GB virus C/Hepatitis G virus infection is frequent in American children and young adults

Role of GB virus C in HIV-1-infected and hepatitis C virus-infected hemophiliac children and adolescents

BACKGROUND

GB Virus C (GBV-C) has been associated with a better prognosis of HIV-1 disease in adults. Little is known about prevalence and interaction between GBV-C, HIV-1, and/or hepatitis C virus (HCV) in hemophiliac children and adolescents.

METHODS

A well-characterized cohort of HIV-1-infected and HIV-1-uninfected hemophiliac children and adolescents followed in the Hemophilia Growth and Development Study (HGDS) were evaluated using quantitative reverse transcription polymerase chain reaction to detect GBV-C RNA in samples from baseline and last follow-up visit.

RESULTS

HIV-1-infected (n = 202) and HIV-1-uninfected (n = 119) patients had a low prevalence of GBV-C infection at baseline (0.9 and 0%), which increased at time of last follow-up visit to 25.2% and 26.3%, respectively. In addition, at the time of the follow-up GBV-C measurement, those GBV-C infected had been followed longer and had higher CD4(+) cell counts and lower HIV-1 viral loads than those GBV-C uninfected. These beneficial effects of GBV-C were no longer significant after controlling for CD4(+) cell count and HIV-1 RNA at baseline. HCV RNA clearance was more common amongst those who were not GBV-C infected than those who became GBV-C viremic.

CONCLUSIONS

This study confirms a positive association of GBV-C with milder course of HIV-1 infection. GBV-C infection was associated with a higher likelihood of persistent HCV infection.

Role of GB virus C in HIV-1-infected and hepatitis C virus-infected hemophiliac children and adolescents

BACKGROUND

GB Virus C (GBV-C) has been associated with a better prognosis of HIV-1 disease in adults. Little is known about prevalence and interaction between GBV-C, HIV-1, and/or hepatitis C virus (HCV) in hemophiliac children and adolescents.

METHODS

A well-characterized cohort of HIV-1-infected and HIV-1-uninfected hemophiliac children and adolescents followed in the Hemophilia Growth and Development Study (HGDS) were evaluated using quantitative reverse transcription polymerase chain reaction to detect GBV-C RNA in samples from baseline and last follow-up visit.

RESULTS

HIV-1-infected (n = 202) and HIV-1-uninfected (n = 119) patients had a low prevalence of GBV-C infection at baseline (0.9 and 0%), which increased at time of last follow-up visit to 25.2% and 26.3%, respectively. In addition, at the time of the follow-up GBV-C measurement, those GBV-C infected had been followed longer and had higher CD4(+) cell counts and lower HIV-1 viral loads than those GBV-C uninfected. These beneficial effects of GBV-C were no longer significant after controlling for CD4(+) cell count and HIV-1 RNA at baseline. HCV RNA clearance was more common amongst those who were not GBV-C infected than those who became GBV-C viremic.

CONCLUSIONS

This study confirms a positive association of GBV-C with milder course of HIV-1 infection. GBV-C infection was associated with a higher likelihood of persistent HCV infection.

GBV-C/hepatitis G virus infection and non-Hodgkin lymphoma: a case control study

We investigated whether there was an association between GBV-C viremia and the development of non-Hodgkin lymphoma (NHL) in 553 NHL cases and 438 controls from British Columbia, Canada. Cases were aged 20-79, diagnosed between March 2000 and February 2004, and resident in Greater Vancouver or Victoria. Cases and controls were tested for GBV-C RNA by RT-PCR and positive samples were genotyped. Overall, GBV-C RNA was detected in 4.5% of NHL cases vs. 1.8% of controls [adjusted odds ratio (OR) = 2.72, 95% confidence interval (CI) = 1.22-6.69]. The association between GBV-C RNA detection and NHL remained even after individuals with a history of prior transfusion, injection drug use and hepatitis C virus sero-positivity were excluded. GBV-C viremia showed the strongest association with diffuse large B cell lymphoma (adjusted OR = 5.18, 95% CI = 2.06-13.71). Genotyping was performed on 29/33 GBV-C RNA positive individuals; genotypes 2a (n = 22); 2b (n = 5) and 3 (n = 2) were identified, consistent with the distribution of genotypes found in North America. This is the largest case-control study to date associating GBV-C viremia and NHL risk. As GBV-C is known to be transmitted through blood products this may have important implications for blood safety.

