GB virus C/hepatitis G virus

GB virus C (GBV-C), or hepatitis G virus (HGV), is a recently discovered enveloped RNA virus belonging to the Flaviviridae family. GBV-C/HGV is transmitted by contaminated blood and/or blood products, intravenous drug use, from mother to child, sexually, and possibly through close social contacts. Several reports indicate a high prevalence of GBV-C/HGV viremia (1-4%) within healthy populations in Europe and North America, and an even higher prevalence (10-33%) among residents in South America and Africa. GBV-C/HGV has been suggested to be a causative agent for non-A-non-E hepatitis. However, several contradictory observations suggest that its ability to cause hepatitis is questionable. Taken together most data suggest that GBV-C/HGV is not a major cause of liver disease despite recent data indicating that it may infect and replicate in hepatocytes.     

Detection of serologic responses to GB virus C/hepatitis G virus infection.

OBJECTIVES: To investigate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) and compare the serologic responses to various GBV-C/HGV markers in eastern Taiwan aborigines. METHODS: We used RT-PCR and anti-HGenv u-plate to investigate the prevalence of GBV-C/HGV in eastern Taiwan aborigines. We also used ELISA, dot blot assay, and Western blot to detect the serologic responses to various GBV-C/HGV markers. RESULTS: The prevalence of GBV-C/HGV RNA in the general population of eastern Taiwan aborigines is about 5% (17/317), while 14% (43/317) have anti-E2 antibodies. There were no significant differences in antibody titer against one consensus core peptide (PPSSAAACSRGSPR) between GBV-C/HGV RNA-positive and -negative sera. Only 23 of 42 serum samples positive in the anti-HGenv u-plate EIA assay were positive (55%) in the dot blot assay. No positive signal was detected by Western blot using either recombinant NS3 or commercial E2 proteins. CONCLUSIONS: Antibodies against one consensus core peptide (PPSSAAACSRGSPR) may not constitute a good marker for the detection of GBV-C/HGV viremia. For the detection of anti-E2 antibodies, the anti-HGenv u-plate assay is more sensitive than the dot blot assay. Western blot assay is not a sensitive method for detecting GBV-C/HGV infection.     

Occult hepatitis B virus infection in hematopoietic stem cell donors in a hepatitis B virus endemic area

BACKGROUND/AIMS: The acquisition of hepatitis B virus (HBV) infection following organ transplantation from donors with occult HBV infection is an important cause of morbidity and mortality. The aim of this study is to determine the prevalence of occult HBV in allogeneic hematopoietic stem cell (HSC) transplantation donors. METHODS: We performed a retrospective study on 124 consecutive hepatitis B surface antigen negative HSC donors. Their serum samples were analyzed by PCR for the pre-S/S, pre-core/core and X regions of the virus. Samples reactive by at least two PCR assays were considered HBV-DNA positive. RESULTS: Nineteen of the 124 HSC donors (15.3%) had occult HBV infection. Sixteen of these 19 donors with occult HBV infection (84.2%) tested positive for hepatitis B core antibody while 78 of 105 subjects (74.3%) without occult HBV infection were also positive (P=0.56). Fourteen of the 19 donors (73.7%) with occult HBV infection tested positive for hepatitis B surface antibody while 67 of the 105 subjects without occult HBV infection were also positive (P=0.45). CONCLUSIONS: The prevalence of occult HBV infection among HSC donors in Hong Kong is high. Anti-HBc and anti-HBs status had no significant correlation with the presence of occult HBV infection.     

GB virus-C/hepatitis G virus infection in a hepatitis C virus endemic village: prevalence in residents with low educational attainment and frequent recovery in females

AIMS/BACKGROUND: GB virus-C/hepatitis G virus (HGV) is a newly identified flavivirus, which may share the same mode of transmission as hepatitis C virus (HCV). The aim of this study was to investigate associated factors of HGV infection and clearance in a HCV endemic village in southern Taiwan. METHODS: Five hundred and ninety-four residents of a village in southern Taiwan were enrolled for hepatitis virus screening. Clinical features were recorded and a questionnaire addressing the possible routes of transmission was filled in by the participating residents. RESULTS: The prevalence of antibody to hepatitis C virus and hepatitis B surface antigen in the 594 residents was 70.7% and 19.5% respectively. Of the 399 residents tested for HGV RNA, GB virus-C/Hepatitis G virus envelop 2 protein (HGV-E2) antibody, and HCV RNA, the prevalence was 13.5%, 25.3%, 53.1% respectively. Multivariate logistic regression analysis showed that low educational attainment was associated with HGV infection, old age and low educational attainment were associated with HCV infection, and female gender was associated with HGV clearance. Alanine aminotransferase (ALT) values were significantly higher for residents with HCV infection alone, HBV infection alone, and co-infection of HCV and HBV than for those without HBV, HCV, and HGV infection. There were no differences in ALT values between subjects with HGV infection alone and those without HBV, HCV, and HGV infections. Residents with co-infection of HGV and HBV, or HGV and HCV had ALT values similar to those with HBV or HCV infection alone. CONCLUSION: HGV infection is common in the HCV endemic village. The transmission of HGV is closely related to low educational attainment. HGV clearance is frequently encountered in females. Co-infection of HGV does not compound hepatocellular inflammation.     

