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Prepublished online as a Blood First Edition Paper on May 31, 2002; DOI 10.1182/blood-2002-03-0798.
TRANSFUSION MEDICINE
From the Institute of Immunology and Transfusion
Medicine, University of Lübeck, Germany.
The objective of this study was to determine the frequency and load
of hepatitis B virus (HBV) DNA in anti-HBc-positive first-time blood
donors; it was designed to contribute to determining whether anti-HBc
screening of blood donations might reduce the residual risk of
posttransfusion HBV infection. A total of 14 251 first-time blood donors were tested for anti-HBc using a microparticle enzyme immunoassay; positive results were confirmed by a second
enzyme-linked immunosorbent assay (ELISA). For the detection of HBV DNA
from plasma samples, we developed a novel and highly sensitive
real-time polymerase chain reaction (PCR) assay. The 95% detection
limit of the method amounted to 27.8 IU/mL, consistent with the World Health Organization (WHO) international standard for HBV DNA. A total
of 216 blood donors (1.52%) tested anti-HBc-positive in both tests,
and 205 of them (16 HBsAg+, 189 HBsAg The risk of transfusion-transmitted hepatitis B
virus (HBV) infection has been reduced by screening all blood donations
for HBV surface antigen (HBsAg) since 1970. It was generally accepted that the disappearance of HBsAg indicates the clearance of HBV. Meanwhile, many reports on positive findings for HBV DNA in the liver
and blood of HBsAg-negative individuals positive for antibodies against
HBV core antigen (anti-HBc) and/or HBsAg (anti-HBs) have been
published.1-8 Blum et al described, in a patient with
HBsAg-negative chronic hepatitis who was positive for anti-HBc,
anti-HBs, and antibodies against HBe antigen (anti-HBe), a latent HBV
infection in hepatocytes with extrachromosomal presence of a
full-length viral genome.9 Michalak et al demonstrated the
long-term persistence of HBV DNA in serum and peripheral blood
mononuclear cells of patients up to 70 months after complete clinical,
biochemical, and serologic recovery from acute viral
hepatitis.10 Rehermann et al showed that traces of HBV
were often detectable in the blood for many years after clinical
recovery from acute hepatitis, despite the presence of serum antibodies
and HBV-specific cytotoxic T lymphocytes (CTLs).11 These
findings suggest that sterilizing immunity to HBV frequently fails to
occur and that traces of virus can maintain the CTL response for
decades, apparently creating a negative feedback loop that keeps the
virus under control, perhaps for life. This was supported by Pasquetto
et al, who showed that cytoplasmic HBV nucleocapsids and their cargo of
replicative DNA intermediates survive CTL-induced apoptosis of
hepatocytes in vitro,12 and by other groups that
demonstrated ongoing viral replication in the liver tissue of patients
and healthy individuals after loss of HBsAg.13-15
Furthermore, reactivation of apparently cured HBV infection has been
described under chemotherapy or immunomodulating therapy after renal
and bone marrow transplantation, and in some of these cases a reverse
seroconversion from anti-HBs to HBsAg has been
observed.16-19
The residual risk of posttransfusion HBV infection has been calculated
by several groups in the United States and Germany on the basis of HBV
incidence data and the duration of the early window period until HBsAg
becomes detectable to be 1:63 000 and less than 1:100 000 blood
donations, respectively.20,21 It has been shown that blood
donations of HBsAg- and anti-HBs-negative but anti-HBc-positive HBV
carriers can cause posttransfusion hepatitis B.22;23 Thus,
Mosley et al suggested that anti-HBc screening of blood donations might
prevent HBV transmission from HBsAg-negative blood donors and that
donors positive for anti-HBs as well should be considered noninfectious
for HBV.24 The feasibility of routine polymerase chain
reaction (PCR) screening of blood donations in a blood bank setting has
been shown by Roth et al.25 In Germany, the Paul Ehrlich
Institute (PEI, Langen, Germany), the institute that defines German
Drug Law and is responsible for specific regulations for the
processing of blood components, decided on the introduction of HCV
nucleic acid amplification technology (NAT) for the release of
erythrocyte and platelet concentrates starting from April 1, 1999. The
value of HBV NAT has been a matter of debate.26-29
However, it seems to be less useful because the nucleic acid load is
often markedly lower than it is in HCV infection, so that an adequate HBV NAT can only be performed on a single (not pooled) blood donation.
