Evaluation of serologic screening of blood donors in India reveals a lack of correlation between anti-HBc titer and PCR-amplified HBV DNA

Hepatitis B Reactivation in Patients Treated with Direct-Acting Antivirals for Hepatitis C

INTRODUCTION

There is limited research about HBV reactivation (HBVr) due to direct-acting antivirals (DAA) for HCV and most are limited by short duration of follow-up, small sample size, and absence of baseline HBV DNA. We aimed to determine the incidence and clinical course of HBVr in HBsAg and/or anti-HBcIgG positive patients treated with DAA for HCV.

METHODS

Seven centers retrospectively analyzed their database on HCV patients treated with DAA between 2015 and 2019. Patients with HBV coinfection or resolved HBV infection were enrolled. Serum transaminases, HBsAg, HBeAg, and HBV DNA were followed every 4 weeks during DAA treatment and every 12 weeks 1 year after treatment. Entecavir or tenofovir disoproxil fumarate was started in case of HBVr. The development of HBVr, HBV flare, liver failure, and mortality were determined.

RESULTS

852 patients received DAA treatment for HCV. Among them, 35 (4.1%) had HBV coinfection and 246 (28.9%) had resolved HBV infection. 257 patients (53.3% male, mean age: 63 ± 9) constituted the study group (29 with coinfection and 228 with resolved infection). Three patients with coinfection were HBV DNA positive. HBVr developed in 10 (34.5%) HBsAg positive patients, either during (n = 3) or 12-48 weeks after finishing DAA treatment. HBV flare and acute liver failure developed in 1 patient (3.4%), each. Two patients with resolved infection developed HBVr (0.87%) and one (0.44%) had HBV flare. Overall, none of the patients died or underwent liver transplantation due to HBVr.

CONCLUSION

Patients with HBV/HCV coinfection have a high risk of HBVr after DAA treatment and should receive antiviral prophylaxis. Patients with resolved infection have a low risk of HBVr and can be monitored by serial ALT measurements.

Prevalence of Anti-HBc Antibodies among HBsAg Negative Individuals and Its Association with Occult Hepatitis B

Introduction  Hepatitis B virus (HBV) infection is an endemic in many Asian countries, and among the major routes of transmission, transfusion is the one that should be prevented. Occult HBV infection (OBI) is defined as the presence of HBV DNA in the absence of detectable HBsAg, with or without anti-HBV antibodies. The aim of this study was to detect the prevalence of anti-HBc total antibodies among the HB surface antigen (HBsAg) negative individuals by way of enzyme-linked immunosorbent assay (ELISA), and detect the presence of HBV DNA among the anti-HBc seropositives by polymerase chain reaction (PCR). Anti-HBs among the HBV DNA positives were also found out by enzyme-linked fluorescent assay (ELFA). Materials and Methods  A total of 910 serum samples was subjected to initial screening for HBsAg by MERILISA HBsAg ELISA kits. The anti-HB core (HBc) total antibody titer was evaluated using MONOLISA ELISA (Biorad) kits. If found negative, the samples were discarded. If found positive, the samples underwent HBV DNA testing by nested PCR. Antibody to hepatitis B surface antigen (anti-HBs) was calculated among the DNA positives by ELFA. Results  A total of 133 samples were positive for anti-HBC total antibody, resulting in an overall prevalence of 14.6%. Overall prevalence of HBV DNA among the anti-HBc seropositives was 2.2%. Conclusion  Among the three HBV DNA positive patients, two belonged to the preoperative screening group, which is an alarming situation. Screening of blood for HBsAg has reduced the incidence of posttransfusion hepatitis, but HBV still remains the major source of transfusion transmitted infection in India.

Neopterin and soluble CD14 (sCD14) levels as immunoactivation markers in aHBc-only cases

Aim: Isolated hepatitis B core antibodies (aHBc)-only pattern complicates the diagnosis of HBV infections. We evaluated neopterin and sCD14 levels in HBV infections. Methods: aHBc-only (n: 102), healthy control (healthy control group [HCG], n: 100), and chronic hepatitis (CHB) groups (n: 70) were investigated. Competitive and sandwich ELISA were used. Results: The mean neopterin levels were significantly lower in the aHBc-only group than those in the CHB group (p = 0.0001). No significant difference was found between the aHBc-only group and the HCG (p = 0.854). The mean sCD14 levels were lower in the aHBc-only group than those in the CHB group (p = 0.0001), but no significant difference was found between the aHBc-only group and HCG (p = 0.402). No significant difference was detected between aHBc-only and HCG for mean sCD14 (p = 0.402) and neopterin levels (p = 0.854). Conclusion: These two biomarkers are not useful for diagnosing the aHBc only pattern.

