High prevalence of GB virus C infection in a group of Italian patients with hepatitis of unknown etiology

Hepatitis B Virus Molecular Epidemiology, Host-Virus Interaction, Coinfection, and Laboratory Diagnosis in the MENA Region: An Update

Hepatitis B virus (HBV) is an enveloped partial double-stranded DNA virus that can cause acute and chronic hepatitis. According to the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), 257 million people are living with HBV. Moreover, 20,900 acute hepatitis B cases were reported in 2016. Hepatitis B is highly prevalent in the African, Western Pacific, Eastern Mediterranean, South-East Asia, and European regions, respectively. Due to the high mutational rate of HBV and lack of reverse transcriptase proofreading activity, ten different genotypes with different geographical distributions have been identified. HBV pathogenesis and severity of infection depend on several host and viral factors, particularly, the genetic variability of both the host and virus. Although HBV infection is a global health concern, there is a lack of adequate studies and reports in the Middle East and North Africa (MENA) region. Here, we provide a review on HBV epidemiology, pathogenesis, host-pathogen interactions, coinfection with selected viruses, and laboratory diagnosis, focusing on studies conducted in the MENA region to determine the current situation of the HBV infection and outline the future study areas.

Association Between TT Virus Infection and Cirrhosis in Liver Transplant Patients

BACKGROUND

Cirrhosis is one of the most severe liver complications, with multiple etiologies. The torque teno virus (TTV), also known as transfusion transmitted virus, which has a high incidence in the world population, is one of the possible increasing risk factors in patients with idiopathic fulminant hepatitis and cryptogenic cirrhosis.

OBJECTIVES

The aim of this study was to evaluate solitary and co-infection with TTV, in patients with cryptogenic and determined cause of cirrhosis.

PATIENTS AND METHODS

In this cross-sectional study, 200 liver transplant patients were consecutively recruited between years 2007 and 2011. Patients were classified, based on recognition of the etiology of cirrhosis to determined (n = 81) and cryptogenic (n = 119) patient groups. The existence of TTV infection was analyzed, using a semi-nested polymerase chain reaction method. The presence of hepatitis B virus (HBV) infective markers, including HBV DNA, hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis B core antibody (HBcAb), and hepatitis B e antibody (HBeAb), was evaluated using qualitative polymerase chain reaction and enzyme linked immunosorbent assay protocols, respectively.

RESULTS

The TTV infection was found in 37 of 200 (18.5%) and 53 of 200 (26.5%) plasma and tissue samples of studied liver transplanted patients, respectively. The TTV genomic DNA was found in 32 (26.9%) and 28 (23.5%) of 119 liver tissue and plasma samples of transplanted patients with cryptogenic cirrhosis, respectively. The genomic DNA of TTV was also diagnosed in 21 (25.9%) and nine (11.1%) of the 81 liver tissue and plasma samples of patients with determined cirrhosis, respectively. Significant associations were found between TTV infection with HBV molecular and immunologic infective markers, in liver transplanted patients, with determined and cryptogenic cirrhosis.

CONCLUSIONS

The diagnosis of the high frequency of solitary TTV and co-infection with HBV, in both liver transplanted patients with cryptogenic and determined cirrhosis, emphasized on the importance of TTV infection in the development of cirrhosis, especially in the cases of cryptogenic ones, prompting for further studies the confirm this agent in the etiology of determined cirrhosis.

Hepatitis viruses (other than hepatitis B and C viruses) as causes of hepatocellular carcinoma: an update

Chronic hepatitis B and C virus infections are universally accepted as causes of hepatocellular carcinoma in humans. Hepatitis A and E viruses cause only acute self-limiting infections of the liver. Of the remaining hepatitis viruses - Delta hepatitis, hepatitis G (GB-C), TT and SEN - all have at some time been incriminated as causes of hepatocellular carcinoma. Delta hepatitis virus requires helper functions from hepatitis B virus to become invasive. Chronic Delta/hepatitis B viral co-infection runs a more severe course than that resulting from chronic hepatitis B virus infection alone, with progression to cirrhosis being more likely and more rapid. A substantial majority of the early studies did not find an increased incidence of hepatocellular carcinoma in co-infected individuals. But more recently, an increased incidence of the tumour has been recorded more often than no increase. Further studies are needed to draw a firm conclusion with regard to the hepatocarcinogenic effect of dual Delta/hepatitis B virus co-infection. With one exception, no published study (of 13) has incriminated chronic infection with hepatitis G virus as a cause of hepatocellular carcinoma. The dissenting study, published in 1999, was the only one performed in the United States. Fewer studies of the hepatocarcinogenic effect of TT virus have been performed. Apart from one study, published in 1999, no convincing evidence is available that supports a causal role for TT virus in hepatocarcinogenesis. The exception was in Japanese patients with high hepatitis C viral loads but independent of chronic hepatitis C virus infection. No evidence has been produced to indicate that SEN virus causes hepatocellular carcinoma.

Hepatitis G Virus Infection in Healthy Individuals, Acute Viral Hepatitis and Persons at Risk for Parenteral Transmission

BACKGROUND

Hepatitis G virus (HGV), transmitted mostly by parenteral route, has been under investigation for its role as an agent for viral hepatitis. This study was carried out to find out the prevalence of HGV in healthy individuals, multi-transfused patients with acute viral hepatitis and those under going dialysis.

