Infection with hepatitis G virus among recipients of plasma products

Status and natural course of GB virus C/hepatitis G virus infection among high-risk groups and volunteer blood donors in Taiwan

BACKGROUND

Hemophilia, thalassemia and uremia patients are at risk of parenterally transmitted infectious agents. The status and nature of the course of GB virus C/hepatitis G virus (GBV-C/HGV) infection among these groups and blood donors in Taiwan was investigated.

METHODS

Serum GBV-C HGV-RNA and antibodies to GBV-C/HGV envelope-2-protein (anti-E2) were determined in 500 blood donors and in 44 hemophilia, 37 thalassemia and 85 uremia patients. Phylogenetic analysis was performed.

RESULTS

The prevalence of GBV-C/HGV-RNA and anti-E2, respectively, was 38.6 and 27.3% in hemophilia patients, 27.0 and 27.3% in thalassemia patients, 14.1 and 10.6% in uremia patients and 3.4 and 7.2% in blood donors. The prevalence of GBV-C HGV exposure was 59.1 and 51.4% in hemophilia and thalassemia patients, respectively, which was significantly higher than that for uremia patients (22.4%; P < 0.01) and blood donors (10.2%; P < 0.001). The anti-E2 seroconversion rate was 66.7% in blood donors and 47.4, 36.8 and 34.6% in thalassemia, uremia (P < 0.05 compared with blood donors) and hemophilia (P < 0.01 compared with blood donors) patients, respectively. Discrepancies in the prevalence of GBV-C HGV and hepatitis C virus infection were found among the three risk groups. Phylogenetic analysis showed that 51 of 56 GBV-C HGV isolates clustered in group 3; the remaining five were of group 2a. Twelve of 39 viremic patients in the risk groups cleared the virus during the 4 year follow-up period; seven developed concomitant anti-E2 reactivity.

CONCLUSIONS

GB virus C hepatitis G virus infection is epidemic among risk groups and GBV-C HGV group 3 is the major strain in Taiwan. In the risk groups, approximately 18% of infections resolve with concomitant anti-E2 seroconversion within 4 years.

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.

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.

Hepatitis G virus infection in haemodialysis and in peritoneal dialysis patients

The aim of this study was to detect hepatitis G virus RNA (HGV RNA) and antibodies against the virus envelope protein E2 (anti-E2) in 107 patients either on maintenance haemodialysis (n = 78) or peritoneal dialysis (n = 29) to evaluate the prevalence of HGV infection and to establish its role in liver disease. The total prevalence of HGV infection was of 15.4% among haemodialysis patients, whereas it was 10.3% among peritoneal dialysis patients. HGV RNA was detected in 2 haemodialysis patients (2.6%) and in 3 peritoneal dialysis patients (10.3%). Anti-E2 was found in 10 haemodialysis patients (7.8%), whilst all peritoneal dialysis patients resulted negative. In only 1 patient the alanine aminotransferase level was elevated. This patient underwent liver biopsy that did not reveal evidence of chronic hepatitis. The lower HGV prevalence in haemodialysis patients, when compared with data reported by other European authors, should be related to the lower rate of polytransfused patients in our series (29.5%). Multiple blood transfusions should be considered as the main factor to explain the different prevalence of HGV infection among various European dialysis centres. Detection of both antibody and viraemia is important to establish the real rate of the infection.

Reducing the risk of infection from plasma products: specific preventative strategies

Collection and testing procedures of blood and plasma that are designed to exclude donations contaminated by viruses provide a solid foundation for the safety of all blood products. Plasma units may be collected from a selected donor population, contributing to the exclusion of individuals at risk of carrying infectious agents. Each blood/plasma unit is individually screened to exclude donations positive for a direct (e.g., viral antigen) or an indirect (e.g. anti-viral antibodies) viral marker. As infectious donations, if collected from donors in the testing window period, can still be introduced into manufacturing plasma pools, the production of pooled plasma products requires a specific approach that integrates additional viral reduction procedures. Prior to the large-pool processing, samples of each donation for fractionation are pooled ('mini-pool') and subjected to a nucleic acid amplification test (NAT) by, for example, the polymerase chain reaction (PCR) to detect viral genomes (in Europe: HCV RNA plasma pool testing is now mandatory). Any individual donation found PCR positive is discarded before the industrial pooling. The pool of eligible plasma donations (which may be 2000 litres or more) may be subjected to additional viral screening tests, and then undergoes a series of processing and purification steps that, for each product, comprise one or several reduction treatments to exclude HIV, HBV HCV and other viruses. Viral inactivation treatments most commonly used are solvent-detergent incubation and heat treatment in liquid phase (pasteurization). Nanofiltration (viral elimination by filtration), as well as specific forms of dry-heat treatments, have gained interest as additional viral reduction steps coupled with established methods. Viral reduction steps have specific advantages and limits that should be carefully balanced with the risks of loss of protein activity and enhancement of epitope immunogenicity. Due to the combination of these overlapping strategies, viral transmission events of HIV, HBV, and HCV by plasma products have become very rare. Nevertheless, the vulnerability of the plasma supply to new infectious agents requires continuous vigilance so that rational and appropriate scientific countermeasures against emerging infectious risks can be implemented promptly.