GB virus C/hepatitis G virus in serum and liver of patients with chronic C and non B non C hepatitis: molecular and immunological aspects

GB virus C/hepatitis G Virus (HGV) is a single-stranded RNA virus that is transmitted parenteraly. This study investigates GB virus C in 62 patients with chronic hepatitis C (CHC) and non B non C hepatitis (CNBNC). The viral E2 protein was examined in the sera of the patients (using western blott assay) while viral replication in the liver was examined by detecting the negative strand of HGV-RNA and its E2 protein in liver tissue using in situ hybridization and immunohistochemical staining respectively. E2 protein was detected in 28% of patients with chronic hepatitis C and in 13.3% of patients with non B non C chronic hepatitis, while not detected in healthy blood donors (0%). HGV- E2 protein and the negative strand of HGV -RNA were detected in hepatocytes of only 3 out of the 13 examined liver biopsies from HGV infected patients (23%). The mean level of ALT in chronic HCV hepatitis patients who were +ve for HGV was significantly lower than those who were -ve for HGV. There was a significant difference between the mean value of HCV -RNA level by real time PCR in sera of hepatitis C positive patients with + ve HGV-E2 when compared with HCV patients with - ve HGV-E2 (p < 0.001). It is concluded that HGV co-infection may occur in some cases with CHC and CNBNC. Sites of replication, other than liver, are suggested as the virus was detected in liver tissue of only 23 % of cases inspite of its presence in their sera.     

Prevalence of hepatitis G virus (HGV) infection in an endemic area of hepatitis C virus (HCV) infection

BACKGROUND/AIMS: We investigated the prevalence of hepatitis G virus infection among inhabitants of a hepatitis C virus endemic area. METHODOLOGY: Two hundred and eighty-eight inhabitants, who underwent medical examinations for health screening, were enrolled in this epidemiological study. HGV RNA and HCV RNA were detected by polymerase chain reaction. We also examined anti-HGV envelope protein (E2) antibodies in all serum samples. RESULTS: In these 288 inhabitants, we found anti-HCV antibodies (HCV-Ab) and HCV RNA in 28.5% and 17.4%, respectively. HGV RNA and anti-HGV E2 were detected in 9 (3.1%) and 16 (5.5%), respectively. One patient was positive for both HGV RNA and anti-HGV E2. The exposure rate, expressed as the percentage of people with HGV RNA and/or anti-HGV E2, was 8.3%, which was significantly lower than the incidence of positive HCV-Ab. Of the 24 patients with HGV RNA and/or anti-HGV E2, 15 (62.5%) were positive for HCV-Ab, of those HCV RNA was detected in 9 (37.5%). Further, we found a higher prevalence of HGV exposure in patients with HCV-Ab than in those without (8.3% vs. 4.4%). CONCLUSIONS: HGV infection was not identical to the epidemic hepatitis C virus infection among inhabitants of this town, suggesting that hepatitis C virus might be less infectious than hepatitis C virus.     

重庆地区HGV感染的分子流行病学

目的 探讨重庆地区HGV感染和基因型特征,了解致病性和传播途径。方法 用RT-PCR和ELlSA方法检测685例献血员和76例血液透析患者HGV感染状况,比较肝功能和重叠感染情况并进行部分病例随访;进行HGV 5-NCR测序。结果 本地存在HGV感染．血液透析患者HGV RNA阳性率(36％)明显高于献血员抗-HGV阳性率(3％),约半数透析患者HGV合并HCV和HBV感染;基因分型表明属于第3组3b亚型。结论 HGV主要经血传播,感染HGV透析患者未发现有明显致病性;基因分型有助于深入探讨病毒致病性和变异。     

The epidemiology of hepatitis C virus infection

The prevalence of hepatitis C virus (HCV) infection varies in different populations, ranging from as low as 0.6% in volunteer blood donors to as high as 80% in injection drug users. The prevalence of HCV in a population can be predicted by risk factors associated with the transmission of infection. These risk factors include injection drug use, blood product transfusion, organ transplantation, hemodialysis, occupational injury, sexual transmission, and vertical transmission. We review the literature regarding the incidence and prevalence of HCV infection and the evidence supporting various modes of HCV transmission.     

