GBV-C HGV IS NOT THE MAJOR CAUSE OF AUTOIMMUNE HEPATITIS/

Recently, GBV-C and HGV - two isolates of the same new flavivirus - we re identified in serum samples of patients with indeterminate hepatiti s and posttransfusion hepatitis, respectively. The pathogenic relevanc e of these viruses is still uncertain. As viral infections are presume d to trigger autoimmune processes, we investigated GBV-C in autoimmune hepatitis as well as in cryptogenic hepatitis, and compared the preva lences to patients with chronic viral hepatitis and those of blood don ors. We found only a slightly higher prevalence of the virus in crypto genic (12%) and autoimmune hepatitis type I-III (6.7%, 10%, and 12.5%) compared to blood donors (4.7%). In contrast, patients with viral hep atitis B, C, and D were more frequently infected with GBV-C (16%, 20%, 36%). These results suggest that GBV-C is not a major cause for induc ing autoimmunity and leading to autoimmune hepatitis, We analyzed the nucleic acid sequences of a representative number of GBV-C positive pa tients (24/42) and found a broad range of nucleotide similarity in the NS3 helicase region (74-100%) among the isolates and the prototype se quences. However, we could not identify a specific sequence, which wou ld point to a certain strain or subtype of the virus associated with a utoimmune or cryptogenic liver disease.