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 controversial. The aim of the present study was to determine whether there is 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 fulminant hepatitis was quantitatively determined using the newly developed realtime detection polymerase chain reaction method, which is based on Taq Man 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 responsible for fulminant hepatitis during the patientsʹ clinical courses. Results: The sensitivity of the PCR was comparable to that of nested PCR and a linear relationship between RNA copy number and threshold cycle was observed for 101 and 106 RNA copies/ml (r=0.99). The serum level of GB virus C RNA closely paralleled that of ALT in all patients. Sequence analysis of the NS3 region isolated from the patientsʹ sera revealed that the same GB 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 etiologically associated with fulminant hepatic failure, and is not merely an inactive bystander introduced by therapeutic plasma exchange.