title: Dried blood spot sampling for hepatitis B virus serology and molecular testing.
abstract: OBJECTIVE
  Dried blood spots (DBS) on filter paper have been successfully used to diagnose and monitor several infectious diseases. The aim was to investigate the performance of DBS in hepatitis B virus (HBV) diagnosis using commercial tests in comparison to standard methods.
  
  
  METHODS
  Paired DBS and plasma samples were collected from 200 patients: 100 patients with HBsAg negative status and 100 patients with HBsAg positive status. In the latter patient, HBeAg reactivity was tested. Ten samples of anti-HBs were collected from people vaccinated against HBV. We also studied 50 patients with positive HBV DNA viral load in plasma and 10 HBV DNA negative patients. HBV genotypes and gene polymerase mutations were determined in 10 randomly selected HBV-infected patients. The DBS sample consisted of 50 µL of whole blood, i.e. a 12-mm paper card.
  
  
  RESULTS
  The sensitivity thresholds of HBsAg and anti-HBs antibody were 0.30 ± 0.08 IU/mL and 18.11 ± 6.05 IU/mL, respectively, for DBS with 98% sensitivity and 100% specificity. Sensitivity was 98% and specificity 100% for the detection of HBV DNA on a blotter, considering an HBV DNA threshold of 914.1 ± 157.8 IU/ml. Ten patients had an HBeAg positive status in plasma, all were detected positive using DBS. HBV genotyping and mutation detection were successfully performed on DBS, with full concordance between the 10 paired DBS and plasma samples.
  
  
  CONCLUSIONS
  This study shows DBS is a reliable alternative to plasma specimens for quantifying and detecting HBsAg, anti-HBs, HBeAg and genotyping. DBS may increase the opportunities for HBV testing and treatment follow-up in hard-to-reach individuals.
authors.affiliation: Laboratoire Alphabio, Marseille, France.
authors.forename: Sofiane
authors.initials: S
authors.lastname: Mohamed
authors.forename: Audrey
authors.initials: A
authors.lastname: Raimondo
authors.forename: Guillaume
authors.initials: G
authors.lastname: Pénaranda
authors.forename: Claire
authors.initials: C
authors.lastname: Camus
authors.forename: Denis
authors.initials: D
authors.lastname: Ouzan
authors.forename: Sophie
authors.initials: S
authors.lastname: Ravet
authors.forename: Marc
authors.initials: M
authors.lastname: Bourlière
authors.forename: Hacène
authors.initials: H
authors.lastname: Khiri
authors.forename: Patrick
authors.initials: P
authors.lastname: Dukan
authors.forename: Daniel
authors.initials: D
authors.lastname: Olive
authors.forename: Philippe
authors.initials: P
authors.lastname: Halfon
mesh_terms: D001800:Blood Specimen Collection / Q000379:methods*; D004279:DNA, Viral / Q000032:analysis; D005838:Genotype; D006509:Hepatitis B / Q000175:diagnosis*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D006801:Humans
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens