Role of Signal-to-Cutoff Ratios in Hepatitis C Virus Antibody Detection

We reviewed results from 12,800 samples tested for hepatitis C virus (HCV) antibody detection in our laboratory by screening (Ortho chemiluminescence immunoassay [CIA]) and supplemental tests (Chiron recombinant immunoblot assay [RIBA]). We found that a signal-to-cutoff (S/Co) ratio of 10.3 was, in our setting, the most efficient cutoff point to improve the diagnostic algorithm of HCV infection.