Detection of occult hepatitis B and window period infection among blood donors by individual donation nucleic acid testing in a tertiary care center in South India

With the introduction of highly sensitive hepatitis B surface antigen immunoassay, transfusion associated HBV infection have reduced drastically but they still tend to occur due to blood donors with occult hepatitis B infection (OBI) and window period (WP) infection. Sera from, 24338 healthy voluntary blood donors were screened for HBsAg, HIV and HCV antibody using Vitros Enhanced Chemiluminescent Immunoassay. The median age of the donor population was 30 (range 18-54) with male preponderance (98%). All serologically negative samples were screened by nucleic acid testing (NAT) for viral DNA and RNA. NAT-positive samples were subjected to discriminatory NAT for HBV, HCV, and HIV and all samples positive for HBV DNA were tested for anti-HBc, anti-HBs, HBeAg. Viral load was determined using artus HBV RG PCR Kit. Of the 24,338 donors screened, 99.81% (24292/24338) were HBsAg negative of which NAT was positive for HBV DNA in 0.0205% (5/24292) donors. Four NAT positive donors had viral load of <200 IU/ml making them true cases of OBI. One NAT positive donor was negative for all antibodies making it a case of WP infection. Among OBI donors, 75% (3/4) were immune and all were negative for HBeAg. Precise HBV viral load could not be determined in all (5/5) NAT positive donors due to viral loads below the detection limit of the artus HBV RG PCR Kit. The overall incidence of OBI and WP infections was found to be low at 1 in 6503 and 1 in 24214 donations, respectively. More studies are needed to determine the actual burden of WP infections in Indian blood donors.

Prevalence of hepatitis B seromarkers and hepatitis C antibodies in blood donors in Basra, Iraq

BACKGROUND

Transfusion-caused hepatitis remains a major problem in Iraq. Therefore, testing for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc) and antibodies to hepatitis C antigen (anti-HCV) is a very important preventative measure. The objective of this study was to establish the prevalence of hepatitis B and C virus seromarkers among blood donors as a foundation for safe blood transfusion in Iraq.

METHODS

A cross-sectional observational study was conducted in the blood banks in Basra, Iraq from 1 January to 31 December 2013. Blood samples were collected and were tested for HBsAg, anti-HBc and anti-HCV using standard laboratory techniques.

RESULTS

A total of 69 915 blood donors were enrolled for the study. A total of 1625 (2.3%) donors have shown serological evidence for hepatitis B virus infection; of those donors, 125 (0.2%) showed a positive test result for both anti-HBc and HBsAg while 1475 (2.1%) had positive anti-HBc results as the only positive test for HBV infection. There was no significant difference between males and females (p=0.28). The prevalence of anti-HCV was 0.1%.

CONCLUSIONS

This is the first large population study of its kind in Basra, Iraq. The prevalence of hepatitis B and C among blood donors is very low in Basra. Around 2% of blood donors had anti-HBc as the only serological evidence of HBV infection. Inclusion of anti-HBc in routine screening of blood donors in Iraq should be encouraged.

Primary liver cancer deaths and related years of life lost attributable to hepatitis B and C viruses in India

BACKGROUND AND AIMS

More than 25,000 people die of liver cancer annually in India. There is little information about the contribution of hepatitis B virus (HBV) and hepatitis C virus (HCV) to these deaths. We conducted a systematic review of published studies on HBV or HCV infection and liver cancer in India and estimated the population attributable fraction (PAF) of liver cancer deaths caused by these infections and the corresponding annual number of deaths and years of life lost (YLL) in the country.

METHODS

We searched the PubMed and Scopus databases, as well as the reference list of relevant articles in the systematic review. For calculation of the number of liver cancer deaths attributable to HBV and HCV, we used two sources of outcome data and two relative risks for the association between HCV and liver cancer.

RESULTS

The PAF was 67% for HBV, 17-19% for HCV, and 71-72% for HBV and/or HCV. The annual attributable number of liver cancer deaths was approximately 17,000 for HBV; 4500 for HCV; and 18,500 for HBV and/or HCV, corresponding to approximately 297,000, 75,000, and 315,000 YLL, respectively. There was little difference in these numbers using the two sources of outcome data or the two risk estimates for HCV.

CONCLUSIONS

Our findings underscore the importance of primary prevention of HBV and HCV by appropriate measures, including vaccination (HBV only), prevention of transfusion-related infections, and increased awareness of the routes of transmission and long-term health outcomes.

A strategical re-thinking on National Blood Donor Pool: Anti-HBc positivity related re-entry mechanisms

BACKGROUND AND OBJECTIVES

Screening of blood donations for antibodies against hepatitis B core antigen (anti-HBc) is used to prevent transfusion transmitted hepatitis B virus (HBV) infection. In this study, we studied the magnitude of blood donor gain by using a re-entry mechanism in our Blood Bank of Gulhane Military Academy of Medicine.

MATERIALS AND METHODS

Between January and May 2013, 5148 voluntary blood donors were screened by ELISA method for HBsAg, anti-HBc total and other screening markers, prospectively. Samples with repeated reactivity for the presence of anti-HBc were further tested with four supplemental assays.

RESULTS

We detected 515 (10%) anti-HBc positive and 4612 (90%) anti-HBc negative cases in 5127 HBsAg negative serum samples. A total of 461 (89.5%) blood units were reactive for at least one additional serologic parameter and 54 were (10.5%) negative. Isolated anti-HBc positivity rate was 1.3% (69/5127). In the isolated anti-HBc positive samples, 54 were also anti-HBe and HBeAg negative. HBV DNA was not detected in any of the samples.

