Fluctuation of serum HCV-RNA levels in untreated blood donors with chronic hepatitis C virus infection

The hepatitis C virus (HCV)‐RNA levels were measured in 281 serum samples from 32 untreated volunteer blood donors prospectively collected over a period of 14–73 months. The HCV‐RNA levels were tested by the branched DNA signal amplification assay. The mean HCV‐RNA levels of each donor ranged from 4.92 log10–6.36 log10 gene equivalents/mL (25%, median, 75% percentile; 5.51, 5.79, 6.12 log10 gene equivalents/mL). The fluctuations of HCV‐RNA levels in individuals, represented by the ratio of the maximum value divided by the minimum value, ranged from a 1.7‐ to a 141‐fold change. Fluctuations with more than a 10‐fold change were observed in five subjects: 11‐, 15‐, 17‐, 96‐ and 141‐fold changes. Eleven subjects were followed for at least 5 years; all subjects had fluctuations of HCV‐RNA levels greater than 3‐fold during the observation period. No blood donor was observed whose HCV levels changed from a high‐level phase to a low‐level phase or from low to high. No subjects cleared HCV during follow‐up, although two had undetectable HCV‐RNA levels transiently. These findings reveal that changes in HCV‐RNA levels occur which are unrelated to treatment with interferon and ribavirin.