GB virus-C/hepatitis G virus infection in an area endemic for viral hepatitis, chronic liver disease, and liver cancer

HGV-HCV/HBV co-infection in India: A pilot study

Background:

Hepatitis G virus (HGV) is newly identified virus, transmitted by infected blood and blood products. Effect of HGV infection on liver diseases is not well known.

Aims:

Co-infection of HGV with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has been reported however; very limited data is available from India. Therefore, we have performed a pilot study for the presence of co-infection of HGV in chronic liver disease patients.

Setting and Design:

The study was performed in research laboratory at P.D. Hinduja National hospital and Medical research center, Mahim, Mumbai. Prospective study was designed.

Methods and Materials:

Forty HBV, HCV related chronic liver disease patients were studied. Forty randomly selected voluntary healthy blood donors visiting our blood bank were included as controls. Serum bilirubin, alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were estimated. HGV infection was detected by using reverse transcriptase molony murine leukemia virus (M-MLV) with the help of HGV 340/625IC kit (Sacace, Italy).

Results and Conclusion:

One HCV positive patient had infection with HGV among 40 HBV/HCV chronic liver disease patients.

Occult hepatitis B virus infection and clinical outcomes of patients with chronic hepatitis C

Although occult hepatitis B virus (HBV) infections in individuals without detectable hepatitis B surface antigen (HBsAg) may occur and have been reported to be common in patients with chronic hepatitis C, the clinical relevance remains controversial. We searched for serum HBV DNA in 210 HBsAg-negative patients with hepatitis C virus (HCV)-related liver disease (110 patients with chronic hepatitis, 50 patients with cirrhosis, and 50 patients with hepatocellular carcinoma) by PCR. Most of the patients had detectable antibodies to HBsAg or HBV core antigen. All of the 110 chronic hepatitis C patients were treated with a combination therapy consisting of interferon plus ribavirin. In addition, 100 HBsAg-negative healthy adults served as controls. Thirty-one of the 210 patients (14.8%) had HBV DNA in their sera, as did 15 of the 100 healthy controls (15%). HBV DNA was not detected in the sera of those negative for serological markers of HBV infection. In patients with chronic HCV infection, the prevalence of occult HBV infection did not parallel the severity of liver disease (14.5% in patients with chronic hepatitis, 8% in patients with liver cirrhosis, and 22% in patients with hepatocellular carcinoma). In addition, the sustained response to combination therapy against hepatitis C was comparable between patients with and without occult HBV infection (38 versus 39%). In conclusion, these data suggest that occult HBV infection does not have clinical significance in chronic hepatitis C patients residing in areas where HBV infection is endemic.

GB virus C/hepatitis G virus infection in patients investigated for chronic liver disease and in the general population in southern Sweden

Serum samples from patients referred for liver biopsy for investigation of suspected chronic liver disease (n = 286) and from healthy middle-aged volunteers (n = 445) were analyzed for markers of exposure to GB virus C/hepatitis G virus (GBV-C/HGV), hepatitis B virus and hepatitis C virus. GBV-C/HGV analyses included GBV-C/HGV PCR for detection of viremia and GBV-C/HGV enzyme-linked immunosorbent assay for anti-GBV-C/HGV E2 antibodies. Liver biopsies were re-evaluated by a hepatopathologist. GBV-C/HGV markers were detected in 97/286 (34%) patients (GBV-C/HGV RNA = 26; anti-GBV-C/HGV E2 antibodies = 74) compared to 86/445 (19%; p < 0.0001) controls (GBV-C/HGV RNA = 7, anti-GBB-C/HGV E2 antibodies = 79). A significantly higher proportion of GBV-C/HGV-exposed subjects in the patient group were viremic compared to controls (27% vs. 8.1%; p = 0.0015). GBV-C/HGV markers were more commonly found in patients with chronic hepatitis B and C. In patients with GBV-C/HGV viremia, a higher occurrence of bile duct degeneration was detected than in non-viremic patients. Markers of GBV-C/HGV infection were over-represented among patients investigated for chronic liver disease, and ongoing GBV-C/HGV viremia was more common in this group than in controls. Apart from a higher prevalence of bile duct degeneration in viremic patients, infection with GBV-C/HGV did not confer any specific histological characteristics.

Persistent hepatitis G virus (HGV) infection in chronic hemodialysis patients and non-B, non-C chronic hepatitis

Three groups of patients have been studied longitudinally for 24 months to analyze the role of hepatitis G virus (HGV) in hepatic disease. Group 1 consisted of 50 patients with non-B, non-C chronic hepatitis, group 2 consisted of 44 hemodialyzed patients, and group 3 consisted of 50 healthy blood donors. The presence of HGV RNA was detected by both reverse transcription-polymerase chain reaction (RT-PCR) and capillary zone electrophoresis (CZE). At the baseline visit the HGV RNA was detected in seven out of 50 patients with non-B, non-C chronic hepatitis, in two out of 44 hemodialyzed patients, and in three out of 50 healthy blood donors. HGV-infected hemodialyzed patients and HGV viremic blood donors had serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels within normal limits. During the follow-up period the two HGV-positive hemodialyzed patients and the three infected healthy blood donors did not show any sign of hepatic disease. There were no significant differences between HGV-positive patients in the three groups at the beginning and at the end of the follow-up. No considerable deterioration of general health conditions was observed on the basis of clinical and laboratory data in HGV-positive chronic hepatitis patients. Finally, HGV does not seem to be responsible for hepatic disease.

