GBV-C/HGV infection in chronic hepatitis C patients: Its effect on clinical features and interferon therapy

A novel virus (GBV-C/HGV) may be associated with some liver diseases including fulminant hepatitis and acute and chronic hepatitis. On the other hand, many investigations showed that this infection does not contribute to liver disease. GBV-C/HGV has been found to occur in association with infection with other hepatitis viruses. We investigated the effect of GBV-C/HGV infection on the clinical features and interferon treatment in patients with chronic hepatitis C. A total of 262 hepatitis C virus (HCV) RNA positive patients with chronic hepatitis were examined in this study. The detection of serum GBV-C/HGV RNA was done by RT-PCR using specific primers from the NS5 regions. Interferon-alpha was given at a dose of 6 MU/day for 16 or 24 weeks. A responder was defined as a patient with ALT normalization and HCV RNA disappearance after treatment. GBV-C/HGV RNA was detected in 28 (11%) patients. No significant difference was detected in clinical features (age, sex, liver-related biochemical tests, and histological examination) between the 28 GBV-C/HGV-positive patients and the GBV-C/HGV-negative patients. Using interferon therapy for hepatitis C, the responder rates of GBV-C/HGV-positive and -negative patients were 14% and 20%, respectively. Of the 28 patients with GBV-C/HGV RNA, GBV-C/HGV RNA was tested after interferon therapy in 16 and of these GBV-C/HGV RNA was not detected in nine patients after therapy. These findings suggest that GBV-C/HGV infection dose not affect the clinical features in patients with HCV and the efficacy of interferon therapy for chronic hepatitis C. J. Med. Virol. 55:98–102, 1998. © 1998 Wiley-Liss, Inc.     

Direct evidence for GB virus C/hepatitis G virus (GBV-C/HGV) superinfection: elimination of resident viral strain by donor strain in a patient undergoing liver transplantation

The viral genome of GB virus C/hepatitis G virus (GBV-C/HGV), a single-strand RNA virus, is subject to considerable variability and at least four genotypes have been suggested based on phylogenetic analysis. While co-infection of GBV-C/HGV with other infectious agents such as hepatitis C virus (HCV) has been frequently observed, there is no report whether or not co-infection and/or superinfection occurs among different GBV-C/HGV strains. By studying a GBV-C/HGV positive recipient/donor pair in the context of undergoing liver transplantation, we have sequenced multiple clones derived from serum samples serially collected over four years. Detailed phylogenetic analyses have been performed with these sequences. The donor was infected with GBV-C/HGV genotype 1 and this strain completely replaced recipient GBV-C/HGV strain (genotype 2) after liver transplantation. The recipient's original viral strain became undetectable during follow-up. Sequence analysis failed to identify genetic recombination between the two genotypes, at least in whole structural domain. This study, therefore, provides direct evidence for GBV-C/HGV superinfection of one strain by another with one of them predominating probably due to replication competition.     

GBV-C/HGV infection in hepatitis C virus-infected deferred Swedish blood donors

Sera from 62 hepatitis C virus (HCV)-infected Swedish blood donors were tested by a nested polymerase chain reaction using primers targeting the 5′-noncoding region of the GB virus-C/hepatitis G (GBV-C/HGV) genome and an enzyme-linked immunosorbent assay that detects antibodies to the envelope protein E2 of GBV-C/HGV (anti-E2). Fourteen (22%) and 21 (34%) of the 62 blood donors were found to be GBV-C/HGV RNA and anti-E2 positive, respectively. None of the blood donors was positive for both GBV-C/HGV RNA and anti-E2. Thus, 35 of 62 (56%) HCV-infected donors had been exposed to GBV-C/HGV infection. At sequencing of the 14 GBV-C/HGV isolates, 12 were identified as subtype 2a and 2 as subtype 2b. One of 7 (14%) donors with mild liver disease such as steatosis and nonspecific reactive hepatitis had been exposed to GBV-C/HGV vs. 34 of 55 (62%) with chronic hepatitis with or without cirrhosis (P = 0.04). All other differences in histology were small between HCV and dual HCV GBV-C/HGV-infected donors. In conclusion, more than half of HCV-infected Swedish blood donors in this study were positive for either GBV-C/HGV RNA or anti-E2. GBV-C/HGV viremia and seropositivity were mutually exclusive. J. Med. Virol. 54:75–79, 1998. © 1998 Wiley-Liss, Inc.     

