How to interpret borderline HCV antibody test results? A comparative study investigating four different anti-HCV assays

Introduction: The introduction of anti-HCV testing has been a milestone in medical history and markedly reduced transfusion-associated hepatitis C. Over the last 20 years, the performance of HCV antibody assays improved strikingly with sensitivities and specificities reaching >98% for most licensed tests. Still, a significant number of samples may yield borderline signal-to-cut-off ratios. Re-testing of samples and application of confirmatory recombinant blot assays or nucleic acid testing is time-consuming and costly. Moreover, false negative results should be avoided in particular in special risk groups such a…