Efficacy of consensus interferon in the treatment of chronic hepatitis C

BACKGROUND AND AIMS

Consensus interferon (CIFN) is a newly developed type I interferon. The aim of this study was to investigate the safety and efficacy of CIFN in the treatment of patients with chronic hepatitis C and to determine the predictors for sustained response.

METHODS

Patients were randomized to receive 3 micrograms or 9 micrograms CIFN three times a week for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum transaminase levels and disappearance of serum hepatitis C virus (HCV)-RNA at the end of treatment and at 24 weeks after stopping treatment. Histologic response was defined as a decrease of at least two points in the Knodell necroinflammatory score at week 48 and was compared with baseline.

RESULTS

There were no serious adverse effects related to CIFN therapy. Overall, 44% of patients receiving 3 micrograms and 48% of patients receiving 9 micrograms had normalization of serum transaminase levels and disappearance of HCV viremia at the end of treatment. At 24 weeks after stopping treatment, 16% of patients in receiving 9 micrograms and 12% of patients receiving 3 micrograms had sustained responses. The histologic responses in patients receiving 9 micrograms and those receiving 3 micrograms were 60% and 36%, respectively. The necroinflammatory score was significantly reduced from baseline to week 48 in both groups. In addition, bodyweight < 60 kg and pretreatment serum HCV-RNA level < 0.5 MEq/mL can serve as predictors for sustained response to CIFN treatment.

CONCLUSIONS

These findings suggest that 9 micrograms CIFN is safe and effective in the treatment of patients with chronic hepatitis C.

Acute liver failure: established and putative hepatitis viruses and therapeutic implications

Any virus that can cause an acute hepatitis will, on occasion, give rise to acute liver failure. Such infections can be separated into those due to the primary hepatitis viral infections A to E and those where hepatitis occurs as part of a systemic viral infection, as with infection with, for instance, Epstein-Barr virus, cytomegalovirus, Varicella zoster virus, adenovirus and Herpes simplex virus. In general, the frequency with which the different hepatitis viruses are responsible for acute liver failure is related to their underlying prevalence in particular countries. An apparent exception is the striking geographical variation in the reported prevalence of acute liver failure due to hepatitis C virus infection, with a much higher proportion of cases generally attributed to this agent in Japan and Taiwan than in Western countries. Recent work has focused on the possible importance of mutant hepatitis B viral strains, co- and super-infection with known hepatitis viruses and certain newly described agents that may account for otherwise unexplained cases of acute liver failure. Despite an improved understanding of the pathogenesis of complicating cerebral oedema and advances in general supportive care, it is likely that the most severely affected patients with acute liver failure due to viral causes will survive only with liver transplantation, at least until approaches for promoting adequate liver regeneration are successfully developed and implemented.

Existence of distinct GB virus C/hepatitis G virus variants with different tropism

To study the existence of GB virus C/hepatitis G virus (GBV-C/HGV) variants with different tropism, we have analyzed the heterogeneity and quasispecies composition of GBV-C/HGV isolated from in vitro-infected peripheral blood mononuclear cells (PBMC) and from sera, livers, and PBMC from two chronically infected patients. For this purpose, the GBV-C/HGV 5' noncoding region (5'NCR) was amplified by reverse transcription-PCR and the amplified products were cloned and sequenced. These analyses showed that the master 5'NCR sequences isolated from the in vitro-infected PBMC and from the PBMC isolated from the patient whose serum was used as the inoculum were identical but different from that of the inoculum. Furthermore, phylogenetic analysis revealed that all PBMC sequences grouped together into a branch which was separate from those of the inoculum. For one of the two chronically infected patients, all the sequences from the PBMC and one from the liver clustered into a single branch while the sequences from the serum and all the other liver sequences grouped together in the other branch. For the other patient, the sequences from the serum and PBMC and three sequences from the liver grouped together into one branch, while the remaining five sequences from the liver were separated in a different cluster. In conclusion, our results support the existence of different GBV-C/HGV variants with different tissue tropism.

Hepatitis G virus (HGV) infection in voluntary and commercial blood donors in India

The prevalence of hepatitis G virus (HGV) has been determined in commercial as well as voluntary blood donors from India by detecting viral RNA genome using reverse transcription polymerase chain reaction (RT-PCR) assay. 45 professional blood donors from private blood banks and 50 healthy controls who opted for voluntary blood donation were recruited for the study. Both the groups were also screened serologically for HBV and HCV infection. The prevalence of HGV in the general population in India was found to be 4% but significantly a higher frequency (46.6%; p<0.001) of HGV was observed in commercial blood donors.

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.

