Detection of hepatitis C virus (HCV) RNA by PCR related to HCV antibodies in serum and liver histology in Swedish blood donors.

Serum samples from 103 blood donors or patients with slightly increased serum levels of liver enzymes were tested for antibodies to hepatitis C virus (anti-HCV) using second generation tests and for HCV RNA by the polymerase chain reaction (PCR). PCR was in a nested configuration, using primer pairs from the 5'-nontranslated region. The anti-HCV antibody was found by enzyme linked immunosorbent assay (ELISA) in 93 patients. The anti-HCV confirmatory second generation recombinant immunoblot assay (RIBA) was positive in 44, indeterminate in 34 and negative in 25 subjects. Histopathological examination of the liver was carried out in 51 subjects. HCV RNA was detected in serum of 39/41 (95%) RIBA positive patients, and in 7/34 (21%) RIBA indeterminate subjects, but in none of the RIBA negative subjects. All but one of the PCR positive patients with a RIBA indeterminate pattern exhibited the C22 band. HCV RNA was found in the serum of all but one patients with chronic active or persistent hepatitis, but also in one RIBA positive subject with normal liver tissue. These results imply that most patients with antibodies to two or more HCV antigens by RIBA will have a chronic replicative HCV infection associated with viraemia. HCV viraemia can also be present in some patients, who have antibodies to only one HCV antigen particularly the C22 epitope.