Mother-to-infant transmission of GB virus type C/HGV

BACKGROUND

The potentially hepatotropic flavivirus-like virus, GB virus type C (GBV-C)/HGV, has been detected in a few patients with acute and chronic hepatitis and in a certain proportion of blood donors and recipients of blood or blood components.

STUDY DESIGN AND METHODS

Sera from 2979 pregnant Japanese women were examined for the presence of GBV-C/HGV RNA by nested RT-PCR. Mothers who were positive for viral RNA and their 34 infants were followed and tested for infection.

RESULTS

Of the 2979 women, 32 (1.1%) were positive for GBV-C/HGV RNA. Twenty-six (76.5%) of 34 babies born to these women were positive for the virus when first tested. A significantly higher titer of viral RNA was observed in mothers whose infants were infected than in those whose infants were uninfected (mean +/- SD, 10(6.3 +/- 0.9) vs. 10(4.6 +/- 0.9)/mL; p<0.001). Twenty-three (96%) of 24 babies born to mothers whose serum viral titers were 10(6) mL or more were infected with the virus. Infants delivered by elective caesarean section had a lower risk (OR, 0.13; 95% CI, 0.02-0.82) than those delivered vaginally or by emergency caesarean section. No other risk factors for mother-to-infant transmission were confirmed.

CONCLUSIONS

GBV-C/HGV is frequently transmitted from mothers to infants in the general population. The most critical factor is the titer of viral RNA in the maternal serum. By the use of elective caesarean section in women with high titers of viral RNA, vertical transmission of the virus may be lessened.

GB virus C/hepatitis G viremia and antibody response to the E2 protein of hepatitis G virus in hemodialysis patients

The aim of this study was to assess the relationship between the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) RNA and that of antibody to the putative E2 protein (anti-E2) in hemodialysis patients. GBV-C/HGV RNA in serum was detected by a reverse transcription polymerase chain reaction (RT-PCR) assay, and anti-E2 was measured in 244 hemodialysis patients by enzyme-linked immunosorbent assay using recombinant E2 protein. The GBV-C/HGV RNA level was determined by competitive RT-PCR with an interval of 1 year. GBV-C/HGV RNA, anti-E2. and both together were detected in 11 (4.5%), in 19 (7.8%), and in 3 patients (1.2%), respectively. Comparison of clinical characteristics between GBV-C/HGV RNA-positive patients and negative patients revealed the longer duration of hemodialysis (9.8 years vs. 6.0 years; p < 0.05), and the greater frequency of anti-hepatitis C virus (HCV) (63.6% vs. 20.3%; p < 0.05) and HCV RNA (36.4% vs. 12.9%; p < 0.05) in GBV-C/HGV RNA-positive patients. The GBV-C/HGV RNA levels of patients who were positive for anti-E2 remained under detection limit (< 10(2) copies/mL), whereas only one of eight patients who were negative for anti-E2 showed a GBV-C/HGV RNA level under detection limit (p < 0.05). The presence of anti-E2 in serum was associated with loss of detectable GBV-C/HGV RNA or with a very small amount of HCV RNA in hemodialysis patients.

Detection of hepatitis B virus infection in wild-born chimpanzees (Pan troglodytes verus): phylogenetic relationships with human and other primate genotypes

Infection with hepatitis B virus (HBV) was detected by serological testing for HBV surface antigen and by PCR assay for HBV DNA in serum samples from two common chimpanzees (Pan troglodytes subsp. verus) born in West Africa. The complete genome sequences obtained by nucleotide sequencing of overlapping DNA fragments amplified by PCR were compared with HBV variants recovered from other primates and with human genotypes A to F. Both chimpanzee sequences were 3, 182 nucleotides in length, and the surface gene sequence predicted the existence of a, d, and w serological determinants. Neither sequence contained stop codons in the precore region. On phylogenetic analysis, the HBV variants infecting the chimpanzees clustered together with a third chimpanzee HBV isolate independently obtained from an infected captive animal (A. J. Zuckerman, A. Thornton, C. R. Howard, K. N. Tsiquaye, D. M. Jones, and M. R. Brambell, Lancet ii:652-654, 1978), with an overall sequence similarity of >94%. This provides strong evidence for a chimpanzee-specific genotype of HBV which circulates in nature. These findings add to the recent evidence for infection in the wild of other Old and New World primates (gibbon, orangutan, and woolly monkey) with species-specific variants of HBV. There is no evidence for close phylogenetic clustering of variants found so far in primates with any of the established HBV genotypes from humans. With the new evidence for the widespread distribution of HBV in primates, hypotheses for the origins of human infection are reviewed.

High rate of GB virus type C/HGV transmission from mother to infant: possible implications for the prevalence of infection in blood donors

BACKGROUND

Because GB virus type C(GBV-C)/HGV (GBV-C/HGV) is blood-borne and sexually transmitted, persons at risk of infection with such viruses have a high prevalence of GBV-C/HGV markers. However, adults with no apparent risk factors, such as blood donors, frequently are positive for GBV-C/HGV markers. Mother-to-infant transmission could explain this high prevalence, but it has been studied only through small series of GBV-C/HGV-infected mothers co-infected with HCV or HIV.

STUDY DESIGN AND METHODS

To determine the rate of mother-to-infant transmission of GBV-C/HGV RNA in women who are HCV- or HIV-negative, a prospective study was performed in a cohort of 288 mothers screened for viral RNA and in the infants born to GBV-C/HGV-infected mothers.

RESULTS

Thirteen mothers (4.5%) were found positive for GBV-C/HGV RNA. Of the infants in whom at least one blood sample was collected between the third and the ninth months of life, 89 percent were positive for viral RNA. The majority of these newborns were negative for GBV-C/HGV RNA at birth and positive after the third month. The viral RNA titers of infants born to GBV-C/HGV-infected mothers appeared as elevated as those of their mothers. All the GBV-C/HGV-infected infants remained positive for viral RNA during the entire study period. No clinical events possibly linked to a primary GBV-C/HGV infection were reported in infants. Serum ALT level and blood count remained within normal values throughout the follow-up of all GBV-C/HGV-infected infants.

CONCLUSION

The frequency of mother-to-infant GBV-C/HGV transmission is elevated and could explain the high prevalence of GBV-C/HGV markers (viral RNA and E2 antibody) in adults at low risk for blood-borne or sexually transmitted viruses, such as 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 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.

[Transfusion safety: emergent or hypothetical risks]

Three categories of emerging risks are studied: 1) A new variant of Creutzfeld-Jakob disease, different from its sporadic form; limited to the British isles (48 of 51 cases), it affects younger patients, and has a higher duration with a predominance of psychiatric symptoms. Environmental risk factors include a previous stay in the British isles and oral transmission via contaminated food. No link has been made evident between blood component (BC) transfusion and occurrence of the disease. A potential risk exists if its agent is found in blood and peripheral lymphoid tissues and if buffy coat from infected animals has been inoculated intracerebrally. Since 1993, prevention measures have been taken: exclusion of donors with a potential risk as well as transfused donors, systematic leukocyte reduction and implementation of disease surveillance. Excluding donors after a several month-stay in the British Isles is being discussed. 2) Novel hepatitis viruses. Hepatitis G virus (HGV) has been detected in 2-4% of blood donors. Ten percent of patients with chronic non-A-E hepatitis are HGV RNA positive. The incidence of HGV infection is higher than expected from PCR studies. HGV has a high prevalence in the world. Novel DNA non-enveloped virus (TTV) has a normal distribution. Its prevalence varies from 2 to 80%, depending on the country. Although it has not been shown to be aggressive for the liver, prolonged follow-up is required. 3) Human herpes virus 8 (HHV8) is associated with Kaposi's sarcoma in 80% of cases. Its prevalence (0-20%) varies depending on the country. Kaposi's sarcoma has never been reported after BC transfusion. PCR-based viral DNA searches have yielded negative results in 19 poly-transfused subjects. Continuous monitoring is required for recipients at risk (e.g., immunosuppressed). In response to a possible health risk, emerging risks govern the "Precaution Principle", so difficult to implement.

Role of hepatitis B virus in non-B, non-C chronic liver disease: in vitro proliferation and interferon-gamma production of peripheral blood mononuclear cells in response to hepatitis B core antigen and its relation to hepatitis activity

OBJECTIVE

Although hepatitis B virus (HBV) DNA has been detected in the sera of patients with chronic liver disease with neither hepatitis B surface antigen nor antihepatitis C virus antibody (non-B, non-C [NBNC] CLD), whether HBV has some pathogenic role in NBNC CLD has not been made clear.

METHODS

To investigate the significance of HBV DNA in NBNC CLD, we performed in vitro stimulation assays of peripheral blood mononuclear cells (PBMCs) in response to hepatitis B core antigen (HBcAg) in 17 NBNC CLD patients.

RESULTS

HBV DNA with an 8-nucleotide deletion in the core promoter region was detected in 13 (76%) of the 17 patients by nested polymerase chain reaction. Interferon-gamma (IFN-gamma) production and proliferation of PBMCs of HBV DNA-positive patients showed a significant increase in response to HBcAg. The histological activity of hepatitis was also found to be significantly associated with the magnitude of IFN-gamma production and proliferation of PBMCs in response to HBcAg. Although five (38%) of the 13 HBV DNA-positive NBNC CLD patients had anti-HBs and/or anti-HBc, there was no difference in response of PBMCs to HBcAg between the HBV DNA-positive and -negative groups.

CONCLUSION

Our observation suggests that HBV may have a pathogenic role in HBV DNA-positive NBNC CLD, even in those patients without any serological markers of HBV.

TT Virus Is Present in a High Frequency of Italian Hemophilic Patients Transfused With Plasma-Derived Clotting Factor Concentrates

The prevalence of the blood-borne TT virus (TTV) in Italian hemophiliacs treated with different preparations of factor VIII was determined. Of the 178 hemophilic patients (mean age, 29 years), TTV-DNA was found in 123 (69%), in comparison to 22 of 100 (22%) blood donors (P &lt; .0001). Of the 123 patients who tested positive for TTV, significant numbers were also infected with human hepatitis viruses and/or human immunodeficiency virus (HIV): 31% had TTV and hepatitis C virus (HCV), 22% had TTV, and at least 2 of the 4 known human blood-borne viruses tested, whereas 15% had TTV alone. The risk of acquiring TTV alone was only slightly higher in recipients of unmodified plasma factor concentrates (78%, odds ratio, 1.24; 95% confidence interval [CI], 0.27 to 5.79) than in patients treated with virus inactivated concentrates (67%), whereas the risk was significantly lower in recipients of recombinant factors (11%, odds ratio, 0.09; 95% CI, 0.01 to 0.52). Serum alanine aminotransferase (ALT) levels were elevated in 2 of 27 patients (7%) with TTV alone compared with 43 of 56 patients (77%) coinfected with TTV and HCV and compared with 16 of 21 patients (76%) with HCV alone. Taken together, these results indicate that TTV frequently infects Italian hemophiliacs treated with plasma-derived factor VIII concentrates, both unmodified and virus-inactivated. Our results do not suggest a causal effect of TTV on chronic liver disease in these patients.

TT Virus Is Present in a High Frequency of Italian Hemophilic Patients Transfused With Plasma-Derived Clotting Factor Concentrates

The prevalence of the blood-borne TT virus (TTV) in Italian hemophiliacs treated with different preparations of factor VIII was determined. Of the 178 hemophilic patients (mean age, 29 years), TTV-DNA was found in 123 (69%), in comparison to 22 of 100 (22%) blood donors (P < .0001). Of the 123 patients who tested positive for TTV, significant numbers were also infected with human hepatitis viruses and/or human immunodeficiency virus (HIV): 31% had TTV and hepatitis C virus (HCV), 22% had TTV, and at least 2 of the 4 known human blood-borne viruses tested, whereas 15% had TTV alone. The risk of acquiring TTV alone was only slightly higher in recipients of unmodified plasma factor concentrates (78%, odds ratio, 1.24; 95% confidence interval [CI], 0.27 to 5.79) than in patients treated with virus inactivated concentrates (67%), whereas the risk was significantly lower in recipients of recombinant factors (11%, odds ratio, 0.09; 95% CI, 0.01 to 0.52). Serum alanine aminotransferase (ALT) levels were elevated in 2 of 27 patients (7%) with TTV alone compared with 43 of 56 patients (77%) coinfected with TTV and HCV and compared with 16 of 21 patients (76%) with HCV alone. Taken together, these results indicate that TTV frequently infects Italian hemophiliacs treated with plasma-derived factor VIII concentrates, both unmodified and virus-inactivated. Our results do not suggest a causal effect of TTV on chronic liver disease in these patients.

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.

A new variant of GB virus C/hepatitis G virus (GBV-C/HGV) from South Africa

Phylogenetic analysis of the 5' non-coding region (5'NCR) sequences has demonstrated that GB virus C/hepatitis G virus (GBV-C/HGV) can be separated into three major groups that correlate with the geographic origin of the isolate. Sequence analysis of the 5'NCR of 54 GBV-C/HGV isolates from 31 blood donors, 11 haemodialysis patients and 12 patients with chronic liver disease suggests the presence of a new variant of GBV-C/HGV in the province of KwaZulu Natal, South Africa. Eleven isolates grouped as group 1 variants (bootstrap support, 90%) found predominantly in West and Central Africa, a further six isolates grouped as group 2 variants (bootstrap support, 58%) found in Europe and North America; five of which grouped as 2a (bootstrap support, 91%) and one as 2b (bootstrap support, 87%), the latter also includes isolates from Japan, East Africa and Pakistan. Although the remaining 37 GBV-C/HGV isolates were more closely related to group 1 variants (bootstrap support, 90%), they formed a cluster, which was distinct from all other known GBV-C/HGV sequences. None of the South African isolates grouped with group 3 variants described from Southeast Asia. Three variants of GBV-C/HGV exist in KwaZulu Natal: groups 1, 2 and a new variant, which is distinct from other African isolates.

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.

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.

GBV-C/HGV infection in children with chronic hepatitis C

The role of GB virus-C/hepatitis G virus (GBV-C/HGV), a recently identified member of the Flaviviridae family, in children with liver disease is not well understood. The aims of this study were to evaluate the prevalence of GBV-C/HGV and to clarify its pathogenic role in young patients with chronic hepatitis C. Sixty-four Japanese children and adolescents with chronic hepatitis C virus (HCV) infection, with a mean age of 9.8 years, were evaluated retrospectively. Twenty-one (32.8%) of the 64 patients were positive for serum GBV-C/HGV RNA. Only 1 (1.6%) of the 64 patients was positive for antibody against the envelope protein E2 of GBV-C/HGV (anti-E2) and GBV-C/HGV. None of them was positive for anti-E2 alone. There was no significant difference in clinical, virological, or histological characteristics between GBV-C/HGV-positive and GBV-C/HGV-negative patients, except for underlying malignant disease. There was no evidence that GBV-C/HGV might affect the response of HCV to interferon therapy in young patients with chronic hepatitis C. The prevalence of GBV-C/HGV infection in young patients with chronic hepatitis C is similar to that in adult patients with chronic hepatitis C, but E2-seroconversion is observed infrequently. Underlying malignant disease is a risk factor for GBV-C/HGV viremia. GBV-C/HGV does not seem to affect the clinical course of young patients with chronic hepatitis C.

GBV-C/hepatitis G virus (HGV) RNA load in immunodeficient individuals and in immunocompetent individuals

The aim of this study was to establish the mean plasma GBV-C/hepatitis G virus (HGV) RNA load in groups of GBV-C/HGV-infected individuals with varied immune status and to determine the most frequent patterns of evolution of the plasma GBV-C/HGV RNA load over time during the natural history of infection. The mean plasma GBV-C/HGV RNA load observed was, from the lowest to the highest: 5.21 log in immunodepressed multiply-transfused patients, 6.45 log in HIV-positive individuals, 6.66 log in immunocompetent multiply-transfused patients, and 6.71 log in blood donors. The difference was significant between the four groups (P < 0.0001). The most frequent pattern of evolution of the plasma GBV-C/HGV RNA load was as follows: after the primary GBV-C/HGV infection, the viral load was elevated from the onset; then, a high, persistent and relatively steady viral RNA level was the rule; and when it occurred, the loss of viremia was not preceded by a decrease before recovery from GBV-C/HGV infection.

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.

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.

The hepatic flaviviridae: summary

Hepatitis C envelope proteins (E1, E2) induce protective neutralizing antibodies. The extent of sequence diversity reflects the host's ability to control viral populations and the response to antiviral therapy. Attempts to prepare effective vaccines against HCV are foiled by lack of prolonged protective immunity. Plasmid vaccines and the use of uninfectious virus-like particles are being developed. HCV induces a cellular humoral immune response, but this is inadequate to clear the virus and the disease becomes chronic. In any patient, the natural history of HCV infection depends on the age when infected, and the presence of other diseases. The transfusion-related disease has a worse prognosis than that transmitted by syringes and needles. The outlook in 'healthy blood donors' is uncertain. Interferon therapy for 3 or preferably 6 months results in a sustained response in about 30% of patients. Negative serum HCV RNA and normal AST values after 3 months of therapy indicates that there may be a sustained response. Whether or not to stop treatment at that time if HCV is still positive remains a matter of debate. The role of interferon treatment in preventing progression to cirrhosis and hepatocellular cancer is still uncertain. Ribavirin therapy alone reduces transaminases and hepatic histology improves. Improved results follow the combination of ribavirin with interferon. Ribavirin may have immuno-modularity and anti-inflammatory actions. Hepatitis G virus (HGV) is unlikely to play a significant role in liver disease in man.

Acute sporadic non-A, non-B hepatitis in Northeastern Brazil: etiology and natural history

In a 4-year follow-up study, patients with acute sporadic non-A, non-B (NANB) hepatitis were evaluated to determine the etiology and natural history of the disease. Acute hepatitis C virus (HCV) was detected in 13 of 43 (30%) of patients, anti-hepatitis E virus (HEV) IgG in 5 (12%), and 25 (58%) were considered non-A-E. The HCV RNA was detected in all HCV patients but none of the non-A-E cases. The initial clinical and biochemical presentation of the HCV and non-A-E cases was quite similar, although 2 of the non-A-E patients had severe disease. The 5 patients who were found to be anti-HEV IgG-reactive recovered within 6 months of follow-up. Of the 13 HCV cases, alanine transaminase (ALT) levels returned to normal in 7 (53. 8%), while 6 (46.2%) continued to show abnormal ALT after 6 months of follow-up. However, 9 (69.2%) of them remained HCV-RNA-positive, denoting virological/biochemical dissociation. Long-term follow-up showed a reappearance of HCV RNA in 2 of the 4 patients who were in virological remission performing 84% of chronicity rate. Acute non-A-E hepatitis patients were less likely to evolve toward chronicity, as compared with acute HCV cases (16% vs. 84%; P =.0001). Only 4 (16%) of the non-A-E patients were hepatitis G virus (HGV)-RNA-positive. Concerning risk factors for acquiring parenterally transmitted viruses, tattooing was the only one that could be associated with HCV transmission (P =.002). No risk factors could be identified for putative non-A-E virus transmission. Liver biopsies performed for chronic HCV patients showed a variable degree of inflammation, while the non-A-E patients presented less severe histological disease.

Intraspousal transmission of GB virus C/hepatitis G virus in an hepatitis C virus hyperendemic area in Japan

OBJECTIVE

An immunoassay for antibodies against an hepatitis G virus (HGV) protein (anti-E2) was recently developed that might serve as a useful marker for diagnosing recovery from HGV infection.

METHODS

We investigated the intraspousal transmission of GB virus C/hepatitis G virus (GBV-C/HGV) using both reverse transcription hemipolymerase chain reaction (RT-hemi-PCR for the 5' untranslated region) and a recently developed anti-E2.

RESULTS

Thirty-two GBV-C/HGV-infected index subjects were selected from an hepatitis C virus hyperendemic area in Japan. Of the 32 subjects, seven (6.4%) were GBV-C/HGV RNA-positive, 24 (21.8%) were anti-E2-positive, and one (0.9%) was both GBV-C/HGV RNA- and anti-E2-positive. Among the 32 spouses of these subjects, GBV-C/HGV RNA, anti-E2, and both GBV-C/HGV RNA and anti-E2 positivity were detected in 0, 6, (18.8%), and one (3.1%) spouses, respectively (the total prevalence of GBV-C/HGV was 7 spouses [21.9%]). Thus, the intraspousal transmission of GBV-C/HGV was undeniable in these seven couples. The respective positive rates of 175 sex- and age-matched controls were 7 (4.0%), 26 (14.9%), and 0 (the total prevalence of GBV-C/HGV was 34 [19.4%]). No significant difference in positive rates was observed between the subjects/spouses and the controls. Five spouses among the seven couples who were positive for any of GBV-C/HGV markers had parenteral risk factors such as blood transfusion, acupuncture, and major surgery.

CONCLUSION

Based on these observations, we cannot draw a definitive conclusion that intraspousal transmission of GBV-C/HGV had occurred among these seven couples.

