological markers (anti-HBc and/or anti-HBs). OBIs are the result of multiple, poorly understood mechanisms including incomplete immune control mutations of the HBsAg antigenic determinants; abnormal expression of S gene; and inhibition of genome transcription. Infectivity for the recipient is high for window period blood and relatively low for OBIs.

RECENT FINDINGS

The number of cases identified by NAT ranges between 1 : 1000 and 1 : 50 000, depending on epidemiology and assay sensitivity whether NAT is implemented in individual donations or pools of samples. OBI donors are generally older than 45 years except in Africa, carry very low viral load (median 11-25  IU/ml) and have normal alanine transaminase levels. Cases carrying anti-HBc alone are more infectious than those with low level of anti-HBs. Evidence of HBsAg escape mutants that are undetected by commercial assays has been published. Inhibition of HBsAg mRNA production and export are potential mechanisms of OBI occurrence.

SUMMARY

HBV blood safety is improved by NAT for HBV DNA when applied to individual donations. Until the sensitivity of NAT is improved, both this method and HBsAg screening are needed to eliminate potentially infectious blood donations. Occult HBV characterization clarifies new facets of HBV natural history.

Pre- and post-transfusion testing for hepatitis B virus surface antigen and antibody in blood recipients: a single-institution experience in an area of high endemicity

Background

Hepatitis B remains the most common transfusion-transmitted viral infection. We explored the current status of pre-transfusion screening and post-transfusion follow-up testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibodies (anti-HBs) in blood recipients from an area of high HBV endemicity.

Methods

A total of 7,780 blood recipients were transfused with at least 1 unit of blood component at a single university hospital in Korea between January 2006 and December 2009. Their medical records were reviewed, and their demographic and transfusion-related data were analyzed.

Results

Pre-transfusion HBsAg and anti-HBs levels were tested in 77.6% (6,037/7,780) of the recipients. The results varied widely according to recipient age. In all, 32.8% (1,982/6,037) of the recipients who were tested had dual negative pre-transfusion results for HBsAg and anti-HBs and, therefore, were at increased risk of HBV transmission. Post-transfusion follow-up testing for HBsAg and/or anti-HBs was performed in 22% (436/1,982) of the increased-risk group.

Conclusions

Our data show that current transfusion-related laboratory testing practice is not sufficient to properly investigate possible post-transfusion infections. Routine laboratory tests, including HBsAg and anti-HBs, should be recommended in transfusion guidelines.

Prevention of post-transfusion hepatitis by screening of antibody to hepatitis B core antigen in healthy blood donors

Background

Transfusion-associated hepatitis B viral infection continues to be a major problem in India even after adoption of mandatory screening for HBsAg by ELISA method. The high incidence of TAHBV is reported in patients receiving multiple transfusions.

Objective

To study the seroprevalence of hepatitis B core antibody among healthy voluntary blood donors

Subjects and Methods

The study was conducted in the department of Transfusion Medicine of a tertiary care referral hospital. A total of 12,232 volunteers after passing through the stringent criteria were selected for blood donation. Donor samples were tested for all mandatory transfusion transmissible infections and anti HBc IgM (Monolisa HBc IgM PLUS:BIO-RAD, France). Reactive results were confirmed by repeat testing in duplicate. Donor data was analyzed using SPSS software and Chi-square test was used to calculate the significance of difference between the groups.

Results

A total of 12,232 healthy voluntary blood donors were recruited. Majority (93.4%) were males. Median age of donor population was 26 years (range: 18–60 years). Eighty six (0.7%) were positive for HBsAg, which comes under “low prevalence (<2%) zone” as per WHO. On screening for HBcAg Ig M, 15 (0.1%) were found to be positive and none were HBsAg reactive. There was no significance of difference in the mean age between reactive and non-reactive donors.

Conclusion

Evaluating the usefulness of anti-HBc screening is critical. Anti HBcAg IgM screening may be included in routine screening of donors as it is an indicator of occult HBV during window period. The cost and the unnecessary wastage of the blood units when they are positive for anti HBsAg along with the core antibody need to be studied.