title: A search for hepatitis C virus polymerase chain reaction-positive but seronegative subjects among blood donors with elevated alanine aminotransferase.
abstract: BACKGROUND
  Previous studies reported the existence of hepatitis C virus (HCV) polymerase chain reaction (PCR)-positive but seronegative sera. This is not surprising in the case of window-phase specimens, because PCR can detect HCV RNA many weeks before the appearance of antibody. To determine whether such sera can also be found in chronically infected subjects, a high-risk population of blood donors with elevated alanine aminotransferase was studied.
  
  
  METHODS
  Freshly frozen plasma from 301 donors with alanine aminotransferase > 100 IU per L was tested with PCR assays that were rigidly controlled for specificity and contamination, and with current and newer versions of assays for anti-HCV. Sera were classified as seropositive if positive in two screening assays and one supplemental assay or if positive in two screening assays and PCR.
  
  
  RESULTS
  New versions of screening assays detected 100 percent of seropositive samples. A second-generation immunoblot assay detected 98 percent of seropositive sera, a second-generation recombinant immunoblot assay detected 96 percent, and an enzyme immunoassay for antibody to the envelope protein of HCV detected 98 percent. Fifty-one of 54 seropositive sera were PCR positive. None of the 247 seronegative samples was reproducibly positive on PCR.
  
  
  CONCLUSIONS
  No PCR-positive but seronegative donors were found in this high-risk donor population. The possible benefit of PCR screening of blood donors can be determined only by large-scale comparative testing of donor populations and may be limited to the detection of window-phase infections.
authors.affiliation: Laboratory of Virology and Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Prince
authors.forename: J W
authors.initials: JW
authors.lastname: Scheffel
authors.forename: B
authors.initials: B
authors.lastname: Moore
mesh_terms: D000410:Alanine Transaminase / Q000097:blood*; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000175:diagnosis; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D008403:Mass Screening / Q000592:standards; D016133:Polymerase Chain Reaction / Q000592:standards*; D012313:RNA / Q000032:analysis; D013997:Time Factors
chemical_list: D018937:Hepatitis C Antibodies; D012313:RNA; D000410:Alanine Transaminase