title: Factors associated with positive predictability of the anti-HCV ELISA method with confirmatory RT-PCR.
abstract: The positive predictability of anti-HCV ELISA is low, especially, in blood donors and in healthy populations. False positive anti-HCV results pose some difficulties in medical practice and in blood screening. The aim of this study was to identify the factors associated with true hepatitis C virus (HCV) infection among anti-HCV ELISA-positives. A case-control analysis was conducted using 354 subjects who were positive for anti-HCV ELISA. All subjects were tested for true HCV infection using the reverse transcriptase polymerase chain reaction (RT-PCR). Tests for serum alanine aminotransferase (ALT), fasting glucose, HBsAg, anti-HBc antibody, alpha-fetoprotein, platelet count and ultrasound of liver were also performed. Epidemiological data were obtained by self-administered questionnaires. Out of 354 subjects, 202 (57.1%) were positive for HCV by RT-PCR and 152 were negative and used as the control group. In multivariate analysis, blood transfusion (odds ratio, OR 2.3, 95% confidence interval, CI 1.3-4.0), elevated ALT (OR 2.2, 95% CI 1.2-4.3) and higher anti-HCV ELISA ratios (more than 3; OR 1.7, 95% CI 1.3-2.1) were associated with true HCV infection. Thrombocytopenia was also associated with the presence of HCV in univariate analysis. These results suggest that a history of blood transfusion, elevated ALT and a high score on anti-HCV ELISA ratios are associated with true HCV infection among anti-HCV ELISA-positives.
authors.affiliation: Department of Family Medicine, University of Ulsan College of Medicine, Seoul, Korea. youngkim@www.amc.seoul.kr
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.forename: H S
authors.initials: HS
authors.lastname: Lee
authors.forename: Y O
authors.initials: YO
authors.lastname: Ahn
mesh_terms: D000328:Adult; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005260:Female; D016174:Hepacivirus; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D018937:Hepatitis C Antibodies