Objective: Hepatitis C virus (HCV) is the leading cause of acute and chronic hepatitis. Diagnosis primarily relies on detecting anti-HCV antibodies, measuring alanine transaminase (ALT) levels, and evaluating HCV-RNA positivity. This study focused on patients with borderline or weakly positive results in two enzyme immunoassaybased blood tests: enzyme-linked fluorescence assay (ELFA) and chemiluminescent immunoassay (CLIA). It compared their anti-HCV antibody index values against their ALT and HCV-RNA outcomes.

Methods: The research included serum samples from 59 patients, collected between October 2018 and November 2019, evaluated using the Signal/Cut-off (S/CO) values in the CLIA system and the Test Value (TV) values in the ELFA system.

Results: The mean S/CO and TV values for HCV antibodies obtained from serum samples were determined as 2.78TV for ELFA test and 2.32 S/CO for CLIA test. Mean ALT level of all serum samples was determined as 28.7U/L. Weak positive results were obtained with CLIA in serum samples of 17 patients (11 Female-6 Male, mean age: 42.2) who had negative results with ELFA, and mean ELFA value was 0.24 TV, and the mean CLIA value was 1.74 S/CO. The mean of borderline cases in ELFA was 0.82TV; mean CLIA was 1.97 S/CO in same group.

Conclusion: The study underscores the importance of validating HCV antibody results obtained from one assay with another system, preferably alongside HCV-RNA testing, and suggests revising the “1 S/CO” and “1 TV” thresholds for positivity in future research to ensure accuracy in diagnosis.