Anti-HCV IgG avidity index in acute hepatitis C

Abstract Background The diagnosis of acute hepatitis C (AHC) is based on seroconversion to positive anti-HCV, which is usually not clinically possible. Objective To determine if avidity of anti-HCV IgG can be used for the diagnosis of AHC infection. Study design We enrolled 40 consecutive patients with AHC, 16 drug addicts (IVDA) with exacerbation of chronic hepatitis C (IVDA e-CHC group), 21 non-IVDA with exacerbation of chronic hepatitis C (IVDA-free e-CHC group) and 40 with chronic hepatitis C (CHC group). HCV avidity index (HCV-AI) was determined by ELISA on sera pre-diluted 1:10 with 1M guanidine. Results On admission, HCV-AI values were significantly lower in the AHC group (mean ± S.D.: 0.50 ± 0.30) than in IVDA-free e-CHC group (0.97 ± 0.08, p p p Conclusion HCV-AI is useful in identifying AHC infection in patients observed within the 8th day from the onset of symptoms.