HGV／GBV—C与HCV混合感染者HGV／GBV—C复制中间体的研究

目的 关于ＨＧＶ／ＢＧＶ－Ｃ组织亲和性的研究尚无结论性资料。我们研究了ＨＧＶ／ＧＢＶ－Ｃ与ＨＣＶ混合感染者ＰＢＭＣ和肝脏中ＨＧＶ／ＧＢＶ－Ｃ复制中间体（负链ＲＮＡ）的存在状况。方法 应用逆转录－巢式ＰＣＲ技术,检测了３２例肝炎患者ＨＧＶ／ＧＢＶ－Ｃ和ＨＶＣ正、负链ＲＮＡ。结果 有２６例ＨＧＶ／ＧＢＶ－Ｃ与ＨＣＶ混合感染者ＰＢＭＣ和肝脏中均未检测到ＨＧＶ／ＧＢＶ－Ｃ负链ＲＮＡ;而在９份ＰＢＭＣ和１５     

肝病患者中庚型肝炎病毒感染的检测

目的探讨临床肝病病人中庚型肝炎病毒（ＧＢＶ－Ｃ／ＨＧＶ）感染情况及临床特点。方法应用庚型肝炎病毒基因组５’ＵＴＲ两对寡核苷酸作为引物，建立逆转录套式聚合酶链反应，检测１６９例不同肝病患者血清标本中ＧＢＶ－Ｃ／ＨＧＶＲＮＡ，并对其中１例ＰＣＲ扩增产物进行克隆及测序。结果１６９例各型肝病病人ＧＢＶ－Ｃ／ＨＧＶＲＮＡ总的检出率为９５％（１６／１６９）。在２９例有手术输血史患者中，３１０％（９／２９）ＧＢＶ－Ｃ／ＨＧＶＲＮＡ呈阳性，明显高于无手术输血史组（５％，Ｐ＜００１）。序列分析显示１株庚肝病毒５’ＵＴＲ部分基因片段与已知庚肝病毒株核苷酸同源性在８９１４％～９８９１％之间。结论ＧＢＶ－Ｃ／ＨＧＶ感染普遍存在于临床肝病患者中，病人感染ＧＢＶ－Ｃ／ＨＧＶ的临床表现未发现有特殊性，ＧＢＶ－Ｃ／ＨＧＶ可能不是非甲～戊型肝炎的主要致病因子。     

Chronic viral hepatitis B and C: an argument against the conventional classification of chronic hepatitis

The classification of chronic hepatitis distinguishing benign chronic persistent hepatitis from severe chronic active hepatitis was constructed without knowledge of well-defined aetiological factors. Better understanding of the different hepatitis-viruses has shed new light on this subject. Chronic viral hepatitis B and C each show typical histological patterns. The validity of the conventional classification has been evaluated by a comparative study of chronic viral hepatitis B and C. 130 biopsies from 110 patients with chronic hepatitis C (CH-C) proven serologically by antibodies (second generation testing) were compared with 105 biopsies from 73 patients with chronic hepatitis B (CH-B). These were scored semi-quantatively. In CH-C, lymphoid follicles and/or aggregates were found in 88.5%, fatty degeneration in 51%, bile duct lesions in 46.2%, and Mallory body-like material in the hepatocytes in 9.2%. The portal lymphocytic infiltration generally predominated over the necro-inflammatory lesions of the parenchyma. Chronic persistent hepatitis (defined by the presence of portal hepatitis) was present exclusively in CH-C. Chronic lobular hepatitis was found exclusively in CH-B. We conclude that the histological criteria described for CH-C are highly suggestive of the diagnosis, that the artificial subdivision of chronic hepatitis into CPH and CAH is obsolete and that the histological assessment of chronic hepatitis should consist of a grading of inflammatory activity (minimal, mild, moderate, severe) and staging of fibrosis (extent of distortion of architecture). The final diagnosis should be based on the demonstration of the aetiological agent.     

