The clinical significance of simultaneous infection with hepatitis G virusin patients with chronic hepatitis C

OBJECTIVES: Hepatitis G virus (HGV) is a recently discovered member of the flavivirus family that has been associated with acute and chronic hepatitis . HGV infection has been reported to coexist in 10-20% of patients with chr onic hepatitis C. The significance of simultaneous infection with HGV and h epatitis C virus (HCV) remains to be clarified, as do the effects on HGV of therapeutic interventions such as interferon treatment or liver transplant ation. The aims of our study were: 1) to examine the frequency of HGV infec tion in the settings of liver transplantation and interferon therapy for he patitis C: and 2) to compare HGV RNA levels before and after liver transpla ntation or interferon treatment. METHODS: Pre-treatment sera were available in 65 patients with chronic hepa titis C treated with interferon; pretransplant sera were available in 49 pa tients transplanted for end stage liver disease associated with chronic hep atitis C. Information collected included age, sex, risk factors for hepatit is, concurrent liver disease, patient and allograft survival, biochemical r esponse to interferon, histological activity index, and degree of fibrosis/ cirrhosis. HCV genotyping was performed by sequencing the NS-5 region. HGV quantitation was performed using a research-based branched DNA (bDNA) assay with a set of probes directed at the 5' untranslated region. RESULTS: HGV was detected in 10 of 49 patients (20%) before transplant and in 13 of 65 patients (20%) treated with interferon. There was a female pred ominance among HGV-positive compared with HGV-negative transplant patients (80% vs 20%: p < 0.01), but such a difference was not observed in the inter feron-treated group. Hepatic iron concentration was lower in hepatic explan ts from patients who were HGV-positive than in those who were HGV-negative (318 +/- 145 mu g/g dry weight vs 1497 +/- 2202 mu g/g dry weight; p = 0.02 ). HCV exposure after 1980 was more common in the HGV-positive patients tha n in those who were HGV-negative for the entire study population (10 of 20 [50%] vs 16 of 66 [24%]; p = 0.03), as well as for the nontransplant subgro up (8 of 12 [67%] vs 12 Of 39 [31%]; p = 0.03). HGV RNA levels declined at 1 yr after transplant in seven of eight patients. Among nine patients teste d during or after interferon treatment, HGV RNA levels declined from pretre atment levels in all and disappeared in three. CONCLUSIONS: Among patients with chronic hepatitis C treated with either in terferon or liver transplantation, the frequency of coinfection with HGV is about 20%. HGV may be a more recent virus in the US than HCV. Confection w ith HGV does not appear to affect the likelihood of response to interferon in patients with hepatitis C. Finally, HGV RNA levels appear to decline aft er both liver transplantation and interferon therapy, suggesting possible s uppression by increased HCV replication in the former case, and a possible drug treatment effect in the latter. (C) 1999 by Am. Cell. of Gastroenterol ogy.