Hepatitis G virus infection in chronic hepatitis C: frequency, features and response to interferon therapy

Detection and phylogenetic analysis of human pegivirus (GBV-C) among blood donors and patients infected with hepatitis B virus (HBV) in Qatar

Human Pegivirus (HPgV), formerly GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is widely spread and has been reported to be associated with non-A-E hepatitis. To our knowledge, no previous study was conducted about HPgV in Qatar. Thus, the objectives of this study were as follows: (i) to determine the rates of HPgV infection in Qatar among healthy blood donors and HBV-infected patients, and (ii) to determine the most predominant HPgV genotype in Qatar. A total of 714 blood plasma samples from healthy donors (612) and HBV-infected patients (102) were collected. RNA was extracted, reversed transcribed, and then subjected for HPgV detection by two round-nested PCR using primers amplifying a 208 bp of 5'-UTR of the HPgV. For genotyping, the 5'-UTR PCR products (from 25 randomly picked samples) were cloned and sequenced. The overall infection rate of HPgV in Qatar was 13.3%. There was no significant difference (P = 0.41) in the infection rates between healthy donor (13.7%) and in HBV-infected patients (10.7%). Moreover, we did not find any significant association between HPgV infection rates and nationality, sex, or age (P > 0.05). Sequence analysis of 40 5'-UTR PCR amplicons yielded the European genotype 2 as most predominant in Qatar, although other genotypes (5 and 7) were also present. Our results indicate that there is no strong correlation between HPgV infection rate, condition, nationality, age, and sex, and genotype 2 is most predominant in Qatar.

Hepatitis G virus

A number of new hepatitis viruses (G, TT, SEN) were discovered late in the past century. We review the data available in the literature and our own findings suggesting that the new hepatitis G virus (HGV), disclosed in the late 1990s, has been rather well studied. Analysis of many studies dealing with HGV mainly suggests the lymphotropicity of this virus. HGV or GBV-C has been ascertained to influence course and prognosis in the HIV-infected patient. Until now, the frequent presence of GBV-C in coinfections, hematological diseases, and biliary pathology gives no grounds to determine it as an “accidental tourist” that is of no significance. The similarity in properties of GBV-C and hepatitis C virus (HCV) offers the possibility of using HGV, and its induced experimental infection, as a model to study hepatitis C and to develop a hepatitis C vaccine.

Dynamics of hepatitis C virus NS5A quasispecies during interferon and ribavirin therapy in responder and non-responder patients with genotype 1b chronic hepatitis C

The quasispecies nature of hepatitis C virus (HCV) may have important implications concerning resistance to antiviral agents. To determine whether HCV NS5A quasispecies composition and dynamics are related to responsiveness to combined interferon (IFN) and ribavirin therapy, extensive sequence analyses of cloned RT-PCR amplification products of HCV-1b NS5A quasispecies of sequential isolates from 15 treated (nine sustained responders and six non-responders) and three untreated patients were performed. Accumulation of mutations in NS5A during therapy was relatively frequent in the V3 domain, but unusual elsewhere. Amino acid changes were the result of the imposition of minor variants that were already present before treatment and always occurred within the first week of therapy. Before treatment, the complexity and diversity of quasispecies were lower in isolates from responders than in those from non-responders, particularly in the V3 domain, where differences in nucleotide entropy (0.35 vs 0.64, P=0.003), genetic distance (0.0145 vs 0.0302, P=0.05) and non-synonymous substitutions (0.0102 vs 0.0203, P=0.036) were statistically significant. These differences became more apparent during treatment, because complexity and diversity remained stable or tended to increase in non-responders, whereas they tended to decrease in responders. These observations suggest that the composition and dynamics of HCV NS5A quasispecies, particularly in the V3 domain, may play a role in the response to combined IFN/ribavirin therapy.

Detection and genotyping of GBV-C virus in the United Arab Emirates

GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is spread widely and has been reported to be associated with non A-E hepatitis. The aim of the current project was to determine the rate of infection and genotypic characteristics of GBV-C in the United Arab Emirates (UAE). A total of 379 plasma/serum samples representing different populations in the UAE and comprising healthy as well as patients positive for HBV and HCV were screened using RT-PCR/nested PCR of the 5'-untranslated region (UTR). National subjects (n=168) and non-nationals residing in the UAE (n=211) were tested. The results obtained showed that the rate of GBV-C infection in healthy nationals, and those positive for HCV or HBV were 11.1%, 14.3%, and 5.7%, respectively, compared to 8.3%, 33.3%, and 8.6%, respectively, in non-nationals. No statistically significant correlation between infection with GBV-C and HCV or HBV (P>0.05) was found. Sequence analysis of the 5'-UTR using 37 and 46 clones from 8 and 6 healthy nationals and non-nationals, respectively, revealed the prevalence of the European/North American genotype 2 when compared to the five reference genotypes in GenBank.

Co-infections with hepatitis G and TT virus in patients with chronic hepatitis C in Hungary

The significance of co-infections with novel hepatitis viruses Hepatitis G (GBV-C, HGV) and TT virus (TTV) in chronic hepatitis C is not clear. We determined the prevalence of HGV RNA and TTV DNA in chronic hepatitis C patients and in asymptomatic hepatitis C virus (HCV) carriers, and assessed the influence of these agents on the course of HCV infection. Seventy-seven patients with chronic hepatitis C--50 of them treated with interferon (IFN)--and 33 HCV carriers with normal alanine aminotransferase have been investigated. Previous HBV infection was detected by testing serum HBsAg and aHBc. HGV RNA and TTV DNA were detected by PCR. In the healthy population, the prevalence of anti-HCV was 0.3%, HGV RNA 8.0% and TTV DNA 18.5%. In chronic hepatitis C HGV RNA occurred in 9.09% and TTV DNA in 40.25% of cases. In IFN-treated patients with sustained remission, the frequency of TTV was 20% vs. 45.7% found in non-responders. Among asymptomatic HCV-carriers, the prevalence of HGV RNA was 9.09% and TTV DNA 75.7%. Neither HGV RNA nor TTV DNA had apparent effect on the HCV infection. TTV was detected with the lowest frequency in persons with sustained remission due to IFN, suggesting antiviral effect of IFN on TTV.

[Is GB virus C alias "hepatitis" G virus involved in human pathology?]