Hepatitis C genotypes in patients with dual hepatitis B and C virus infection

In patients with chronic hepatitis B and C virus (HBV, HCV) infection, an inverse relationship in the replicative activity of the two viruses has been reported. In the present study the genotype of HCV was evaluated in 34 consecutive cases found with hepatitis B surface antigen (HBsAg) and anti-HCV in the serum, in order to identify its possible influence in determining the pattern of HBV/HCV interaction. Nineteen patients were HCV-RNA positive and could be genotyped: 8 were infected by HCV-1 (3 by HCV-1a and 5 by HCV-1b), 10 by HCV-2, and only 1 by HCV-3. Among these, 3 were HBV-DNA positive, compared to 10 of 15 HCV-RNA-negative patients (P = 0.003), and all 3 were coinfected with HCV-2. Mean alanine aminotransferase (ALT) levels were similar between patients infected with HCV-1 and HCV-2. Among 7 patients with cirrhosis 5 were infected by HCV-2, while 6 of 12 of those without cirrhosis had HCV-1 infection. In conclusion, HBV replication was inhibited more efficiently by HCV-1 than by HCV-2. Cirrhosis was frequently found in patients with dual HBV and HCV-2 infection. © 1996 Wiley-Liss, Inc.     

Different genotypes of hepatitis C virus are associated with different severity of chronic liver disease

The presence of the “Japanese type” NS4 region was investigated in two series of patients (53 from Italy and 58 from Japan) with hepatitis C virus (HCV)-related chronic liver disease. The two populations were homogeneous as regard to age, male/female ratio, histological diagnosis, and serum aminotransferase activities. Genomic amplification was carried out by “nested” poly-merase chain reaction (PCR) with a pair of primers synthesized according to the sequence of JK-1 isolated in Japan. The presence of viral replication was confirmed further by PCR amplification of the 5′NC region. The NS4 region of the Japanese strain was detected in 24 sera (45%) from Italy and in 44 (71%) from Japan. NS4-posi-tive patients were significantly older and showed an ALT serum level significantly lower (P < 0.01) than NS4 negative cases in each group. Cirrhosis was significantly (P < 0.0007) more common in NS4-positive than in NS4-negative patients. The HCV genotype was subsequently obtained according to Okamoto. All the NS4-positive patients were infected by Type II, whereas in NS4-negative patients all four genotypes were present though Type II still constituted the majority. Cirrhosis was associated exclusively with Type II both in NS4-positive and -negative subjects. These data indicate that, although the pos-itivity for NS4 “Japanese” region seems to be associated with a more aggressive liver disease, the most prevalent Type II predicts more specifically those who are likely to develop cirrhosis. Since the same findings were obtained in two population from different areas of the world, the genotype of HCV appears to be one of the major determinants of the progression of chronic active hepatitis to cirrhosis. © 1994 Wiiey-Liss, Inc.     

Early viral kinetics and treatment outcome in combination of high-dose interferon induction vs. pegylated interferon plus ribavirin for naive patients infected with hepatitis C virus of genotype 1b and high viral load

An investigation was carried out to determine whether early viral monitoring could predict efficiently the virological response to combination therapy of two different regimens in treatment-naive chronic hepatitis C patients infected with genotype 1b with high baseline viral load. Patients were randomly assigned to receive interferon (IFN) alpha-2b induction (6 MU daily for 2 weeks) followed by 6 MU thrice weekly for 46 weeks (IFN/R group; n = 20), or pegylated IFN alpha-2b (1.5 microg/kg) weekly for 48 weeks (PEG/R group; n = 28), in combination with ribavirin (600-1,000 mg daily). Serum HCV RNA was quantitated at 0, 6, 12, 24, and 48 hr post-dose, weekly during the first 4 weeks, and thereafter viral kinetics were assessed every 4 weeks. The sustained virological response rates in the IFN/R and PEG/R groups were 40% (8/20) and 43% (12/28), respectively. The non-virological response rates were 40% (8/20) and 39% (11/28), respectively. The cumulative virological response rates were similar in both groups. Multivariate analyses identified no independent baseline variables linked to sustained virological or non-virological response. Early log viral load changes from baseline in both groups were significantly greater at all time-points after 24 hr in virological response patients than in non-virological response patients (P < 0.001 for all). On the receiver operating characteristics curves for prediction of non-virological response, the area under the curves (0.951-1.000), sensitivity (90%-100%), and negative predictive value (96%- 100%) were similar at any time-points after 24 hr. For prediction of sustained virological response, sensitivity of 80% with 86% negative predictive value was observed for negative HCV RNA at week 12, with the highest area under the curves value of 0.919. The results suggest that early monitoring of viral kinetics is a useful measure to predict virological response, and might facilitate development of rational and effective therapeutic strategies.     