The epidemiology of TT virus (TTV) infection in a hepatitis C and B virus hyperendemic area of southern Taiwan

TT virus (TTV) is a newly isolated DNA virus from the serum of a patient with posttransfusion hepatitis of unknown etiology in 1997. To evaluate the clinical and molecular characteristics of TT virus (TTV) in a hepatitis C virus (HCV) and B (HBV) hyperendemic area (Masago), 200 residents were enrolled in the study. The sera were tested for alanine aminotransferase (ALT), HCV RNA and GB virus C/Hepatitis G virus (HGV) RNA, TTV DNA, HBsAg, anti-HCV and antibodies to HGV E2-protein (anti-E2). TTV DNA was positive in 99 of the 200 sera with a prevalence rate of 49.5%. The prevalence of HBsAg, anti-HCV, HCV RNA, HGV RNA, anti-E2 and HGV exposure (defined as positive for serum HGV RNA and/or anti-E2) was 38.9%, 69.5%, 64.5%, 17.0%, 25.5% and 39.5%, respectively. Neither clinical nor virological factors were associated with TTV viremia. The rate of ALT abnormality was significantly elevated in HCV RNA-positive (34.9%) than -negative (7.0%) residents (p < 0.001). HCV viremia was the only factor significantly associated with ALT elevation by multiple logistic regression (odds ratio: 6.96; 95% C.I.: 2.60-18.7). We concluded that in this HCV/HBV hyperendemic area, the prevalence of TTV DNA was high. No significant clinical factor was observed to be associated with TTV infection. TTV infection is not related to abnormal ALT levels and ALT abnormality was mainly attributable to HCV but not TTV, HBV or HGV infection.     

Influence of GB virus-C/hepatitis G virus infection on the long-term course of chronic hepatitis B

Abstract: Aims/Background: The clinical significance of GB virus-C/hepatitis G virus (GBV-C/HGV) infection in chronic hepatitis B is not well known and its role in the outcome of liver disease was investigated. Methods: HGV-RNA and antibody to HGV (anti-E2) were studied in 125 patients with chronic hepatitis B (41 with multiple hepatitis virus exposure), 82 asymptomatic HBsAg carriers and 103 healthy adults. Results: In chronic hepatitis B, HGV-RNA was more frequent in patients with HDV infection and/or anti-HCV positivity than in those without (29% vs 6%, p<0.0001), mainly in drug addicts (38%). At diagnosis the overall prevalence of any marker (HGV-RNA plus anti-E2) was similar in chronic hepatitis due to HBV alone (17%), in HBsAg carriers (16%) and in healthy adults (17%) and increased to 58% in those exposed to HDV and/or HCV. During 1–11 years of follow-up, HGV infection persisted in 70% of patients with chronic hepatitis B. About 40% of HGV persistently coinfected patients underwent sustained biochemical remission, whereas continuing disease activity was observed in 80% of patients who cleared HGV-RNA. Conclusions: In chronic HBV infection the rate of exposure to HGV is similar to that in healthy adults, except for high risk patients. Long lasting HGV coinfection or anti-E2 seroconversion did not modify the course of chronic hepatitis B.     

GB virus C/hepatitis G virus infection among patients with hepatocellular carcinoma in the inshore area of the Yangtze river, China

To investigate the association between GB virus C/hepatitis G virus (GBV-C/HGV) infection and the development of hepatocellular carcinoma (HCC) in H city, in the inshore area of the Yangtze River, where high prevalence of HCC has been reported, we determined hepatitis B virus (HBV) and hepatitis C virus (HCV) markers, GBV-C/HGV-RNA and GBV-C/HGV E₂ antibody (anti-HG E₂) among 114 HCC patients and the same number of age- and sex-matched controls. There were no significant differences in the clinical and demographic characteristics between them, except for serum alanine aminotransferase level and history of liver diseases. There was a significant difference of hepatitis B virus surface antigen (HBsAg) prevalence between the HCC patients (75.4%) and the controls (20.2%; P < 0.01). Hepatitis C virus antibody was detected in 4.4% of the HCC patients, compared with 1.7% of the controls. GB virus-C/HGV-RNA and anti-HG E₂ were detected in 14.9 and 1.7% of the HCC patients, respectively, compared with 7.0 and 1.7% of the controls, respectively. Nucleotide sequences and molecular evolutionary analysis showed the strains of GBV-C/HGV-RNA were classified into genotype 2 and 3 (HG and ASIA type). An effect analysis showed an odds ratio (OR) for developing HCC from GBV-C/HGV infection among HBsAg-positive subjects was 14.9, with a 95% CI of 4.9–45.4. HBsAg infection alone was 13.83 (95% CI 7.4–25.9) and GBV-C/HGV infection alone, 3.74 (95% CI 1.1–13.1), respectively. These data indicate that HBV infection is considered to be one of the major risk factors in patients with HCC and although GBV-C/HGV infection was observed in both the HCC and the control groups, it might not play an important role in the development of HCC in this area.