GB virus-C alias "hepatitis" virus G was discovered in 1995 as a putative causative virus of non A-E hepatitis. It is a very common virus found in 1 to 5% of eligible blood donors in developed countries. Numerous studies over seven years led to the exclusion of its role as a significant etiological agent of hepatitis. Its in vivo replication site is still unknown. Its direct involvement in the induction of significant hepatic or extra-hepatic diseases could not be demonstrated. However, coinfections with other viruses may contribute to changes in the evolution of both liver disease (negatively) and HIV/AIDS (favourably). Today, no country has decided to screen GBV-C in blood donors. However, more studies are necessary before the absence of influence of GBV-C infection on human health in the context of other viral infections could be confirmed definitely. This article is a review of the literature on a possible involvement of GBV-C in pathologies whether associated or not to other infections.

Characterization and evolution of NS5A quasispecies of hepatitis C virus genotype 1b in patients with different stages of liver disease

The quasispecies nature of hepatitis C virus (HCV) is thought to play a central role in modulating viral functions. Recent work has linked NS5A protein with viral replication, resistance to interferon (IFN), and control of cellular growth, probably through the interaction of its protein kinase R (double stranded RNA-activated protein kinase, PKR) binding domain (PKR-bd) with cellular PKR, but knowledge of how PKR-bd viral population evolves during disease progression is limited. Since we have previously described an association between amino acid composition of the PKR-bd and the presence of HCC, in this report we further investigated the dynamic behavior of viral population parameters by sequencing an average of 20 clones per sample in 27 samples from 19 untreated patients with different degrees of liver disease, 8 of whom were followed over time. Viral population parameters varied widely from patient to patient, but no differences were observed in the complexity, diversity, types of nucleotide changes, or evolutionary pattern of the quasispecies according to the stage of liver disease. In five samples, we detected "quasispecies-tails"; that is, clones whose minimum genetic distance to the remaining clones of their own quasispecies were higher than the maximum genetic distance found between any other two clones of the same sample. In summary, independent of the degree of liver disease, or the mutations detected within the consensus sequence of the PKR-bd, the NS5A of HCV presents a flexible and variable quasispecies structure that remains largely stable during the natural course of an HCV infection, highlighting the central role of NS5A protein in viral life cycle.

Genotype distribution of the GB virus C in citizens of São Paulo City, Brazil

There has been several studies worldwide on phylogenetics and genotype distribution of the GB-virus C / Hepatitis G virus (GBV-C/HGV). However, in their great majority, those investigations were based on some epidemiologically linked group, rather than on a representative sampling of the general population. The present is a continuation of the first study in Brazil with such a population; it addresses the GBV-C/HGV phylogenetics and genotype distribution based on samples identified among more than 1,000 individuals of the city of S o Paulo. For this purpose, a 728 bp fragment of the 5 non-coding region (5 NCR) of the viral genome, from 24 isolates, was sequenced and subjected to phylogenetic analysis. Genotypes 1, 2a and 2b were found at 8.3% (2/24), 50% (12/24) and 41.7% (10/24), respectively. In conclusion S o Paulo displays a genotype distribution similar to the published data for other States and Regions of Brazil, endorsing the notion that types 1 and 2 would have entered the country with African and European people, respectively, since its earliest formation.

Outbreak of nosocomial hepatitis C virus infection resolved by genetic analysis of HCV RNA

In July 2000, symptomatic acute hepatitis C was diagnosed in five patients who had attended the emergency room of a municipal hospital on the same day, about 6 weeks before. Investigation of the remaining 65 patients visited at the emergency room on that day disclosed that 8 patients had a positive anti-hepatitis C virus (anti-HCV) test and 4 of them had biochemical evidence of acute anicteric hepatitis. HCV RNA was detected in 12 of the 13 anti-HCV-positive patients. Phylogenetic analysis of the nonstructural 5A (NS5A) and E2 regions showed that 10 patients, including all 9 with acute hepatitis, were infected with a closely related HCV strain, while the remaining 2 patients harbored unrelated strains. Flushing of intravenous catheters with heparin retrieved from a multidose heparin solution in saline was carried out for all the patients involved in the hepatitis outbreak but in only 1 of 23 (4%) matched controls recruited among HCV-noninfected patients attending the emergency room on the same day, and this was the only significant difference concerning risk factors for HCV infection between patients and controls. Thus, accidental contamination of a multidose heparin solution with blood from an unrecognized HCV carrier was identified as the source of this nosocomial outbreak of hepatitis C.

Influence of the genetic heterogeneity of the ISDR and PePHD regions of hepatitis C virus on the response to interferon therapy in chronic hepatitis C

Two genomic regions of hepatitis C virus (HCV), the interferon sensitivity-determining region (ISDR) of the non-structural 5A gene (NS5A) and the protein kinase-RNA activated (PKR)-eukariotic transcription factor (eIF2-alpha) phosphorylation homology domain (PePHD) of the structural E2 gene, interact in vitro with the interferon-inducible cellular PKR protein kinase. Mutations within these regions might, therefore, influence the response to interferon therapy. Viral load at baseline and sequence heterogeneity of HCV in NS5A and E2 regions was studied in 74 HCV-1b and in 12 HCV-3a infected patients with chronic hepatitis C who were treated with interferon. As previously reported by us, in a smaller series of patients in which the ISDR region was analyzed [Saiz et al. (1998) Journal Infectious Diseases 177:839-847], in the present study a low viral load and a high number of amino acid mutations within the ISDR, but not within the PePHD region, were significantly associated with long-term response to interferon among HCV-1b infected patients. No relationship between these viral features and response to therapy was disclosed in patients infected with HCV-3a.

GB virus C/hepatitis G virus (GBV-C/HGV): still looking for a disease

GB Virus C and Hepatitis G Virus (GBV-C/HGV) are positive, single-stranded flaviviruses. GBV-C and HGV are independent isolates of the same virus. Transmission via the blood-borne route is the commonest mode, although vertical and sexual transmission is well documented. GBV-C/HGV is distributed globally; its prevalence in the general population is 10 fold higher in African countries than in non-African countries. High prevalences of GBV-C/HGV have been found in subjects with frequent parenteral exposure and in groups at high risk of exposure to blood and blood products. The clinical significance of human infection with GBV-C/HGV is currently unclear. The virus can establish both acute and chronic infection and appears to be sensitive to interferon. Only some 12-15% of chronic Non-A, B, C hepatitis cases are infected with GBV-C/HGV. A direct association with liver pathology is still lacking and it is not yet clear as to whether GBV-C/HGV is indeed a hepatotropic virus. Current evidence suggests that the spectrum of association of GBV-C/HGV infection with extrahepatic diseases ranges from haematalogical diseases, aplastic anaemia, human immunodeficiency virus (HIV)-positive idiopathic thrombocytopenia and thalassemia, through to common variable immune deficiency and cryoglobunemia.

