RESUMO
INTRODUCTION: To evaluate a new test based on simultaneous detection of HCV antibodies and antigen (Monolisa HCV Ag/Ab ULTRA; Bio-Rad, Marnes la Coquette, France). METHODS: We studied samples from two groups of patients and 7 commercial HCV seroconversion panels (75 samples). Group 1: 1360 serum samples from patients referred for routine testing of anti HCV antibodies. Group 2: 333 serum samples from 183 hemodialysis patients. All samples were tested by the Ortho HCV 3.0 technique (Ortho-Clinical Diagnostics, Amersham, UK) and the Monolisa HCV Ag-Ab ULTRA technique. RESULTS: Group 1: Seventy-four of 1360 serum samples were positive by Ortho HCV and 77 by Monolisa. In 1353 samples, the results with the two tests were concordant: 1281 negative and 72 positive. Five samples were positive only by Monolisa and 2 only by Ortho (overall agreement: 99.5%). Group 2: Results were concordant in 325 samples, 308 negative and 17 positive. Seven samples were positive by Monolisa and negative by Ortho. The sensitivity of the Monolisa test in hemodialysis patients was clearly higher than that of the Ortho test (100% and 70.8%, respectively). Monolisa detected HCV infection in 43 of 75 samples from the seroconversion panels; only 18 positive samples were detected by Ortho HCV. Monolisa reduced the window period by up to 72 days. CONCLUSIONS: Our data indicate high agreement between the Monolisa and Ortho tests in samples from the general population. In hemodialysis patients, however, Monolisa was more sensitive. In addition, the Monolisa test significantly reduced the window period of HCV infection.