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.

The spectrum of hepatobiliary disease in primary hypogammaglobulinaemia

OBJECTIVE

To study the prevalence of hepatobiliary disease in a clinically and immunologically well-characterized group of 88 adult Norwegian patients with primary hypogammaglobulinaemia.

SUBJECTS

Eighty-eight patients with primary hypogammaglobulinaemia were followed and signs and symptoms of liver disease were recorded. The patients were examined clinically and radiologically on a regular basis with liver biopsies performed when indicated. All patients were tested for hepatitis C virus (HCV) RNA, hepatitis G virus (HGV) RNA and hepatitis B virus (HBsAg).

RESULTS

Twenty-one patients were HCV RNA-positive, all having signs of chronic liver disease. Only four patients were HGV RNA-positive, of whom two were also HCV RNA-positive. Amongst the 67 HCV RNA-negative patients, 26 had signs of chronic liver disease, including two who were HGV RNA-positive. HCV RNA-negative patients with liver disease had received intravenous immune globulin substitution more frequently, had a longer history of any form of immune globulin substitution and had a greater incidence of common variable immunodeficiency than patients without signs of liver disease. In most cases (21 of 26 patients) the liver disease was relatively mild. Three patients had granulomatous liver disease, with a relatively aggressive course in all three.

CONCLUSION

Hepatobiliary disease is a frequent complication in primary hypogammaglobulinaemia. Liver disease in HCV RNA-negative patients usually has a mild course. HGV does not seem to be a major cause of chronic liver disease in these patients.

GB virus C/hepatitis G virus infection in HIV infected patients with haemophilia despite treatment with virus inactivated clotting factor concentrates

AIM

To determine the frequency of GB virus C (GBV-C)/hepatitis G virus (HGV) infection before and after switch to the use of virus inactivated concentrates in haemophiliac patients infected with human immunodeficiency virus (HIV).

PATIENTS AND METHODS

Initial and follow up sera from 49 children with haemophilia were analysed for the presence of GBV-C/HGV RNA and antibodies to HGV (anti-HGV). All patients had been infected with HIV while receiving concentrates without virus inactivation before 1984 and were subsequently treated with virus inactivated concentrates.

RESULTS

In the first available serum sample (1987 or later), two of 49 patients were GBV-C/HGV RNA positive and two further patients were anti-HGV positive. During follow up (mean, 6 years), 14 patients developed markers of GBV-C/HGV infection. Eleven of these had received no blood products except clotting factor concentrates that had been prepared with virus inactivation.

CONCLUSIONS

Despite being treated with virus inactivated clotting factor concentrates, HIV positive patients with haemophilia are at an increased risk of manifesting GBV-C/HGV infection. We hypothesise that GBV-C/HGV is transmitted by these clotting factor concentrates. However, we cannot rule out the emergence of markers of GBV-C/HGV infection as a result of the progression of immune impairment in the course of HIV infection.

Age-dependent acquisition of hepatitis G virus/GB virus C in a nonrisk population: detection of the virus by antibodies

Until now there have been few seroepidemiological data for hepatitis G virus/GB virus type C (HGV/GBV-C). A four-antigen HGV/GBV-C immunoblot was established to examine 446 serum specimens from healthy individuals without risk factors for parenteral viral transmission. These individuals were divided into seven groups according to age. Seroprevalence rates were low for children and adolescents (5.6%) and increased for the age groups assumed to be the most sexually active (15.3 to 26.8%). Remarkably, none of the 80 individuals who tested positive for HGV/GBV-C antibodies were simultaneously positive for HGV/GBV-C viremia. From our data we conclude that HGV/GBV-C infection is widespread in the general population (16 to 25%). The development of an antibody response is associated with clearance of HGV/GBV-C viremia. Due to the lack of risk factors for HGV/GBV-C infection of blood, other efficient transmission routes must exist. It must be assumed that HGV/GBV-C transmission may be linked to sexual activity.

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.

Absence of hepatitis G virus within liver tissue of patients undergoing liver transplantation for cryptogenic cirrhosis

BACKGROUND

Epidemiological studies have detected up to a 9% incidence of hepatitis G (HGV)-RNA in patients with acute and chronic liver disease of unknown etiology. We sought to clarify the role of HGV as a causative agent in cryptogenic cirrhosis by analyzing archival liver tissue for HGV-RNA in patients undergoing orthotopic liver transplantation.

METHODS

Using a computer database, we identified 54 patients who underwent orthotopic liver transplantation for cryptogenic cirrhosis. After using rigorous serologic and histopathologic screening guidelines, 20 patients were studied, 7 of whom had concurrent hepatocellular carcinoma (HCC). RNA was extracted from archival paraffin-embedded liver tissue; HGV sequences were amplified by nested reverse transcription-polymerase chain reaction using primers designed from the 5' noncoding region.

RESULTS

HGV-RNA was absent from all 20 liver specimens, including those 7 with HCC. Beta-actin RNA, used as a positive control for cellular RNA, was isolated from all 20 liver specimens, including the 7 with HCC.

CONCLUSIONS

Utilizing a highly sensitive reverse transcription-polymerase chain reaction assay for HGV-RNA, we were unable to detect HGV-RNA within the livers of patients with cryptogenic cirrhosis or in the HCC arising within them. This lends further evidence to HGV infection not being a cause of cryptogenic cirrhosis and not being associated with the development of HCC in cryptogenic cirrhosis.

