title: X region deletion mutants associated with surface antigen-positive hepatitis B virus infections.
abstract: OBJECTIVE
  The finding of antibodies against the polymerase of hepatitis B virus in renal dialysis patients before the incubation phase of infection implies underlying virus replication. Hence, the aim of the study was to test for virus during infection.
  
  
  METHODS
  Viremia was assayed in virus-infected and control patients using the polymerase chain reaction and Southern blotting.
  
  
  RESULTS
  Six months before the appearance of surface antigen, most patients had detectable core region, but few patients were X region positive. Three months after surface antigen appeared, most carriers had detectable core and X products. Three years after surface antigen appeared, 5 of 8 carriers with persistent hepatitis B e antigen and 1 of 8 carriers with corresponding antibody had these products. Cloning and sequencing showed deletions within the X/precore region of viral DNA.
  
  
  CONCLUSIONS
  Infection with X region mutants precedes that of wild-type virus, and they reappear after wild-type virus is eliminated in carriers.
authors.affiliation: Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Feitelson
authors.forename: L X
authors.initials: LX
authors.lastname: Duan
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.forename: B S
authors.initials: BS
authors.lastname: Blumberg
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000032:analysis; D017353:Gene Deletion; D006509:Hepatitis B / Q000821:virology*; D006511:Hepatitis B Antigens / Q000235:genetics*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D015534:Trans-Activators / Q000235:genetics*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D004279:DNA, Viral; D006511:Hepatitis B Antigens; D006514:Hepatitis B Surface Antigens; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein