Spontaneous elimination of serum hepatitis C virus (HCV) RNA in chronic HCV carriers: a population-based cohort study.

The natural course of hepatitis C virus (HCV) infection has not been fully elucidated. To investigate whether HCV is spontaneously eliminated in chronic carriers, a long-term population-based cohort study was conducted on 435 chronic HCV carriers. Individual characteristics, serum HCV RNA, and liver function tests were analyzed, and ultra sonography (US) was performed in all subjects. Subjects were followed up for 7.2 +/- 2.4 years (mean +/- SD). Serum HCV RNA was spontaneously eliminated in 16/435 (3.7%) individuals during this period; thus, the incidence of spontaneous elimination of serum HCV RNA was 0.5%/year/person. Multivariate analysis revealed that both a low value of ZTT and no US finding of chronic liver disease were associated with spontaneous viral elimination in HCV carriers. Three of these 16 individuals had chronic hepatitis, and 13 of them had normal ALT levels. When the neutralization of binding (NOB) assay that evaluates inhibition of the HCV envelope-2 protein binding to human cells was examined using sera from these 16 individuals, the NOB antibody was detected in only 3 cases with chronic hepatitis. These results suggest that serum HCV RNA is spontaneously eliminated in chronic HCV carriers in a population, and that the development of NOB antibody is associated with a natural resolution of chronic hepatitis in the minority of them.