Retrospective analysis of non-A-E hepatitis: possible role of hepatitis B and C virus infection

In an effort to determine the cause of non-A-E hepatitis, a retrospective study was undertaken on a group of patients with hepatitis but without serological infection markers of hepatitis viruses A-E. A total of 60 patients admitted to Beijing Ditan Hospital during the period of September 1997 and September 1999 were chosen for this study. These patients were diagnosed as either acute or chronic hepatitis, but no serological markers of hepatitis viruses A-E were detected. Since TT virus (TTV), human parvovirus B19 (B19), SEN virus (SENV), and GB virus C/HGV were reported to be associated with hepatitis, attempts were made to detect the presence of these viruses in the sera of patients with non-A-E hepatitis by a nested polymerase chain reaction (nPCR) method. Also, more sensitive nPCR and RT-nPCR methods were used to determine HBV DNA and HCV RNA in these patients. Results derived from these analyses demonstrate that HBV DNA was detected in most of these patients (47/60, 78.3%), suggesting that HBV infection played a major role in occult non-A-E hepatitis and detection of HBV DNA by more sensitive PCR methods such as nPCR should be considered for diagnosis of HBV infection. In addition, HCV RNA was detected in three (5%) of these patients. However, GBV-C (HGV) RNA was not detected, and TTV, B19, and SENV appear not to be associated with non-A-E hepatitis, as the prevalence rates of these viruses in patients with non-A-E hepatitis were similar to those in patients with viral hepatitis A-E. The results from this study indicate that co-infection of TTV or B19 with HBV did not increase the severity of the disease.     

Evidence for extensive genotypic diversity and recombination of GB virus C (GBV-C) in Germany

Multiple genotypes of GB virus C (GBV-C)-a non-pathogenic flavivirus-have been identified to date, although they are not uniformly distributed worldwide. It has also been suggested that GBV-C genotype may play a role in modulating HIV disease; however, the prevalence and genotype distribution of GBV-C has not been adequately studied in most countries. Among 408 HIV positive subjects in Germany, 97 (23.8%) had detectable GBV-C RNA. Based on sequencing of the 5' untranslated region (5'-UTR), the GBV-C genotypes were 1 (n=8; 8.2%), 2 (n=81; 83.5%), and 3 (n=2; 2.1%), as well as a unique genotype not previously reported (n=6; 6.2%). Among 17 samples also sequenced in the envelope 2 (E2) region, 14 had concordant genotype results when comparing the 5'-UTR and E2, while evidence of intergenotypic recombination was observed among E2 sequences from 3 individuals. These results suggest that genotypic diversity and viral recombination contribute to the overall genetic variability of GBV-C.     

CD4+/CD8+ ratio of liver-derived lymphocytes is related to viraemia and not to hepatitis C virus genotypes in chronic hepatitis C.