A high frequency of GBV-C/HGV coinfection in hepatitis C patients in Germany

AIM: To detect infection rate of GBV-C/HGV in hepatitis C patients, to determine the methods of higher sensitivity and the primers of higher efficiency for GBV-C/HGV RNA detection and to study the dominant subtype and mutation of GBV-C/HGV.

METHODS: Quantitative RT-PCR for detection pf HCV RNA concentration in serum samples, RT-nested PCR with two sets of primers for detection of GBV-CRNA, RT-PCR ELISA with two sets of primers for detection of HGV RNA, nucleotide sequence and putative amino acid sequence analysis.

RESULTS: The positive rates of GBV-C RNA at the 5’-NCR and NS3 region in 211 serums amples from the patients with HCV infection were 31.8% and 22.8% respectively. The positive rates of HGV RNA at the 5’-NCR and NS5 region in the same samples were 47.9% and 31.8% respectively. The total positive rate of GBV-C/HGV RNA was as high as 55.5%. HCV copy numbers in the patients without GBV-C/HGV coinfection were statistically higher than that in the patients with GBV-C/HGV coinfection (P < 0.01). Frequent mutation of nucleotide residue was present in the amplification products. Frameshift mutation was found in two samples with GBV-C NS3 region nucleotide sequences. All nucleotide sequences from amplification products showed higher homology to HGV genome than to GBV-C genome even though part of the sequences were amplified with GBV-C primers.

CONCLUSION: A high frequency of GBV-C/HGV coinfection existed in the hepatitis C patients. RT-PCR ELISA was more sensitive than RT-nested PCR for detection of GBV-C/HGV RNA. The primers derived from the 5’-NCR was more efficient than those derived from the NS3 and NS5 regions. A reverse relationship was found to exist between HCV RNA concentration and GBV-C/HGV infection frequency. HGV was the dominant subtype of the virus in the local area. The major mutations of GBV-C/HGV genomes were random mutation of nucleotide residue.

GB virus C/hepatitis G virus (GBV-C/HGV): still looking for a disease

GB Virus C and Hepatitis G Virus (GBV-C/HGV) are positive, single-stranded flaviviruses. GBV-C and HGV are independent isolates of the same virus. Transmission via the blood-borne route is the commonest mode, although vertical and sexual transmission is well documented. GBV-C/HGV is distributed globally; its prevalence in the general population is 10 fold higher in African countries than in non-African countries. High prevalences of GBV-C/HGV have been found in subjects with frequent parenteral exposure and in groups at high risk of exposure to blood and blood products. The clinical significance of human infection with GBV-C/HGV is currently unclear. The virus can establish both acute and chronic infection and appears to be sensitive to interferon. Only some 12-15% of chronic Non-A, B, C hepatitis cases are infected with GBV-C/HGV. A direct association with liver pathology is still lacking and it is not yet clear as to whether GBV-C/HGV is indeed a hepatotropic virus. Current evidence suggests that the spectrum of association of GBV-C/HGV infection with extrahepatic diseases ranges from haematalogical diseases, aplastic anaemia, human immunodeficiency virus (HIV)-positive idiopathic thrombocytopenia and thalassemia, through to common variable immune deficiency and cryoglobunemia.

Seroprevalence of GB virus C/hepatitis G virus-RNA and anti-envelope antibody in high-risk populations in Taiwan

BACKGROUND

GB Virus C (GBV-C)/hepatitis G virus (HGV) was identified in 1995-1996 as a transfusion-transmissible virus. The diagnosis of GBV-C/HGV infection is based on the detection of GBV-C/HGV-RNA by using polymerase chain reaction. Recently, an enzyme immunoassay detecting the antibodies to the viral protein, E2 envelope protein (anti-envelope) of GBV-C/HGV, has been developed.

METHODS

Serum GBV-C/HGV-RNA and anti-envelope antibody were determined in 76 cases of intravenous drug users (IVDU), 76 patients with regular hemodialysis and in 80 prostitutes to evaluate the GBV-C/HGV infection rate among high-risk populations in Taiwan. Seventy-six healthy blood donors were randomly selected and were used as a control group.

RESULTS

The prevalence of GBV-C/HGV-RNA in high-risk populations was 33% for IVDU, 16% for patients with hemodialysis and 13% for prostitutes, which was significantly higher than the 3% obtained in the control group (P < 0.05 for all groups). The prevalence of anti-envelope antibody was 13% for IVDU, 21% for patients with hemodialysis and 23% for prostitutes, which was not significantly different from the control group (11%). Among the 99 subjects who had positive GBV-C/HGV markers, 97 were tested for exclusive positivity for either GBV-C/HGV-RNA or anti-envelope antibody.

CONCLUSIONS

The presence of serum anti-envelope antibody usually indicates the clearance of serum GBV-C/HGV-RNA in patients infected with GBV-C/HGV. GBVirus-C/HGV infection in high-risk populations, determined by the presence of serum GBV-C/HGV-RNA, may underestimate the true level of past and present infection.

Insignificant role of hepatitis G virus infection in patients with liver enzyme elevations of unknown etiology

Hepatitis G virus (HGV) may cause acute and chronic infection in humans but its role in parenchymal liver injury and chronic hepatitis is obscure. In this study, the importance of HGV was investigated in patients with elevated aminotransferases alanine transaminase/aspartate transaminase (ALT/AST) levels of unknown etiology. We included 56 patients with elevated ALT/ AST levels of unknown etiology and 81 healthy controls in the study. HGV RNA was investigated by the reverse transcription polymerase chain reaction. The other possible causes of transaminase elevation were excluded with detailed biochemical and serologic tests. Liver biopsy was performed on 47 patients for histologic examination. HGV RNA was detected in only two patients (3.3%) and in one control (1.2%). There was no statistical difference between the groups. Liver biopsy revealed minimal inflammatory changes and steatosis in HGV RNA-positive patients. These observations indicated that HGV prevalence is not different from that of the general population in patients with liver transaminases elevation of unknown etiology. The role of this novel virus in the pathogenesis of chronic liver injury of unknown etiology appears insignificant in our geographic area.

