Infection with hepatitis G virus among recipients of plasma products

Reconstruction of the historic time course of blood-borne virus contamination of clotting factor concentrates, 1974-1992

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

Human pegivirus-1 infection in kidney transplant recipients: A single-center experience

Kidney transplantation is the treatment of choice for patients with end-stage renal disease. In the posttransplant period, the induced immunosuppression leads to an increased risk of developing infectious diseases, a leading cause of death after kidney transplantation. Human pegivirus-1 (HPgV-1) is considered a nonpathogenic human virus and is highly frequent in individuals parenterally exposed, however, its impact on kidney transplantation outcome is poorly understood. Given the scarcity of epidemiological data for this infection on organ recipients in Brazil, we conducted a study in a single center for kidney transplantation in Rio de Janeiro, aiming to determine HPgV-1 prevalence and genotypic distribution. Serum samples from 61 renal recipients, followed up for the first year after transplantation, were evaluated for viral RNA and genotypes were determined by sequencing of the 5'-untranslated region. HPgV-1 RNA was detected in 36.1% (22/61) of patients. Genotype 2 was the most commonly found (80.9%), followed by genotypes 3 (9.5%), 1, and 5, in 4.8% each. Statistical comparisons did not reveal any significant impact of HPgV-1 in patient outcome. Further epidemiologic studies are needed to understand if immunosuppression may interfere in HPgV-1 persistence rates and if viremia might impact graft dysfunction rates in kidney recipients.

Molecular and Clinical Profiles of Human Pegivirus Type 1 Infection in Individuals Living with HIV-1 in the Extreme South of Brazil

Human pegivirus type 1 (HPgV-1) infection has been associated with a beneficial effect on the prognosis of human immunodeficiency virus type 1 (HIV-1)-coinfected individuals. However, the mechanisms involved in this protection are not yet fully elucidated. To date, circulating HPgV-1 genotypes in HIV-1-infected individuals have not yet been identified in the extreme south of Brazil. The present study aimed to determine the genotypic circulation of HPgV-1 and the influence of HPgV-1 status and persistence time on the evolution of HIV-1 infection. A retrospective cohort of 110 coinfected individuals was analyzed. Samples were subjected to viral RNA extraction, cDNA synthesis, nested PCR, and genotyping. Genotypes 1 (2.8%), 2 (47.9% of subtype 2a and 42.3% of subtype 2b), and 3 (7%) were identified. In antiretroviral treatment-naïve subjects HPgV-1 subtype 2b was associated with lower HIV-1 viral load (VL) rates (p = 0.04) and higher CD4+ T-cell counts (p = 0.03) than was subtype 2a, and the positivity for HPgV-1 was associated with higher CD4+ T-cell counts (p = 0.02). However, there was no significant difference in HIV-1 VL between HPgV-1-positive and HPgV-1-negative subjects (p = 0.08). There was no significant association between the different groups in HPgV-1 persistence and median HIV-1 VL (p = 0.66) or CD4+ T-cell counts (p = 0.15). HPgV-1 subtype 2b is associated with better prognosis of HIV-1 infection. Although HPgV-1 infection is persistent, our data suggest that the time of infection does not influence HIV-1 VL or CD4+ T-cell counts in coinfected subjects.

High prevalence and autochtonous transmission of human pegivirus (HPgV-1) in blood donors in the extreme southern of Brazil

Recent studies have suggested that human pegivirus 1 (HPgV-1) may have some pathogenic potential. In the southernmost region of Brazil, studies on HPgV-1 are scarce, and circulating genotypes have not yet been identified. The current study aimed to evaluate the prevalence of HPgV-1 among blood donors from the southernmost region of Brazil and identify the genotypes involved with associated factors. A cross-sectional study was conducted with 281 blood donors, who had their plasma subjected to RNA extraction, complementary DNA synthesis, HPgV-1 detection by nested polymerase chain reaction, and subsequent genotyping. The observed prevalence of HPgV-1-RNA was 21.7%. The only variable that was significantly associated with virus infection was the relationship status of the donor. Single or no fixed partner blood donors were twice as likely to have HPgV-1 (95% CI, 1.12 to 4.56; P = 0.02). Genotype 2-subtypes 2b (69%) and 2a (29%)-was the most prevalent. In the absence of risk factors for parenteral transmission, it is likely that sexual transmission was the route of infection in the individuals studied. Further work will be needed to determine whether this virus is inert in the population, or if there are potential deleterious effects in infected individuals.

