title: Diagnostic performance of serological assays for anti-HBs testing: Results from a quality assessment program.
abstract: Post-vaccination testing after hepatitis B vaccination is indispensable to evaluate long-term immunological protection. Using a threshold level of antibodies against hepatitis B surface antigen (anti-HBs) to define serological protection, implies reproducible and valid measurements of different diagnostic assays.
  
  
  
  In this study we assess the performance of currently used anti-HBs assays.
  
  
  
  In 2013, 45 laboratories participated in an external quality assessment program using pooled anti-HBs serum samples around the cutoff values 10IU/l and 100IU/l. Laboratories used either Axsym (Abbott Laboratories), Architect (Abbott Laboratories), Access (Beckman-Coulter), ADVIA Centaur anti-HBs2 (Siemens Healthcare Diagnostics), Elecsys, Modular or Cobas (Roche Diagnostics) or Vidas Total Quick (Biomerieux) for anti-HBs titre quantification. We analysed covariance using mixed-model repeated measures. To assess sensitivity/specificity and agreement, a true positive or true negative result was defined as an anti-HBs titre respectively above or below the cutoff value by ≥4 of 6 assays.
  
  
  
  Different anti-HBs assays were associated with statistically significant (P<0.05) differences in anti-HBs titres in all dilutions. Sensitivity and specificity ranged respectively from 64%-100% and 95%-100%. Agreement between assays around an anti-HBs titre cutoff value of 10IU/l ranged from 93%-100% and was 44% for a cutoff value of 100IU/l.
  
  
  
  Around a cutoff value of 10IU/l use of the Access assay may result in false-negative results. Concerning the cutoff value of 100IU/l, a sample being classified below or above this cutoff relied heavily on the specific assay used, with both the Architect and the Access resulting in false-negative results.
authors.affiliation: Academic Collaborative Centre for Public Health AMPHI, Department of Primary and Community Care, Radboud University Nijmegen Medical Centre, The Netherlands; Department of Medical Microbiology, School of Public Health and Primary Care (CAPHRI), Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands. Electronic address: Stijn.Raven@radboudumc.nl.
authors.forename: Stijn
authors.initials: S
authors.lastname: Raven
authors.affiliation: Academic Collaborative Centre for Public Health AMPHI, Department of Primary and Community Care, Radboud University Nijmegen Medical Centre, The Netherlands.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Hautvast
authors.affiliation: Centre for Infectious Disease Control, Netherlands Institute of Public Health and the Environment, Bilthoven, The Netherlands; Centre of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Jim van
authors.initials: JV
authors.lastname: Steenbergen
authors.affiliation: Academic Collaborative Centre for Public Health AMPHI, Department of Primary and Community Care, Radboud University Nijmegen Medical Centre, The Netherlands.
authors.forename: Reinier
authors.initials: R
authors.lastname: Akkermans
authors.affiliation: MCA Laboratory, Queen Beatrix Hospital, Winterswijk, The Netherlands; On behalf of the Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), The Netherlands.
authors.forename: Cas
authors.initials: C
authors.lastname: Weykamp
authors.affiliation: Academic Collaborative Centre for Public Health AMPHI, Department of Primary and Community Care, Radboud University Nijmegen Medical Centre, The Netherlands.
authors.forename: Francis
authors.initials: F
authors.lastname: Smits
authors.affiliation: Department of Sexual Health, Infectious Diseases and Environmental Health, South Limburg Public Health Service, The Netherlands; Department of Medical Microbiology, School of Public Health and Primary Care (CAPHRI), Maastricht University Medical Center (MUMC+), Maastricht, The Netherlands.
authors.forename: Christian
authors.initials: C
authors.lastname: Hoebe
authors.affiliation: Department of Medical Microbiology, Leiden University Medical Centre, The Netherlands.
authors.forename: Ann
authors.initials: A
authors.lastname: Vossen
mesh_terms: D006509:Hepatitis B / Q000175:diagnosis*; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D059021:Laboratory Proficiency Testing; D011785:Quality Assurance, Health Care; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
chemical_list: D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines
keywords: Diagnostic test; Hepatitis B; Serology