METHOD

The study included 200 healthy individuals and 180 patients, comprising acute viral hepatitis (100 cases), multi-transfused patients (50 cases) and patients undergoing dialysis (30 cases). HGV RNA and Hepatitis C virus (HCV) RNA was detected by reverse transcription and polymerase chain reaction (RT-PCR) in all. Viral marker studies for hepatitis A, B and E were carried out by ELISA in acute viral hepatitis cases. In healthy individuals, in patients with multiple transfusions or those undergoing dialysis, marker studies for HBV and HCV were carried out.

RESULT

The prevalence of HGV in healthy individuals was 2.5% (5/200), in non A-E hepatitis 3% (3/100), in multi-transfused patients 4% (2/50) and in patients undergoing dialysis 6.67% (2/30). There was no significant difference in the prevalence rate of HGV infection in healthy individuals and in patients with non A-E hepatitis.

CONCLUSION

Depending on prevalence rate, HGV could not be implicated as cause of acute viral hepatitis. Persons with parenteral risk factor (multiple blood transfusions and those undergoing dialysis) had higher prevalence rate as compared to healthy individuals.

GB virus C infection in pregnancy: maternal and perinatal importance of the infection

OBJECTIVES

The more effective way of transmission of GB virus C (GBV-C) is parenteral, but sexual and vertical transmission seem to be the main way of spreading. We evaluated the prevalence and the effect of GBV-C infection on pregnant women, vertical transmission and viral effects on the newborn.

STUDY DESIGN

This study has consecutively enrolled 879 pregnant women. All patients had blood sampling to determine GBV-C RNA, serologic tests for chronic viral infections and seric tests of hepatic damage. The newborns from infected mothers had blood sampling to detect the presence of GBV-C at birth, and after 3 and 6 months. Positive babies were checked until 18 months.

RESULTS

36 (4.1%) women resulted GBV-C positive. Among the positive patients none presented complications during pregnancy. Neither embryonic-fetal abnormalities nor relevant differences in fetal birth weight and week of gestation at delivery were found. 20 out of 36 babies had a follow-up. At birth, 13 (65%) babies were positive. 4 out of 9 vaginal deliveries (44%) and 9 out of 11 cesarean sections (82%) resulted positive to GBV-C RNA. The risk of GBV-C vertical transmission was not significantly increased by type of delivery (p=0.274). At 3 months, 13 babies were GBV-C positive (65%) and 7 were negative (35%). At the end of the follow-up, 9 babies were positive (45%), while 11 were negative (55%).

CONCLUSION

The percentage of patients positive to GBV-C RNA was comparatively high (4.1%). This prevalence, in a population without particular risk factors, confirms that common ways of transmission, such as the sexual and vertical ones, might have an important role in viral diffusion. Our data suggest that the infection does not influence the course of pregnancy. The rate of transmission found in our study is high. Type of delivery does not seem to be actually involved in vertical transmission and the protective role of cesarean section has not been confirmed.

Prevalence and clinical role of GBV-C infection after cardiac surgery in childhood: a study on 414 patients

OBJECTIVES

GB-virus C (GBV-C) and hepatitis C virus (HCV) share similar modes of transmission. We, therefore, examined the prevalence and clinical role of GBV-C and HCV in patients after cardiac surgery in childhood.

METHODS

We analysed blood samples of 414 patients and compared them to 487 controls. Evidence of liver disease and risk factors for infection was analysed.

RESULTS

Overall prevalence of GBV-C infection was 22.5% in the patients, compared to 6.2% in the controls (HCV infection 11.3 vs. 0.7%). GBV-C RNA was detected in 8.2% of the patients vs. 3.7% in the controls (HCV RNA in 6 and 0%, respectively). Eleven patients had detectable RNA of GBV-C and HCV. 63.4% of patients infected with GBV-C and 46.8% of patients infected with HCV cleared the virus from circulation. GBV-C infection was not associated with hepatitis. Liver disease was not more frequent in patients co-infected with HCV and GBV-C.

CONCLUSIONS

before 1991 have a substantial risk for HCV and GBV-C infection. However, GBV-C infection seems not to be associated with a liver disease. Co-infection with GBV-C and HCV has no influence on long-term clinical outcome or viral clearance of HCV infection.

Hepatitis G Virus: Prevalence in Blood Donors in Armed Forces

BACKGROUND

A new RNA virus designated hepatitis G virus (HGV) was recently identified. Because HGV has less than 25% sequence or amino acid homology with hepatitis C virus (HCV) and other established Flaviviridae, it is considered to be a new genus in this growing family of hapatotropic viruses. Hepatitis G virus has been associated with hepatitis and is transmitted through parenteral and sexual route.

MATERIAL AND METHODS

A study comprising 500 healthy voluntary blood donors (service personnel) was under taken to find out prevalence of HGV. HGV RNA was detected by reverse transcriptase - polymerase chain reaction (RT-PCR). Hepatitis B surface antigen (HbsAg) and antibody to HCV were detected by Enzyme Linked Immunosorbent Assay (ELISA).

RESULTS

Thirteen donors (2.6%) were positive for HGV RNA. 17 donors (3.4%) were positive for antibody to hepatitis C virus (HCV) by ELISA. Co-infection of HGV with hepatitis B virus (HBV) was seen in 5 donors and with HCV infection in 2 donors. Co-infection of HGV, HBV and HCV was not seen in any donor.

CONCLUSION

So far there is no conclusive evidence that HGV produces hepatitis. But presence of HGV in hepatitis cases casts a doubt on this finding. Prevalence rate in blood donors may be helpful in future studies when the exact role of HGV is known.