GBV-C/HIV-1 coinfection is associated with low HIV-1 viral load and high CD4+ T lymphocyte count

GB virus C (GBV-C) is a lymphotropic virus with a low level or non-existent replication in the liver. The interaction between HIV-1 and GBV-C apparently reduces the progression of HIV-1 infection to AIDS and improves the quality of life of HIV-1 infected individuals. A cross-sectional study was established to determine the possible effect of HIV-1/GBV-C coinfection on HIV-1 viral load and CD4⁺ T lymphocyte counts. Samples from 313 HIV-1 infected persons from the Virus Laboratory of the Federal University of Pará as well as demographic and clinical information were obtained from medical records. This study used a nested PCR method to determine GBV-C viremia. The prevalence of HIV-1/GBV-C coinfection was 17%. There were no significant differences in the distribution according to age, sex or ethnicity between the groups. The differences in HIV-1 viral load and CD4⁺ T lymphocyte count between the HIV-1 and HIV-1/GBV-C groups were highly significant, indicating that coinfection results in lower viral loads and higher CD4⁺ T lymphocyte counts compared to HIV-1 mono-infection. The results indicate a protective effect among coinfected individuals.

Prevalence and vertical transmission of human pegivirus among pregnant women infected with HIV

OBJECTIVE

To determine the prevalence of human pegivirus (HPgV) and factors associated with vertical transmission among pregnant women infected with HIV.

METHOD

A retrospective cross-sectional study was conducted among pregnant women treated at an HIV reference service in Rio Grande, Brazil, between January 1, 2010, and January 1, 2015. The polymerase chain reaction was used to diagnose HPgV infection among the women and their neonates. Clinical, obstetric, and neonatal data were obtained from medical records.

RESULTS

Infection with HPgV was detected among 16 (25%) of 63 women and 5 (8%) of 63 newborns, corresponding to a vertical transmission rate of 31%. Multivariate analysis demonstrated that the absence of prenatal care was the only risk factor for vertical transmission of HPgV (prevalence ratio 19.61, 95% confidence interval 1.29-297.48; P=0.032).

CONCLUSION

Prenatal care could protect against vertical transmission of HPgV among women infected with HIV; however, studies among HIV-negative individuals are still required to verify this correlation.

Co-infections and transmission networks of HCV, HIV-1 and HPgV among people who inject drugs

Co-infections with human immunodeficiency virus type 1 (HIV-1) and human pegivirus (HPgV) are common in hepatitis C virus (HCV)-infected individuals. However, analysis on the evolutionary dynamics and transmission network profiles of these viruses among individuals with multiple infections remains limited. A total of 228 injecting drug users (IDUs), either HCV- and/or HIV-1-infected, were recruited in Kuala Lumpur, Malaysia. HCV, HIV-1 and HPgV genes were sequenced, with epidemic growth rates assessed by the Bayesian coalescent method. Based on the sequence data, mono-, dual- and triple-infection were detected in 38.8%, 40.6% and 20.6% of the subjects, respectively. Fifteen transmission networks involving HCV (subtype 1a, 1b, 3a and 3b), HIV-1 (CRF33_01B) and HPgV (genotype 2) were identified and characterized. Genealogical estimates indicated that the predominant HCV, HIV-1 and HPgV genotypes were introduced into the IDUs population through multiple sub-epidemics that emerged as early as 1950s (HCV), 1980s (HIV-1) and 1990s (HPgV). By determining the difference in divergence times between viral lineages (ΔtMRCA), we also showed that the frequency of viral co-transmission is low among these IDUs. Despite increased access to therapy and other harm reduction interventions, the continuous emergence and coexistence of new transmission networks suggest persistent multiple viral transmissions among IDUs.

