Evaluation of hepatitis C antibody testing in saliva specimens collected by two different systems in comparison with HCV antibody and HCV RNA in serum

Two different ELISA assays, the Ortho HCV 3.0 ELISA (Ortho Diagnostics Syst ems) and the Mono-Lisa anti-HCV Plus (Sanofi Diagnostics Pasteur) were eval uated for the detection of hepatitis C virus (HCV) antibody in saliva sampl es. Specimens were collected from 152 individuals who participated in a lon gitudinal cohort study on HIV infection, and who used illicit drugs. Saliva specimens were collected using two different systems: Salivette (Sarstedt) and Omni-Sal (Saliva Diagnostic Systems). Saliva specimens were tested fol lowing modified protocols by both ELISAs, and the results were compared wit h serum specimens that were tested according to the instructions of the man ufacturer. Serum samples of 102 (67%) participants were positive by both as says, and 50 persons were negative for HCV antibody. A total of 99 of the 1 02 serum specimens were confirmed as positive using Ortho Riba HCV 3.0 (Ort ho Diagnostics System) and Deciscan HCV (Sanofi Diagnostics Pasteur), and 3 yielded discrepant results. As no cut-off level is known for testing saliv a samples by ELISA, 3 different levels were chosen: mean (M) + standard dev iation (SD), M + 2 SD, and M + 3 SD of the optical densities of saliva test s of the 50 HCV serum antibody negative persons. At a level of M + SD and M + 2 SD the Salivettel Mono-Lisa combination gave the greatest proportion o f HCV antibody positive saliva specimens obtained from the 102 HCV serum an tibody positive participants, 88% and 79%, respectively. Differences betwee n the various collection systems and assay combinations were not significan t statistically. In 76 of the 102 persons with HCV antibodies in serum, HCV RNA was detected in serum. Salivary presence of HCV RNA, however, could no t be demonstrated. The results show that the assays compared are unsuitable for diagnostic use, but the sensitivities of the assays are acceptable for use in epidemiological studies. J. Med. Virol. 64:13-20, 2001. (C) 2001 Wi ley-Liss, Inc.