The natural course of hepatitis C virus infection 18 years after an epidemic outbreak of non-A, non-B hepatitis in a plasmapheresis centre

Background-The natural history of hepatitis C virus (HCV) infection is vari able and factors determining the course of the illness are unclear. Aims-To determine the natural course of HCV infection in a well characteris ed group of patients 18 years after ana epidemic outbreak of non-a, non-B h epatitis at a plasmapheresis centre. Methods-Between 1994 and 1996, 20 of 30 affected individuals were studied. HCV infection was confirmed using second and third generation ELISA test ki ts. HCV RNA was detected by a polymerase chain reaction (PCR) method and HC V genotyping was performed by analysing amplicons from the conserved 5'-non translated region generated by nested PCR. Thirty two liver biopsies were c arried out in 14 patients. Results-HCV antibodies were detected in all subjects. Eighteen patients had abnormal liver enzymes and 17 were HCV RNA positive, all of whom were infe cted with genotype 1a. Ninety per cent of this cohort showed evidence of ch ronic HCV infection with 50% having progressive liver disease and 20% cirrh osis 18 years after acute onset of non-A, non-B hepatitis. Considerable var iation in disease outcome occurred between individuals and no correlation w ith clinical features of the acute illness was found. Conclusions-Variability in the consequences of HCV infection in cases infec ted with the same virus suggests that host factors are important in determi ning disease outcome. The factors which determine differences in the natura l history of the disease still remain to be elucidated.