The aim of this 5-year prospective study was to reevaluate the
prevalence of anti-HBc among German first-time blood donors and to
determine the frequency and load of HBV DNA in anti-HBc-positive plasma samples using a sensitive real-time PCR assay. Thus, it was intended to contribute to determining whether routine anti-HBc screening of blood donations provides any concrete benefits with regard
to HBV risk reduction.
Blood specimens
Standard and control specimens
Hepatitis B serology Anti-HBc screening was performed using an automated microparticle enzyme immunoassay (AxSYM Core; Abbott, Wiesbaden, Germany). Reactive samples were retested in duplicate and considered to be repeatedly reactive if at least 1 of the 2 repetitions also gave a positive result. Repeatedly reactive samples were confirmed by a second enzyme-linked immunosorbent assay (ELISA) (Enzygnost Anti-HBc monoclonal; Dade Behring, Liederbach, Germany). Only samples that were positive for anti-HBc in both tests were included in this study. Those samples were also tested for HBsAg (Ortho Antibody to HBsAg ELISA Test System 3; Ortho-Clinical Diagnostics, Neckargemünd, Germany), HBeAg (AxSYM HBe; Abbott), anti-HBc immunoglobulin M (IgM) (AxSYM Core-M; Abbott), anti-HBe (AxSYM Anti-HBe; Abbott), and anti-HBs (AxSYM AUSAB; Abbott). HBsAg-positive samples were confirmed by a second test (AxSYM HBsAg (V2); Abbott) and an appropriate neutralization assay (AxSYM HBsAg Confirmatory Assay; Abbott).Nucleic acid isolation DNA was prepared from 1 mL or, if available, 2 mL EDTA-plasma using the NucliSens Extractor (Organon Teknika, Boxtel, The Netherlands).31,32 To increase the nucleic acid yield, we added a first incubation step of samples together with the lysis buffer, which is based on guanidine thiocyanate at 60°C with horizontal shaking at 110 rpm for 30 minutes. The further isolation procedure was performed according to the manufacturer's protocol for sample volumes between 200 and 2000 µL. Total nucleic acids from up to 2 mL plasma were eluted in 50 µL elution buffer of which 20 µL was investigated in one PCR experiment to detect HBV DNA and 3 µL was studied in a -actin control PCR.
TaqMan PCR For amplification and simultaneous detection of PCR products, we developed a novel approach based on the TaqMan Universal PCR Master Mix (manufactured by Roche Molecular Systems, Branchburg, NJ; distributed by Applied Biosystems, Weiterstadt, Germany) on the ABI Prism 7700 SDS (Applied Biosystems). Primers and fluorogenic TaqMan probe for HBV DNA detection were chosen after comparative analysis of 65 sequences containing the C region of the HBV genome, which were available from the GenBank Nucleotide Database using OMIGA software version 2.0 (Oxford Molecular, Oxford, United Kingdom). The sequences of the oligonucleotides are provided in Table 1. In addition, we performed a standard nucleotide-nucleotide BLAST Search via Internet at http://www.ncbi.nlm.nih.gov/Blast for the chosen oligonucleotides. For the forward primer, TaqMan probe, and reverse primer, we found 809, 779, and 818 hits, respectively, to HBV sequences that had been submitted to various databases. The sequence alignments ensured that the primers were homologous at the last 10 nucleotides at the 3' end to 797 (98.52%) and 811 (99.14%) of the sequences, respectively. The TaqMan probe showed 100% homology or only 1 mismatch to 774 (99.36%) of the HBV hits, in comparison with 5 HBV sequences where 2 mismatches were found, which would probably lead to a loss of sensitivity. A total of 128 non-HBV BLAST hits each to only 1 of the HBV oligonucleotides ensured that no other organism could be detected with this method. The HBV TaqMan probes were labeled with VIC as reporter and TAMRA as quencher dyes and custom synthesized (Applied Biosystems); the HBV primers were synthesized elsewhere (TIB Molbiol, Berlin, Germany).