[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.

Investigation of HGV and TTV infection in sera and saliva from non-hepatitis patients with oral diseases

AIM: To determine the frequencies of HGV and TTV infections in serum and saliva samples of non-hepatitis patients with oral diseases in Hangzhou area, and to understand the correlation between detected results of HGV RNA and/or TTV DNA in sera and in saliva from the same patients.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection were performed in the serum and saliva samples from 226 non-hepatitis patients with oral diseases, and nucleotide sequence analysis.

RESULTS: Twenty-seven (11.9%) and 21 (9.3%) of the 226 serum samples were only positive for HGV RNA and TTV DNA, respectively. 10 (4.4%) and 9 (3.9%) of the 226 saliva samples were only positive for HGV RNA and TTV DNA, respectively. And 7 (3.1%) of the serum samples and 2 (0.9%) of the saliva samples showed the positive amplification results for both HGV RNA and TTV DNA. 12 saliva samples from the 34 patients (35.3%) with HGV or HGV/TTV viremia and 11 saliva samples from the 28 patients (39.3%) with TTV or HGV/TTV viremia were HGV RNA detectable, respectively, including two patients positive for both HGV RNA and TTV DNA in serum and saliva samples. No saliva samples from the 226 patients were found to be HGV RNA or TTV DNA detectable while their serum samples were negative for HGV or TTV. Homologies of the nucleotide sequences of HGV and TTV amplification products from the serum and saliva samples of the two patients compared with the reported sequences were 88.65%-91.49% and 65.32%-66.67%, respectively. In comparison with the nucleotide sequences of amplification products between serum and from saliva sample from any one of the two patients, the homologies were 98.58% and 99.29% for HGV, and were 98.65% and 98.20% for TTV, respectively.

CONCLUSION: Relatively high carrying rates of HGV and/or TTV in the sera of non-hepatitis patients with oral diseases in Hangzhou area are demonstrated. Parts of the carriers are HGV and/or TTV positive in their saliva. The results of this study indicate that dentists may be one of the populations with high risk for HGV and/or TTV infection, and by way of saliva HGV and TTV may be transmitted among individuals.

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

OBJECTIVES

To investigate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) and compare the serologic responses to various GBV-C/HGV markers in eastern Taiwan aborigines.

METHODS

We used RT-PCR and anti-HGenv u-plate to investigate the prevalence of GBV-C/HGV in eastern Taiwan aborigines. We also used ELISA, dot blot assay, and Western blot to detect the serologic responses to various GBV-C/HGV markers.

RESULTS

The prevalence of GBV-C/HGV RNA in the general population of eastern Taiwan aborigines is about 5% (17/317), while 14% (43/317) have anti-E2 antibodies. There were no significant differences in antibody titer against one consensus core peptide (PPSSAAACSRGSPR) between GBV-C/HGV RNA-positive and -negative sera. Only 23 of 42 serum samples positive in the anti-HGenv u-plate EIA assay were positive (55%) in the dot blot assay. No positive signal was detected by Western blot using either recombinant NS3 or commercial E2 proteins.

CONCLUSIONS

Antibodies against one consensus core peptide (PPSSAAACSRGSPR) may not constitute a good marker for the detection of GBV-C/HGV viremia. For the detection of anti-E2 antibodies, the anti-HGenv u-plate assay is more sensitive than the dot blot assay. Western blot assay is not a sensitive method for detecting GBV-C/HGV infection.

GB virus C/hepatitis G virus

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

GB virus-C infection in patients infected with the human immunodeficiency virus

Hepatitis virus infections are frequent in patients suffering from HIV infection due to similar transmission routes of these viruses. In addition, hepatitis virus infections lead to impaired survival in HIV positive patients. The recently discovered flavivirus GB virus C (alias Hepatitis G Virus) was initially believed to be another hepatitis virus. While there is still some minor discussion whether GB virus C (GBV-C) plays a role in fulminant hepatic failure, there is no evidence that this virus is responsible for chronic liver disease. Thus this 'orphan virus' still seeks its disease. In this review we concentrate on the published data concerning the co-infection of GBV-C and HIV. By summarizing the studies available, we show evidence for a beneficial influence of GBV-C on HIV infection. Many studies demonstrated a high prevalence of GBV-C infection in HIV positive patients due to its parenteral and sexual transmission. However, in contrast to the expectations, GBV-C does not aggravate the course of patients suffering from HIV infection. Even though not uniformly found, one often sees higher CD4 counts in patients with ongoing GBV-C viral replication. Likewise, a lower viral load appears to be accompanied by the presence of GBV-C RNA in the serum. In addition, longitudinal studies indicate that GBV-C infection slows down the progression to AIDS and eventually to death. GBV-C probably influences HIV infection associated disease by either directly inhibiting HIV replication or enhancing the immune competence to cope with HIV. Still the definitive mechanism how GBV-C could inhibit the progression to AIDS and eventually death needs to be identified.

High frequencies of HGV and TTV infections in blood donors in Hangzhou

AIM: To determine the frequencies of HGV and TTV infections in blood donors in Hangzhou.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection in the sera from 203 blood donors, and nucleotide sequence analysis were performed.

RESULTS: Thirty-two (15.8%) and 30 (14.8%) of the 203 serum samples were positive for HGV RNA and TTV DNA, respectively. And 5 (2.5%) of the 203 serum samples were detectable for both HGV RNA and TTV DNA. Homology of the nucleotide sequences of HGV RT-nested PCR products and TTV semi-nested PCR products from 3 serum samples compared with the reported HGV and TTV sequences was 89.36%, 87.94%, 88.65% and 63.51%, 65.77% and 67.12%, respectively.

CONCLUSION: The infection rates of HGV and/or TTV in blood donors are relatively high, and to establish HGV and TTV examinations to screen blood donors is needed for transfusion security. The genomic heterogeneity of TTV or HGV is present in the isolates from different areas.

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.

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.

Prospective follow-up of patients with GBV-C/HGV infection: specific mutational patterns, clinical outcome, and genetic diversity

An association between a specific mutational pattern within the nonstructural (NS)3 region of GB virus-C/hepatitis G virus (GBV-C/HGV) genome and fulminant hepatic failure has been suggested recently. The mutational pattern consists of 3-6 nucleotide mutations of which one is leading to an amino acid exchange. In the present study, patients with GBV-C/HGV mono-infection (n = 24) or GBV-C/HGV and HCV co-infection (n = 20) were investigated prospectively. In 6/44 patients (14%) the mutational pattern within GBV-C/HGV NS3 previously associated with fulminant hepatic failure was identified by direct sequence analysis of the NS3 region. All 44 patients were asymptomatic clinically and had normal liver functions at initial presentation and after a median follow-up of 2.2 years. In 22/24 patients with GBV-C/HGV mono-infection and all patients with GBV-C/HGV and HCV co-infection GBV-C/HGV RNA remained detectable at the end of the study period, whereas two patients infected with GBV-C/HGV alone became negative for GBV-C/HGV RNA and developed GBV-C/HGV anti-E2 antibodies indicating recovery from GBV-C/HGV infection. Aminotransferase levels remained elevated or became normal independent of the persistence of serum GBV-C/HGV RNA. The median rate of nucleotide substitutions in GBV-C/HGV mono-infected and HCV co-infected patients was 3.4 x 10(-3) and 3.2 x 10(-3) per site per year, respectively. In conclusion, the prevalence of the mutational pattern within NS3 region of GBV-C/HGV associated previously with fulminant hepatic failure is about 14% and not associated specifically with severe liver disease. Over a median follow-up of 2.2 years less than 5% of patients cleared spontaneously GBV-C/HGV and no correlation between viraemia and elevated liver enzymes was observed.

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.

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.

Molecular epidemiology of GB virus C/hepatitis G virus in Athens, Greece

The relevance of GB virus C/hepatitis G virus (GBV-C/HGV) infections in liver pathology remains unclear. To investigate the epidemiology of GBV-C/HGV in Athens, Greece, sera from 512 subjects were screened for present and past markers of GBV-C/HGV infection using a reverse transcription-polymerase chain reaction (RT-PCR) and a serological assay, respectively. GBV-C/HGV RNA was detected in 18/56 (32.1%), 12/42 (28.6%), and 16/55 (29.1%) patients with acute hepatitis B, C, or non-A-E, and in 5/58 (8.6%) and 18/68 (26.5%) patients with chronic hepatitis B or C, respectively, as well as in 50/133 (37.6%) hemodialysis patients and 10/100 (10%) healthy individuals. The data indicated that GBV-C/HGV seroprevalence is age-dependent; thus, GBV-C/HGV RNA and anti-E2 positivity were shown to be associated with younger age [odds ratio 0.98, 95% confidence interval (CI) 0. 97-1.00, P = 0.017] and older age (odds ratio 1.03, 95% CI 1.01-1.05, P = 0.002), respectively. No significant associations were identified between GBV-C/HGV RNA status and alanine aminotransferase (ALT) levels in either hepatitis or hemodialysis patients. Nevertheless, GBV-C/HGV RNA-positive acute non-A-E hepatitis patients were more likely to manifest a more severe clinical form of acute hepatitis (P = 0.024). Phylogenetic analysis of partial 5'-untranslated region sequences isolated from 18 viremic individuals showed that most GBV-C/HGV strains circulating in the greater metropolitan area of Athens belong to the 2a subgroup. A genetically diverse type 2 sequence that may represent a novel subtype within group 2 was also characterized.

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.

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 of GB virus C/Hepatitis G virus infection among various populations in Surabaya, Indonesia, and identification of novel groups of sequence variants

A molecular epidemiological study was performed to investigate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) infection among various populations in Surabaya, Indonesia. The prevalence of GBV-C/HGV RNA, determined by reverse transcription-PCR for a portion of the NS3 region of the viral genome, was 2.7% (4 of 150) among randomly collected blood donor sera, which were all negative for both hepatitis B virus surface antigen and antibodies against hepatitis C virus (HCV). On the other hand, the prevalence among anti-HCV-positive blood donors was 17.8% (13 of 73), with the ratio being significantly higher than that observed with the anti-HCV-negative blood donors (P < 0.001). A high prevalence of GBV-C/HGV infection was also observed among patients with chronic liver disease, such as chronic hepatitis (5.7%), liver cirrhosis (11. 5%), and hepatocellular carcinoma (7.0%), and patients on maintenance hemodialysis (29.0%). No correlation was observed between GBV-C/HGV viremia and serum alanine aminotransferase levels in the populations tested, suggesting the possibility that GBV-C/HGV does not cause apparent liver injury. Phylogenetic analysis of sequences of a portion of the 5' untranslated region and the E1 region of the viral genome identified, in addition to a previously reported then novel group of GBV-C/HGV variants (group 4), another novel group of variants (group 5). This result suggests that GBV-C/HGV can be classified into at least five genetic groups. GBV-C/HGV isolates of group 4 and group 5 were each shown to comprise approximately 40% of the total Indonesian isolates.

