title: Diagnosing acute hepatitis C in HIV-infected patients: nucleic acid testing compared with antibody and antigen-antibody detecting methods.
abstract: BACKGROUND
  Early diagnosis of hepatitis C virus (HCV) infection in HIV-infected patients has significant implications for patient management. However, the currently recommended serological screening strategy for identifying such patients could be improved. Little is known about the performance of routine antibody-only tests, compared with newer serological antigen-antibody detection assays and nucleic acid testing in this patient group.
  
  
  OBJECTIVE
  To compare the performance of antibody and antigen-antibody detecting methods with nucleic acid testing in the diagnosis of acute HCV in HIV-infected individuals.
  
  
  METHODS
  123 samples from 25 HIV-infected patients with acute HCV infection were tested retrospectively. The time of infection was estimated. The performance of antibody, antigen-antibody and nucleic acid detecting methods in diagnosing acute HCV infection was assessed and the sensitivity of the assays compared.
  
  
  RESULTS
  Only 20% of samples that were positive for HCV RNA were simultaneously positive for HCV antibody. In contrast, 68% of the total number of samples were positive and 32% negative by the antigen-antibody assay. Patients became antibody-positive on average 7 months after HCV RNA was detected.
  
  
  CONCLUSIONS
  In HIV-infected patients nucleic acid testing is the most sensitive means of diagnosing acute HCV C infection. A serological assay offering combined detection of antibody and antigen enhances sensitivity of detection, compared to antibody-only assays.
authors.affiliation: Department of Virology, Imperial College Healthcare NHS Trust, St. Mary's Hospital, Praed Street, London W2 1NY, United Kingdom. e.nastouli@imperial.ac.uk
authors.forename: Eleni
authors.initials: E
authors.lastname: Nastouli
authors.forename: Emma C
authors.initials: EC
authors.lastname: Thomson
authors.forename: Peter
authors.initials: P
authors.lastname: Karayiannis
authors.forename: Janice
authors.initials: J
authors.lastname: Main
authors.forename: Myra
authors.initials: M
authors.lastname: McClure
authors.forename: David
authors.initials: D
authors.lastname: Muir
mesh_terms: D000328:Adult; D000956:Antigens, Viral / Q000097:blood* / Q000276:immunology; D015658:HIV Infections / Q000150:complications*; D006508:Hepatitis Antibodies / Q000097:blood* / Q000276:immunology; D006526:Hepatitis C / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood* / Q000235:genetics; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000956:Antigens, Viral; D006508:Hepatitis Antibodies; D012367:RNA, Viral