TT virus infection in patients with chronic hepatitis B or C: influence on clinical, histological and virological features

Concomitant infection with TT virus and hepatitis B virus (HBV) or hepatitis C virus (HCV) is common. However, the effect of TTV infection on chronic hepatitis B or C is unknown. The prevalence of TTV infection, the effect of TTV infection on the clinical, histological and virological features of patients with chronic hepatitis B or C, and the influence of TTV infection on the HCV response to interferon alfa therapy were studied. A total of 100 asymptomatic hepatitis B surface antigen carriers, 220 patients with HBV-related chronic liver diseases, and 110 patients with chronic hepatitis C treated with interferon alfa (3 million units subcutaneously three times a week for 24 weeks) were enrolled. Serum HCV RNA and serum TTV DNA were detected by the polymerase chain reaction (PCR). Serum HBV DNA and serum HCV RNA level were quantified by branched DNA assays. Infection with TTV was detected in 21.5% of HBV carriers and 37% of HCV carriers. TTV infection had little effect on the clinicopathological course of chronic HBV infection. In chronic hepatitis C, clinical features, histological severity, serum HCV RNA levels, and the response to interferon alfa therapy did not differ between those with and without TTV infection. The loss of serum TTV DNA did not correlate with the biochemical response as did in the loss of serum HCV RNA. In conclusion, TTV infection is found frequently in patients with chronic hepatitis B or C in Taiwan; however, coinfection with TTV does not affect the clinicopathological course of chronic hepatitis B or C and the response to interferon alfa therapy.

TT viral infection through blood transfusion: retrospective investigation on patients in a prospective study of post-transfusion hepatitis

AIM: To investigate the role of blood transfusion in TT viral infection (TTV).

METHODS: We retrospectively studied serum samples from 192 trans fusion recipients who underwent cardiovascular surgery and blood transfusion between July 1991 and June 1992. All patients had a follow-up every other week for at least 6 months after transfusion. Eighty recipients received blood before screening donors for hepatitis C antibody (anti-HCV), and 112 recipients received screened blood. Recipients with alanine aminotransferase level > 2.5 times the upper normal limit were tested for serological markers for viral hepatitis A, B, C, G, Epstein Barr virus and cytomegalovirus. TTV infection was defined by t he positivity for serum TTV DNA using the polymerase chain reaction method.

RESULTS: Eleven and three patients, who received anti-HCV uns creened and screened blood, respectively, had serum ALT levels > 90 IU/L. Five patients (HCV and TTV:1; HCV, HGV, and TTV:1; TTV:2; and CMV and TTV:1 ) were positive for TTV DNA, and four of them had sero-conversion of TTV DNA.

CONCLUSION: TTV can be transmitted via blood transfusion. Two recipients infected by TTV alone may be associated with the hepatitis. However, whether TTV was the causal agent remains unsettled, and further studies are necessary to define the role of TTV infection in chronic hepatitis.

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.

Prevalence and implication of TT virus infection: minimal role in patients with non-A-E hepatitis in Taiwan

TT virus (TTV) is a newly identified human DNA virus and little is known about its clinical significance. The aim of the study was to explore the prevalence of TTV infection in different risk populations and in patients with various liver diseases. Viral DNA was studied in 190 high-risk individuals, 97 household contacts, 52 patients with acute hepatitis A, 32 patients with non-A-E hepatitis including 13 fulminant hepatitis, 200 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 100 patients with chronic hepatitis C, and 100 healthy adults. TTV infection was more frequent in high-risk groups (26-70%), patients with acute or fulminant non-A-E hepatitis (42-45%), and hepatitis C carriers (36%) than in healthy adults (10%) and hepatitis B carriers (15%). However, most of subjects with TTV infection alone had no or only mild hepatitis, and the same rate of TTV DNA in pre-hepatitis serum samples and constant serum TTV titers during hepatitis episodes were observed in two patients with acute non-A-E hepatitis. Phylogenetic analysis of the Taiwanese TTV isolates showed genetic heterogeneity and most (68%) isolates were TTV type 1. No particular strain was found to be associated with fulminant non-A-E hepatitis.

Hepatitis G virus: relevance to oral health care

OBJECTIVE

To review the current literature on the hepatitis G virus (HGV) infection, with particular attention to the aspects of interest for the dental staff.

MATERIAL AND METHODS

The authors searched for original research and review articles on specific aspects of the HGV infection including virology, epidemiology, transmission, natural history, and dental zaspects of HGV infection. The relevant articles were evaluated and reviewed.

RESULTS

HGV is a parenterally transmitted RNA virus that may cause acute, chronic, and fulminant liver disease; however, the real pathogenic potential of this virus and its possible effect on other hepatitic infections is still to be clarified. Preliminary studies have failed to demonstrate strong relationships between HGV infection and any oral disease. At present, data on the prevalence of HGV infection among health care workers are scarce. Nevertheless, in view of the potential transmission rates of HGV and the lack of effective immunization, HGV should be regarded as a potential occupational hazard for medical and dental staff.

CONCLUSION

Many virological, medical, and oral aspects of HGV infection need to be further investigated; nevertheless, until related data are available, HGV should be considered to be an infection that may be transmitted during dental care.

Chronic infection with hepatitis G virus in relation to hepatocellular carcinoma among non-Asians in Los Angeles County, California

BACKGROUND

The recently identified hepatitis G virus (HGV) is a hepatotropic RNA virus belonging to the Flaviviridae family. The virus causes chronic viremia, and exposure to blood products is a recognized route of transmission in humans. To the authors' knowledge there is scant information regarding the hepatocarcinogenic potential of HGV. The current study examined the association between HGV infection and the risk of hepatocellular carcinoma.

METHODS

A population-based, case-control study involving 144 non-Asian patients with hepatocellular carcinoma who were ages 18-74 years at diagnosis and 252 community controls of similar age, gender, and race was conducted in Los Angeles, California. Study subjects were assessed for serologic markers of infections with the hepatitis B virus (hepatitis B surface antigen, antibody to the hepatitis B core antigen, and antibody to the hepatitis B surface antigen), hepatitis C virus (HCV) (anti-HCV and HCV RNA), and HGV (HGV RNA).

RESULTS

Twelve of the 144 hepatocellular carcinoma patients (8.3%) and 5 of the 252 control subjects (2.0%) were positive for serum HGV RNA. The presence of HGV RNA in the serum was associated with a statistically significant 5.4-fold risk of hepatocellular carcinoma (95% confidence limit, 1.8, 16.6). The excess risk for hepatocellular carcinoma among HGV-infected individuals was independent of the effects of hepatitis B and hepatitis C infections.

CONCLUSIONS

Chronic infection with HGV may play a role in the development of hepatocellular carcinoma. If the observed statistical association is a causal one, then infection with HGV may account for approximately 8% of hepatocellular carcinoma cases occurring in non-Asians in Los Angeles, California.

GBV-C/HGV and HCV infection in mixed cryoglobulinaemia

Recently, a new, suspected hepatotropic virus has been identified. Named GBV-C/HGV, this virus shares with the hepatitis C virus (HCV) routes of transmission and molecular organization. Indeed, a proportion of HCV-infected patients (10-25%) are also carriers of GBV-C/HGV. Since mixed cryoglobulinaemia (MC) is closely associated with HCV infection, the aim of this study was to determine the prevalence of GBV-C/HGV infection in MC patients, and to investigate whether the double infection influenced the clinical and/or laboratory aspects of the disease. 52 patients affected by MC were studied. 100 patients affected by HCV-positive chronic liver disease (CLD) without MC were used as control group. To determine the prevalence of GBV-C/HGV infection in general population, 150 blood donors were studied, as well as 80 patients affected by non-A-E CLD. Among the MC patients, only five (9.6%) were positive for both HCV and GBV-C/HGV infection. No difference was found between patients with and without double infection as regards main clinical and laboratory aspects. Among HCV-positive CLD cases, 27 were positive for double infection. Among blood donors, the prevalence of GBV-C/HGV infection was 8.0%, whereas in cases with cryptogenetic CLD the prevalence was 5.0%. In conclusion, these data show that GBV-C/HGV infection does not play any role in the pathogenesis of MC.

GB virus-C/hepatitis G virus infection in Taiwan: a virus that fails to cause a disease?

Recently, an RNA virus designated GB virus-C or hepatitis G virus (GBV-C/HGV) was identified; however, its clinical significance remains uncertain. This discovery prompted us to investigate the virological, epidemiological and clinical implications of GBV-C/HGV infection in Taiwan where chronic liver diseases and liver cancer are endemic. Our results showed that genetic heterogeneity of GBV-C/HGV isolates exists, and primers from the highly conserved 5' untranslated region of viral genome can efficiently detect GBV-C/HGV RNA. Epidemiological surveys showed that GBV-C/HGV infection is common in high-risk groups in Taiwan, and its coinfection does not aggravate the course of chronic hepatitis B or C. A prospective study of transfusion-transmitted GBV-C/HGV infection also showed GBV-C/HGV does not cause classic hepatitis in most patients. In addition, GBV-C/HGV plays a minimal role in causing fulminant hepatitis. Like hepatitis C virus, sexual transmission of GBV-C/HGV exists. The risk increases with prolonged duration of exposure. In addition, high-titered maternal viremia and mode of delivery are associated with the mother-to-infant transmission of GBV-C/HGV. Interestingly, we found that GBV-C/HGV exerts no suppression on levels of chronic hepatitis B or hepatitis C viremia, and GBV-C/HGV responds to interferon; however, ribavirin plus interferon does not induce a higher sustained response. As to the replication sites of GBV-C/HGV, our preliminary results showed liver and peripheral blood mononuclear cells are not the major sites for GBV-C/HGV replication, and thus GBV-C/HGV is not a primary hepatotropic virus. In conclusion, transfusion and exchange of body fluids indeed can transmit GBV-C/HGV; however, current lines of evidence suggest that GBV-C/HGV fails to cause a disease.

Pathogenicity of GBV-C/HGV infection

Extensive studies of GBV-C/HGV in acute and chronic hepatitis non-A-non-E have failed to provide hard evidence for a major role in this disease. Persistent GBV-C/HGV viraemia is in most cases associated with normal ALT levels, and only in a minority of patients are mild elevations of aminotransferases found. Its disease-inducing capacity is questionable and the findings accumulated so far are best explained by looking at GBV-C/HGV as a well-adapted, predominantly parenterally transmitted, persistent virus; it might be transmitted concomitantly with another, still unidentified hepatitis non-A-non-E virus. This does not exclude the possibility that GBV-C/HGV might, in some rare cases and under certain circumstances, induce a hepatitis-like illness as seen with other viruses such as EBV or CMV. GBV-C/HGV definitely plays a minor role only, if any, in post-transfusion and community-acquired hepatitis non-A-non-E.

Hepatitis C virus genotypes and viremia and hepatocellular carcinoma in the United States

OBJECTIVE

Hepatitis C virus (HCV) is a well recognized cause of hepatocellular carcinoma (HCC). The pathogenic significance of HCV genotypes in hepatocarcinogenesis is undefined. The aim of this study was to investigate the genotypic distribution and viremic level of HCV in patients with HCV-associated cirrhosis with or without HCC.

METHODS

A total of 28 HCV-infected patients with HCC (HCC+) and 38 patients with HCV-associated cirrhosis without HCC (HCC-) were studied. HCV genotype was assessed by the genotype-specific polymerase chain reaction (PCR) method of Okamoto and restriction fragment length polymorphism (RFLP) of the 5' untranslated region (5' UTR). Hepatitis C viremia was quantitated with the branched-chain DNA (bDNA) assay.

RESULTS

Using the Okamoto method, we found genotype 1b in 64% of the HCC+ group and 74% of the HCC- group, 36% of the HCC+ group and 16% of the HCC- group were coinfected with a combination of genotype 1b and another genotype. Using the RFLP method, we found genotype 1b in 41% of the HCC+ group and in 24% of the HCC- group. Other genotypes accounted for 18% of the HCC+ group and 55% of the HCC- group; no combination genotypes were identified. Poor concordance occurred between the two genotyping methods. Mean bDNA levels were not significantly different between the two groups.

CONCLUSIONS

Our study demonstrates that no particular HCV genotypes were associated with HCC and genotype did not appear to influence the development of HCV-associated HCC.

Etiology of sporadic acute viral hepatitis in Taiwan: the role of hepatitis C virus, hepatitis E virus and GB virus-C/hepatitis G virus in an endemic area of hepatitis A and B

The etiology of sporadic acute hepatitis was studied in 334 consecutive patients from Taiwan (237 men and 97 women, aged 16-81 years), with emphasis on the role of hepatitis C virus (HCV), hepatitis E virus (HEV), and GB virus-C/hepatitis G virus (GBV-C/HGV) in acute non-A, non-B (NANB) hepatitis and in HBsAg carriers with superimposed acute hepatitis. According to the conventional diagnostic criteria, there were 12 cases (3.6%) of acute hepatitis A, 17 cases (5.1%) of acute hepatitis B, 128 cases (38.3%) of acute NANB hepatitis, and 177 cases (53.0%) of acute hepatitis in HBsAg carriers (those who were HBsAg positive but IgM anti-HBc negative). Among 128 cases of acute NANB hepatitis, 70 (54.7%) had acute hepatitis C (HCV RNA positive), 5 (3.9%) had acute hepatitis E (IgM anti-HEV positive), and the other 53 (41.4%) were presumably acute hepatitis non-A-E. The prevalence of acute hepatitis A, B, E, and non-A-E showed no significant sex difference, whereas acute hepatitis C was significantly more prevalent in females. The prevalence of acute hepatitis A and B decreased and that of acute hepatitis C increased significantly with increasing age. In contrast, acute hepatitis E and non-A-E showed no significant age predominance. Of 177 HBsAg carriers with acute hepatitis, 64 (36.1%) demonstrated non-B hepatotropic virus superinfection, with HCV being the most common (60.9%), followed by hepatitis D, E, and A viruses, and the other 55 (31.1%) and 58 (32.8%) were presumed to have acute exacerbation of chronic hepatitis B or superimposed acute hepatitis non-A-E, respectively. Serum GBV-C/HGV RNA was detected in 3-4% of acute hepatitis non-A-E cases, suggesting its limited role in these cases.

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.

Minimal role of GB virus-C/hepatitis G virus in fulminant and subfulminant hepatitis in Taiwan

BACKGROUND

The role of GB virus-C/hepatitis G virus (GBV-C/HGV) in fulminant hepatitis (FH) and subfulminant hepatitis (SFH) remains unclear.

METHODS

Thirty-two FH or SFH patients, with adequate clinical information and serum specimens, were studied. Serum samples were tested for hepatitis markers and genomes of hepatitis A-E viruses, as well as GBV-C/HGV.