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.

Risk and clearance of GB virus C/hepatitis G virus infection in homosexual men: A longitudinal study

The risk and clearance of GB virus type C (GBV-C)/hepatitis G virus (HGV) infection was investigated in a cohort of homosexual men (n=180; median follow-up time, 7 years). The interaction between GBV-C/HGV RNA and antibodies against the E2 region of the virus, and the clinical impact of chronic GBV-C/HGV infection were studied. GBV-C/HGV RNA was detected by RT-PCR, and E2 antibodies were assessed by an immunoassay. At baseline, 63% of the participants had evidence of previous or current GBV-C/HGV infection. The GBV-C/HGV incidence rate was 2 per 100 person-years (95% confidence interval 0. 9-3.8) and was similar to the HIV incidence. The incidence of GBV-C/HGV infection was significantly higher in those reporting unprotected anal intercourse (3.6 per 100 person-years compared to 0 in the group without such sexual contacts). The occurrence of E2 antibodies was strongly associated with GBV-C/HGV RNA clearance. A loss of E2 antibodies was observed at a rate of 1.5 per 100 person-years. It was higher among HIV-infected individuals. Chronic GBV-C/HGV infection was not associated with clinical or biochemical evidence of liver disease.

Analysis of hepatitis G virus infection markers in blood donors and patients with hepatitis

The incidence and clinical significance of hepatitis G virus (HGV) is still not fully known. The aim of our study was to assess the frequency of HGV RNA and antibody to HGV E2 protein (anti-E2) in Polish blood donors and patients with hepatitis, and to compare the sequence of HGV clones with those reported by others. Two-hundred and nineteen blood donors and 83 patients with hepatitis were studied. HGV was detected in 3.2% and anti-E2 in 24.2% of blood donors and in 26.5% and 8.4% of patients with hepatitis, respectively. HGV was detected as a co-infection with HCV in four of 18 patients with chronic hepatitis, in four of 16 patients with acute hepatitis and in one of six patients with fulminant liver failure (FLF), and as a co-infection with HBV in one of six patients with FLF and in three of 10 patients with chronic hepatitis. In non-A-C hepatitis, eight of 23 patients with acute hepatitis and one of four patients with FLF were positive for HGV but all 10 patients with chronic cryptogenic hepatitis were negative. In the follow-up studies of patients with HGV alone, a correlation with viraemia and clinical symptoms was observed in two patients, but in three others HGV RNA was detected in spite of clinical resolution. Two HGV clones were sequenced, and the sequence of the HGV helicase region of the HGV isolates from donor and patient were homologous to those described by others. Hence, the frequency of HGV RNA in blood donors is similar to that obtained in other countries but the anti-E2 (marker of a past infection) frequency is higher. The incidence of HGV RNA and anti-E2 in hepatitis patients suggests that HGV plays a role in liver pathology, but careful analysis of individual cases does not confirm this.

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.

Partial nucleotide sequencing of the NS3/helicase region of hepatitis G virus to prove vertical transmission

To study non-parental transmission of hepatitis G virus and/or GB virus C (HGV/GBV-C), we sequenced and compared the NS3/helicase region of the virus for five HGV/GBV-C RNA-positive mothers and their 11 children who had experienced neither blood transfusion nor overt hepatitis and were negative for HBV, HCV and HIV, except in one mother coinfected with HCV. The nucleotide sequences of the familial HGV/GBV-C isolates showed high similarity of 99-100% (mean 99.8%, 100% at the deduced amino acid level) between mother and her child(ren) in each family. These findings strongly suggest the spontaneous occurrence of mother-to-child transmission of HGV/GBV-C as reported previously. They also suggest that nucleotide sequence analysis on the NS3/helicase region of HGV/GBV-C may be a useful tool to study HGV/GBV-C transmission.

Detection of HGV in serum and peripheral blood mononuclear cells of maintenance haemodialysis patients

The aim of the present study was to investigate the prevalence of hepatitis G virus (HGV) and also hepatitis C virus (HCV) infections in maintenance haemodialysis patients, and to identify extrahepatic sites as HGV reservoirs. HGV RNA was detected in the serum of 6/61 (10%) patients and in the peripheral blood mononuclear cells of 2/61 (3%) patients (one of whom was serum negative). These findings suggest that lymphoid cells constitute an extrahepatic HGV reservoir. HCV RNA was detected in 7/61 (11%) patients. Five of these patients (71%) were identified as carrying HCV genotype 1b. Co-infection with HCV and HGV was detected only in one patient. Haemodialysis patients are at risk for HGV infection, by nosocomial routes or via transfusions. HGV itself does not seem to be an important cause of hepatitis since all six HGV RNA positive patients not co-infected by HCV or HBV showed normal ALT values.