Is There Any Association between Hepatitis G Virus (HGV), Other Hepatitis Viruses (HBV, HCV) and Behçet's Disease?

Infectious agents, especially viruses, have been implicated in the pathogenesis of Behçet's disease (BD). The aim of this study was to determine whether BD is associated with hepatitis viruses. In this study, the serological markers of hepatitis (HBsAg, anti-HBs, anti-HBc and anti-HCV) and viral nucleic acid (HGV-RNA) were studied in the sera of 35 patients, all of whom fulfilled the diagnostic criteria of the International Study Group for BD, and the results were compared with those of 36 healthy controls. The prevalences of HBsAg, anti-HBs, anti-HBc in BD patients were 2.9%, 45.7%, and 31.4%, respectively, which were not significantly different from those in healthy controls. None of the subjects in either group were found to be positive for anti-HCV. HGV-RNA was detected in two patients with BD and in none of the healthy controls. In conclusion, BD does not seem to be associated with hepatitis viral infections including hepatitis B, C, or G.

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.

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 modulating HIV disease

GB virus C (GBV-C) is a member of the Flaviviridae family and the most closely related human virus to HCV. However, GBV-C does not replicate in hepatocytes, but rather in lymphocytes. GBV-C has a worldwide distribution and is transmitted sexually, parenterally and through mother-to-child transmission. Thus, co-infection with HCV and HIV is common. Until now, no human disease has been associated with GBV-C infection. However, there are several reports of a beneficial effect of GBV-C on HIV disease progression in vivo. Different mechanisms to explain these observations have been proposed, including modification of antiviral cytokine production, HIV co-receptor expression, direct inhibition of HIV-1 entry, T-cell activation and Fas-mediated apoptosis. Further understanding of these mechanisms may open new strategies for the treatment of HIV/AIDS.

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.

Faster HIV-1 disease progression among Brazilian individuals recently infected with CXCR4-utilizing strains

Introduction

Primary HIV infection is usually caused by R5 viruses, and there is an association between the emergence of CCXR4-utilizing strains and faster disease progression. We characterized HIV-1 from a cohort of recently infected individuals in Brazil, predicted the virus's co-receptor use based on the env genotype and attempted to correlate virus profiles with disease progression.

Methods

A total of 72 recently infected HIV patients were recruited based on the Serologic Testing Algorithm for Recent HIV Seroconversion and were followed every three to four months for up to 78 weeks. The HIV-1 V3 region was characterized by sequencing nine to twelve weeks after enrollment. Disease progression was characterized by CD4+ T-cell count decline to levels consistently below 350 cells/µL.

Results

Twelve out of 72 individuals (17%) were predicted to harbor CXCR4-utilizing strains; a baseline CD4<350 was more frequent among these individuals (p = 0.03). Fifty-seven individuals that were predicted to have CCR5-utilizing viruses and 10 individuals having CXCR4-utilizing strains presented with baseline CD4>350; after 78 weeks, 33 individuals with CCR5 strains and one individual with CXCR4 strains had CD4>350 (p = 0.001). There was no association between CD4 decline and demographic characteristics or HIV-1 subtype.

Conclusions

Our findings confirm the presence of strains with higher in vitro pathogenicity during early HIV infection, suggesting that even among recently infected individuals, rapid progression may be a consequence of the early emergence of CXCR4-utilizing strains. Characterizing the HIV-1 V3 region by sequencing may be useful in predicting disease progression and guiding treatment initiation decisions.

Frequency and genotypic distribution of GB virus C (GBV-C) among Colombian population with Hepatitis B (HBV) or Hepatitis C (HCV) infection

BACKGROUND

GB virus C (GBV-C) is an enveloped positive-sense ssRNA virus belonging to the Flaviviridae family. Studies on the genetic variability of the GBV-C reveals the existence of six genotypes: genotype 1 predominates in West Africa, genotype 2 in Europe and America, genotype 3 in Asia, genotype 4 in Southwest Asia, genotype 5 in South Africa and genotype 6 in Indonesia. The aim of this study was to determine the frequency and genotypic distribution of GBV-C in the Colombian population.