Influence of RNA titre and amino acid changes in the NS5A region of GB virus c/hepatitis G virus on the effectiveness of interferon therapy

BACKGROUND

A relationship between the pretreatment RNA titre of GB virus C/hepatitis G virus (GBV-C/HGV) and the effectiveness of interferon (IFN) therapy has been reported previously. However, the influence of changes in the amino acid sequence of the NS5A region of GBV-C/HGV on the effectiveness of IFN therapy has not been examined, although this influence has been explored in patients with chronic hepatitis caused by hepatitis C virus. We examined the relationship between changes in the amino-acid sequence of the NS5A region and the effectiveness of IFN therapy.

METHODS

The subjects were 10 patients with chronic hepatitis C coinfected with GBV-C/HGV and treated with IFN. The pretreatment level of GBV-C/HGV-RNA (copies/mL) in their sera was measured by real-time detection polymerase chain reaction (PCR) assay. At 6 months after cessation of therapy, four of 10 patients had become negative for GBV-C/HGV-RNA (CR, complete response) and six patients were still positive for GBV-C/HGV-RNA (NR, non-response). We determined the nucleotide sequence of the NS5A region (amino acid residues 1865-2279; NS5A1865-2279) of pretreatment GBVC/HGV-RNA by direct sequencing.

RESULTS

The pretreatment GBV-C/HGV-RNA level of CR patients (7.8 x 10(4) - 6.2 x 10(5), mean 3.30 x 10(5)) was significantly lower than that of NR patients (6.3 x 10(7) - 7.2 x 10(8), mean 3.55 x 10(8); P< 0.01). The number of amino acid substitutions in NS5A1865-2279 was five to seven (mean 5.8 +/- 1.0) in CR patients, and four to eight (mean 6.8 +/- 1.6) in NR patients, a difference that is not significant. Moreover, there were no amino acid substitutions or sites of substitution in NS5A1865-2279 that were specific to either group.

CONCLUSIONS

The effectiveness of IFN therapy for GBV-C/HGV is strongly related to the pretreatment GBV-C/HGV-RNA level, but is not related to changes in NS5A1865-2279.

Genetic evolution of GB virus C/hepatitis G virus (GBV-C/HGV) under interferon pressure

The epidemiology and clinical features of chronic GBV-C/HGV infection have largely been explored, but there is little information about the mechanisms enabling GBV-C/HGV to cause persistent infection. Since analysis of the genomic variation of GBV-C/HGV under interferon pressure might provide some insight into this issue, we analyzed the nucleotide sequence variation of the 5'NC and NS3 regions in GBV-C/HGV isolates obtained sequentially from seven patients co-infected with HCV and treated with interferon. A reduction of GBV-C/HGV-RNA serum level below the detection limit of the RT-PCR assay was observed during treatment in all patients, but upon interferon withdrawal, viral RNA remained undetectable in only two patients. Among the five patients who did not clear GBV-C/HGV-RNA, viral strains emerging after treatment were identical to those present at baseline in three cases. In a further case, in whom GBV-C/HGV-RNA re-emerged during therapy (breakthrough episode), several mutations appeared in relapse samples. In the remaining patient, with a mixed infection before therapy, only one of the two GBV-C/HGV strains present at baseline was detected upon treatment withdrawal. These data raise the possibility that positive selection may act over GBV-C/HGV genome during interferon therapy, and contribute to persistence of infection with this virus.

Prevalence of hepatitis G virus in healthy children in liver disease, and human immunodeficiency virus-1 infection: response to interferon

BACKGROUND

A new virus of the Flaviviridae family, the hepatitis G virus (HGV/HGBV-C), has been identified recently. The purpose of this study was to determine the prevalence of HGV infection in healthy children, in patients with liver disease, and in human immunodeficiency virus (HIV)-1-infected patients. The role of HGV in the clinical course of chronic HCV, the response to interferon-alpha2b, and the possible implications of intravenous gamma-globulin in the transmission of the virus were also evaluated.

METHODS

Fifty healthy children, 66 patients with a variety of liver diseases, 19 patients with acquired immune deficiency syndrome (AIDS), and various batches of commercial intravenous immunoglobulins were investigated. Viral HGV RNA (5'NCR-NS5) and anti-HGV envelope protein E2 were assayed.

RESULTS

The prevalence of HGV infection was 6% in the healthy children and 42% in the liver disease group. Viremia and anti-E2 were found in 11% and 79% of patients with AIDS. Four (27%) of 15 patients with chronic HCV, receiving treatment with interferon, were coinfected by HGV and became HGV-RNA negative during therapy. One year after the end of interferon therapy, three of them were again HGV RNA positive.

CONCLUSIONS

The prevalence of HGV infection is high in healthy children higher in children affected with liver disease, but its potential pathologic implication is questionable, and further studies are warranted. Hepatitis G virus is sensitive to interferon therapy, although the infection often recurs after discontinuation of treatment.

Prevalence and route of transmission of infection with a novel DNA virus (TTV), hepatitis C virus, and hepatitis G virus in patients infected with HIV

OBJECTIVES

To evaluate the prevalence, route of transmission and clinical significance that current co-infection with TT virus (TTV), hepatitis C virus (HCV), and hepatitis G virus (HGV) have in HIV-1-infected patients.

DESIGN

Presence of TTV, HCV, and HGV was analyzed in plasma samples from 160 HIV-1-infected patients with parenteral (38 intravenous drug users [IVDUs] and 41 patients with hemophilia) or sexual (39 homosexuals and 42 heterosexuals) risk of exposure, and in 168 volunteer blood donors. Alanine aminotransferase (ALT) levels and CD4+ counts were also analyzed.

METHODS

HCV and HGV RNA were detected by specific reverse transcriptase (RT) nested polymerase chain reaction (PCR) and TTV DNA by specific heminested PCR.

