Spontaneous viral clearance following acute hepatitis C infection: a systematic review of longitudinal studies

Abstract

Summary. A large number of studies have reported on spontaneous viral clearance rates in acute hepatitis C infection, however most have been small, and reported rates have varied quite widely. To improve the precision of the estimated rate of spontaneous viral clearance, a systematic review was conducted of longitudinal studies. Factors associated with viral clearance were also examined. Inclusion criteria for studies were: longitudinal assessment from time of acute hepatitis C; hepatitis C virus RNA analysis as determinant of viral clearance; untreated for acute hepatitis C. Information on study population, and factors that may influence viral clearance were extracted from each study. Viral clearance was defined among individuals with at least 6 months follow‐up following acute hepatitis C. The number of subjects with viral clearance was expressed as a proportion for each study and a weighted mean for proportion was calculated. A total of 31 studies were examined. Study populations included nine studies of post‐transfusion hepatitis, 19 of acute clinical hepatitis, and three of sero‐incident cases. In total, data was available for 675 subjects and the mean study population was 22 (range 4–67). The proportion with viral clearance ranged from 0.0 to 0.8, with a weighted mean of 0.26 (95% CI 0.22–0.29). Factors associated with viral clearance were female gender and acute clinical hepatitis C study population. Further studies are required to more clearly define predictors of clearance and guide therapeutic intervention strategies.