title: Anti-HBc screening of blood donors: a comparison of nine anti-HBc tests.
abstract: OBJECTIVE
  Since voluntary introduction of hepatitis B virus (HBV) minipool nucleic acid amplification technology (NAT) at the German Red Cross, the expected residual risk of a transfusion-associated HBV infection has been estimated to be 1 : 500,000 - about 10 times higher than for human immunodeficiency virus (HIV) or hepatitis C virus (HCV) infection. Donors demonstrating chronic positivity for antibody to hepatitis B core antigen (anti-HBc), negativity for hepatitis B surface antigen (HBsAg) and polymerase chain reaction (PCR)-negative with a low virus load are a major cause of this increased risk.
  
  
  METHODS
  Ten-thousand blood donors from our blood-donation centre were screened for anti-HBc using the current PRISM HBc and the new PRISM HBcore assay to evaluate the diagnostic sensitivity and specificity of these tests. PRISM HBc- or PRISM HBcore-reactive samples were further analysed using seven additional tests for anti-HBc, two tests for antibody to hepatitis B surface antigen (anti-HBs), one test for antibody to hepatitis B envelope antigen (anti-HBe) and three HBV NAT assays.
  
  
  RESULTS
  From a total of 10,000 donors, nine and 14 samples were reactive only in the PRISM HBc and the PRISM HBcore, respectively, whereas 165 samples were reactive in both anti-HBc assays. Further analysis of these 188 anti-HBc-reactive specimens in a total of nine different anti-HBc assays revealed concordant results for 162 (86.2%) specimens. Sample cut-off values for anti-HBc were significantly (P < 0.01) lower for anti-HBc-only reactive samples compared with specimens that were also reactive for anti-HBs or anti-HBe.
  
  
  CONCLUSIONS
  Both PRISM anti-HBc assays revealed that approximately 1.8% of non-prescreened blood donors from Germany were reactive for anti-HBc. Although sensitivity was comparable between both assays, specificity was increased significantly with the PRISM HBcore. High anti-HBc sample cut-off values were indicative for reactivity in other HBV parameters and for concordant results in the nine different anti-HBc assays. Look-back investigations are necessary to estimate the infection risk both of anti-HBc-only positive and of anti-HBc/anti-HBs-positive blood transfusions.
authors.affiliation: Institute of Transfusion Medicine and Immunohematology, German Red Cross, Johann Wolfgang Goethe University, Frankfurt, Germany. mschmidt@bluspende.de
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.forename: C M
authors.initials: CM
authors.lastname: Nübling
authors.forename: H
authors.initials: H
authors.lastname: Scheiblauer
authors.forename: M
authors.initials: M
authors.lastname: Chudy
authors.forename: L A
authors.initials: LA
authors.lastname: Walch
authors.forename: E
authors.initials: E
authors.lastname: Seifried
authors.forename: W K
authors.initials: WK
authors.lastname: Roth
authors.forename: M K
authors.initials: MK
authors.lastname: Hourfar
mesh_terms: D001782:Blood Donors; D005858:Germany; D006509:Hepatitis B / Q000517:prevention & control; D006512:Hepatitis B Core Antigens / Q000235:genetics / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000302:isolation & purification; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D012680:Sensitivity and Specificity; D019562:Viral Load
chemical_list: D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens