Hepatitis C virus (HCV) viremia in HIV-infected patients without HCV antibodies detectable by third-generation enzyme immunoassay

BACKGROUND: The detection of hepatitis C virus antibody (anti-HCV) by enzyme immunoassay to screen HCV infection in HIV-1-infected individuals may yield false negative results, especially in patients with advanced immunosuppression. In such cases, a diagnosis would be possible only by use of a viral RNA detection technique. Third-generation anti-HCV enzyme immunoassays seem to have superior performance compared to second-generation immunoassays in this context. METHODS: A cross-sectional study was conducted to ascertain the presence of HCV by polymerase chain reaction (PCR) in 61 HIV-1-infected patients with CD(4)(+) cell counts <200 cells/mm(3), and no detectable HCV antibodies by a third-generation enzyme immunoassay. RESULTS: Six (10%) of 61 patients tested HCV-RNA positive by PCR assay. There was one patient who seroconverted during observation. Hence, there were five patients with HCV viremia without detectable antibodies to HCV throughout the study, which represents 8.2% (95% confidence interval: 2.8-18.4) of 61 HIV-1-infected patients. All five carriers of HCV viremia had CD4 counts <100 cells/mm(3) and were diagnosed with an opportunistic disease at some stage. CONCLUSIONS: The HCV viremia and no detectable HCV antibodies by third-generation immunoassay were found only in individuals with a CD(4) count of <100 cells/mm(3). Molecular assays to detect HCV-RNA should be considered as an important tool to diagnose hepatitis C in HIV-1-infected patients with advanced immunosuppression.