GB virus C (GBV-C/HGV) and E2 antibodies in children preliver and postliver transplant

The association of GB virus type C (GBV-C) virus and clinical disease is uncertain. The role of GBV-C and (Envelope) E2 antibody in children with liver transplants has not been determined. This study's aim is to examine the prevalence of GBV-C in children with liver transplants, to assess the relationship of GBV-C to posttransplant hepatitis, and to determine the role of E2 antibodies. Sera from 34 children, preliver and postliver transplant, between 1989-1996 were tested for GBV-C (Ribonucleic acid) RNA by the automated Abbott LCx PCR assay. Anti-E2 antibodies were detected by an Abbott immunoassay. Recent posttransplant liver biopsies were examined for hepatitis. The results of the study determined that pretransplant, four children (12%) were GBV-C RNA positive. Posttransplant, 14 (42%) children were GBV-C RNA positive. The GBV-C RNA positive conversion rate was 33% (CI 17.2-55.7%). Patients received blood products from a mean of 68 +/- 34 donors, which correlated with GBV-C acquisition. There was no difference in the incidence (32%versus 36%; p = 0.726) or severity (grade 2.00 versus 0.68; p = 0.126) of posttransplant hepatitis in the liver biopsies of GBV-C RNA negative and/or positive children, respectively. Pretransplant, nine of 32 children were anti-E2 positive. Posttransplant, eight of 32 children were anti-E2 positive, including five children who were anti-E2 positive pretransplant. Of nine children who were anti-E2 positive and GBV-C RNA negative pretransplant, three became GBV-C RNA positive posttransplant. The results of this study conclude that the prevalence of GBV-C infection in children postliver transplantation is high and that blood product transfusions correlate with GBV-C acquisition. Also, no correlation was found between GBV-C RNA and the incidence or severity of posttransplant hepatitis. Finally, E2 antibody presence before transplantation failed to provide complete protection from GBV-C acquisition.

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.

Analysis of hepatitis G virus/GB virus C quasispecies and replication sites in human subjects

Although the hepatitis G virus is unlikely to be a primary hepatotropic virus, its replication sites remain unclear. Using highly strand-specific Tth-based reverse transcriptase PCR we searched for the presence of the viral RNA negative strand in various autopsy tissues in two patients who died of end-stage liver disease. In addition, amplified viral sequences were compared in the 5' untranslated and the putative capsid regions by the single-strand conformation polymorphism (SSCP). Negative strand HGV RNA was detected in bone marrow and spleen from both patients and in lymph node tissue from one. All amplified sequences from a given patient were identical when compared by SSCP and direct sequencing. This lack of difference in the composition of quasispecies recovered from various tissues suggests the presence of a single, common viral compartment in the infected host.

High prevalence of GB virus C in Brazil and molecular evidence for intrafamilial transmission

The prevalence of GB virus C (GBV-C) in candidate Brazilian blood donors with normal and elevated alanine aminotransferase levels was found to be 5.2% (5 of 95) and 6.5% (5 of 76), respectively. Among Brazilian patients, GBV-C was found in 9.5% (13 of 137) of cases of hepatitis not caused by hepatitis A virus (HAV), HBV, HCV, HDV, or HEV (non-A-E hepatitis) and in 18.2% (8 of 44) of individuals infected with HCV. Molecular characterization of GBV-C by partial sequencing of the NS3 region showed clustering between members of a single family, implying intrafamilial transmission. In conclusion, these results together suggest that contagion mechanisms which facilitate intrafamilial transmission of GBV-C may partially explain the high prevalence of viremic carriers worldwide.

In vitro infection of human peripheral blood mononuclear cells by GB virus C/Hepatitis G virus

GB virus C (GBV-C), also known as hepatitis G virus, is a recently discovered flavivirus-like RNA agent with unclear pathogenic implications. To investigate whether human peripheral blood mononuclear cells (PBMC) are susceptible to in vitro GBV-C infection, we have incubated PBMC from four healthy blood donors with a human GBV-C RNA-positive serum. By means of (i) strand-specific reverse transcription-PCR, cloning, and sequencing; (ii) sucrose ultracentrifugation and RNase sensitivity assays; (iii) fluorescent in situ hybridization; and (iv) Western blot analysis, it has been demonstrated that GBV-C is able to infect in vitro cells and replicate for as long as 30 days under the conditions developed in our cell culture system. The concentration of GBV-C RNA increased during the second and third weeks of culture. The titers of the genomic strand were 10 times higher than the titers of the antigenomic strand. In addition, the same predominant GBV-C sequence was found in all PBMC cultures and in the in vivo-GBV-C-infected PBMC isolated from the donor of the inoculum. GBV-C-specific fluorescent in situ hybridization signals were confined to the cytoplasm of cells at different times during the culture period. Finally, evidence obtained by sucrose ultracentrifugation, RNase sensitivity assays, and Western blot analysis of the culture supernatants suggests that viral particles are released from in vitro-GBV-C-infected PBMC. In conclusion, our study has demonstrated, for the first time, GBV-C replication in human lymphoid cells under experimental in vitro infection conditions.

Chronic cryptogenic hepatitis in childhood is unrelated to hepatitis G virus

OBJECTIVES

The aim of this study was to define the features of chronic cryptogenic hepatitis (CCH) in childhood and to investigate whether it is related to hepatitis G virus infection.

METHODS

Forty-six children (24 males; age range, 1.5 to 17 years) with CCH were studied. CCH was diagnosed when serum alanine aminotransferase concentrations were more than 1.5 times normal for longer than 6 months without any apparent cause of liver disease.