CONCLUSION

Applying the EDQM criteria would decrease our blood donor loss from 10% to 5.4%. As alternative re-entry mechanisms have already been presented in the literature, institution of a new policy is needed to enhance the limited blood donor pool in our system.

Sensitivity of individual donor nucleic acid testing (NAT) for the detection of hepatitis B infection by studying diluted NAT yield samples

BACKGROUND

Screening blood donors for the presence of hepatitis B virus surface antigen (HBsAg) has been the backbone of blood safety. However, occult hepatitis B infection (OBI) in donors can be missed when only HBsAg screening is used. Nucleic acid testing (NAT) is capable of detecting OBI among donors. The aim of our study was to analyse the sensitivity of NAT for detecting OBI.

MATERIAL AND METHODS

The kits used during the study for serology testing were BioRad Monolisa™ HBsAg Ultra (HBsAg screening), Abbott Architect for anti-HBcAg (total) and anti-HBsAg testing, and Vitros® by Ortho Clinical Diagnostics for anti-HBcAg (IgM). Procleix Ultrio was used for individual donor-NAT (ID-NAT) and Abbott m2000 for estimation of HBV DNA. Out of 28,134 HBsAg non-reactive donors, 25 were ID-NAT-reactive. Of these 25 NAT yield samples, 18 were studied further at different dilutions from 1:2 to 1:16. The doubling dilutions were made with HBV non-reactive AB plasma. Undiluted samples were used for all serological tests and for HBV DNA estimation.

RESULTS

Of the 18 samples studied, nine were NAT-reactive at a dilution of <1:4 and five out of these showed presence of antibody to core antigen (IgG+IgM). Antibody to surface antigen was present in only two of the nine NAT-reactive samples, one with antibody to core antigen and the other without. Six had a viral load in the range from <10 to 38 IU/mL whereas the viral load in the remaining three samples was not determined. Among the other nine samples which were NAT-reactive at dilutions≥1:4, antibody to core antigen (IgG+IgM) was present in seven.

DISCUSSION

Our study showed that ID-NAT testing along with HBsAg screening could detect most potentially HBV infectious donors (including those with OBI). NAT screening for HBV on diluted samples could compromise blood safety because samples with a low viral load will escape detection.

Serological characterization of occult hepatitis B virus infection among blood donors in India

INTRODUCTION

Discovery of hepatitis B infections characterized by the presence of viral genome without detectable HBsAg (Occult Hepatitis; OBI) has initiated a considerable amount of research in this regard. Our study is a serological and molecular characterization of OBI among the donors who donated at our blood bank during the study period.

MATERIAL AND METHOD

During the study period HBsAg ELISA non reactive ID-NAT reactive donors samples were screened for presence of antibody against HBc, HBs and HBe. Molecular analysis of these NAT yield samples was undertaken for detection of the viral load and genotyping.

RESULT

We studied 28,134 HBsAg ELISA non reactive donor samples. On testing them with ID-NAT, HBV DNA was detected in 25 samples. Eighteen samples out of these 25 NAT yield were further worked up. The 66.6% of the NAT yield samples (12 out of 18) were reactive for antibody against HBc. The 25% (3 out of 12) of these NAT yield samples having antibody against core antigen also had antibody against HBs. The 27.7% (5 out of 18) of NAT yield detected by ID-NAT did not have any detectable serological marker in blood. Four out of 12 core antibody positive NAT yield samples had genotype A HBV infection.

CONCLUSION

As per our study molecular detection of HBV DNA by ID-NAT, we were able to analyze 18 HBV NAT yield cases among 28,134 HBsAg ELISA non reactive donors. Out of 18, 12 donors were OBI whereas the rest (6) were in window period (WP yield) of HBV infection. One out of every 3.6 NAT yield detected by ID-NAT was non reactive for all serological markers.

Blood supply safety in Afghanistan: a national assessment of high-volume facilities

BACKGROUND

Little information is available regarding blood supply safety in Afghanistan. The purpose of this study was to assess blood safety through serologic and observational measures in Afghanistan.

STUDY DESIGN AND METHODS

This cross-sectional assessment included the 40 highest-volume facilities collecting and transfusing blood nationally identified in a previous survey. At each facility, study representatives completed a standardized instrument assessing staff performance of transfusion-related activities and performed rapid testing for human immunodeficiency virus, syphilis, and hepatitis B and C with rapid diagnostic tests on clinically discarded specimens. Reactive samples received confirmatory testing. Descriptive statistics were generated, with differences analyzed using chi-square or Fisher's exact tests.

RESULTS

Between November 2010 and May 2011, a total of 332 blood donor collection procedures were observed. Only 52.4% of observed encounters correctly screened and deferred donors by international criteria. Public and private facilities demonstrated glove use, proper sharps disposal, and patient counseling and relayed screening test results in less than 75% of observed events, significantly less likely than military facilities (p < 0.01). Of 1612 specimens assessed, confirmed cases of hepatitis B (n = 6), hepatitis C (n = 1), and syphilis (n = 3) were detected among units already prescreened and accepted for transfusion.

CONCLUSION

Lapses in proper donor screening contributed to the presence of confirmed-positive units available for transfusion, as detected in this study. Steps must be taken to ensure standardization of testing kits requirements, documentation, and mandatory training and continuing education for blood bank staff with regard to counseling, drawing, processing, and transfusion of blood products.

Prevalence of HBc-Ab among HBs-Ag negative healthy blood donors in south of Iran

Background:

The risk of infection with transfusion-transmitted viruses, such as Hepatitis B virus (HBV), has been reduced markedly. However, a zero-risk blood supply remains a popular goal. Anti-hepatitis B core antigen (anti-HBc) is considered to be an effective marker for occult HBV infection, and it has served a significant role in improving blood safety. The purpose of this study was to determine the seroprevalence of anti-HBc antibodies among blood donors.

Methods:

During a period of six months in 2012, 1000 blood donors in Bandar Abbas were investigated for the presence of HBV infection markers. We used ELISA for the detection of HBsAg and chemiluminescence for the detection of HBsAb and anti-HBc antibodies.

Results:

The prevalence of positive anti-HBc among the 1000 donors was 8.3%. Almost 2.3% of the donors were reactive for anti-HBc and negative for HBsAg.

Conclusions:

The study showed that more than 2% of healthy blood donors in Bandar Abbas already have been exposed to HBV, although their HBsAg tests were negative. We suggest screening for anti-HBc to improve the safety of the blood supply.

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.

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

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.

Hepatitis B core antibody testing in Indian blood donors: A double-edged sword!

BACKGROUND

Until lately, anti-HBc antibodies were considered an effective marker for occult Hepatitis B virus (HBV) infection and have served their role in improving blood safety. But, with the development of advanced tests for HBV DNA detection, the role of anti-HBc in this regard stands uncertain.

MATERIALS AND METHODS

Anti-HBc and HBsAg ELISA and ID-NAT tests were run in parallel on donor blood samples between April 1, 2006 and December 31, 2010 at the Department of Transfusion Medicine, Indraprastha Apollo Hospitals, New Delhi. A positive ID-NAT was followed by Discriminatory NAT assay.

RESULTS

A total of 94 247 samples were tested with a total core positivity rate of 10.22%. We identified nearly 9.17% of donors who were reactive for anti-HBc and negative for HBsAg and HBV DNA. These are the donors who are potentially non-infectious and may be returned to the donor pool.

CONCLUSION

Although anti HBc testing has a definite role in improving blood safety, centers that have incorporated NAT testing may not derive any additional benefit by performing anti-HBc testing, especially in resource-limited countries like ours.

Hepatitis B core IgM antibody (anti-HBcIgM) among hepatitis B surface antigen (HBsAg) negative blood donors in Nigeria

BACKGROUND

Transfusion associated Hepatitis B virus (TAHBV) continues to be a major problem despite mandatory screening for Hepatitis B surface Antigen (HBsAg). Presence of HBsAg is the common method for detecting hepatitis B infection. Unfortunately, this marker is not detected during the window period of the infection. Nigeria being a developing country cannot afford DNA testing of all collected units of blood which serve as the only possibility of achieving zero risk of transfusion associated HBV. Five different serological makers of hepatitis B virus (HBV) infection were therefore assessed to evaluate the reliability of using HBsAg marker alone in diagnosis of HBV infection among blood donors and to detect the serological evidence of the infection at the window period. This will preclude the possibility of transmitting hepatitis B through transfusion of Hepatitis B surface antigen (HBsAg) negative blood in Nigeria.

METHODS

Between July and August 2009, 92 blood donors were enrolled for the study. The prevalence of 5 different markers of Hepatitis B virus infection was detected using Enzyme Linked Immunosorbent Assay (ELISA). Demographic factors were assessed during the study.

RESULTS

HBsAg and its antibody (anti-HBs) was detected in 18 (19.6%) and 14(15.2%) of the 92 blood donors respectively. Anti-HBc IgM was found in 12(13.0%) of the 92 blood donors while Hepatitis B envelope antigen (HBeAg) and its antibody (anti-HBe) were detected in 4(8.9%) and 12(26.7%) respectively from 45 donors sampled. HBeAg is a marker of high infectivity and appears after HBsAg. At least one serological marker was detected in 30(32.6%) of the blood donors. Five (5.4%) of the 92 donors had anti-HBc IgM as the only serological evidence of hepatitis B virus infection.

CONCLUSIONS

The result of this study shows that five donors have anti-HBcIgM as the only serological evidence of HBV infection. Inclusion of anti-HBcIgM in routine screening of blood donors in Nigeria should be encouraged. This is the first study to assess anti-HBcIgM in the country.

Anti-hepatitis B core antigen testing with detection and characterization of occult hepatitis B virus by an in-house nucleic acid testing among blood donors in Behrampur, Ganjam, Orissa in southeastern India: implications for transfusion

Background

Occult hepatitis B virus (HBV) infection might transmit viremic units into the public blood supply if only hepatitis B surface antigen (HBsAg) testing is used for donor screening. Our aim was to evaluate the prevalence of occult HBV infection among the HBsAg negative/antiHBc positive donations from a highly HIV prevalent region of India.

Methods

A total of 729 HBsAg negative donor units were included in this study. Surface gene and precore region were amplified by in house nucleic acid test (NAT) for detection of occult HBV infection and surface gene was analyzed after direct sequencing.