A human genomic sequence that was found to be detectable in human
plasma was coamplified separately as a PCR control to prevent any
false-negative results due to failure of nucleic acid isolation or PCR
inhibition (TaqMan Threshold values were calculated as the upper 10-fold SD of the background fluorescence signal measured over the baseline from cycles 3 to 30. Highly positive samples (threshold cycle [CT] < 30) must be calculated separately by setting the baseline to the cycle before the exponential increase of the first PCR kinetics is to be observed. Results were interpreted as follows: CT less than 40 is positive; CT equal to 40 is negative. To determine the 95% detection limit of the TaqMan HBV PCR, we investigated semilogarithmic dilutions of the first WHO international standard for HBV DNA NAT assays described above. The standard plasma preparation containing 1 × 106 IU/mL HBV DNA, genotype A, HBsAg subtype adw was diluted with HBV DNA-negative fresh frozen plasma (FFP) to 102.5, 102, 101.5, 10, and 100.5 IU/mL. Twenty-four 1-mL plasma samples of each concentration were processed in 5 consecutive runs separately through all steps of nucleic acid isolation and PCR. The quantification of HBV DNA-positive samples was carried out by means of a standard curve derived from these validation experiments. Statistics All statistical analyses were performed using SPSS 9.0 for Windows. The Kolmogorow-Smirnov goodness-of-fit test was used to evaluate whether the results were normally distributed. Because spot checks had proven positive, significances of differences were analyzed using the Student t test. Correlation coefficients and corresponding significances were analyzed by the Pearson test. The 95% detection limit was calculated by means of probit analysis.
HBV serology A total of 216 (1.52%) of 14 251 first-time blood donors tested anti-HBc-positive in both tests, and 16 of them were identified as HBsAg carriers. Thus, 200 (1.40%) of our first-time blood donors were negative for HBsAg and positive for anti-HBc. Not a single sample tested positive for HBeAg or for anti-HBc IgM. An overview of the serologic test results is provided in Table 2. Most anti-HBc-positive samples also showed anti-HBe and anti-HBs. In contrast, anti-HBc alone was to be seen rarely (0.08% of all). A total of 57 (0.40%) of the 14 251 donors were repeatedly reactive in the first but negative in the second anti-HBc assay.
HBV DNA The 95% detection limit of the TaqMan HBV PCR from 1 mL plasma samples related to the WHO HBV DNA standard preparation was calculated by probit analysis and amounted to 27.79 IU/mL plasma (Tables 3 and 4). Figure 1 shows the distribution of the standard samples ranging from 102.5 to 100.5 IU/mL tested in 5 validation experiments for estimating the detection limit. Because the detection limit was calculated on 1 mL plasma samples, it would correspond theoretically to about 14 IU/mL for 2 mL plasma specimens. A total of 205 of the anti-HBc-positive first-time blood donors (16 HBsAg-positive, 189 HbsAg-negative) were tested for HBV DNA, and in 62 cases 2 mL samples were available. In 14 (87.50%) of the HBsAg-positive blood donors HBV-DNA was repeatedly detected, and in 3 (1.59%) of the HBsAg-negative blood donors HBV DNA was also repeatedly found (Table 5). In the 3 HBV DNA-positive, HBsAg-negative cases, anti-HBe as well as anti-HBs (> 100 IU/L) were also detectable.
Quantification of HBV DNA showed low levels below 1000 IU/mL for
HBsAg-positive and HBsAg-negative samples as well (Figure 2). Even 6 of the 14 HBsAg-positive and
HBV DNA-positive samples were quantified to be below 100 IU/mL. The
data of HBV DNA quantification in comparison with the anti-HBs levels
of the 3 HBsAg-negative samples did not show the reverse correlation
(r = 0.03, P = .998), which might
have been expected. In Figure 3, an
example of an amplification plot of 1 of the 3 HBsAg-negative samples
is given to illustrate the unambiguous positive result.