RESULTS

No patient had acute symptomatic onset or had received a blood transfusion. Three had undergone minor surgical procedures. All appeared to be healthy during follow-up (median, 4.2 years; range, 1 to 10 years). Hypertransaminasemia was the only aberrant liver function test. Elevated serum alanine aminotransferase values alternated with normal values in 40 children (86.9%). Five children (10.8%) had a spontaneous sustained (>12 months) remission of hypertransaminasemia. Twelve (26%) had laboratory signs of autoimmunity, but none fulfilled the criteria for autoimmune hepatitis. Of 20 children who underwent liver biopsy, 13 (65%) had minimal chronic hepatitis, 4 (20%) had mild chronic hepatitis and 3 (15%) had moderate chronic hepatitis. Serum hepatitis G virus RNA was detected in 2 girls (4%) whose risk factor was a hepatitis G virus-infected mother and a minor surgical procedure, respectively. In 12 families at least 1 other member had chronic liver disease.

CONCLUSIONS

Childhood CCH seems to be a symptomless disease characterized by isolated hypertransaminasemia with onset during the first 4 years of life and mild to moderate histologic liver lesions. Although the frequency of spontaneous remissions is low, childhood CCH seems, in the short run, to be a nonprogressive disease. Hepatitis G virus does not play a major role in CCH.

Absence of the negative strand of GBV-C/HGV RNA from the liver

BACKGROUND/AIMS

The pathogenic role of the human virus GBV-C/HGV remains unclear as information on tissue specific tropism and sites of replication of GBV-C/HGV is limited and controversial. The aim of this study was to determine whether the liver is the site of GBV-C/HGV replication.

METHODS

We utilized the strand-specific Tth RT-PCR assay to investigate the presence of the positive- and negative-strand of GBV-C/HGV RNA in liver and serum samples from 12 patients with chronic GBV-C/HGV infection; four were infected with GBV-C/HGV alone, six were coinfected with HCV and two with HBV. A control group of six patients infected with HCV alone was included. The presence of the positive- and negative-strand of HCV RNA was also investigated in the same samples.

RESULTS

All liver specimens were negative for the presence of the replicating negative-strand of GBV-C/HGV RNA. Positive-strand GBV-C/HGV RNA was found in 6 of the 12 liver samples and was detectable only at low levels, most probably reflecting serum contamination. By contrast, the negative strand of HCV RNA was detected in high titers in the liver of all HCV-infected and -coinfected subjects with less than a 100-fold difference from the positive strand. In serum samples only the positive strands of GBV-C/HGV and HCV RNA were detected in comparable titers.

CONCLUSIONS

The results of this study suggest that GBV-C/HGV is not replicating in the liver and, taken together with the bulk of evidence against hepatopathogenicity, they argue against the new agent being a hepatotropic virus. We suggest that the acronymic term of this agent GBV-C/HGV is used with the understanding that it is not a hepatitis virus.

Chronic liver disease in central Harlem: the role of alcohol and viral hepatitis

For reasons not yet determined, chronic liver disease (CLD) has been a leading cause of excess morbidity and mortality in central Harlem. We conducted a case series and case-control analysis of demographic, clinical, epidemiological, and alcohol-intake-related information from patients with CLD and age- and sex-matched hospitalized control patients. Patients' sera were tested for markers of viral hepatitis. The presumed etiology of CLD among case-patients was as follows: both alcohol abuse and hepatitis C virus (HCV) infection, 24 persons (46% of case-patients); alcohol abuse alone, 15 (29%); HCV infection alone, 6 (12%); both alcohol abuse and chronic hepatitis B virus (HBV) infection, 3 (6%); and 1 each (2%) from: 1) schistosomiasis, 2) sarcoidosis, 3) unknown causes, and 4) alcohol abuse, chronic HBV, and HCV combined. In the case-control analysis, patients who had both alcoholism and either HBV (odds ratio [OR]: 6.3; 95% CI: 0. 5-334) or HCV (OR: 2.9; 95% CI: 1.3-6.2) were at increased risk for CLD, whereas patients who had only one of these three factors were not at increased risk for CLD. Patients who tested positive for the hepatitis G virus (HGV) did not have a significantly increased risk of CLD, and neither severity of CLD nor mortality was greater among these patients. Most patients in central Harlem who had CLD had liver damage from a combination of alcohol abuse and chronic viral hepatitis. Alcohol and hepatitis viruses appear to be synergistically hepatotoxic; this synergy appears to explain both the high rate of CLD in central Harlem and the recent reductions in this rate. Persons at risk for chronic HBV and HCV infection should be counseled about their increased risk of CLD if they consume excessive alcohol. Morbidity and mortality from liver disease could be decreased further by a reduction in alcohol consumption among persons who have chronic HBV and HCV infection, avoidance of needle sharing, and hepatitis B vaccination.

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%.

Prevalence of GB virus C/hepatitis G virus ribonucleic acid and anti-hepatitis G virus-E2 antibodies among Japanese children with histories of transfusions or with liver diseases

To clarify the prevalence of Japanese children thought to be at a risk for infection with GB virus-C (GBV-C)/hepatitis G virus (HGV), we investigated the detection rates of serum GBV-C/ HGV ribonucleic acid (RNA) by reverse transcription-seminested PCR and serum anti-HGV-E2 antibody by ELISA in 162 children with histories of blood or plasma product transfusions or with liver diseases and performed phylogenetic analysis of the 5' noncoding region sequences of GBV-C/HGV genomes. Children with histories of transfusions were divided into those who had been treated with antineoplastic agents for malignant diseases (malignant group) and those who had received transfusions for nonmalignant diseases (nonmalignant group). Children with liver diseases were divided into hepatitis B (HBV), hepatitis C (HCV), and non-A-C hepatitis groups. We detected GBV-C/ HGV RNA in 11 of 33 (33.3%) and anti-HGV-E2 in 1 of 27 (3.7%) children in the malignant group and in 3 of 56 (5.4%) and 1 of 53 (1.9%) children, respectively, in the nonmalignant group. Neither GBV-C/HGV RNA nor anti-HGV-E2 was detected in the HBV and non-A-C hepatitis groups. GBV-C/HGV RNA and anti-HGV-E2 were detected in 7 of 23 (30.4%) and in 1 of 18 (5.6%) children, respectively, in the HCV group. All children positive for either GBV-C/HGV RNA or anti-HGV-E2, except one whose route of GBV-C/HGV infection suggested mother-to-infant transmission, had histories of transfusions. The phylogenetic analysis showed that all isolates in this study were divisible into three groups and that most of them were clustered into group 3 (Asian group).