Results

A total of 220 (30.1%) HBsAg negative donors were antiHBc positive, of them 66 (30%) were HBV DNA positive by NAT. HBV DNA positivity among 164 antiHBc only group, was 27.1% and among 40 antiHBs positive group was 30.0%. HBV/D (93.3%) was predominant and prevalence of both HBV/C and HBV/A was 3.3%. Single or multiple amino acids substitutions were found in 95% samples.

Conclusion

Thus, a considerable number of HBV infected donors remain undiagnosed, if only HBsAg is used for screening. Addition of antiHBc testing for donor screening, although will lead to rejection of a large number of donor units, will definitely eliminate HBV infected donations and help in reducing HBV transmission with its potential consequences, especially among the immunocompromised population. The HBV genetic diversity found in this donor population are in accordance with other parts of India.

Clinical significance of antibody to hepatitis B core antigen in multitransfused hemodialysis patients

BACKGROUND

In spite of the progress made in the prevention of transfusion transmitted infections over the last few years, transmission of HBV infection through transfusion of HBsAg negative blood has been documented.

OBJECTIVES

To assess the frequency and clinical significance of anti-HBc in multitransfused hemodialysis patients.

MATERIALS AND METHODS

One hundred and forty-three hemodialysis patients who had been receiving blood regularly with an average of 39.4 +/- 7.579 months on hemodialysis were enrolled in this study. HBV markers (HBsAg, anti-HBc, anti-HBs) were measured in these patients and in 100 healthy controls by the ELISA technique. The following data were obtained for all patients: socio demographic data, number of blood transfusions and some laboratory investigations.

RESULTS

In our patients, anti-HBc was positive in 9%, anti HBs in 7%, coexistant HbsAg/anti-HBc in 2.8% and anti HBc/anti HBs in 18.9%, meanwhile no patients were positive for HBsAg alone. In patients with only positive anti-HBc, the levels of anti-HBc were significantly related to abnormal results of liver function. In patients with positive anti-HBs/anti-HBc (n = 27), 18 patients had abnormal liver function, and 9 patients had normal liver function with no significant difference between them.

CONCLUSIONS

This study suggests that hepatitis B prevalence in our multitransfused hemodialysis patients is far in excess of that anticipated on the basis of HBsAg prevalence. Absence of HBsAg in the blood of hemodialyzed patients may not be sufficient to ensure lack of circulating HBV, and isolated positivity of anti-HBc may be a possible indicator of active hepatitis B infection.

Anti-HBc screening in Indian blood donors: Still an unresolved issue

AIM: To study the seroprevalence of antibody to hepatitis B core antigen (anti-HBc) in healthy blood donors negative for HBsAg and to evaluate whether anti-HBc detection could be adopted in India as a screening assay for HBV in addition to HBsAg.

METHODS: A total of 1700 serum samples collected from HBsAg-negative healthy blood donors were tested for the presence of anti-HBc antibody (IgM + IgG). All samples reactive for anti-HBc antibody were then investigated for presence of anti-HBs and for liver function tests (LFTs). One hundred serum samples reactive for anti-HBc were tested for HBV DNA by PCR method.

RESULTS: Out of 1700 samples tested, 142 (8.4%) blood samples were found to be reactive for anti-HBc. It was significantly lower in voluntary (6.9%) as compared to replacement donors (10.4%, P = 0.011). Seventy-two (50.7%) anti-HBc reactive samples were also reactive for anti-HBs with levels > 10 mIU/mL and 70 (49.3%) samples were non-reactive for anti-HBs, these units were labeled as anti-HBc-only. These 142 anti-HBc reactive units were also tested for liver function test. HBV DNA was detected in only 1 of 100 samples tested.

CONCLUSION: Keeping in view that 8%-18% of donor population in India is anti-HBc reactive, inclusion of anti-HBc testing will lead to high discard rate. Anti-HBs as proposed previously does not seem to predict clearance of the virus. Cost effectiveness of introducing universal anti-HBc screening and discarding large number of blood units versus considering ID NAT (Individual donor nuclic acid testing) needs to be assessed.

Isolated core antibody hepatitis B in sub-Saharan African immigrants

Chronic hepatitis B virus (HBV) infection is a major health problem in sub-Saharan Africa, where prevalence is > or =8%, and is increasingly seen in African immigrants to developed countries. A retrospective audit of the medical records of 383 immigrants from sub-Saharan Africa attending the infectious diseases clinics at the Royal Melbourne Hospital was performed from 2003 to 2006. The HBV, human immunodeficiency virus (HIV) and hepatitis C virus (HCV) serological results are reported, with a focus on the isolated core antibody HBV pattern (detection of anti-HBc without detection of HBsAg or anti-HBs). Two-thirds (118/174, 68%) of those tested had evidence of HBV infection with detectable anti-HBc. Chronic HBV infection (serum HBsAg detected) was identified in 38/174 (22%) and resolved HBV infection (both serum anti-HBs and anti-HBc detected) in 45/174 (26%). The isolated core antibody pattern was identified in 35/174 (20%), of whom only 1/35 (3%) had detectable serum HBV DNA on PCR testing, indicating occult chronic HBV (OCHB). Only 8/56 (14%) patients with negative anti-HBc had serological evidence of vaccination (serum anti-HBs detected). HIV infection was detected in 26/223 (12%). HCV antibodies were detected in 10/241 (4%), of whom 8 (80%) had detectable HCV RNA. Viral co-infection was detected in only 2/131 (1.5%) patients tested for all three viruses. The isolated core antibody HBV pattern was common among sub-Saharan African patients in our study. These patients require assessment for OCHB infection and monitoring for complications of HBV.