The prevalence of anti-HBc in our first-time blood donor population was markedly lower than that recently described (8.71%) for an adult German population.33 This finding may have been due to the blood donor selection prior to testing, to our criteria that called for reactivity in 2 different anti-HBc assays, and to regional differences in the prevalence of HBV infection between Northern and Southern Germany. However, this also means that routine anti-HBc screening of blood donations would lead to a lower loss of blood donors or, rather, blood donations, than expected. High frequencies of HBV DNA findings have been described at 10% to 15% in "anti-HBc alone"-positive sera.34 This serologic constellation has also been reported to be associated with posttransfusion HBV infection.22-24,35 Thus, 2 recent studies from Greece and Japan tested HBsAg-negative, anti-HBc-positive blood donors with "low-titered" anti-HBs for HBV DNA but not all anti-HBc-positive donors.36,37 In our study, only 12 (5.56%) of all anti-HBc-positive samples tested "anti-HBC alone"-positive after supplementary testing using a second ELISA, and none of these samples were positive for HBV DNA. On the contrary, our 3 HBsAg-negative but viremic blood donors were positive for anti-HBe and anti-HBs as well. However, this serologic constellation was the most frequent in 144 (66.67%) of the anti-HBc-positive blood donors. Thus, our results are concordant with other findings of HBV DNA after complete serologic recovery from acute HBV infection.1,2,4-8,10,11 The results of HBV DNA quantification showed very low levels of viremia in the 3 HBsAg-negative blood donors as well as in the HBsAg-positive donors. We could not find any reverse correlation between the levels of HBV DNA and anti-HBs on the 3 HBsAg-negative, HBV DNA-positive samples. This fact might have been expected if we allege that HBV DNA load corresponds to intact virus particles, which would form immune complexes together with anti-HBs. The sensitivity of our TaqMan HBV PCR after the enrichment of total nucleic acids from 1 or 2 mL plasma by means of the NucliSens Extractor was acceptable. It seems likely that we would have found even more HBV DNA-positive blood donors after investigating the nucleic acids of larger quantities of plasma. The transmission of HBV via liver allografts from donors after complete serologic recovery from HBV infection has been widely documented.38-44 Only the question regarding the infectivity and the infectious dose of such blood donations remains. The inoculation of small amounts of serum and lymphocytes from 3 patients who were HBsAg-negative, anti-HBs-positive, anti-HBc-positive, and HBV DNA-positive into 3 chimpanzees did not lead to infections in any of the animals.45 However, the authors of this study admitted that the amounts of serum or lymphocytes may have been lower than the infectious dose required for such inoculations. To determine the rate of HBV transmissions via anti-HBc-positive and HBsAg-negative blood donations, retrospective studies on regular blood donors and their respective recipients are necessary. Routine anti-HBc screening of blood donations could probably prevent some transfusion-transmitted HBV infections. In an alternative scenario, routine HBV DNA screening of blood donations would not be suitable during this phase of serologically recovered HBV infection, because the low levels of HBV DNA would require tests from large volumes of plasma from the single blood donation. However, in the early window period until HBsAg becomes detectable, NAT using minipools of up to 25 blood donations has been suggested to be effective.46 It would also be of interest to see whether the detection of HBV RNA transcripts, which has been demonstrated from peripheral blood mononuclear cells as well as from plasma specimens, might be of diagnostic value for screening blood donations.47,48
The authors thank Diana Sander, Andrea Reimer, Petra Glessing, Kirsten Jacobsen, Tanja Quandt, Jessica Brodzinski, and Ulla Thiessen for their excellent technical assistance. Thanks are also due to Una Doherty and Dr J. Keogh for assisting us in editing the English form of this manuscript.
Submitted March 14, 2002; accepted May 4, 2002.
Prepublished online as Blood First Edition Paper, May 31, 2002; DOI 10.1182/blood-2002-03-0798.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Holger Hennig, Institute of Immunology and Transfusion Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; e-mail: hennig{at}immu.mu-luebeck.de.