RESULTS

Of the cases of FH/SFH studied, one (3%) was caused by anti-tuberculosis agents, 26 (81%) had hepatotropic virus infection, and five (16%) had no identifiable cause. Of the 26 patients with hepatotropic virus infection, five had acute hepatitis B infection (one with acute hepatitis D virus (HDV) co-infection), one had acute hepatitis C infection, 16 were hepatitis B surface antigen carriers with reactivation or superimposed by unidentified agent(s) (two had triple virus infections), three were hepatitis B carriers with HDV superinfection, and one had GBV-C/HGV infection in addition to exposure to halothane. GBV-C/HGV-RNA was detected in only three of 32 patients (9%) and all had a history of blood transfusion or co-existing causative factors. Of the 26 patients with hepatotropic virus infection, 18 were tested for antibodies against GBV-C/HGV envelope protein and seven were reactive, suggesting past infection.

CONCLUSIONS

The role of GBV-C/HGV in causing FH and SFH is minimal in Taiwan and HBV infection remains the major aetiology. These findings also suggest the existence of as yet unrecognized agents, responsible for such catastrophic illnesses.

Prevalence of GB virus-C/hepatitis G virus infection in patients with cryptogenic chronic liver disease and in patients with primary biliary cirrhosis or Wilson's disease

OBJECTIVE

To assess the role of hepatitis G virus (HGV) in cryptogenic chronic liver disease (CLD), we investigated the prevalence of HGV RNA among patients with cryptogenic CLD, patients with nonviral CLD (primary biliary cirrhosis [PBC] and Wilson's disease [WD]) and subjects without clinically evident liver disease (controls).

METHODS

Ninety patients with cryptogenic CLD (43 with chronic hepatitis, 20 with cirrhosis, and 27 with hepatocellular carcinoma [HCC]), 143 patients with PBC, 22 patients with WD, and 134 controls were recruited. HGV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and antibodies against HGV E2 protein (anti-E2) by an immunoassay test.

RESULTS

HGV RNA was detected in 7.8% of patients with cryptogenic CLD (chronic hepatitis, 9.3%; cirrhosis, 5.0%; HCC, 7.4%), in 2.4% of patients with PBC or WD, and in 2.2% of controls. As a consequence, a positive association of HGV infection with cryptogenic CLD was found (odds ratio, 3.1; 95% confidence interval [CI], 1.0-9.7; p = 0.05). No difference was observed between HGV RNA-positive and -negative patients by age, sex, histology, or liver function tests. Anti-E2 prevalence did not differ between patients with cryptogenic CLD (26.5%), patients with PBC (28.1%), and controls (22.1%). Transfusion history was associated with HGV RNA but not with anti-E2 seropositivity.

CONCLUSIONS

Although an association was found between cryptogenic CLD and HGV infection, the role of the virus seems far from important, the proportion of cryptogenic CLD attributable to it being only 5.2%.

High prevalence of GB virus C/hepatitis G virus RNA in patients infected with human immunodeficiency virus

Prevalence of GBV-C/HGV was determined in a cohort of HIV-infected patients, via a reverse transcription-polymerase chain reaction detection of RNA in serum, amplifying the NS5 region of GBV-C/HGV genome. GBV-C/HGV RNA was detected in 143 (37.7%) of 379 patients, with similar results in the different HIV risk groups: 25/56 (44.6%) in intravenous drug users, 66/161 (41%) in homo- and bisexual men, 35/108 (32.4%) in heterosexual patients, 6/20 (30%) in transfusion recipients (P=0.41). There was no difference according to the presence or absence of hepatitis C virus infection. In univariate analysis, GBV-C/HGV genome prevalence was lower in patients over 50 years old (18.2%), compared to other age groups (20-29 years: 34.2%; 30-39 years: 44.3%; 40-49 years: 36.7%, P=0.03), as well as in patients with normal CD4 cell count (29.2% vs. 45.4% between 200-500/mm3, and 35.3% below 200 CD4/mm3, P=0.012) and individuals with a chronic hepatitis B. However, in the multivariate analysis, the only prognostic factor of GBV-C/HGV RNA positivity was the presence of a chronic hepatitis B, compared to the absence of any HBV marker, or a previous exposition to HBV (presence of anti-HBc and/or anti-HBs, absence of HBsAg), or the presence of anti-HBs alone.

Quantitative analysis of GBV-C RNA in liver and serum by strand-specific reverse transcription-polymerase chain reaction

BACKGROUND/AIMS

Although GB virus C (GBV-C) is frequently detectable in patients with liver diseases, it is not known whether it actually replicates in the liver. Therefore we have quantitatively examined the strand-specific RNA of this virus.

METHODS

Fourteen patients (two GBV-C RNA only seropositive, seven both GBV-C RNA and HCV RNA seropositive, and five HCV RNA only seropositive) were examined. Extracted RNAs from sera and liver specimens of these patients were serially diluted and strand-specific RNAs of GBV-C and HCV were quantitatively measured using strand-specific primers by reverse transcription-polymerase chain reaction.

RESULTS

Positive-strand GBV-C RNA in serum was detected in all nine GBV-C RNA seropositive cases, and negative-strand RNA was detected in three, uncertain in three, and undetected in three. Positive-strand GBV-C RNA in the liver was detected in seven and undetected in two, while negative-strand RNA in the liver was undetected in eight and uncertain in one. On the other hand, positive-strand HCV RNA was detected in serum from all 12 HCV RNA seropositive patients and negative-strand HCV RNA was detected in one, uncertain in seven, and undetected in four. Positive-strand HCV RNA was detected in the liver from all 12 HCV RNA seropositive patients, and the presence of negative-strand HCV RNA in the liver was confirmed in 10 and uncertain in the remaining two.