RESULTS

TTV DNA was detected in 39% of the patients and in 14% of the volunteer blood donors. HCV and HGV infections were detected in 42% and in 14% of the patients, and in 0% and 3% of the blood donors, respectively. Prevalences of TTV and HCV infection were higher among patients with parenteral (62% and 68%) than in those with sexual (17% and 16%) risk of exposure. A higher prevalence of TTV infection (but not of HCV or HGV infection) was observed among patients with hemophilia (76%) than IVDUs (47%), and among homosexuals (26%) than among heterosexuals (10%). Abnormal ALT levels were related with the presence of HCV infection, independently of the detection of TTV DNA. TTV infection did not seem to alter the levels of CD4+ T cells.

CONCLUSIONS

Prevalence of current TTV infection is high among HIV-infected patients with parenteral risk of exposure, but TTV is also transmitted through sexual routes; detection of TTV does not seem to influence the clinical or immune status of HIV-infected patients.

Biochemical and virological response to interferon therapy in patients with chronic hepatitis C, co-infected with hepatitis G virus

It is still unclear whether hepatitis G virus (HGV) and hepatitis C virus (HCV) co-infection influences the natural course of chronic HCV infection and the response to interferon (IFN) therapy. In this study, we investigated the HGV RNA changes and responses to IFN therapy of HGV RNA-positive hepatitis C patients. The presence of HGV RNA in 264 patients who received IFN therapy at our institute was examined using the nested reverse transcription-polymerase chain reaction with primers deduced from the 5' non-coding region (5'-NCR) of the HGV. We also analysed the nucleotide sequences of the 5'-NCR and HGV before and after IFN therapy. Twelve (4.5%) of the 264 patients with chronic hepatitis C were HGV RNA positive. Of these 12 patients, full information was available in nine. Of those nine, seven became HGV RNA negative during IFN therapy but in six of the seven a relapse occurred. HCV RNA was not detected 1 year after IFN therapy in six patients. The serum alanine aminotransferase (ALT) levels of all the HCV RNA-negative patients post-treatment was within the normal range, irrespective of their HGV RNA status. Nucleotide sequences did not change after IFN therapy in any patient. Hence, we confirm that HGV is sensitive to IFN therapy but the liver damage caused by HGV infection is very mild or does not modify the liver function tests.

Hepatitis G virus: molecular organization, methods of detection, prevalence, and disease association

This article reviews data on hepatitis G virus (HGV) prevalence and possible disease associations in various groups of patients. An important fraction of acute or chronic hepatitis cases probably have a viral etiology and are not attributable to known hepatitis viruses. Therefore, researchers continually are looking for new hepatitis viruses. Among the agents found are members of GB hepatitis viruses, including GB-C virus, or HGV. This review presents the history of the discovery of HGV, its molecular biology and some methods of detection; results of clinical and molecular studies of HGV infection also are discussed.

Efficacy and tolerance of interferon-alpha(2b) in the treatment of chronic hepatitis C virus infection in haemodialysis patients. Pre- and post-renal transplantation assessment

BACKGROUND

Hepatitis C virus (HCV) infection represents an important problem for the dialysis population due to its high prevalence and the long-term development of chronic liver disease, particularly following renal transplantation.

METHODS

In order to assess the efficacy and tolerance of interferon (IFN) in the treatment of chronic hepatitis C in haemodialysis (HD) patients and their clinical course following renal transplantation, a multicentre, randomized, open-label study was conducted to compare IFN therapy vs a control group.

RESULTS

Nineteen HCV RNA-positive patients received 3 x 10(6) U of IFN s.c., three times a week (post-HD), and 17 HCV RNA-positive patients were assigned to the control group. Tolerance to IFN therapy was good in nine patients, while treatment was discontinued in the other 10 due to the occurrence of side effects. HCV RNA was negative at the end of treatment in 14 out of 19 patients (74%) receiving IFN and in one patient (5%) in the control group. Six out of the 14 patients who initially responded to IFN therapy had a virological relapse (43%). Eight patients (42%) remained HCV RNA-negative, three of them until the day that renal transplantation (RT) was performed (7, 12 and 27 months, respectively), as did five patients on HD during the follow-up (27+/-5 months). Eight out of the nine patients (89%) who completed therapy were HCV RNA-negative at the end of treatment, and seven of them (78%) remained HCV RNA-negative during the follow-up on dialysis (21+/-8 months). Mean transaminase (ALT) values were significantly decreased following IFN therapy, while no changes were observed during the follow-up period in the control group. Fifteen patients (10 in the treatment group and five in the control group) underwent RT. Three patients in the treatment group were HCV RNA-negative at RT, and one of them had a virological relapse 20 months after RT, while the other two remained HCV RNA-negative at 3 months and 24 months after RT, respectively. In contrast to the control group, transaminase (ALT) remained within normal limits in all patients in the treatment group. Finally, during the post-RT follow-up, the transaminase mean values were significantly lower in treated patients vs patients in the control group (P<0.05).

CONCLUSIONS

It is concluded that the biochemical and virological response to IFN therapy is good in HD patients. In addition, IFN therapy appears to exert a beneficial effect on the course of liver disease following RT, regardless of the virological response. Despite the fact that IFN therapy was discontinued in 10 out of the 19 patients due to the occurrence of side effects, these disappeared following discontinuation of therapy. Therefore, IFN therapy is advisable for HCV-infected dialysis patients who are candidates for RT.

Molecular evidence of mother-to-infant transmission of hepatitis G virus among women without known risk factors for parenteral infections

Hepatitis G virus (HGV) RNA was detected in 18 of 133 pregnant women from Tanzania without known risk factors for HGV infection and in 7 of 18 children born to HGV RNA-positive mothers. Molecular evidence of mother-to-infant transmission was obtained only for three of seven children. HGV RNA was also detected in 4 of 42 children born to non-HGV-infected women. Thus, mechanisms other than materno-filial may play an important role in HGV transmission during early childhood.

Infection with a novel human DNA virus (TTV) has no pathogenic significance in patients with liver diseases

BACKGROUND/AIMS

A recently identified DNA virus, termed TT virus (TTV), has been associated with post-transfusional hepatitis, and a high prevalence of TTV infection in patients with acute or chronic liver disease of unknown etiology has been reported from Japan, but few data are available about TTV infection in other countries.

METHODS

Using hemi-nested-PCR amplification to detect TTV-DNA sequences in serum, we investigated TTV infection in blood donors and in patients with liver diseases of varied etiology.

