Posttransfusion hepatitis B transmitted by blood from a hepatitis B surface antigen-negative hepatitis B virus carrier

A female blood donor at our institution was implicated in three cases of clinical posttransfusion hepatitis B. She had given blood 25 times in 8 years. Twenty-seven recipients were followed up, and about one-half of those who were still living had serologic markers of hepatitis B virus (HBV) infection. The donor was repeatedly negative for hepatitis B surface antigen (HBsAg) and antibody, but she had high titers of antibody to hepatitis B core antigen. We conclude that blood from this HBsAg-negative blood donor was capable of transmitting hepatitis B.     

Sensitivity of hepatitis B virus DNA transcription-mediated amplification testing in hepatitis B surface antigen-positive blood donations

BACKGROUND: The objective was to evaluate the performance of nucleic acid testing (NAT) in the detection of hepatitis B virus (HBV) infection in hepatitis B surface antigen (HBsAg)-positive blood donations. STUDY DESIGN AND METHODS: A total of 253 HBsAg- and anti-hepatitis B core antigen (HBc)-positive samples (50 hepatitis B e antigen [HBeAg]-positive and 203 anti-HBe-positive) from blood donations collected in France were studied. The samples were investigated with a blood screening assay (Procleix Ultrio, Chiron/Gen-Probe) in minipool (MP; x8) and in individual-donation (ID) testing. All nonreactive samples were retested once, and nonreactive MP samples were assayed for viral load (VL). RESULTS: All 50 HBeAg-positive samples were reactive in MP-NAT and ID-NAT. Of the 203 anti-HBe-positive donations, 80.3 percent were MP- and ID-reactive, 17.2 percent were MP-nonreactive and ID-reactive, and 2.5 percent were nonreactive in ID-NAT. Overall the sensitivity of ID-NAT was 98 percent versus 84 percent for MP-NAT. After retesting, 16 of the 35 MP-nonreactive and/or ID-reactive donations became MP-reactive and 2 of the ID-nonreactive donations became NAT-reactive. The capacity of Procleix Ultrio to detect HBV DNA was not related to HBsAg subtype, but correlated with the VL: the mean VL in the group of MP-nonreactive samples was 1,420 copies per mL vs. 17,000 copies per mL in the group of 40 MP-reactive samples. CONCLUSION: These results demonstrate that HBV-NAT in ID format is far more effective in detecting viremia in chronic HBsAg carriers than in MP-NAT. The sensitivity of the NAT assay needs to be improved to be considered for replacing the current HBsAg assays, especially when anti-HBc testing is not performed.     

Hepatitis B virus transfusion risk in China: proficiency testing for the detection of hepatitis B surface antigen

Because of the high prevalence of Hepatitis B virus (HBV), HBsAg tests play an extremely significant role in donor screening in China. In our multicentre study, the HBsAg assays used in blood screening were evaluated for their analytical sensitivity and the ability to detect mutants. A panel of eight samples was sent to 85 blood banks. The panel included four HBsAg‐positive serum samples at concentrations of 0·16, 0·46, 0·9 and 1·73 IU mL^?1; three recombinant HBsAg mutants (G145R, T131I and K141E) with defined concentrations and one negative sample. All laboratories were required to detect the samples with their routine procedures.All the 85 blood banks reported their results before the closing date, and 170 data sets were submitted. The wild‐type samples at concentrations of 1·73 and 0·9 IU mL^?1 were correctly identified as positive in all data sets, whereas the other two samples (at concentrations 0·16 and 0·46 IU mL^?1) were not consistently detected as positive. Regarding the mutants, significantly different results were reported among all the assays involved. All users of Hepanostika HBsAg Ultra and most users (16/17) of Abbott Murex HBsAg Version 3 detected all mutant samples, whereas some of the commercial assays failed to detect any of the three mutant samples. Some HBsAg assays with unsatisfactory sensitivities and capabilities of mutant detection were used by a large percentage of blood banks, which might lead to a high transfusion risk in China. A list of assays of high sensitivity and good ability of mutant detection should be recommended for use in blood screening.     