The pathogenic mechanisms that lead to chronic hepatitis C are unknown. As hepatitis C virus (HCV) has been shown to induce T cell response, we assessed whether a particular T lymphocyte subset could be preferentially detected in the liver of patients with chronic hepatitis C in relation to viraemia or HCV genotypes. The immunophenotypes of liver-derived lymphocytes were analysed in 26 patients by flow cytometry and immunohistochemistry. Viraemia was quantified by branched DNA assay. Using this assay, HCV RNA was not detectable in six patients. HCV RNA was detected in 20 patients, and titres ranged from 8 to 137 x 10(6) Eq/ml. Genotyping was performed using a line probe assay. Type 1a, 1b, 2a, 3a and 4a were found to infect 2, 10, 2, 7 and 3 patients, respectively. The CD4+/CD8+ ratio of liver-derived lymphocytes was significantly higher (P < 0.01) in patients with detectable viraemia than in patients without detectable viraemia. In contrast, neither the percentage of gamma/delta T lymphocytes nor that of CD2+CD57+ cells was different in the groups. When comparing the CD4+/CD8+ ratio, the percentage of gamma/delta T lymphocytes or CD2+CD57+ cells according to genotype, the differences were not significant. These results suggest that the CD4+/CD8+ ratio of liver-derived lymphocytes is related to viraemia but not to HCV genotypes in patients with chronic hepatitis C, and that T lymphocytes may be involved in the pathogenesis of liver lesions in chronic hepatitis C.     

Interferon therapy in chronic hepatitis C virus: Evidence of different outcome with respect to different viral strains

The aim of the study was to assess the role of different viral strains of hepatitis C virus (HCV) in determining the outcome of the alpha-interferon (IFN) therapy. Fifty-seven patients (34 from Italy and 23 from Japan) with HCV-positive liver disease were enrolled in the study. The NS4 region of HCV was amplified in sera by “nested” polymerase chain reaction (PCR) using a primer pair synthesized according to the sequence of JK-1. The NS4 region was positive in 14 (41%) Italian and in 13 (56%) Japanese patients. In positive patients the sequence of the NS4 region was also obtained. Subsequently, HCV genotype was determined in all patients by PCR amplification of the core region. All patients received recombinant alpha2a-interferon (IFN), 6 million units 3 times a week for 1 month followed by 3 million units 3 times a week for 5 months. The patients were followed for 1 year after the end of treatment. At the end of the follow-up, 17 (30%) had sustained normal levels of serum alanine aminotransferase (ALT). The outcome of treatment was not correlated with race, age, sex, histology, and pretreatment ALT level, but was significantly (P < 0.00001) associated with the presence of both the NS4-JK-1 region and HCV type II. Among the 27 NS4-positive patients, only 1 patient (3.7%) achieved a complete response, whereas the remaining 26 patients (96.3%) either were non-responders or relapsed after IFN was discontinued. In contrast, among the 30 NS4-JK-1-negative patients, 15 (53%) had a sustained remission. HCV genotyping showed type I in 3 (6%), type II in 40 (74%), type III in 4 (7%), and type IV in 3 (6%) cases. Coinfection was present in 4 (7%), while in 3 cases amplification was not obtained. Patients with type II were all non-responders or relapsers, while a response to the treatment was oberved in 17 of 17 (100%) of the remaining patients. These data indicate that the presence of JK-1 variant of HCV or HCV type II is almost always predictive of a poor response rate Of IFN therapy. © 1995 Wiley-Liss, Inc.     

A novel subtype of GB virus C/hepatitis G virus genotype 1 detected uniquely in patients with hemophilia in Japan

GB virus C (GBV-C) or hepatitis G virus (HGV) has been transmitted to Japanese patients with hemophilia through the frequent use of unheated blood products. Sequence analysis showed that most of the viruses isolated from these patients belonged to GBV-C/HGV genotype 1, which is usually found in persons from Africa. This may point to the origin of this virus in Japanese patients with hemophilia. The phylogeny of 11 GBV-C/HGV isolates from Japanese patients with hemophilia was investigated by a detailed analysis with a fragment spanning from the 5' non-coding region to part of the E1 gene. Except for one that belonged to the genotype 3 cluster, all isolates were GBV-C/HGV type 1. Five main clades exist within the GBV-C/HGV genotype 1 sequences. These isolates are grouped in 2 defined clades. Three of the isolates are clustered in subtype 1c clade whereas the other 7 strains formed a new statistically well-supported monophyletic group (named subtype 1e). Our results suggest that GBV-C/HGV type 1 can at present be classified into at least 5 clades and in this group a majority of Japanese patients with hemophilia was infected with a GBV-C/HGV of a unique and newly described subtype within genotype 1.     