CONCLUSION

GBV-C is considered to be far less hepatotropic than HCV, and it is suggested that GBV-C might not be replicating in the liver.

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

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 400% 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.

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.

HGV/GBV-C infection in liver transplant recipients: antibodies to the viral E2 envelope glycoprotein protect from de novo infection

BACKGROUND/AIMS

Liver transplantation for endstage liver cirrhosis provides a useful model to investigate the pathogenetic role of hepatotropic viral agents. Recently, a new member of the Flaviviridae family, provisionally named HGV/GBV-C virus, has been associated with acute and chronic non A-E hepatitis. We studied 136 patients with cirrhosis consecutively transplanted at our institution for evidence of hepatitis G virus infection and correlation with the patients' clinical course.

METHODS

All patients survived for at least 6 months after transplantation (median follow-up 44 months) and underwent routine liver biopsies. Hepatitis G virus infection was studied using both direct viral RNA identification by RT-PCR and indirect detection of antibodies to the E2 glycoprotein.

RESULTS

There was a high frequency of the hepatitis G virus among patients undergoing liver transplantation, with HGV RNA and anti-E2 prevalence rates of 18.4% and 26.5%, respectively. HGV RNA prevalences significantly increased after transplantation (47.8%), with 47.3% rate of new infections in susceptible subjects. Anti-E2 antibodies were significantly more prevalent among patients transplanted for HCV-related cirrhosis and represented a strong protective factor against hepatitis G virus reinfection or recurrent infection. No correlation was found between HGV RNA or anti-E2 prevalences and survival after transplantation or rates of recurrent liver damage.

CONCLUSIONS

All available evidence suggests that, although liver transplant patients are heavily exposed to hepatitis G virus both before and after transplantation, hepatitis G virus does not induce liver disease in this setting. Most infections appear to be self-limited and induce a protective immunity which is marked by the presence of anti-E2 antibodies.

Prevalence of hepatitis G virus RNA in the sera of patients with HIV infection

OBJECTIVE

The routes of transmission of the hepatitis G virus (HGV) are similar to those responsible for infection with HIV. We sought to evaluate the prevalence of HGV RNA in the sera of HIV-infected patients.

METHODS

The sera of 157 HIV-infected patients were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) using established primers for HGV. Patients were divided into group 1 (positive circulating hepatitis B surface antigen [HBsAg]), group 2 (positive anti-hepatitis C virus [HCV] antibody) and group 3 (without markers for HBV or HCV).

RESULTS

The overall prevalence of HGV RNA was 22%; prevalence was higher in group 1 (49%) than in groups 2 (16%) or 3 (7%). Patients with positive HGV RNA had laboratory values similar to HGV RNA-negative patients except for higher CD4 counts. Patients with an estimated risk duration of < or = 14 years were more likely to be HGV RNA-positive than patients at risk for >15 years. HGV RNA was found as frequently in patients with a homosexual lifestyle as in injection drug users (IDU). Multivariable analysis showed that the presence of HBsAg was the strongest factor associated with the presence of HGV RNA in serum.

CONCLUSIONS

Patients with HIV and HBV coinfection are significantly more likely to be HGV RNA-positive. Patients with a risk factor duration for >15 years were less likely to be HGV RNA-positive, pointing to a decrease in HGV RNA prevalence over time. This study supports the notion that homosexual lifestyle, in addition to injection drug usage and blood product transfusion, is a risk factor for HGV infection.

Natural history and molecular biology of hepatitis G virus/GB virus C

BACKGROUND

The hepatitis G virus (HGV) or GB virus C (GBV-C) is a new member of the Flaviviridae family. The virus is transmitted by transfusion of blood, infusion of some blood products, and by parenteral exposure to blood during intravenous drug use (IVDU) and haemodialysis. Transmission from mother to infant and by sexual contact has also been documented. Although the virus has been found in patients with acute and chronic hepatitis, evidence of disease association has not been forthcoming. The majority of patients carry the virus in the absence of liver enzyme abnormalities.

OBJECTIVES

To review what is currently known about HGV/GBV-C in order to evaluate its similarity with other members of the Flaviviridae and the association of the virus with disease.

RESULTS

The genomic organisation of the virus is typical for Flaviviridae, with long 5' and 3' untranslated regions (UTR). However, a clearly identifiable nucleocapsid encoding region is lacking. Polyprotein synthesis is mediated through an internal ribosome entry site (IRES) contained within the 5' UTR. Phylogenetic tree analysis of sequences derived from this region has demonstrated the existence of at least three genotypes. Apart from serum, HGV-RNA has been detected in lymphocytes also, but the quasispecies present in the two compartments appear to be different. The envelope glycoprotein E2 lacks a hypervariable region and is potentially the target of a neutralising antibody response.