One-year experience of nucleic acid technology testing for human immunodeficiency virus Type 1, hepatitis C virus, and hepatitis B virus in Thai blood donations

BACKGROUND: Blood donations collected at the National Blood Center, the Thai Red Cross Society, Bangkok, in 2007 were tested by nucleic acid amplification technology (NAT) using the Chiron TIGRIS/Procleix Ultrio test and the Roche cobas s 201/cobas TaqScreen multiplex (MPX) test.
STUDY DESIGN AND METHODS: The sensitivity, specificity, and robustness were determined by testing 486,676 seronegative blood donations. Samples from each day of collection were divided into two sets; the odd-numbered samples were tested individually on the TIGRIS and the even-numbered samples were tested in pools of 6 on the cobas s 201. The status of reactive samples was confirmed by duplicate testing of samples from the plasma bag to calculate the test specificity. Reactive samples were tested on the alternate system and followed up.
RESULTS: The analytical sensitivity of both systems met the 95% limits of detection claimed by the respective package inserts. No cross contamination was seen with either system. Test specificity was 99.93 and 99.90% for the Procleix Ultrio and cobas TaqScreen tests, respectively. The NAT yield rates for human immunodeficiency virus Type 1 (HIV-1), hepatitis C virus (HCV), and hepatitis B virus (HBV) were 1:97,000, 1:490,000, and 1:2800, respectively. Several occult HBV donors, the majority of whom were detected by both tests, were also identified. The HIV-1 and HCV window cases were detected with both tests.
CONCLUSION: The performances of the systems and tests indicated that both were acceptable for routine NAT by the National Blood Center, the Thai Red Cross Society. However, the Procleix Ultrio test appeared to be less sensitive than the cobas TaqScreen test for HBV.     

Hepatitis B virus DNA and hepatitis B surface antigen levels in chronic hepatitis B

Despite universal vaccination, chronic hepatitis B (CHB) continues to be a major health burden worldwide, with an estimated 350–400 million people infected with the virus. Over the past decade, rapid progress has been made with regards to antiviral therapy for CHB, from conventional interferon to pegylated interferon, and with the earliest oral agent lamivudine to the current, more potent drugs such as entecavir and tenofovir. There have also been new developments in the diagnostic and monitoring tools for CHB. Qualitative hepatitis B surface antigen (HBsAg) testing has been used to diagnose patients infected with CHB. More recently, quantitative HBsAg titers have been used to predict treatment outcome when measured at baseline or early into treatment. The progress on the use of hepatitis B virus (HBV) DNA levels has been more rapid. Serum HBV DNA levels have been shown to be important in the natural history of CHB infection, with higher levels being significantly associated with the development of cirrhosis and hepatocellular carcinoma. For patients receiving antiviral therapy, the baseline and early on-treatment HBV DNA levels are important in determining treatment outcomes. Monitoring of HBV DNA levels during therapy will allow for early detection of drug resistance. The end-of-treatment and post-treatment HBV DNA levels have been demonstrated to be important indicators of treatment success and relapse, respectively. With newer and more powerful antiviral agents, and with the development of quantitative assays that are highly sensitive, further studies are needed to optimize the use of these tools and agents in the modern management of CHB.     

Hepatitis B virus and hepatitis B surface antigen in human albumin products

A collection of 1,985 lots of normal serum albumin (NSA) and 1,361 lots of plasma protein fraction (PPF) prepared between 1958 and 1974 were tested for the presence of hepatitis B surface antigen (HBsAg). Twenty-one percent of NSA lots and 71 per cent of PPF lots were HBsAg-positive by radioimmunoassay. There was considerable variation in frequency of HBsAg-positive lots among the 17 different manufacturers of NSA and the six manufacturers of PPF.In general, those lots prepared from volunteer donor plasma and placental material demonstrated lower rates of HBsAg-positivity than those prepared from commercial donor plasma. A striking decrease in the prevalence of HBsAg-positive lots of both NSA and PPF occurred during the period 1971 to 1973, coincident with the onset of routine screening of all plasma for HBsAg. Although NSA and PPF can be HBsAg-positive, they probably do not transmit type B hepatitis. Serologic tests for HBsAg and antibody to HBsAg revealed that albumin products prepared from infectious, icterogenic plasma were infectious prior to pasteurization, but that they no longer transmitted type B hepatitis after heat treatment at 60 C for ten hours.     