Influence of CD4+ lymphocyte counts on GB virus C/hepatitis G virus carriership in HIV-positive individuals

The duration of the GB virus C or hepatitis G virus (GBV-C/HGV) carriership varies according to the patient group studied. The immune competence of the host may be important. GBV-C/ HGV was studied in human immunodeficiency virus (HIV)-infected persons and an attempt was made to correlate the presence of viral RNA or E2 antibodies with CD4+ lymphocyte counts. Of 138 HIV-positive subjects, 30 were GBV-C/HGV RNA-positive and 20 others were E2 antibody-positive, whereas in healthy GBV-C/HGV-infected persons, the proportion of E2 antibody carriers was much higher. On the other hand, a relationship was not found between CD4+ lymphocyte counts and the presence of GBV-C/HGV RNA in the HIV-infected persons. This result does not necessarily imply that the CD4+ lymphocyte count does not affect viral clearance, but the results could be due to the trans-sectional nature of this study. A longitudinal assessment should clarify this point.

GB virus C/hepatitis G virus infection in hemodialysis patients: determination of seroprevalence by a four-antigen recombinant immunoblot assay

GB Virus C/Hepatitis G Virus (GBV-C/HGV) was identified recently and only two assays, consisting of a single recombinant protein, have been described for determination of the seroprevalence of this virus. An immunoblot assay was devised, which contains four recombinant GBV-C/HGV proteins. In this study, serum samples from 154 patients on maintenance hemodialysis were examined to assess the rate of seroreactivity against GBV-C/HGV. All sera were tested for the presence of antibodies by an in-house recombinant immunoblot assay, for GBV-C/HGV viremia by RT-PCR, and for HCV infection by PCR and by serological assays. Antibody reactivity against GBV-C/HGV was detected in 20.8% (n = 32) and viremia was found in 6.5% (n = 10) of the patients. In no case were viremia and GBV-C/HGV antibodies detected in parallel. HCV infection was observed in 15.6% (n = 24) by RT-PCR. In 20 of these patients, HCV antibodies were detected by enzyme immuno assay (EIA) and immunoblot assay. However, four of the HCV PCR-positive patients were negative by both serological tests. Only two patients were viremic for GBV-C/HGV and HCV in parallel. It is concluded that antibody reactivity against GBV-C/HGV is common among patients on maintenance hemodialysis. In contrast to HCV, parallel occurrence of GBV-C/HGV viremia and GBV-C/HGV seroreactivity was not observed. This suggests that GBV-C/HGV infection might be self-limiting.

Histological changes during clearance of chronic hepatitis B virus infection by adoptive immunity transfer

BACKGROUND

Serological clearance of hepatitis B surface antigen (HBsAg) has been described after reception of hepatitis B surface antibody positive marrow, via allogeneic bone marrow transplantation (BMT). Histological changes during the clearance of HBsAg are unknown.

METHODS AND RESULTS

We described two chronic hepatitis B carriers (both hepatitis B e antigen negative), who cleared HBsAg after allogeneic bone marrow transplantation. Both received hepatitis B surface and core antibody positive human leucocyte antigen identical donors' marrow and had serological clearance of HBsAg 15 and 7 weeks after allogeneic BMT, respectively. Both events were preceded by hepatic flare. Both patients were also treated with famciclovir for the prevention of hepatitis B reactivation after BMT. Histological examination during the flare showed only mild necroinflammatory activity with multiple foci of confluent necrosis, associated with moderate lymphocytic infiltration. The majority of these lymphocytes were cluster of differentiation (CD) 8 positive. Using immunohistochemistry, there was no detectable hepatic expression of hepatitis B core antigen. However, HBsAg was positive, mainly in the area of confluent necrosis. Using in situ hybridization, hepatitis B virus (HBV) DNA was detected in the nucleus of 5% of hepatocytes, but not in the cytoplasm.

CONCLUSIONS

At their last follow up, 22 and 16 months after BMT, the serum of both patients remained HBsAg negative, hepatitis B surface antibody positive and HBV-DNA negative by branched DNA assay.

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%.

GB virus type C infection in patients treated for childhood acute lymphoblastic leukemia

BACKGROUND

The purpose of this study was to determine the prevalence of GB virus type C (GBV-C) infection in subjects treated for childhood acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma.

STUDY DESIGN AND METHODS

One hundred forty patients (82 males) aged 4 to 27 years (median, 11) diagnosed with ALL between 1976 and 1993, were prospectively followed for a median of 5 years (range, 0.1-17) after completion of therapy. Stored sera were tested for antibody to hepatitis C virus (HCV), HCV RNA, antibody to GBV-C E2 (anti-E2), and GBV-C RNA.

