title: Photochemical inactivation of duck hepatitis B virus in human platelet concentrates: a model of surrogate human hepatitis B virus infectivity.
abstract: BACKGROUND
  Photochemical decontamination of platelet concentrates (PCs) has been demonstrated by the use of 8-methoxypsoralen and ultraviolet A light. Systems for studying the inactivation of blood-borne viruses facilitate the evaluation of photochemical decontamination protocols.
  
  
  METHODS
  Duck hepatitis B virus (HBV), a model for human HBV, was adapted for the study of hepadnavirus inactivation. A highly specific in vitro infectivity assay used primary duck hepatocyte cultures and was followed by the detection of replicated duck HBV sequences.
  
  
  RESULTS
  Duck HBV-infected primary duck hepatocyte cultures produced authentic infectious virus. High-titer (> 10(9) virus genome equivalents/mL) duck HBV-infected sera were completely inactivated in serum or PCs by the use of 100 micrograms per mL of 8-methoxypsoralen and 70 J per cm2 of ultraviolet A light. Intracellular duck HBV (> 4.2 log10) in PCs was also inactivated. Culture results were confirmed by a sensitive duckling infectivity assay that indicated that 6.3 log10 of infectious duck HBV had been inactivated by photochemical decontamination.
  
  
  CONCLUSIONS
  The sensitivity of the culture assay was comparable to that of the duckling assay using polymerase chain reaction gene amplification to detect duck HBV. Duck HBV inactivation in PCs was dependent on the dose of ultraviolet A light and independent of 8-methoxypsoralen concentrations of 100 to 300 micrograms per mL: 100 micrograms per mL 8-methoxypsoralen inactivated 4 to 5 log10 of virus in conjunction with 20 to 40 J per cm2 of ultraviolet A light. The polymerase chain reaction-enhanced duck HBV culture system has utility in optimizing photochemical decontamination protocols.
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Eble
authors.forename: L
authors.initials: L
authors.lastname: Corash
mesh_terms: D000818:Animals; D001483:Base Sequence; D001792:Blood Platelets / Q000821:virology*; D004372:Ducks; D015611:Hepatitis B Virus, Duck / Q000187:drug effects / Q000528:radiation effects*; D006515:Hepatitis B virus / Q000472:pathogenicity*; D006801:Humans; D008730:Methoxsalen / Q000494:pharmacology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D014466:Ultraviolet Rays; D014766:Viremia / Q000628:therapy*
chemical_list: D008730:Methoxsalen