RESULTS

The prevalence of TTV infection was 13.7% in blood donors (23/168), 18.6% in chronic hepatitis C (19/102), 28.6% in chronic hepatitis B (16/56), 29.9% in hepatocellular carcinoma (20/67), 9.1% in cryptogenic chronic liver disease (2/22) and 39.6% in fulminant hepatitis (19/48). The prevalence of TTV infection in patients with virus-induced or idiopathic fulminant hepatitis was similar. Comparison of TTV-infected and non-infected patients did not reveal significant differences concerning demographic, epidemiological or histopathological features. In patients with hepatitis C, response to interferon therapy was not related to TTV infection. Phylogenetic analysis of TTV isolates showed that at least three different types of TTV are present in Spain.

CONCLUSIONS

Our data suggest that TTV infection is frequent among blood donors and patients with acute liver disease. However, pathogenic effects associated with TTV infection were not observed.

The clinical significance of simultaneous infection with hepatitis G virus in 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 chronic hepatitis C. The significance of simultaneous infection with HGV and hepatitis C virus (HCV) remains to be clarified, as do the effects on HGV of therapeutic interventions such as interferon treatment or liver transplantation.

THE AIMS OF OUR STUDY WERE

1) to examine the frequency of HGV infection in the settings of liver transplantation and interferon therapy for hepatitis C; and 2) to compare HGV RNA levels before and after liver transplantation or interferon treatment.

METHODS

Pre-treatment sera were available in 65 patients with chronic hepatitis C treated with interferon; pretransplant sera were available in 49 patients transplanted for end stage liver disease associated with chronic hepatitis C. Information collected included age, sex, risk factors for hepatitis, concurrent liver disease, patient and allograft survival, biochemical response 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 predominance among HGV-positive compared with HGV-negative transplant patients (80% vs 20%; p < 0.01), but such a difference was not observed in the interferon-treated group. Hepatic iron concentration was lower in hepatic explants from patients who were HGV-positive than in those who were HGV-negative (318 +/- 145 microg/g dry weight vs 1497 +/- 2202 microg/g dry weight; p = 0.02). HCV exposure after 1980 was more common in the HGV-positive patients than 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 subgroup (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 tested during or after interferon treatment, HGV RNA levels declined from pretreatment levels in all and disappeared in three.

CONCLUSIONS

Among patients with chronic hepatitis C treated with either interferon or liver transplantation, the frequency of coinfection with HGV is about 20%. HGV may be a more recent virus in the US than HCV. Coinfection with HGV does not appear to affect the likelihood of response to interferon in patients with hepatitis C. Finally, HGV RNA levels appear to decline after both liver transplantation and interferon therapy, suggesting possible suppression by increased HCV replication in the former case, and a possible drug treatment effect in the latter.

Amino acid substitutions in NS5A region of GB virus C and response to interferon therapy

GB virus C (GBV-C) is related to hepatitis C virus (HCV) and has a similar genomic structure. Some predictors for the efficacy of interferon (IFN) therapy on HCV have been reported: genotype, viral load, IFN dose, and the amino acid substitutions in the NS5A region, designated as the interferon sensitivity determining region (ISDR). To evaluate the correlation between the amino acid substitutions in the GBV-C NS5A region and the response to IFN therapy, single-strand conformation polymorphism (SSCP) analysis was performed in the 12 concomitantly GBV-C-and HCV-infected patients who received IFN therapy at three time points: before, end-point, and after the IFN therapy. The region in the GBV-C NS5A studied includes the amino acids that exhibit some homology to the ISDR and the various substitutions. By SSCP analysis, amplicons were separated into 1-4 bands, which indicated the existence of heterogeneity in each host. However, the deduced amino acid sequences in these bands exhibited no characteristic differences among these strains irrespective of response to IFN therapy. Of the 32 strains separated by SSCP, 7 strains were responders, and 25 were nonresponders. The mean amino acid substitution, compared with the consensus sequence of nonresponders, was 1.00+/-0.93 among responders, and 1.40+/-0.85 among non-responders (P= NS). No correlation between the amino acid sequence in the GBV-C NS5A region and response to IFN therapy was found, indicating that the GBV-C NS5A region dose not act as the ISDR.

Amino acid substitutions in NS5A region of GB virus C and response to interferon therapy

GB virus C (GBV-C) is related to hepatitis C virus (HCV) and has a similar genomic structure. Some predictors for the efficacy of interferon (IFN) therapy on HCV have been reported: genotype, viral load, IFN dose, and the amino acid substitutions in the NS5A region, designated as the interferon sensitivity determining region (ISDR). To evaluate the correlation between the amino acid substitutions in the GBV-C NS5A region and the response to IFN therapy, single-strand conformation polymorphism (SSCP) analysis was performed in the 12 concomitantly GBV-C-and HCV-infected patients who received IFN therapy at three time points: before, end-point, and after the IFN therapy. The region in the GBV-C NS5A studied includes the amino acids that exhibit some homology to the ISDR and the various substitutions. By SSCP analysis, amplicons were separated into 1-4 bands, which indicated the existence of heterogeneity in each host. However, the deduced amino acid sequences in these bands exhibited no characteristic differences among these strains irrespective of response to IFN therapy. Of the 32 strains separated by SSCP, 7 strains were responders, and 25 were nonresponders. The mean amino acid substitution, compared with the consensus sequence of nonresponders, was 1.00+/-0.93 among responders, and 1.40+/-0.85 among non-responders (P= NS). No correlation between the amino acid sequence in the GBV-C NS5A region and response to IFN therapy was found, indicating that the GBV-C NS5A region dose not act as the ISDR.

Correlation of interferon treatment response with GBV-C/HGV genomic RNA and anti-envelope 2 protein antibody

The clinical significance of GB virus C/hepatitis G virus (GBV-C/HGV) co-infection was studied retrospectively in 100 consecutive patients with hepatitis C virus (HCV) infection. All 100 patients had been treated with interferon-alpha (IFN-alpha). Co-infection with GBV-C/HGV and HCV was detected in 10 of the 100 patients (10%) and anti-envelope 2 region (anti-E2) antibody was detected in 25 patients. None of the patients with GBV-C/HGV RNA had anti-E2 antibody. Co-infected patients were younger (P < .005) and their serum transaminase levels were lower than HCV-only infected patients (P< .01). In 7 of the 10 co-infected patients, HCV RNA was eradicated from serum after IFN-alpha treatment and normal alanine transaminase (ALT) levels continued in 6 of these 7 patients. In one patient who was negative for HCV RNA but positive for GBV-C/HGV RNA, the ALT level relapsed transiently. The rate of clearance of HCV and normalization of the ALT level was significantly higher in co-infected patients than in HCV-only infected patients (P < .05). GBV-C/HGV RNA disappeared from 6 of the 10 co-infected patients (60%) upon cessation of IFN-alpha treatment. However, continuous clearance of GBV-C/HGV was observed in only two patients and anti-E2 antibody could not be detected in the serum of these patients. These results indicate that co-infected patients tend to be younger and more sensitive to IFN-alpha treatment. However, long-term clearance of GBV-C/HGV after IFN-alpha treatment may be difficult. Moreover, anti-E2 antibody may act to neutralize GBV-C/ HGV.

Relationship of the genomic complexity of hepatitis C virus with liver disease severity and response to interferon in patients with chronic HCV genotype 1b infection [correction of interferon]

In patients with chronic hepatitis C, the influence of the genetic heterogeneity of the hepatitis C virus (HCV) on the progression of liver disease and on the responsiveness to interferon therapy is a matter of controversy. In this study we evaluated the genetic complexity of HCV by single-strand conformation polymorphism (SSCP) analysis of amplicons from the hypervariable region 1 (HVR1) in 168 patients with chronic genotype 1b HCV infection, of whom 122 received a single course of interferon therapy (3 MU, three times weekly for 6 months). No correlation was observed between the degree of genetic complexity of HCV (indicated by the number of bands in the SSCP assay) and patient age, serum alanine aminotransferase activity, or serum HCV-RNA concentration, measured by competitive polymerase chain reaction. HCV genomic complexity was not related to gender nor to the presumed source of infection. The number of SSCP bands detected in serum samples from patients with chronic hepatitis, either mild (8.1 +/- 3.9), moderate (8.0 +/- 3.3), or severe (9.2 +/- 3.3), and in patients with liver cirrhosis, either compensated (8.0 +/- 2.9), decompensated (6.3 +/- 2.9), or with superimposed hepatocellular carcinoma (9.5 +/- 2.9), was similar. The number of SSCP bands detected in patients with sustained response (7.5 +/- 3. 9), transient response (8.3 +/- 2.9), or no response (8.2 +/- 3.6) to interferon administration was similar as well. These observations suggest that the genetic complexity of hypervariable region (HVR1) of HCV, as estimated by SSCP analysis, is not related to the severity of liver injury nor to the type of response to interferon therapy. Thus, information offered by SSCP analysis of HVR1 of HCV in chronic HCV genotype 1b infection does not appear to be useful in the clinical management of these patients. (HEPATOLOGY 1999;29:897-903.)

Prevalence, implication, and viral nucleotide sequence analysis of GB virus-C/hepatitis G virus infection in acute fulminant and nonfulminant hepatitis

The clinical impact of GB virus-C (GBV-C)/hepatitis G virus (HGV) infection on various causes of acute hepatitis and fulminant hepatitis is controversial. In this study, serum samples from 164 patients with acute hepatitis of various causes, 34 asymptomatic hepatitis B virus (HBV) carriers, and 34 healthy adults were tested for GBV-C/HGV RNA by reverse transcription-nested polymerase chain reaction using primers based on the 5'-untranslated region. Nucleotide sequences of GBV-C/HGV RNA from various groups were compared. The prevalence of GBV-C/HGV RNA was significantly higher in patients with acute hepatitis D virus (HDV) superinfection than in HBV carriers or healthy controls (10/37 vs. 2/34, P < 0.02; 10/37 vs. 1/34, P < 0.005). GBV-C/HGV RNA was detected in 11.1% of acute hepatitis A patients, 9.5% of acute hepatitis B patients, 15.8% of acute hepatitis C patients, 12.5% of acute hepatitis E patients, 11.8% of chronic hepatitis B patients with acute exacerbation, and 11.1% in patients with non-A to -E hepatitis; each was not significantly higher than that in HBV carriers or healthy adults. There were no significant differences in gender, age, serum albumin, bilirubin, and alanine aminotransferase levels nor in the occurrence of fulminant hepatitis (6/28 vs. 36/136) between patients with or without GBV-C/HGV RNA. All six patients with fulminant hepatitis who had GBV-C/HGV RNA were complicated by infection with hepatitis B, C, or D. The GBV-C/HGV clones from 21 patients with or without fulminant hepatitis belonged to group 3. No particular strain of GBV-C/HGV was associated with fulminant hepatitis.

Transfusion virology: progress and challenges

Discoveries of new human viruses and new technologies for their detection have made, and will continue to make, major contributions to the safety of blood transfusion. This article discusses the practical issues involved in the implementation of additional serological screening tests for viruses such as human T-lymphotropic virus, and reviews current information on the prevalence and pathogenicity of more recently discovered viruses, such as hepatitis G virus (HGV) or GB virus-C (GBV-C) and human herpes virus 8, a potential aetiological agent of Kaposi's sarcoma. Progress in the technology behind nucleic acid amplification techniques, such as the polymerase chain reaction (PCR), makes direct detection of viruses such as human immunodeficiency virus and hepatitis C virus possible. The use of such methods for screening will allow the earlier detection of acutely-infected individuals and the elimination of transmission from 'window' period donations before seroconversion for antibody. Establishing a framework for PCR-based screening would also enable the testing for others such as hepatitis A virus, parvovirus B19 and GBV-C/HGV for which serological detection methods cannot be or have not been developed.