Changing prevalence of hepatitis C virus genotypes: molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan

To determine the hepatitis C virus (HCV) genotype distribution in Taiwan and to clarify the relationship between genotype and the pathogenesis of HCV infection, 1,164 subjects positive for serum HCV antibodies and HCV RNA from three HCV hyperendemic areas (Masago, Tzukuan, and Taoyuan) and a tertiary referral center in Taiwan were studied during 1995-1997. HCV genotypes and viral loads were determined using Okamoto's method and branched DNA assay, respectively. Genotype 1b was the most prevalent in Tzukuan (61.9%), Taoyuan (76.9%), and the referral center (47.0%). By contrast, genotype 2a was the major HCV type in Masago (63.5%). Prevalence of genotype 1b positively and that of genotype 2a negatively correlated to age, regardless of study populations (P < 0.01). Based on multivariate analysis, the significant factors associated with the presence of cirrhosis, with or without hepatocellular carcinoma, in chronic hepatitis C patients were genotype 1b and age. In conclusion, these results underline that independent HCV outbreaks continue in HCV hyperendemic areas in Taiwan, concomitant with a changing relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and the pathogenesis of HCV infection.     

GB virus C (GBV-C) infection in patients with chronic hepatitis C. Influence on liver disease and on hepatitis virus behaviour: Effect of interferon alfa therapy

The aim of this study was to evaluate, in patients with chronic hepatitis C, 1) the prevalence and the epidemiological characteristics of GB virus C (GBV-C) infection, 2) the influence of GBV-C on hepatitis C virus (HCV) infection, 3) the pathogenicity of GBV-C in the absence of treatment and under interferon therapy, and 4) the effect of interferon alfa on GBV-C and HCV replications. One hundred fifteen patients with chronic hepatitis C were studied. Before treatment, they were tested for GBV-C RNA by PCR and GBV-C genotype was determined for positive samples. Pretreatment information was collected, including age, gender, source of HCV, estimated duration of HCV infection, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score on liver biopsy, HCV genotype, HCV viral burden and anti-HCV core IgM antibodies. The genetic complexity of the hypervariable region 1 (HVR1) of HCV was studied by PCR-Single Strand Conformation Polymorphism. All patients were treated with 3 to 9 mega units of interferon alfa-2a three times per week for 3 to 6 months. The influence of GBV-C on the evolution of ALT and HCV replication during and after treatment was studied, and GBV-C and HCV RNA were monitored monthly by PCR during this period. Eighteen patients (16%) were GBV-C RNA-positive. Among 11 samples studied, GBV-C genotype 2a was present in 9 cases, 2b in one case and type 3 in one case. GBV-C RNA-positive patients were significantly younger than GBV-C RNA-negative ones (38.4 ± 11.5 vs. 47.4 ± 14.0, P = 0.012), a result independent of the route of transmission and the disease duration. No difference between GBV-C RNA-positive and -negative patients was found for other epidemiological parameters (e.g. gender, risk factor for parenteral viral infections, disease duration and HCV genotypes), or for the characteristics of HCV infection and related liver disease (e.g. HCV RNA level, genetic complexity of the HVR1, anti-HCV core IgM, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score). GBV-C did not influence the rates of ALT normalization at months 3, 6 and 12 and of sustained hepatitis C virological response at month 12 of treatment follow-up. During treatment, GBV-C viremia became undetectable in 12 patients (67%) but relapse occurred after treatment withdrawal in all the nine patients with sufficient follow-up. In the remaining six patients (33%), GBV-C resisted interferon. Whatever the effect of interferon on GBV-C replication, the ALT levels correlated with the presence of HCV RNA. In conclusion, GBV-C infection is frequent in patients with chronic hepatitis C, who are mainly, but not exclusively, infected by GBV-C genotype 2a. GBV-C positive patients are significantly younger than GBV-C negative ones. GBV-C does not seem to affect HCV replication, liver disease and responses of HCV infection and liver disease to interferon therapy. GBV-C is sensitive to 3 mega units of interferon alfa administered three times per week in two-thirds of the patients, but relapse is constant with this dosage after treatment withdrawal. J. Med. Virol. 54:26–37, 1998. © 1998 Wiley-Liss, Inc.