Performance of an antigen-antibody combined assay for hepatitis C virus testing without venipuncture

Background: Hepatitis C virus (HCV) is underdiagnosed and therefore increasing the opportunities for HCV testing without venipuncture may be useful. Objectives: We evaluated the analytical performance of a modified, commercially available, combined HCV antigen-antibody assay (cEIA) (Monolisa (R) HCV-Ag-Ab-ULTRA) and a commercially available point-of-care (POC) device (OraQuick (R) HCV) on fingerstick blood (FSB) and oral mucosal transudate (OMT). Study design: FSB, OMT and serum samples were collected from 113 cases of HCV-antibody-positive patients and 88 HCV-antibody-negative controls. The HCV-antibody-positive group included 63 patients with quantifiable HCV-RNA (56%) and 17 HIV/HCV co-infected patients (15%). FSB and OMT specimens were collected as dried blood spots (DBSs) or with the OraSure collection system, before testing with cEIA. Results: With FSB specimens, the cEIA and the POC device exhibited 100% specificity and 98.2% and 97.4% sensitivity, respectively. The specificity of the cEIA in FSB sharply decreased if stored 3 days at room temperature. With OMT specimens, the cEIA sensitivity (71.7%) and specificity (94.3%) were significantly lower than the performance of OraQuick (R) HCV (sensitivity, 94.6%; specificity, 100%). The optical densities obtained with the cEIA in FSB and OMT were lower in HIV/HCV co-infected patients compared with HCV monoinfected patients. Conclusion: The cEIA using FSB specimens collected on DBSs preserved in appropriate storage conditions was a reliable alternative, equivalent to the POC assay, for HCV testing without venipuncture. The cEIA was not adapted for HCV testing on OMT. (C) 2012 Elsevier B.V. All rights reserved.