Hepatitis G virus infection in Egyptian children with chronic renal failure (single centre study)

BACKGROUND

Hepatitis G virus (HGV) is an RNA virus. It is mainly transmitted through exposure to contaminated blood although other routes may also exist. Patients with chronic renal failure (CRF) are at high risk of acquiring HGV because they require frequent blood transfusions. Ongoing HGV infection can be only diagnosed by demonstrating viremia in patient sample by reverse transcriptase (RT) PCR. Antibodies to the envelop protein E2 (anti E2) of HGV is an indicator of virus clearance and testify past HGV contact. This cross sectional study was done to assess the frequency of HGV exposure (ongoing and past infection) in Egyptian children with CRF and to study the possible risk factors of infection.

METHODS

This study included 100 children with CRF [34 on regular haemodialysis (HD) and 66 before the start of dialysis (predialysis)]. All patients sera were tested for HGV RNA by RT-PCR, anti E2, hepatitis C virus (HCV) antibody, hepatitis B surface antigen (HBsAg), and hepatitis B core antibody (HBcAB). Twenty five healthy children of matched age & sex were used as controls.

RESULTS

HGV RNA was positive in 9 (26.5%) of HD and 9 (13.6%) of predialysis children. Anti E2 was positive in 14 (41.2%) of HD and 19 (28.8%) of predialysis children.In comparison to controls; CRF (n = 100); HD and predialysis children had significantly higher prevalence of anti E2 [4% VS 33% for all CRF cases; (p = 0.002)& 41.2% (p = 0.002) and 28.8% (p = 0.01); for HD and predialysis groups; respectively]. HGV RNA was significantly more prevalent only in HD children in comparison to controls (p = 0.03). HD and predialysis children did not have significant difference in the prevalence of HGV RNA (p = 0.16) or anti E2 (p = 0.26).HGV exposure was not correlated with positivity of anti HCV (p = 0.32), HCV RNA (0.09), HBsAg/HBcAB (p = 1), age (p = 0.06), or gender (p = 0.83). It was significantly correlated with duration of the disease (p < 0.001). Ongoing HGV infection was significantly more prevalent with frequent blood transfusion (p < 0.001). There were no significant differences in serum levels of ALT (p = 0.09), total bilirubin (p = 0.1) and albumin (p = 0.06) in children with ongoing infection in comparison to healthy controls.

CONCLUSIONS

The frequency of HGV exposure in Egyptian children with CRF appears to be high and is mainly related to frequent blood transfusions and longer disease duration. HGV infection in these children is not associated with significant changes in hepatic biochemical parameters.

The prevalence of GB virus C/hepatitis G virus RNA among healthy and HCV-infected Catalan children

GB virus C (GBV-C) is a blood-borne flavivirus. The prevalence of GBV-C viremia among healthy adults is 0.5% to 4% and, to date, no disease has been definitely associated with GBV-C infection. We conducted a cross-sectional study to evaluate GBV-C viremia prevalence in a group of 327 healthy children with normal alanine amino transferase (ALT) levels (Group A) and elevated ALT levels (Group B) of unknown origin, and among 38 pediatric patients with mother-to-child-transmitted hepatitis C virus (HCV) infection (Group C). No statistically significant differences were observed between prevalences in Groups A and B (2.2% vs 6.7%, p = 0.06). None of the children in Groups A or B who tested positive for GBV-C RNA showed any clinical symptoms. The prevalence of GBV-C viremia in Group A was lower than for patients in Group C (2.2% vs 13.2%, p = 0.007); no differences were observed in HCV infection characteristics between those patients who were co-infected with GBV-C and those who were not. In conclusion, while GBV-C viremia is more frequent among HCV-infected pediatric patients, it is neither associated with liver disease nor has any influence on HCV-related chronic hepatitis.

