Transmission of GB virus C by blood transfusions during heart surgery

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.

Investigation of saliva, faeces, urine or semen samples for the presence of GBV-C RNA

GBV-C/HGV has been demonstrated to be distributed worldwide with a prevalence in blood donors higher than HCV. This distribution in the general population probably requires an effective non-parenteral route of transmission. A previous study was performed to evaluate the presence of GBV-C/HGV in serum. Saliva, faeces and urine samples of 30 patients (15 males and 15 females) and 15 semen samples from patients whose serum gave a GBV-C/HGV RNA positive result were then tested by a sensitive polymerase chain reaction (PCR) test. Five semen supernatant samples (33.3%) tested positive--four of them belonged to HIV positive patients--and two saliva samples contained GBV-C/HGV sequences (6.6%)--one from a HIV-positive patient. An internal control was used to detect PCR nonspecific inhibitors in the samples. The data suggest possible non-parenteral routes of transmission from this virus. Its presence in body fluids other than serum has clinical implications other than possible hepatic damage that remain to be investigated.

Prevalence of GBV-C/hepatitis G virus viremia and anti-E2 in Canadian blood donors

BACKGROUND AND OBJECTIVES

GB virus C (GBV-C)/hepatitis G virus (HGV) is a recently recognized parenterally and sexually transmitted agent. The prevalence of GBV-C/HGV markers in Canadian blood donors has not been previously studied and was therefore determined.

MATERIALS AND METHODS

Blood donors [identity unlinked (IU), short-term temporarily deferred (STTD) and autologous groups] and donor samples with antibodies to hepatitis C (anti-HCV) or hepatitis B core were tested for GBV-C/HGV RNA and for antibodies to E2 antigen (anti-E2).

RESULTS

GBV-C/HGV RNA was found in 1.1% and anti-E2 in 7.3% of the combined IU/STTD donor group. Viremia was much more common in anti-HCV-positive samples (12.5%); anti-E2 was present in >50% of this group. In the STTD group, female gender was significantly associated with viremia.

CONCLUSION

GBV-C/HGV infection is relatively common in Canadian donors, and a small proportion are viremic. The association of female gender and viremia was unexpected. Further study is needed to clarify the epidemiology and natural history of GBV-C/HGV infection.

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.

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/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.

Dynamics of GB virus C viremia early after orthotopic liver transplantation indicates extrahepatic tissues as the predominant site of GB virus C replication

The principal site of GB virus C (GBV-C) replication is unknown. To determine whether hepatic GBV-C replication is important for the maintenance of a measurable viremia level in GBV-C infection, the influence of hepatectomy followed by liver transplantation on GBV-C viremia was investigated. GBV-C RNA levels were determined by a quantitative TaqMan polymerase chain reaction (PCR) in 12 patients with pretransplantation GBV-C infection before and daily after orthotopic liver transplantation (OLT) for 25 to 28 days. Compared with the pretransplantation values (mean, 12.4 +/- 3.9 x 10(7) copies/mL), mean GBV-C RNA levels declined significantly by 1 log by day 1 after OLT (mean, 3.5 +/- 1.6 x 10(7) copies/mL), but subsequently remained relatively stable on this high level for the entire observation period, indicating ongoing high-level virus replication (mean GBV-C RNA levels on days 7 and 28 were: 1.7 +/- 0. 5 x 10(7) and 2.8 +/- 0.7 x 10(7) copies/mL; P = ns). Thus, at the end of the follow-up, mean GBV-C RNA levels were not significantly different from that of the 1st and 7th postoperative day and remained significantly lower compared with the pretransplantation values. However, in 2 of the 12 patients, different kinetics were observed. Both already had low-level viremia pre-OLT (0.02 and 0.002 x 10(7) copies/mL) and became persistently GBV-C RNA-negative 2 days after OLT. In 5 patients, liver tissues were collected 6 to 9 days after OLT and investigated for GBV-C RNA. All but 1 were GBV-C RNA-negative in the liver, although 2 of them had rather high serum GBV-C RNA levels at this time. The kinetics of GBV-C viremia observed in our study were neither influenced by the immunosuppressive therapy nor by the number of blood and blood product transfusions given after OLT. In addition, they were quite different from those observed in patients with chronic hepatitis C in whom early reinfection of the graft could be demonstrated by a steady increase in HCV RNA levels starting 3 days after OLT and exceeding preoperative levels by day 8. From our data, one can conclude that the liver is certainly not the major site of GBV-C replication in most patients. However, one cannot exclude that host or viral factors exist that predispose GBV-C replication predominantly in the liver.