The prevalence of occult hepatitis B virus infection in type 2 diabetes mellitus patients

AIM

The prevalence of occult hepatitis B virus (HBV) infection is relatively frequent among patients with immune suppression. The impairment of the immune system is well demonstrated in diabetics. We aimed to investigate the prevalence of occult HBV infection among hepatitis B core antibody (HbcAb)+/- hepatitis B surface antibody (anti-HBs) positive type 2 diabetes mellitus patients.

MATERIALS AND METHODS

The study involved 100 HBcAb+/-anti-HBs type 2 diabetes mellitus patients and 100 age and sex matched, HBcAb+/-anti-HBs healthy blood donors. Exclusion criteria were positive serology for HBsAg, hepatitis C virus or HIV, diagnosis of malignancy or earlier organ transplantation history, use of immunosuppressive therapy. All patients were questioned about their past medical history and were tested for serum alanine aminotransferase and HBV DNA level.

RESULTS

The diabetic patients did not differ significantly from healthy controls in terms of sex and age. HBV DNA was detected in 11% of the diabetic patients (1 x 10-5 x 10 copies/ml) and in 3% of the controls (4 x 10-1 x 10 copies/ml). The difference between groups was statistically significant (P<0.05). The history of blood transfusion, surgery, and vaccination for HBV and alcohol use were similar in both groups (P>0.05). The serum alanine aminotransferase levels in diabetic patients were close to those of controls (26.2+/-16.4 IU/l vs. 23.9+/-9.7 IU/l; P>0.05).

CONCLUSION

These data suggest that the prevalence of occult HBV infection is higher in diabetics compared with healthy controls and this may contribute to the increased prevalence of primary hepatocellular carcinoma in diabetics.

Determination of hepatitis B virus DNA incidence, viral load, and mutations in blood donors with HBsAg and anti-HBs-negative serology and antibodies to hepatitis B core antigen

BACKGROUND

The aim of the present study was to determine hepatitis B virus DNA incidence, viral load, and mutations in blood donors with HBsAG and anti-HBs negative serology and antibodies to hepatitis B core antigen.

METHODS

Blood samples were collected from 1000 blood donors with HBsAg-negative test results. Anti-HBc total screening was performed using the ELISA method. HBsAg-negative/anti-HBc total-positive samples were tested for anti-HBs, anti-HBc IgM, HBeAg, and anti-HBe. Samples with isolated anti-HBc were determined for viral load of HBV DNA using real-time PCR.

RESULTS

Anti-HBc total was established as positive in 200 (20%) of the 1000 blood donors. While anti-HBs was negative in 59 (29.5%) of the 200 anti-HBc-positive samples, it was found to be positive in 141 (70.5%) of them. All of the other hepatitis B markers were negative in all of the anti-HBs-negative samples. HBV DNA was not detected in the sera of the isolated anti-HBc-positive blood donors with real-time PCR.

CONCLUSION

Although we could not detect HBV DNA in the sera of the isolated anti-HBc-positive blood donors, findings in the literature suggest that anti-HBc testing should be used in combination with HBsAg for the screening of blood donors to reduce risk. After that, the most appropriate algorithm to follow can be HBV DNA screening of donors.

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.

Detection of a premature stop codon in the surface gene of hepatitis B virus from an HBsAg and antiHBc negative blood donor

BACKGROUND

In blood donors, HBV infection is detected by the presence of serum hepatitis B surface antigen (HBsAg). However, some mutations in the surface gene region may result in altered or truncated HBsAg that can escape from immunoassay-based diagnosis. Such diagnostic escape mutants pose a potential risk for blood transfusion services.

RESULTS

In the present study, we report a blood donor seronegative for HBsAg and antiHBc, but positive for antiHBs who was HBV DNA positive by PCR. Sequencing of the HBsAg gene revealed presence of a point mutation (T-A) at 207th nucleotide of the HBsAg ORF, which resulted in a premature stop codon at position 69. This results in a truncated HBsAg gene lacking the entire 'a' determinant region. However, follow-up of the donor after 2 years revealed clearance of HBV DNA from the serum.

CONCLUSION

The case illustrates an unusual mutation, which causes HBsAg negativity. The finding emphasizes the importance of molecular assays in reducing the possibility of HBV transmission through blood transfusion. However, developing more sensitive serological assays, capable of detecting HBV mutants, is an alternative to expensive and complex amplification-based assays for developing countries.

Significant increase in HBV, HCV, HIV and syphilis infections among blood donors in West Bengal, Eastern India 2004-2005: Exploratory screening reveals high frequency of occult HBV infection

AIM: To evaluate the prevalence of markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) and human immunodeficiency virus (HIV) among blood donors in Kolkata, Eastern India for two consecutive years and to conduct a pilot study to explore the presence of HBV DNA among hepatitis B surface antigen (HBsAg) negative but anti-HBc positive blood donors.