Blood safety and the choice of anti-hemophilic factor concentrate

Hemophilia is a congenital disorder due to the deficiency of the activity of factor VIII (classical hemophilia A) or IX (Christmas disease or hemophilia B). Bleeding is common and may result in long-term complications or even death. Bleeding may be treated or prevented by infusion of factor concentrates however these drugs are not without risk. Clinicians often feel ill prepared to provide accurate and impartial information regarding these drugs. This review will provide the reader with an historical yet up to date perspective on blood safety as it relates to the choice of concentrates to treat hemophilia.

The spectrum of safety: a review of the safety of current hemophilia products

The safety of whole blood and blood products has been ensured by several different mechanisms introduced over the years, each of which reduces the risk of blood-borne infectious diseases. An exhaustive donor selection and screening process aims to exclude individuals at risk for infectious disease, and numerous screening tests are used to detect infectious pathogens in collected blood. During processing, blood is further subjected to various removal or inactivation procedures directed against specific pathogens, as well as additional screening with nucleic acid testing or polymerase chain reaction (PCR)-based assays. Despite these measures, sporadic cases of infection continue to occur, caused by both known pathogens and newly emergent ones. Other challenges remain to be met, including the detection of infectious blood donated during the seronegative window period of infection and the rapid identification of and screening for emerging infectious diseases.

GB virus C epidemiology in Denmark: different routes of transmission in children and low- and high-risk adults

With the demonstration of an effect of GBV-C infection on the outcome of HIV infection, it has become important to understand the epidemiology of GBV-C. The purpose of this study was to determine the prevalence in high- and low-risk populations. The following populations were tested: school children, 9 and 15 years of age (n = 901), blood donors (n = 5,203), hospital employees (n = 1,432), and prisoners and injecting drug users (n = 447). In-house RT-PCR for GBV-CRNA was used together with a commercial ELISA for anti-E2 (Boehringer, Germany). In addition, questionnaires for risk factors for transmission and serological tests for HIV and hepatitis were applied. The overall prevalence of GBV-CRNA was 1.4% among children, 2.2% among blood donors, 2.2% among hospital employees, 12.5% among non-injecting prisoners, and 34.9% among drug injectors. Correspondingly anti-E2 was found in 0.3%, 12.3%, 25.0%, and 42.7%. Among hospital employees, independent risk factors for GBV-C were professions with blood exposure and sexual risk partners. Among prisoners and drug users, injecting and a sexual risk index were associated independently with GBV-C. Based on these results, the following hypothesis is suggested: GBV-C is transmitted frequently at birth or early childhood and this leads to chronic infection in most cases. Sexual transmission is the most important route of transmission in the adult population but this infection is usually transient. Blood borne transmission plays a role among health care workers and injecting drug users and GBV-C should be further evaluated as a surrogate marker for professional blood exposure.

Hepatitis C-Z: recent advances

In this review, recently identified hepatitis viruses (hepatitis C, hepatitis D, hepatitis E, hepatitis F, hepatitis G, transfusion transmissible virus) are described, and the implications for paediatric liver disease discussed.

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/hepatitis G virus replicates in human haematopoietic cells and vascular endothelial cells

A novel flavivirus, GB virus C (GBV-C)/hepatitis G virus (HGV), has been detected in chronic liver disease patients. It is known that the viral RNA can be detected in ∼5% of American blood donors. However, the implications for liver disease and the sites of virus replication remain unknown. Possible sites of virus replication were studied by using cell lines and/or primary cells derived from human lymphoid cells, myeloid cells, hepatocytes and endothelial cells. RNA was detected by virus strand-specific RT–PCR and GBV-C/HGV antigen was detected with a rabbit polyclonal anti-E2 (envelope 2) antibody by Western blot analysis. Negative-strand RNA, representative of replicating virus, was detected in lymphoid and megakaryocytoid cell lines and primary vascular endothelial cells. In addition, an increase in virus titre over time was demonstrated and viral antigen was detected, and virus could be passaged to infect fresh cells. However, viral RNA or antigen could not be detected in any of the hepatocyte lines tested. These results indicate that the replication site of GBV-C/HGV is not primarily in hepatocytes and that detection of replicating virus in hepatic tissue may reflect virus replication in haematopoietic cells and/or vascular endothelial cells present in the liver.