1. Brechot C, Degos F, Lugassy C, et al. Hepatitis B virus DNA in patients with chronic liver disease and negative tests for hepatitis B surface antigen. N Engl J Med. 1985;312:270-276[Abstract]. 2. Marcellin P, Martinot-Peignoux M, Loriot MA, et al. Persistence of hepatitis B virus DNA demonstrated by polymerase chain reaction in serum and liver after loss of HBsAg induced by antiviral therapy. Ann Intern Med. 1990;112:227-228[Medline] [Order article via Infotrieve]. 3. Kaneko S, Miller RH, Di Bisceglie AM, Feinstone SM, Hoofnagle JH, Purcell RH. Detection of hepatitis B virus DNA in serum by polymerase chain reaction. Application for clinical diagnosis. Gastroenterology. 1990;99:799-804[Medline] [Order article via Infotrieve]. 4. Loriot MA, Marcellin P, Bismuth E, et al. Demonstration of hepatitis B virus DNA by polymerase chain reaction in the serum and the liver after spontaneous or therapeutically induced HBeAg to anti-HBe or HBsAg to anti-HBs seroconversion in patients with chronic hepatitis B. Hepatology. 1992;15:32-36. 5. Paterlini P, Driss F, Nalpas B, et al. Persistence of hepatitis B and hepatitis C viral genomes in primary liver cancers from HBsAg-negative patients: a study of a low-endemic area. Hepatology. 1993;17:20-29. 6. Gomes SA, Yoshida CF, Niel C. Detection of hepatitis B virus DNA in hepatitis B surface antigen-negative serum by polymerase chain reaction: evaluation of different primer pairs and conditions. Acta Virol. 1996;40:133-138[Medline] [Order article via Infotrieve]. 7. Hennig H, Dennin RH, Haase D, Kirchner H. [HBV-DNA positive findings in HBsAg negative blood donors and patients]. Beitr Infusionsther Transfusionsmed. 1997;34:26-30[Medline] [Order article via Infotrieve]. 8. Yotsuyanagi H, Yasuda K, Iino S, et al. Persistent viremia after recovery from self-limited acute hepatitis B. Hepatology. 1998;27:1377-1382[CrossRef][Medline] [Order article via Infotrieve]. 9. Blum HE, Offensperger WB, Walter E, Offensperger S, Gerok W. Latent hepatitis B virus infection with full-length viral genome in a patient serologically immune to hepatitis B virus infection. Liver. 1988;8:307-316[Medline] [Order article via Infotrieve]. 10. Michalak TI, Pasquinelli C, Guilhot S, Chisari FV. Hepatitis B virus persistence after recovery from acute viral hepatitis. J Clin Invest. 1994;94:907[Medline] [Order article via Infotrieve]. 11. Rehermann B, Ferrari C, Pasquinelli C, Chisari FV. The hepatitis B virus persists for decades after patients' recovery from acute viral hepatitis despite active maintenance of a cytotoxic T-lymphocyte response. Nat Med. 1996;2:1104-1108[CrossRef][Medline] [Order article via Infotrieve].
12.
Pasquetto V, Wieland S, Chisari FV.
Intracellular hepatitis B virus nucleocapsids survive cytotoxic T-lymphocyte-induced apoptosis.
J Virol.
2000;74:9792-9796 13. Loriot MA, Marcellin P, Walker F, et al. Persistence of hepatitis B virus DNA in serum and liver from patients with chronic hepatitis B after loss of HBsAg. J Hepatol. 1997;27:251-258[CrossRef][Medline] [Order article via Infotrieve]. 14. Mason AL, Xu L, Guo L, Kuhns M, Perrillo RP. Molecular basis for persistent hepatitis B virus infection in the liver after clearance of serum hepatitis B surface antigen. Hepatology. 1998;27:1736-1742[CrossRef]. 15. Marusawa H, Uemoto S, Hijikata M, et al. Latent hepatitis B virus infection in healthy individuals with antibodies to hepatitis B core antigen. Hepatology. 2000;31:488-495[CrossRef][Medline] [Order article via Infotrieve]. 16. Marusawa H, Imoto S, Ueda Y, Chiba T. Reactivation of latently infected hepatitis B virus in a leukemia patient with antibodies to hepatitis B core antigen. J Gastroenterol. 2001;36:633-636[Medline] [Order article via Infotrieve]. 17. Marcellin P, Giostra E, Martinot-Peignoux M, et al. Redevelopment of hepatitis B surface antigen after renal transplantation. Gastroenterology. 1991;100:1432-1434[Medline] [Order article via Infotrieve]. 18. Dhedin N, Douvin C, Kuentz M, et al. Reverse seroconversion of hepatitis B after allogeneic bone marrow transplantation: a retrospective study of 37 patients with pretransplant anti-HBs and anti-HBc. Transplantation. 1998;66:616-619[CrossRef][Medline] [Order article via Infotrieve]. 19. Nordbo SA, Skaug K, Holter E, Waage A, Brinch L. Reactivation of hepatitis B virus infection in an anti-HBc and anti-HBs positive patient after allogeneic bone marrow transplantation. Eur J Haematol. 2000;65:86-87[CrossRef][Medline] [Order article via Infotrieve].