RESULTS

Thirty-eight patients (27%) were exposed to GBV-C: 30 were positive for GBV-C RNA (mostly type 2) and 8 were positive for anti-E2. Anti-E2 and GBV-C RNA were mutually exclusive: 61 patients (43%) were positive for HCV RNA, 16 (11%) were coinfected with GBV-C and HCV. Alanine aminotransferase (ALT) levels were increased (>35 mU/mL) in 32 (23%) of 137: 3 of 20 who were positive for GBV-C and negative for HCV, 7 of 15 who were positive for GBV-C and HCV, 15 of 44 who were negative for GBV-C and positive for HCV, and 7 of 58 who were negative for GBV-C and HCV (p<0.001). Median ALT values were significantly higher in patients positive for GBV-C and HCV than in those who were positive for GBV-C and negative for HCV (35 vs. 13 mU/mL, p = 0.003). Thirty-one of 38 patients with GBV-C markers were retested: GBV-C RNA was lost in 16 of 30 tested, but 7 were still GBV-C RNA positive up to 50 months later, 3 tested positive for anti-E2 up to 27 months later, and 1 was positive for GBV-C RNA and anti-E2 26 months later, while 20 tested negative for both.

CONCLUSION

GBV-C did not behave as a liver pathogen, because ALT alterations were unrelated to GBV-C status, but, rather, were related to HCV infection or coinfection. GBV-C RNA was frequently lost over a relatively short period, though in some cases, it was retained for a longer time. Anti-E2 rarely coexisted with GBV-C RNA and might be short-term.

Prevalence of GB virus type C/hepatitis G virus RNA and of anti-E2 in individuals at high or low risk for blood-borne or sexually transmitted viruses: evidence of sexual and parenteral transmission

BACKGROUND

The first epidemiologic evidence of GB virus type C (GBV-C)/hepatitis G virus (HGV) infection showed a high prevalence of asymptomatic carriers in blood donors and in populations at risk for blood-borne viruses. However, by using only viral RNA polymerase chain reaction, those studies underestimated the true spread of GBV-C/HGV infection. The combined detection of GBV-C/HGV RNA and of anti-E2 (which reflects recovery from infection) is necessary to define accurately the prevalence of GBV-C/HGV.

STUDY DESIGN AND METHODS

The presence of both anti-E2 and GBV-C/HGV RNA was searched for in 1438 serum samples collected from various groups of individuals at low or high risk for blood-borne or sexually transmitted viruses (blood donors, organ donors, unselected pregnant women, immunocompetent or immunodepressed multiply transfused patients, HIV-positive or HIV-negative homosexual men, intravenous drug addicts).

RESULTS

The presence of GBV-C/HGV RNA and/or anti-E2 (exposure to GBV-C/HGV) was frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV appeared also to be sexually transmitted, with transmission from male to female more efficient than vice versa. A particularly elevated level of exposure to GBV-C/HGV was observed in homosexual men. In immunocompetent individuals, the prevalence of anti-E2 was about twice that of GBV-C/HGV RNA, which suggests the frequency of recovery from GBV-C/HGV infection. Most of the GBV-C/HGV RNA-positive individuals had no biochemical evidence of liver damage.

CONCLUSIONS

GBV-C/HGV is frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV is not a hepatitis virus, and it seems appropriate to rename it.

Transfusion-transmitted diseases: risks, prevention and perspectives

During the past decades major improvements in blood safety have been achieved, both in developed and developing countries. The introduction of donor counseling and screening for different pathogens has made blood a very safe product, especially in developed countries. However, even in these countries, there is still a residual risk for the transmission of several pathogens. For viruses such as the human immunodeficiency virus (HIV), and the hepatitis viruses B and C, this is due mainly to window-period donations. Furthermore, the threat of newly emerging pathogens which can affect blood safety is always present. For example, the implications of the agent causing new variant Creutzfeld-Jakob disease for transfusion practice are not yet clear. Finally, there are several pathogens, e.g. CMV and parvo B19, which are common in the general donor population, and might pose a serious threat in selected groups of immunosuppressed patients. In the future, further improvements in blood safety are expected from the introduction of polymerase chain reaction for testing and from the implementation of photochemical decontamination for cellular blood products. The situation in transfusion medicine in the developing world is much less favorable, due mainly to a higher incidence and prevalence of infectious diseases.

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.

GBV-C/HGV coinfection in HIV-1-positive men: frequent detection of viral RNA in blood plasma but absence from seminal fluid plasma

Sequential paired samples of blood and seminal fluid were obtained from a cohort of 54 HIV-1-infected homosexual males. The prevalence of GBV-C/HGV RNA in the cell-free fractions of some of these patients was determined using reverse-transcription polymerase chain reaction (RT-PCR). To assess the effects of HIV-1 and HCV infection upon GBV-C/HGV RNA status, blood CD4 cell counts, HCV RNA status, and HIV-1 proviral DNA and viral RNA titres were also determined. GBV-C/HGV RNA was detected in 8/30 (27%) of the blood plasma samples obtained at the start of the study, and was present at a frequency of 14/64 (22%) in all the blood plasma samples tested. By contrast, GBV-C/HGV RNA was not detected in the 26 seminal fluid samples obtained at the start of the study, including 8 samples obtained from patients for which GBV-C/HGV RNA was detected in the corresponding blood sample. Of the samples tested for the presence of both GBV-C/HGV and HCV RNA, there was no evidence of coinfection. Although GBV-C/HGV RNA detection rates were significantly higher in individuals with blood CD4 cell counts greater than 200 cells per microlitre, there were no significant differences in the median blood CD4 cell counts or HIV-1 proviral DNA or viral RNA titres observed between the GBV-C/HGV-positive and -negative individuals. The failure to detect GBV-C/HGV RNA in seminal fluid samples obtained from this cohort would suggest that further studies need to be carried out to determine the roles of sexual transmission and of seminal fluid in GBV-C/HGV infection.