Hepatitis G virus infection in acute fulminant hepatitis: prevalence of HGV infection and sequence analysis of a specific viral strain

Hepatitis G virus (HGV) is a recently discovered RNA virus, which belongs to the Flaviviridae family. Although HGV infection is usually not associated with elevated serum transaminases, some recent studies have reported that HGV infection is found in a significant number of patients with fulminant hepatitis and may play a role in its etiopathogenesis. In this study the prevalence of HGV infection was determined in 500 healthy blood donors and in 24 patients admitted to hospital because of acute liver failure caused by fulminant hepatitis. The presence of HGV RNA was tested in sera, obtained at admission and before any transfusion was given, by a sensitive seminested reverse transcriptase-polymerase chain reaction (RT-PCR) assay specific for detection of the non-structural (NS)5 region. Nine of the 500 blood donors (1.8%) and two of the 24 patients (8.3%) were found to be HGV RNA positive. One patient was co-infected with HCV and was known to be an intravenous (i.v.) drug user. After intensive supporting treatment, this patient recovered completely. The second patient had no serological markers of known viral hepatitis infection, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and herpes simplex virus (HSV). This patient was successfully transplanted. From both patients, from HGV RNA-positive healthy blood donors and from other patients coinfected with HCV, a part of the HGV NS3 region (nucleotides 4191-4345, EMBL entry U45966) was cloned and sequenced. Sequence comparison revealed that the NS3 region of HGV in patients with fulminant hepatitis contained three nucleotide substitutions as part of the six substitutions described in previous work. These nucleotide substitutions were not found in the tested blood donors or in patients with HCV co-infection. Our findings therefore support the concept of the association of fulminant hepatitis with infection of a specific HGV strain.

Prevalence and genotypes of GB virus C/hepatitis G virus (GBV-C/HGV) and hepatitis C virus among patients infected with human immunodeficiency virus: evidence of GBV-C/HGV sexual transmission

The development of new antiretroviral agents may improve survival of HIV-infected individuals, and therefore chronic viral hepatitis may become more relevant in these patients. The presence of GBV-C/HGV and hepatitis C virus (HCV) RNA were investigated by reverse transcriptase-nested polymerase chain reaction in plasma from 168 Spanish HIV-infected patients belonging to four different risk groups: intravenous drug users (IVDUs), hemophiliacs, homosexuals, and heterosexuals. GBV-C/HGV-RNA and HCV-RNA were detected in 18% and 43% of the patients, respectively. The prevalence of current infection with these viruses was notably high, 19% for GBV-C/HGV and 69% for HCV, among individuals with parenteral risk of infection (intravenous drug abusers and hemophiliacs), but sexual transmission with GBV-C/HGV was also suggested because 16.5% of patients with sexual risk, either homosexual or heterosexual, had GBV-C/HGV-RNA in plasma. Although investigation of GBV-C/HGV-RNA possibly underestimates the actual prevalence of infection with GBV-C/HGV, the above data suggest that sexual contact may play a relevant role in the spread of this virus. Phylogenetic analysis showed no evidence for clustering of NS3 sequences into different genotypes or subtypes of GBV-C/HGV.

HGV: the identification, biology and prevalence of an orphan virus

Hepatitis G virus (HGV) and GB virus C (GBV-C) (both hereinafter referred to as HGV) were independently identified in patients with hepatitis of unknown aetiology. HGV is a positive-sense RNA virus of the family Flaviviridae. The virus can establish both acute and chronic infection and appears to be sensitive to interferon. Horizontal transmission is mainly parenteral, although other routes such as vertical have been well documented. High risk groups include intravenous drug users (i.v.DUs), the multiply transfused, haemodialysis patients and haemophiliacs. Up to 90% of i.v.DUs are positive for either HGV-RNA or antibodies to HGV envelope-2 protein (anti-E2). HGV is frequently detected in patients with HBV and HCV infection. Its link to hepatitis has now become less certain. Only around 3-6% of non-A E hepatitis cases are HGV viraemic, clearly showing that HGV is not the major cause of idiopathic hepatitis as originally hoped. Around 1-5% of volunteer blood donors in developed countries are HGV viraemic, but the prevalence is 10-20% in the general population in some developing countries. At present, it is not known whether HGV is associated with other diseases in humans, is a passenger virus, or only becomes virulent under certain conditions.

The effect of treatment with alpha-interferon on hepatitis G/GBV-C viraemia. The CONSTRUCT Group

BACKGROUND

Hepatitis G virus (HGV) or GBV-C is frequently detected in patients co-infected with hepatitis C virus (HCV). This study investigated host and virologic factors influencing the response to HGV/GBV-C to alpha-interferon treatment.

METHODS

HGV/GBV-C was detected and quantified by nested polymerase chain reaction. The influence of variables such as liver biopsy appearance, liver function abnormalities, and response of HCV to interferon treatment was monitored.

RESULTS

Fourteen of the 25 HGV/GBV-C-infected patients treated with interferon (3-6 MIU three times a week for 6 months) became non-viraemic during treatment, although all relapsed after treatment withdrawal at 6 months, with no net change in virus load between 0 and 12 months.

CONCLUSIONS

Predictive factors for clearance of HGV/GBV-C viraemia by interferon were pre-treatment severity of liver disease (median Knodell score of 4, compared with 7 for non-responders; P = 0.030) and alanine aminotransferase levels (median, 114, 182 for non-responders; P = 0.039). Clearance was associated with the treatment response of HCV. Nine of 13 who cleared HGV/GBV-C also cleared HCV, compared with 3 of 11 HGV/GBV-C non-responders; P = 0.05). The shared susceptibility of HGV/GBV-C and HCV to interferon treatment suggests a link between the mechanism of clearance of the two viruses.

Influence of GB virus C viraemia on the clinical, virological and histological features of early hepatitis C-related hepatic disease

BACKGROUND/AIMS

GB virus C is a newly described RNA virus. The aims of this study were to determine the prevalence of GB virus C infection in patients with chronic type C hepatitis and to examine the clinical, virological and histological features in hepatitis C and GB virus C co-infected patients.

METHODS/RESULTS

One hundred and sixty patients with hepatitis C infection were studied. GBV-C RNA was detected in 33/160 (20.6%) patients; co-infected patients with hepatitis C and GB virus C infection were significantly younger (p=0.04). No difference was found between the two groups according to gender and biochemical parameters. Seventy-two of the 160 patients, for whom a liver tissue specimen taken simultaneously with the serum was available and who had compensated liver disease, were studied separately. The source of infection, duration of infection, HCV genotype and HCV RNA concentrations did not differ between 15/72 patients with dual infection and 57/72 with hepatitis C infection alone. Patients with co-infection had significantly higher degrees of portal and periportal inflammation (p=0.0006 and 0.01, respectively). No difference was observed in parenchymal activity score or extent of fibrosis.

CONCLUSIONS

These results indicate a relatively high prevalence of GB virus C infection in younger patients with chronic hepatitis C, suggesting a common route of transmission. Although GB virus C co-infection does not alter the biochemical and virological profile of patients with HCV hepatitis, there is an association between GB virus C and hepatitis C viraemia and portal and periportal inflammation.