Journal of Clinical Laboratory Analysis 10:269-276 (1996) Evaluation of a New Automated Third-Generation Anti-HCV Enzyme Immunoassay D. Lavanchy, J. Steinmann, 1 A. Moritz,2 and P.C. Frei Centre Hospita/ier Universitaire Vaudois, Division d'lmmunologie et Allergie, CH-1011 Lausanne, Switzerland; 1 Staatliches Hygiene-lnstitut, Abteilung tor Klinische Virologie, Bremen, Germany; 2 Roche Diagnostic Systems, Basie, Switzerland The new Cobas Core Anti-HGV EIA was evaluated in two centers for its ability to de- tect antibodies directed to hepatitis C virus in human serum. This assay, which can be run fully automated on a random access ana- lyzer, was compared with three other com- mercially available screening tests: the Ortho HCV 3.0 ELISA, the Murex anti-HGV, and theAbbott HCV EIAsecond generation. Posi- tive or discrepant results were further inves- tigated using the Wellcozyme HCV Western Blot or the Abbott Matrix HCV assays. The results obtained from analyzing 5045 serum samples showed a high correlation between the Cobas CoreAnti-HCV EIA and the other screening assays, ranging from 98.9% to 99.9%. Diagnostic specificities and sensitivities ranged from 99.7% to 100% and from 98.8% to 100%, respectively. In this study, the Cobas Core Anti-HGV EIA proved to be a very convenient test, able to perform at the highest levels of sensitivity and specificity. © 1996 Wiley-Liss, Inc. Key words: hepatitis C viruses, diagnosis laboratory, immunoassay, automation INTRODUCTION Hepatitis C virus (HCV) has been recognized as the major etiological agent of posttransfusion hepatitis world- wide (I). In addition, it has been shown to be a major agent of sporadic hepatitis in certain parts of the world (2). HCV causes per sisten t infections in most cases, leading to the development of chronic hepatitis and liver cirrhosis in approximately 50% and 10 % of cases, respec- tively (3). A significant number of patients with liver cir- rhosis will also develop primary hepatocellular carcinoma (4). Because of its high propensity to cause asymptomatic infection, the global importance of HCV has been under- estimated in the past. The prevalence of viral hepatitis has been shown to be variable with figures of0.5-1 % reported for countries with low endemicity; 1.5-2.5 % for southern Europe or Japan (5), peaking at 11-20% for a country like Egypt (6). Reliable diagnosis of hepatitis C virus infec- tion is therefore an important need. In this study, we evaluated a new third-generation anti- HCV screening assay based on recombinant antigens that contain no fu sion portions of unrelated proteins. Panels of serum samples were analyzed by the new assay and results were compared with those of different commercially avail- able assays. The new third-generation Cobas CoreAnti-HCV EIA was run on a fully automated random access analyzer (Cobas Core). © 1996 Wiley-Liss, Inc. MATERIALS AND METHODS Serum Samples A total of 5,045 samples were used in this study, conducted at two independent centers: Centre Hospitalier Universitaire Vaudois, Division d 'Immunologie et Allergie, CH- I 011 Lausanne, Switzerland (Center 1) and Staatliches Hygiene- Institut,Abteilung fiir klinische Virologie, St.-Jiirgen-Str., D- 28205 Bremen, Germany (Center 2). The various groups of subjects tested are listed in Table 1. Anti-HCV antibody posi- tive samples were preselected using either the Murex anti- HCV screening assay (Center 1) or the Abbott HCV EIA second-generation assay (Center 2). Furthermore, 2,000 samples from anti-HCV negative blood donors, predefined using the Murex anti-HCV (Center 2), and 245 samples (both centers) representing different groups known to possibly cause ambiguous results in EIAs ("tricky panel") were studied. In addition, 7 samples with known HCV genotype (1 with geno- type 1, 1 with genotype 1b, 2 with genotype 2a, 2 with geno- type 3a, 1 with genotype 4a); 29 samples with single reactivity to HCV antigens (Center 1), and 4 commercially available Received September 25, 1995 ; accepted March 17, 1996. Address reprint requests to Dr. P.C. Frei, Centre Hospitalier Universitaire Vaudois, Division d'lmmunologie et Allergie, CH- I 011 Lausanne, Swit- zerl and.