Possible association between serum GB virus C RNA level and disease activity in fulminant hepatitis type G

Background/Aims: Whether GB virus C causes serious liver diseases remains c ontroversial. The aim of the present study was to determine whether there i s an etiological relationship between GB virus C and fulminant hepatitis. Methods: The level of GB virus C RNA in the sera of three patients with ful minant hepatitis was quantitatively determined using the newly developed re altime detection polymerase chain reaction method, which is based on Tag Ma n chemistry. The NS 3 region of the viral genome isolated from the sera was sequenced at several time points to confirm whether the same virus was res ponsible for fulminant hepatitis during the patients' clinical courses. Results: The sensitivity of the PCR was comparable to that of nested PCR an d a linear relationship between RNA copy number and threshold cycle was obs erved for 10(1) and 10(6) RNA copies/ml (r=0.99). The serum level of GB vir us C RNA closely paralleled that of ALT in all patients. Sequence analysis of the NS3 region isolated from the patients' sera revealed that the same G B virus C strain infected the patients during their entire clinical courses , despite plasma exchange therapy. Conclusions: These observations suggest that GB virus C may be etiologicall y associated with fulminant hepatic failure, and is not merely an inactive bystander introduced by therapeutic plasma exchange.