20.
Schreiber GB, Busch MP, Kleinman SH, Korelitz JJ.
The risk of transfusion-transmitted viral infections.
N Engl J Med.
1996;334:1685-1690
21.
Glück D.
[Risk of HIV, HCV, and HBV transmission by blood products. Current data 1997 and 1998 22. Larsen J, Hetland G, Skaug K. Posttransfusion hepatitis B transmitted by blood from a hepatitis B surface antigen-negative hepatitis B virus carrier. Transfusion. 1990;30:431-432[Medline] [Order article via Infotrieve]. 23. Norder H, Hammas B, Larsen J, Skaug K, Magnius LO. Detection of HBV DNA by PCR in serum from an HBsAg negative blood donor implicated in cases of post-transfusion hepatitis B. Arch Virol Suppl. 1992;4:116-118[Medline] [Order article via Infotrieve]. 24. Mosley JW, Stevens CE, Aach RD, et al. Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients. Transfusion. 1995;35:5-12[CrossRef][Medline] [Order article via Infotrieve]. 25. Roth WK, Weber M, Seifried E. Feasibility and efficacy of routine PCR screening of blood donations for hepatitis C virus, hepatitis B virus, and HIV-1 in a blood-bank setting. Lancet. 1999;353:359-363[CrossRef][Medline] [Order article via Infotrieve]. 26. Allain JP, Hewitt PE, Tedder RS, Williamson LM. Evidence that anti-HBc but not HBV DNA testing may prevent some HBV transmission by transfusion. Br J Haematol. 1999;107:186-195[CrossRef][Medline] [Order article via Infotrieve]. 27. Busch MP, Kleinman SH, Jackson B, Stramer SL, Hewlett I, Preston S. Committee report. Nucleic acid amplification testing of blood donors for transfusion-transmitted infectious diseases: report of the Interorganizational Task Force on Nucleic Acid Amplification Testing of Blood Donors. Transfusion. 2000;40:143-159[CrossRef][Medline] [Order article via Infotrieve]. 28. Sacher RA, Schreiber GB, Kleinman SH. Prevention of transfusion-transmitted hepatitis. Lancet. 2000;355:331-332[Medline] [Order article via Infotrieve]. 29. Otake K, Nishioka K. Nucleic acid amplification testing of hepatitis B virus. Lancet. 2000;355:1460[Medline] [Order article via Infotrieve]. 30. Saldanha J, Gerlich W, Lelie N, Dawson P, Heermann K, Heath A. An international collaborative study to establish a World Health Organization international standard for hepatitis B virus DNA nucleic acid amplification techniques. Vox Sang. 2001;80:63-71[CrossRef][Medline] [Order article via Infotrieve]. 31. Beld M, Habibuw MR, Rebers SP, Boom R, Reesink HW. Evaluation of automated RNA-extraction technology and a qualitative HCV assay for sensitivity and detection of HCV RNA in pool-screening systems. Transfusion. 2000;40:575-579[CrossRef][Medline] [Order article via Infotrieve]. 32. Jongerius JM, Bovenhorst M, van der Poel CL, et al. Evaluation of automated nucleic acid extraction devices for application in HCV NAT. Transfusion. 2000;40:871-874[CrossRef][Medline] [Order article via Infotrieve]. 33. Jilg W, Hottentrager B, Weinberger K, et al. Prevalence of markers of hepatitis B in the adult German population. J Med Virol. 2001;63:96-102[CrossRef][Medline] [Order article via Infotrieve]. 34. Grob P, Jilg W, Bornhak H, et al. Serological pattern "anti-HBc alone": report on a workshop. J Med Virol. 2000;62:450-455[CrossRef][Medline] [Order article via Infotrieve]. 