Hepatitis G virus infection: clinical characteristics and response to interferon

Abstract

A new member of the Flaviviridae family has recently been cloned and completely sequenced. The new virus, tentatively named hepatitis G virus (HGV) and known to be closely related to GB virus C (GBV-C), is transmitted by blood and blood products, intravenous drug use and other behaviour associated with a high risk of parenteral exposure to blood. The association of the virus with hepatitis is demonstrated by the presence of raised liver transaminase (alanine aminotransferase, ALT) levels in patients infected with HGV in the absence of other identifiable causes of hepatitis. No patient sera from groups exposed to blood and blood products were found to be positive when tested for the presence of GBV-A or GBV-B sequences, two other recently described flaviviruses. Forty-five per cent of the HGV-infected patients investigated had normal ALT suggesting the existence of a normal carrier state. Persistent infection of up to 13 years duration was observed. Co-infection with hepatitis B or hepatitis C viruses (HBV and HCV) was commonly seen presumably because of shared risk factors. None of five patients with fulminant hepatic failure was positive for HGV infection. The virus is sensitive to interferon-alpha, but sustained responses were not seen with the treatment regimens used for HBV and HCV. Viral titres increased during immunosuppression following liver transplantation and the higher levels of viraemia were in one case accompanied by elavated ALT. Whether HGV (GBV-C) replicates in the liver in some or all cases remains to be established. Preliminary data suggest that it is present within peripheral blood lymphocytes.

The Prevalence of Hepatitis C and Hepatitis G Virus Infection in Patients with B Cell Non-Hodgkin Lymphomas in Greece: A Hellenic Cooperative Oncology Group Study

“…The fact that only 1 out of the 10 HGV-positive patients with B cell NHL received a blood transfusion prior to testing for hepatitis G means that this could not account for the high prevalence of hepatitis G in the B cell NHL group. On the other hand, this prevalence is much lower than the prevalence of HGV infection described in multitransfused patients (18–33%) [18]. …”

“…The link between HGV infection and NHL is not adequately covered in the literature. Considering (1) the high prevalence of HGV in patients with chronic HCV infection (approximately 20%) [2], (2) the identification of HGV in lymphocytes [18]and (3) the high prevalence of HGV infection in a population of B cell NHL patients reported in a recent study from Germany [19], one can put forward the hypothesis that HGV could also be lymphotropic.…”

Current Status of Hepatitis G Virus (GBV-C) in Transfusion: Is It Relevant?

“…A similar proportion, 17 of 86 (20%), were HGVpositive prior to transplantation (62 of the patients were HBV-or HCV-positive) [31]. In 2 patients who had under gone liver transplantation and were positive for HGV-RNA prior to transplantation, viral titres increased substantially presumably because of the immunosuppressants that these patients received [24], …”

Hepatitis G:A Virus in Search of a Disease

“…14 In contrast, a number of other studies have failed to strongly implicate HGV, finding HGV RNA in 0 of 5, 9 1 of 7, 15 and 0 of 20 16 patients with FHF. Although data remain fairly sparse, a role for HGV in causing FHF remains tenuous and if HGV does in fact play an etiologic role in FHF, it appears to do so in a distinct minority of patients.…”