Serum HCV RNA levels assessed by quantitative NASBA@: stability of viral load over time, and lack of correlation with liver disease

Background/Aims: We used the hepatitis C virus quantitative NASBA@ technique to evaluate the stability of viral load within individuals with chronic hepatitis C, to determine the range of viraemic load between individuals, and to assess the usefulness of hepatitis C virus RNA quantitation in predicting the severity of underlying hepatitis C virus-induced liver disease. Methods: Hepatitis C virus RNA was determined, using the quantitative NASBA@ assay, in multiple serum samples from 11 individuals with chronic hepatitis C over an average time period of 11 months (range=3-23 months), and in single serum samples from a further 10 individuals. Results: In lo/11 individuals the hepatitis C virus RNA titres were within one log,, copies/ml of each other during this time period. In the eleventh, there was a rise of 1.36 log,, copies/ml in two serum samples taken 8 months apart. The viraemic load varied by 2.79 log,, copies/ml serum between individuals. There were no correlations between mean RNA levels and total biopsy scores (either Knodell or Sheffield scores), or the individual components of the biopsy scoring systems, except the sinusoidal infiltration component of the Sheffield score. There was also no difference in viral RNA levels between those infected with type 1 as compared to type 3 virus, with a mean level in both groups of 7.2 log,, copies/ml. Conckusions: Hepatitis C virus serum RNA level is stable within individuals within the studied time period. Viral load varies between infected individuals but is not a useful prognostic indicator of the severity of virus-induced liver disease.