献血者血液乙型肝炎病毒表面抗原确认试验

目的 对使用国产HBsAg酶联免疫吸附试验(ELISA)一步法试剂盒检测无偿献血者血液(包括机采血小板献血体检者)的可靠性进行评价.方法 对无偿献血者血液样品,使用国产的HBsAg酶联免疫吸附试验(ELISA)试剂盒进行测定.结果 呈阳性反应者、3种试剂检测结果不一致的部分可疑结果者和3种试剂检测为阴性者,使用珠海丽珠试剂公司研发的乙型肝炎病毒表面抗原(HBsAg)确认试剂盒(中和试验法) 初步进行确认试验.确认试验方法参照丽珠公司提供的说明书进行.结果 132例样品中阳性反应或可疑阳性反应者123例被确认为阳性者106例,其中有17例可疑结果者常规确认试验结果为"阴性".经3种试剂再测,结果仍为可疑.9例0.074≤样品A值＜Cut off的样品和随机抽取的9例阴性样品常规确认试验结果仍为阴性.8例单一试剂呈阳性反应者常规确认为假阳性.结论 国产HBsAg ELISA试剂测定结果为阳性、弱阳性和可疑的样品应使用适当方法进行确认,排除假阳性,以保证结果准确.目前国产HBsAg酶联免疫吸附试验(ELISA)一步法试剂盒有较高的灵敏度,特异性尚待提高.     

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.     

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.     

Hepatitis B reactivation in patients with hepatitis B core antibody positive and surface antigen negative on immunosuppressants

Hepatitis B viral (HBV) reactivation in the immunosuppressed is a significant problem even in patients who have achieved serological clearance due to the persistence of HBV as cccDNA. HBV reactivation will continue to pose a significant healthcare burden given the high prevalence of HBV and increasing use of immunosuppressants. Screening of hepatitis B surface antigen, antibody to Hepatitis B core antigen antibody and HBV DNA levels should be done routinely in all patients planned for significant immunosuppressant use. We aimed to examine the factors affecting reactivation risk. This depended on HBV disease status, the underlying disease requiring immunosuppression, and the specific immunosuppressive regime. While antiviral prophylaxis can prevent reactivation, it increases cost and still has risk of delayed reactivation after stopping antivirals and close follow-up and on-demand treatment is a good alternative for patients at risk of reactivation.     

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

BACKGROUND: This study was performed to determine the prevalence of antibodies to hepatitis B core antigen (anti‐HBc) among Korean blood donors and frequencies of hepatitis B virus (HBV) DNA and antibodies to hepatitis B surface antigen (anti‐HBs) in anti‐HBc–positive donors. STUDY DESIGN AND METHODS: A total of 12,461 consenting blood donors were consecutively enrolled from Korean Red Cross Blood Services from April to October 2008. All of the donors were screened for anti‐HBc with an electrochemiluminescence immunoassay. Repeat‐reactive anti‐HBc–positive donors were assayed for anti‐HBs and for HBV DNA using a multiplex test (Cobas TaqScreen, Roche Molecular Systems) on individual donation. RESULTS: Of the 12,461 donors, 1682 (13.5%) were reactive for anti‐HBc. Among different age groups, there was a steady increase in the anti‐HBc–positive rate, ranging from 2.0% in the age group of less than 20 years to 80.0% in the age group of 60 years and older (p < 0.0001). Of the anti‐HBc–positive donors, 1523 (90.5%) were anti‐HBs positive. HBV DNA was detected in two donors who were anti‐HBc positive and hepatitis B surface antigen negative. The prevalence of occult HBV infection was 0.016%, and the HBV nucleic acid test (NAT) yield was 1 in 838 (0.12%). CONCLUSION: This study helps to determine the current status of hepatitis B infection and the prevalence of occult HBV infection in the blood donor population in Korea. We estimate that in Korea, up to 161 units per million donated units from blood donors may contain HBV DNA. Although the potential infectivity of these units has been debated upon, the HBV NAT assay could prevent certain transfusion‐transmitted HBV infections.     