CONCLUSION

Molecular analysis of HGV reveals close similarity of the virus with HCV. However, an association of the virus with liver disease remains unresolved and no association of the virus with hepatocellular carcinoma has been reported.

African origin of GB virus C/hepatitis G virus

Ninety-four GB virus C/hepatitis G virus (GBV-C/ HGV) RNA-positive serum samples were obtained from all over the world. We found that all 15 GBV-C/HGV isolates from the Pygmies and the Bantu in the Central African region had a 12-amino acid indel (i.e. insertion or deletion) in the non-structural protein (NS) 5A region. Phylogenetic analyses of the NS5A region, using GBV-A as an outgroup, showed that these 15 isolates had diverged from the common ancestor much earlier than the remaining isolates, indicating an African origin of GBV-C/HGV.

Past and present hepatitis G virus infections in areas where hepatitis C is highly endemic and those where it is not endemic

We reported previously on an area in Japan where over 30% of the inhabitants were positive for hepatitis C virus (HCV) antibody. In the present study, clinical features of hepatitis G virus (HGV) infection in this area of high endemicity were compared to those in an area where HCV is not endemic. A total of 400 individuals were selected randomly from those who were medically screened for liver disease in 1993; 200 were from the high-endemicity area, and the other 200 were from the no-endemicity area. HGV RNA was measured by reverse transcription and PCR with primers in the 5' noncoding region. Antibody to HGV envelope protein E2 was measured by an enzyme-linked immunosorbent assay. Prevalence of any HGV marker in the high-endemicity area (32%) was significantly (P < 0.0001) higher than that in the no-endemicity area (6%); similar differences, 32% versus 3% (P < 0.0001), had been observed for HCV markers (HCV RNA and HCV antibody). In areas of both high and no endemicity, HCV markers were significantly more prevalent in individuals with any HGV marker than in those without HGV markers, and age-specific prevalence of HGV markers was distributed similarly to that of any HCV marker. Among possible routes of HGV transmission that were analyzed, folk medicine was significant in the high-endemicity area, but blood transfusion was the major route in the no-endemicity area. The rate of accompanying viremia in HGV infection (15%) was significantly lower than that in HCV infection (78%) (P < 0.0001). In conclusion, HGV infection was highly prevalent in the area of high HCV endemicity and was closely associated with HCV infection. HGV seemed to be transmitted via the practice of folk medicine as well as blood transfusion. HGV resulted in a chronic carrier state less frequently than did HCV.

Hepatitis G virus infection in normal and prospectively followed posttransfusion children

A recently identified RNA virus, hepatitis G virus (HGV), has been investigated for its role in causing non-A-E hepatitis. The frequency and clinical outcome of HGV infection in children was studied. Two hundred apparently healthy children aged 6 mo to 12 y, and 90 children who had undergone open heart surgery in a prospective study for posttransfusion hepatitis were included in this study. The serum samples were tested for HGV RNA by nested reverse transcription-PCR with primers from the 5'-untranslated region. The HGV RNA viremic rate was found to be 1% (2/200) in apparently healthy children, 30% in children after open heart surgery. Among the 90 children, three were HGV-infected before the surgery. Twenty-four (28%) of the remaining 87 children tested positive for HGV RNA within 6 mo after the surgery. Sixty-five percents of these viremic children eventually became persistently infected at 1 y after surgery. No HGV RNA-positive children exhibited elevated alanine aminotransferase levels during the follow-up period. No coinfections of HGV with the hepatitis C virus or hepatitis B virus were found. Patients of younger age appeared more likely to become chronic carriers. Anti-HCV screening did not reduce the prevalence of HGV infection. In conclusion, in children with open heart surgery, the risk of transfusion-transmitted HGV infection and the chronicity rate have been found to be high. Young age is a risk factor of persistent infection.

Relative colonizing abilities of human fecal and K 12 strains of Escherichia coli in the large intestines of streptomycin-treated mice

Male CD-1 mice, fed streptomycin in their drinking water, were used to study colonization of the mouse intestine by both fecal Escherichia coli strains isolated from healthy humans and Escherichia coli K12 strains which are routinely used as hosts for recombinant DNA. Prior to use in mice, all the strains were made resistant to streptomycin. Several facts emerged from these studies: (a) Strains isolated from different healthy humans colonized the mouse intestine with equal ability (approximately 10(8) cells/g feces), but may have colonized biochemically distinct sites. (b) K12 strains tested had, at most, one hundredth the colonizing ability of human fecal strains. (c) Rifampicin-resistant mutants of strains which contain one or no plasmids were poor colonizers relative to their parents. (d) Rifampicin-resistant mutants of strains which contain six or more plasmids retained the colonizing abilities of their parents. (e) Introduction of the F-amp or pJBK5 plasmid into HS-4, a human fecal strain which does not normally carry these plasmids, reduced its colonizing ability 1000-fold. (f) Strains used in this study colonized the mouse caecum and colon exclusively. The system presented here offers a simple, rapid test to determine whether a specific genetic alteration in a bacterium (e.g. antibiotic resistance) results in enhanced, reduced, or unchanged colonizing ability. Such a test might prove to be of value as a part of the clinical testing of antibiotics.