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).

Persistent hepatitis G virus infection after neonatal transfusion

BACKGROUND

Recently two Flaviviridae-like viruses have been discovered and named GB virus C and hepatitis G virus. Molecular characterization showed them to be different subtypes of the same virus. An association with posttransfusion hepatitis and with sporadic and fulminant hepatitis was reported, but most infected people remain asymptomatic. Data concerning hepatitis G virus infection in infants and children have not been reported to date. The prevalence of hepatitis G virus infection in children after transfusion of blood products in the neonatal period was studied.

METHODS

Serum samples from 251 children, who had received blood products in the first 4 weeks of life and who had been reexamined as part of another study at a mean interval of 37 months (range, 10-70) after last transfusion, were analyzed for hepatitis G virus infection. Follow-up examinations were performed in 14 of 19 hepatitis G virus-positive children 12 to 17 years after the last transfusion. Presence of hepatitis G virus RNA in serum was determined by a reverse transcription polymerase chain reaction assay with nested primers from the helicase region of the hepatitis G virus. To prove specificity of the hepatitis G virus, reverse transcription polymerase chain reaction assay and compare follow-ups with initial sequences, direct sequencing of the NS3 and NS5 regions of the hepatitis G virus was performed.

RESULTS

Hepatitis G virus RNA was detected in 19 of 251 patients (7.6%); sequence analysis showed the isolates to be of hepatitis G virus type. None of the patients with hepatitis G virus infection had evidence of liver disease, although 3 patients were coinfected with hepatitis C virus. Four of 14 patients who were reinvestigated after a mean of 15 years showed persistent hepatitis G virus infection. Each of the 4 children was healthy. In none were clinical signs of liver disease observed; liver function test results were within the normal range.

CONCLUSIONS

Children receiving blood transfusions in the neonatal period are at increased risk of hepatitis G virus infection with a high rate of chronic infection. However, as in the findings in several studies of adult transfusion recipients, in the current results, no association between hepatitis G virus infection and clinical or biochemical signs of hepatitis or extrahepatic disease could be seen.

Blood transfusion: influence of transfusion therapy on outcome

Few studies have addressed the influence of different transfusion therapies on outcome in a convincing way. Proven adverse impact of allogeneic blood on outcome is minimal. Acute mortality has declined to about 1 : 500,000 and the rate of transfusion-transmitted infections is decreasing, too. Data on postoperative infections and non-Hodgkin's lymphoma as possible adverse effects are controversial. Evidence for an increased risk of tumour recurrences is lacking. Alternatives to allogeneic blood may have appreciable risks: perioperative blood recovery had a fatality rate of more than 1 : 40,000. Reduction of allogeneic blood exposure may not be equated with improved outcome.

Detection of GBV-C/HGV RNA in saliva and serum, but not in urine of infected patients

Saliva and urine samples from six GB virus C (GBV-C)/hepatitis G virus (HGV)-infected renal transplant patients were tested by RT-PCR. Viral RNA was detected in all saliva samples, but the viral RNA titers in saliva were 100 to 10,000 lower than those in the corresponding sera. Comparative sequence analysis of the amplified 354 bp DNA from one patient revealed full identity of GBV-C/HGV variants present in serum and saliva. None of the urine samples from the six patients was found to contain GBV-C/HGV RNA. High prevalence of GBV-C/HGV RNA in saliva of infected individuals may contribute to a wide spread of GBV-C/HGV infection, at least in some settings.