Distinguishing acute from symptomatic chronic hepatitis C virus (HCV) infection by site-directed serology of the HCV structural proteins.

To distinguish acute from symptomatic chronic hepatitis C virus (HCV) infection, site-directed serology was done on the complete core, envelope 1, and envelope 2 proteins using multiple peptide assays. Serum samples were obtained from 7 patients with clinically confirmed acute HCV infections and from 36 patients with symptomatic chronic HCV infections. At onset of symptoms, all patients with acute infection had HCV RNA in serum, 1 had > 2 strong core peptide reactivities (A405 > 1.0), and the number of core reactivities increased with time in 6 patients. In contrast, 35 of 36 chronic-phase patients with HCV RNA in serum had 3-12 strong core reactivities (P < .001). Envelope 2 antibodies were found in 2 acute-phase and in 32 chronic-phase HCV patients (P < .01). Thus, a serum sample with HCV RNA from a patient with hepatitis can be classified as acute or chronic using site-directed serology of the HCV structural proteins.