Diagnostic Reliability of Architect Anti-HCV Tests and Diagnostic Cost of False Positivity

Abstract

Objective: We aimed to determine the cutoff value of anti-hepatitis C virus (HCV) in the diagnosis of real positive patients based on the chemiluminescence immunoassay (CIA) test kit absorbance routinely used in our laboratory and to reveal the potential cost-effectiveness of confirmatory tests for false-positive samples. Methods: All anti-HCV CIA test results between 2016 and 2019 were retrospectively screened and sample/cutoff (S/Co) values of the patients were recorded. Among these, the results that were confirmed with HCV RNA polymerase chain reaction (PCR) test were included. Results: Of the 257 patients included in the study, 84 (32.68%) were positive for HCV RNA. The optimal S/Co value was 8.58 with sensitivity and specificity values being 95.24% and 85.55%, respectively. According to this 8.58 S/Co value, the anti-HCV test was reactive in 105 cases and 80 (76.2%) of these cases had active HCV infection. To prevent false nega- tivity, the additional cost of using 1.0 S/Co value to our institution was 4114.64 USD. In our institution, approximately 6.25 working hours is spent to finalize the HCV RNA PCR test. The hours spent for S/Co of 1.0 and 8.58 was 1606.25 and 658.25, respectively. Conclusion: False-positive anti-HCV results are an economic burden on countries. At least, different S/Co values might be used in accordance with the purpose of screening and preva- lence of HCV infection in different laboratories and different populations