Comparative study of 5' UTR and NS3R primers for the detection of GB virus C/hepatitis G virus RNA in Japanese

AIMS/BACKGROUND

Many epidemiological studies of new hepatitis viruses, including GB virus C (GBV-C) and hepatitis G virus (HGV), have used polymerase chain reaction (PCR) primers designed for the third nonstructural region (NS3R). However, a homology study of GBV-C and HGV genomes revealed that the 5' untranslated region (5'UTR) was more conserved than NS3R.

METHODS

We attempted to detect GBV-C/HGV using PCR primers corresponding to the 5' UTR, and compared its incidence to that derived from NS3R primers. Furthermore, PCR products amplified using the 5' UTR primers were sequenced and subjected to phylogenetic analysis.

RESULTS

In patients with chronic hepatitis C, the prevalence of GBV-C/HGV by PCR with the NS3R and 5' UTR primers was 5.1% (4/78) and 17.9% (14/78), respectively, and in patients on hemodialysis, it was 0% (0/81) and 5.9% (5/85), respectively. We could not detect GBV-C/HGV in patients with non-A-C liver disease. The incidence of GBV-C/HGV by 5' UTR primers was higher than by NS3R primers. After DNA sequencing at 5' UTR, phylogenetic analysis showed two types of GBV-C/HGV, Jap and HGV types.

CONCLUSION

5' UTR primers proved highly sensitive for detection of GBV-C/HGV and were superior to the NS3R primers.

Antibodies to the E2 protein of GB virus C/hepatitis G virus: low prevalence in Asian countries

Epidemiological investigations of GB virus C (GBV-C)/hepatitis G virus (HGV), an infectious agent discovered in 1995/1996, are facilitated by a recently developed immunoassay for the detection of antibodies to the viral envelope 2 protein (anti-E2). We used this assay to establish GBV-C/HGV prevalence in seven European, African, and Asian countries. A total of 1579 serum samples from healthy adults lacking prior exposure to known parenteral risk factors was screened. Anti-E2 positivity ranged from 13.6% (Italy) to 7.7% (Mauritius) in the European and African countries investigated. Anti-E2 prevalence was exceedingly low in the Philippines and Sri Lanka. This observation might be attributable to socio-economical and demographic factors.

Multicyclic reverse transcription-polymerase chain reaction assay system for quantification of GB virus-C/hepatitis G virus RNA in serum

A new quantitative reverse transcription-polymerase chain reaction (RT-PCR) method is described for analyzing the amount of GB virus-C (GBV-C)/hepatitis G virus (HGV) RNA in serum. This multicyclic RT-PCR (MRT-PCR) method used oligonucleotide primers deduced from the 3' noncoding region (3'NCR) that is highly conserved among GBV-C/HGV isolates. Quantitation of GBV-C/HGV RNA using MRT-PCR ranged between 10(2) and 10(10) copies/ml when PCR cycle number was regulated at exponential amplification of the products. Competitive RT-PCR (CRT-PCR) was carried out with mutant RNA and sample that had been measured by MRT-PCR. Quantitation of GBV-C/HGV RNA using both methods agreed. MRT-PCR detected viral RNA in a single step PCR, and demonstrated a high degree of sensitivity that was equal to that of the RT-PCR procedure, which used nested primers deduced from the non-structural (NS) 3 region. The MRT-PCR method for quantitation of GBV-C/HGV RNA in serum may prove useful for diagnosis.

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 in liver tissue and in sera from patients with chronic hepatitis C

Forty-eight persons (M = 45, F = 3; age range = 20-53, mean = 32.2) affected with chronic hepatitis C were tested for HGV/GBV-C RNA and HCV-RNA by nested PCR and DEIA in serum and in liver specimens to evaluate the prevalence and the impact of HGV/GBV-C coinfection in patients with chronic HCV-related hepatitis. Sera were also assayed for antibodies to HGV/GBV-C E2 protein. Serum HGV/GBV-RNA could be detected in nine (19%) patients, and anti-E2 antibodies in 22 (46%) patients. The presence of HGV/GBV-C RNA or anti-E2 antibodies was mutually exclusive. The cumulative prevalence of HGV/GBV-C infection was 65% (31/48); the majority of these patients (26/31, 84%) were intravenous drug users (IVDUs). In eight of nine patients viraemic for HGV/GBV-C, RNA positivity could be revealed even in liver specimens; these eight patients were also positive for HCV-RNA both in serum and the liver and did not exhibit any specific association with HCV genotype. HGV/GBV-C RNA negative strand RT-PCR testing was negative in all of the eight liver specimens, providing little support to the hypothesis that liver represents the primary site of HGV/GBV-C replication. Moreover, patients with HGV/GBV-C and HCV coinfection were comparable to those with HCV infection alone in terms of biochemistry and liver histology.