METHODS: Seroprevalence of HBsAg, anti-HCV and anti-HIV was studied among 113 051 and 106 695 voluntary blood donors screened in 2004 and 2005, respectively. Moreover, a pilot study on 1027 HBsAg negative donors was carried out for evaluating the presence of HBV DNA by PCR on HBsAg negative/anti-HBc positive donors.

RESULTS: A statistically significant increase in the prevalence of HBV (1448 vs 1768, P < 0.001), HIV (262 vs 374, P < 0.001), HCV (314 vs 372, P = 0.003) and syphilis (772 vs 853, P = 0.001) infections was noted among blood donors of Kolkata West Bengal in 2005 as compared to 2004. Moreover, the exploratory study on 1027 HBsAg negative donors revealed that 188 (18.3%) of them were anti-HBc positive out of which 21% were positive for HBV DNA.

CONCLUSION: The findings of this study underscore the significantly increasing endemicity of hepatitis viruses, syphilis and HIV among the voluntary blood donors of our community. The pilot study indicates a high rate of prevalence of HBV DNA among HBsAg negative/anti-HBc positive donors and thus emphasizes the need for a more sensitive and stringent screening algorithm for blood donations.

Anti-hepatits B core antigen testing, viral markers, and occult hepatitis B virus infection in Pakistani blood donors: implications for transfusion practice

BACKGROUND

The purpose of this study was to determine the seroprevalence of anti-hepatitis B core antigen (HBc) and the impact of its testing along with other markers of hepatitis B, hepatitis B virus (HBV) DNA, hepatitis C virus antibody (anti-HCV), and syphilis in Pakistani blood donors.

STUDY DESIGN AND METHODS

The study design was cross-sectional. A total of 966 donors were selected randomly for testing of anti-HBc and HBV markers, including HBV DNA, of 94,177 blood donors who were routinely screened for hepatitis B surface antigen (HBsAg), anti-HCV, human immunodeficiency virus antibody (anti-HIV), Treponema pallidum hemagglutination assay (TPHA), and malarial parasites from 2003 to October 2005.

RESULTS

The seroprevalence of various infectious markers was as follows: HBsAg, 2.16 percent; anti-HCV, 4.16 percent; anti-HIV, 0.004 percent; TPHA, 0.75 percent; and malaria, 0.002 percent. Anti-HBc prevalence in HBsAg-negative, HBV DNA-negative blood donors was 167 of 966 (17.28%), with 76 percent demonstrating anti-HBs positivity. Younger donors with mean age of 25 years were exposed to HBV to a lesser extent compared to those with a mean age of 29 years. Anti-HBc positivity was significantly higher in anti-HCV-reactive individuals. HBV DNA was detectable in 5 blood donors who were HBsAg-, anti-HBc-positive and were categorized as having occult HBV infection.

CONCLUSIONS

The study shows that more than 17 percent of healthy, young blood donors in Pakistan are already exposed to HBV, with two-thirds showing anti-HBs levels of greater than 100 mIU per mL. One in 200 blood donors who are HBsAg-, anti-HBc-positive, however, have occult HBV infection, with likelihood of transmission of hepatitis B in recipients of blood components derived from them. HBsAg-negative individuals who are anti-HBc-negative and those who are anti-HBc-positive, anti-HBs-positive, and HBV DNA-negative should be selected as regular blood donors to minimize transmission due to occult hepatitis B infection.

Preliminary results of HBV DNA testing of Polish haemophilia patients--lack of occult HBV infection

Identification of hepatitis B virus (HBV) infection in the absence of surface antigen (HbsAg) became possible with the introduction of HBV DNA detection methods. Such occult HBV infection was diagnosed recently in about half of the Japanese HBsAg-negative haemophilia patients. The aim of our study was to assess the prevalence of occult HBV infection in Polish severe haemophilia population on the sample of 115 haemophilia A and B patients (mean age 34.9 +/- 10.9) treated with non-virus inactivated clotting factor preparations before 1995. HBV DNA was detected in nine HBsAg-positive patients (7.8%). The mean HBV DNA load was 72,800 IU mL(-1) (250-400,000 IU mL(-1)). Hepatitis C virus (HCV) RNA was found in six out of nine HBV-positive patients. In conclusion, HBV DNA was identified only in HBsAg-positive patients. Unlike in Japan, the frequency of occult HBV infection in Polish haemophilia population seems extremely rare or absent.