A novel hepatitis B virus surface antigen immunoassay as sensitive as hepatitis B virus nucleic acid testing in detecting early infection

BACKGROUND: The aim was to considerably enhance the sensitivity of hepatitis B virus (HBV) surface antigen (HBsAg) detection and investigate whether the window period for HBV detection could be reduced.
STUDY DESIGN AND METHODS: A high-sensitivity chemiluminescent enzyme immunoassay (CLEIA) was developed for quantitative HBsAg detection by a combination of monoclonal antibodies, each one for a specific epitope of HBsAg, and by improving the conjugation technique. The sensitivity of the assay was compared with that of the existing chemiluminescent immunoassay (CLIA). Commercially available seroconversion panels and samples of HBV-infected chimpanzees were tested with the developed prototype to assess whether the window period for HBsAg detection could be reduced to that for DNA detection.
RESULTS: Compared to the existing CLIA, the CLEIA prototype detected HBsAg with approximately 230-fold higher sensitivity and showed a reduced window period. HBsAg detection by the CLEIA prototype and HBV DNA detection by polymerase chain reaction (PCR) occurred simultaneously. The mean time for the CLEIA prototype to first detect HBsAg was approximately 17.4 days less than that for the existing systems. Further, CLEIA prototype enabled HBsAg detection even in anti-HBs–positive seroconversion samples. In the inoculated chimpanzees the HBsAg and HBV DNA became detectable simultaneously and concentrations increased in parallel, whereas HBsAg remained detectable longer than HBV DNA in the declining phase of viremia.
CONCLUSION: The CLEIA prototype yielded results comparable with those of HBV DNA PCR. This novel high-sensitivity assay may be useful for early detection of HBV infection and monitoring patients with a history of infection.     

PRISM hepatitis B surface antigen detection of hepatits B virus minipool nucleic acid testing yield samples

BACKGROUND: Hepatitis B virus (HBV) residual risk has been estimated at 1:63,000-1:205,000 and introduction of more sensitive serological tests and nucleic acid testing (NAT) would reduce that risk. Sensitivity of the recently licensed Abbott PRISM hepatitis B surface antigen (HBsAg) CLIA and minipool (MP) HBV NAT has been described as comparable and thus the need for HBV NAT has not been compelling. In this study, eight samples identified as yield samples with MP HBV NAT were tested using the PRISM test. STUDY DESIGN AND METHODS: Seven samples were identified using the Roche COBAS AmpliScreen HBV test and one additional sample was obtained from the clinical trial for the Roche cobas TaqScreen MPX test. Each of these samples was reactive by MP HBV NAT and nonreactive for HBsAg using one of three licensed enzyme immunoassay (EIA) tests. After licensure of the PRISM HBsAg, aliquots were tested with this assay, and DNA quantitation and genotyping were repeated where sample volume permitted. RESULTS: Three samples (2000, 2300, and 61,000 copies/mL) produced reactive results with PRISM. Four samples with viral loads less than 300 copies per mL produced nonreactive results. One sample, originally quantitated at 37,000 copies per mL (but 3850 copies/mL in repeat testing) was also nonreactive by PRISM. Genotyping of this sample indicated a type C genotype with no mutations. CONCLUSION: Adding serological sensitivity of PRISM CLIA reduced the NAT yield from the original 1: 385,555 to 1:610,488. However, MP HBV NAT still provides additional sensitivity over CLIA, even for a donation with a viral load of almost 4000 copies per mL.