35. Weber B, Melchior W, Gehrke R, Doerr HW, Berger A, Rabenau H. Hepatitis B virus markers in anti-HBc only positive individuals. J Med Virol. 2001;64:312-319[CrossRef][Medline] [Order article via Infotrieve]. 36. Zervou EK, Dalekos GN, Boumba DS, Tsianos EV. Value of anti-HBc screening of blood donors for prevention of HBV infection: results of a 3-year prospective study in Northwestern Greece. Transfusion. 2001;41:652-658[CrossRef][Medline] [Order article via Infotrieve]. 37. Yotsuyanagi H, Yasuda K, Moriya K, et al. Frequent presence of HBV in the sera of HBsAg-negative, anti-HBc-positive blood donors. Transfusion. 2001;41:1093-1099[CrossRef][Medline] [Order article via Infotrieve]. 38. Wachs ME, Amend WJ, Ascher NL, et al. The risk of transmission of hepatitis B from HBsAg(-), HBcAb(+), HBIgM(-) organ donors. Transplantation. 1995;59:230-234[Medline] [Order article via Infotrieve]. 39. Lowell JA, Howard TK, White HM, et al. Serological evidence of past hepatitis B infection in liver donor and hepatitis B infection in liver allograft. Lancet. 1995;345:1084-1085[CrossRef][Medline] [Order article via Infotrieve]. 40. Douglas DD, Rakela J, Wright TL, Krom RA, Wiesner RH. The clinical course of transplantation-associated de novo hepatitis B infection in the liver transplant recipient. Liver Transpl Surg. 1997;3:105-111[CrossRef]. 41. Roche B, Samuel D, Gigou M, et al. De novo and apparent de novo hepatitis B virus infection after liver transplantation. J Hepatol. 1997;26:517-526[Medline] [Order article via Infotrieve]. 42. Dickson RC, Everhart JE, Lake JR, et al. Transmission of hepatitis B by transplantation of livers from donors positive for antibody to hepatitis B core antigen. The National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database. Gastroenterology. 1997;113:1668-1674[CrossRef][Medline] [Order article via Infotrieve]. 43. Dodson SF, Issa S, Araya V, et al. Infectivity of hepatic allografts with antibodies to hepatitis B virus. Transplantation. 1997;64:1582-1584[CrossRef][Medline] [Order article via Infotrieve]. 44. Uemoto S, Inomata Y, Sannomiya A, et al. Posttransplant hepatitis B infection in liver transplantation with hepatitis B core antibody-positive donors. Transplant Proc. 1998;30:134-135[CrossRef][Medline] [Order article via Infotrieve]. 45. Prince AM, Lee DH, Brotman B. Infectivity of blood from PCR-positive, HBsAg-negative, anti-HBs-positive cases of resolved hepatitis B infection. Transfusion. 2001;41:329-332[Medline] [Order article via Infotrieve]. 46. Sato S, Ohhashi W, Ihara H, Sakaya S, Kato T, Ikeda H. Comparison of the sensitivity of NAT using pooled donor samples for HBV and that of a serologic HBsAg assay. Transfusion. 2001;41:1107-1113[CrossRef][Medline] [Order article via Infotrieve]. 47. Mei SD, Yatsuhashi H, Parquet MC, et al. Detection of HBV RNA in peripheral blood mononuclear cells in patients with and without HBsAg by reverse transcription polymerase chain reaction. Hepatol Res. 2000;18:19-28[Medline] [Order article via Infotrieve].
48.
Su Q, Wang SF, Chang TE, et al.
Circulating hepatitis B virus nucleic acids in chronic infection: representation of differently polyadenylated viral transcripts during progression to nonreplicative stages.
Clin Cancer Res.
2001;7:2005-2015
© 2002 by The American Society of Hematology.
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