Epidemiology of HBV infection in Asian blood donors: Emphasis on occult HBV infection and the role of NAT

Hepatitis B virus (HBV) infection is endemic in many Asian countries. Among many transmission routes, transfusion is the one that should be prevented. The first major success in enhancing transfusion safety came with the implementation of hepatitis B surface antigen (HBsAg) in the early 1970s. However, the studies quoted in this review demonstrate that transmission by blood components negative for HBsAg can still occur in the acute phase of infection during the seronegative window period, or during chronic stages of infection (i.c. "occult" HBV infection, OHB). OHB is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg, with or without any HBV antibodies. Because of limitations in current blood screening practices, OHB is an overlooked source of HBV transmission. For policy development on screening for HBV infection in blood donors, it would be useful to assess the relative contribution of the above two sources of transfusion-transmitted HBV infection from HBsAg-negative donations. New screening policy should be evaluated on the basis of available data or newly designed studies. While anti-HBc screening can climinate residual risk of occult HBV transmission by transfusion in low-endemic areas, it would not be practical in most parts of the world where the prevalence of anti-HBc is >10% as too many otherwise healthy donors will be ineligible. On the contrary, studies mentioned in this paper indicate that nucleic acid amplification test (NAT) or new HBsAg tests of enhanced sensitivity would be effective in the screening of blood donors for OHB in highly endemic countries. However, the cost-effectiveness of blood screening tests is a major concern in Asia. We therefore have systemically reviewed the literature on prevalence and infectivity of OHB in Asian countries and the possible role of NAT for identifying blood donors in the pre-HBsAg window phase or in later stages of OHB.

Prevalence of viral markers among first-time Arab blood donors in Kuwait

BACKGROUND

The aim of this study was to assess the effect of blood donation modes on the prevalence of viral markers among Arab first-time blood donors in Kuwait.

STUDY DESIGN AND METHODS

Donor ethnic background was classified as Kuwaiti nationals and non-Kuwaiti Arabs. A total of 26,874 donors were screened in 2002 for the following viral markers: hepatitis C virus antibody (anti-HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), human immunodeficiency virus-1 and -2 antibody (anti-HIV-1 and -2), HIV p24, and human T lymphotropic virus-I and -II antibody (anti-HTLVI/II). All samples positive for the presence of anti-HBc were tested for anti-HBs. Among these donors, 12,798 were first-time donors of which 74 percent were replacement and 26 percent were volunteers.

RESULTS

The prevalence of HCV among replacement donors was significantly higher than the volunteer group. The difference between the two modes of blood donations, however, was not significant for HBsAg. The prevalence of anti-HCV among Kuwaiti national and non-Kuwaiti Arab first-time donors was 0.8 and 5.4 percent, respectively, whereas the prevalence of HBsAg was 1.1 and 3.5 percent, respectively, with the difference being significant at a p level of <0.0001. The difference observed for prevalence of anti-HBc among Kuwaiti national and non-Kuwaiti Arab donors (17 and 33.3%, respectively) was significant (p < 0.0001). Among first-time donors, 13.7 percent were positive for the presence of anti-HBs, indicating that 13.7 percent of the total Arab donor population might have had a previous infection and possible immunity to hepatitis B virus (HBV).

CONCLUSION

A high prevalence of HBV and HCV was found among non-Kuwaiti Arab donors. The prevalence of anti-HCV was only significantly higher among replacement versus volunteer first-time donors. Therefore, there is a need to develop a strategic plan that incorporates the diverse background of the blood donors living in Kuwait.

Hepatitis B virus DNA in blood donors with anti-HBc as a possible indicator of active hepatitis B virus infection in Yucatan, Mexico

Hepatitis B virus (HBV) may be present in serum even when negative for HBV surface antigen (HBsAg). If routine screening of sera for anti-HBV core antigen (anti-HBc) is not done, low-level HBV viraemia may not be identified. A study was done on the presence of HBV DNA in serum samples from Mexican blood donors negative for HBsAg. Sera from 158 volunteer blood donors, negative for HBsAg and anti-HBs, but positive for anti-HBc, were analysed using nested polymerase chain reaction (PCR). HBV DNA was detected in sera from 13 (8.23%) of the 158. Specificity of the PCR-amplified products was corroborated using Southern blot. Single strand conformation polymorphism (SSCP) analysis showed identical SSCP-banding patterns for all 13 PCR products, suggesting similar cDNA sequences. Occult HBV infection was observed in approximately 8% of anti-HBc only donors. The absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure lack of circulating HBV, and blood containing anti-HBc only may be infectious until proven otherwise.

Low rate of occult hepatitis B virus infection among anti-HBc positive blood donors living in a low prevalence region in Brazil

OBJECTIVE

The aim of this study was to determine the rate of occult hepatitis B virus (HBV) infection among blood donors living in a geographic region of low (5.6%) anti-HBc prevalence.

SUBJECTS AND METHODS

Sera from 150 candidate blood donors whose blood was rejected due to total anti-HBc reactivity (despite absence of HBsAg) were tested for anti-HBs and IgM anti-HBc antibodies, as well as for HBeAg/anti-HBe. Serum HBV DNA was sought by using a PCR assay able to amplify part of the surface gene. Viral load was measured in the PCR positive samples.

RESULTS

The pattern 'anti-HBc alone' (without HBsAg and anti-HBs antibodies) was found in 64 (42.7%) subjects. IgM anti-HBc and anti-HBe antibodies were detected in 2 (1.3%) and 80 (53.3%) samples, respectively. No sample was HBeAg-reactive. HBV DNA was repeatedly found in five (3.3%) samples, three of which were anti-HBs positive and two anti-HBs negative. All five HBV DNA positive samples showed a low viral load (<1000copies/ml).

CONCLUSIONS

The data indicated a low rate of occult infection among anti-HBc positive, HBsAg negative blood donors living in a region of low prevalence of infection. Viral load was very low in all HBV infected subjects.