METHODS

Two groups were analyzed: i) 408 Colombian blood donors infected with HCV (n = 250) and HBV (n = 158) from Bogotá and ii) 99 indigenous people with HBV infection from Leticia, Amazonas. A fragment of 344 bp from the 5' untranslated region (5' UTR) was amplified by nested RT PCR. Viral sequences were genotyped by phylogenetic analysis using reference sequences from each genotype obtained from GenBank (n = 160). Bayesian phylogenetic analyses were conducted using Markov chain Monte Carlo (MCMC) approach to obtain the MCC tree using BEAST v.1.5.3.

RESULTS

Among blood donors, from 158 HBsAg positive samples, eight 5.06% (n = 8) were positive for GBV-C and from 250 anti-HCV positive samples, 3.2%(n = 8) were positive for GBV-C. Also, 7.7% (n = 7) GBV-C positive samples were found among indigenous people from Leticia. A phylogenetic analysis revealed the presence of the following GBV-C genotypes among blood donors: 2a (41.6%), 1 (33.3%), 3 (16.6%) and 2b (8.3%). All genotype 1 sequences were found in co-infection with HBV and 4/5 sequences genotype 2a were found in co-infection with HCV. All sequences from indigenous people from Leticia were classified as genotype 3. The presence of GBV-C infection was not correlated with the sex (p = 0.43), age (p = 0.38) or origin (p = 0.17).

CONCLUSIONS

It was found a high frequency of GBV-C genotype 1 and 2 in blood donors. The presence of genotype 3 in indigenous population was previously reported from Santa Marta region in Colombia and in native people from Venezuela and Bolivia. This fact may be correlated to the ancient movements of Asian people to South America a long time ago.

Prevalence and clinical significance of GB virus type C/hepatitis G virus coinfection in patients with chronic hepatitis C undergoing antiviral therapy

Coinfection with GBV-C/HGV in patients with chronic hepatitis C (CHC) may influence clinical course and response rates of antiviral therapy. Aim of the study was to investigate the prevalence of GBV-C/HGV/HCV coinfection and its influence on outcome of interferon/ribavirin combination therapy. Three hundred and four patients with CHC [m/f = 211/93, age: 42 (18-65)] were investigated. HGV RNA detection was performed by polymerase chain reaction prior to and 6 months after the end of antiviral therapy. HGV/HCV coinfection could be identified in 37/304 (12.2%) patients with intravenous drug abuse as the most common source of infection (N = 21, (56.8%)). The predominant HCV genotype in coinfected individuals was HCV-3a (HCV-3a: 51.4%, HCV-1: 37.8%, HCV-4: 10.8%). HGV coinfection was more prevalent in patients infected with HCV-3 compared to HCV-1 or HCV-4 [19/45 (42.2%) vs. 14/185 (7.6%) vs. 4/52 (7.7%), P < 0.01]. Patients with HGV/HCV coinfection were younger [35 (18-56) vs. 43 (19-65), years; P < 0.01], and advanced fibrosis (F3-F4) was less frequent (22.2% vs. 42.9%, P < 0.05). A sustained virological response was achieved more frequently in HGV/HCV coinfected patients [26/37 (70.3%)] than in monoinfected patients [120/267 (44.9%), P < 0.01]. HGV RNA was undetectable in 65.7% of the coinfected patients at the end of follow-up. Intravenous drug abuse seems to be a major risk factor for HGV coinfection in patients with chronic hepatitis C. Coinfection with HGV does not worsen the clinical course of chronic hepatitis C or diminish response of HCV to antiviral therapy. Interferon/ribavirin combination therapy also clears HGV infection in a high proportion of cases.

Prevalence, incidence density, and genotype distribution of GB virus C infection in a cohort of recently HIV-1-infected subjects in Sao Paulo, Brazil

BACKGROUND

The results of previous studies elsewhere have indicated that GB virus C (GBV-C) infection is frequent in patients infected with the human immunodeficiency virus type 1 (HIV-1) due to similar transmission routes of both viruses. The aim of this study was to determine the prevalence, incidence density and genotypic characteristics of GBV-C in this population.

METHODOLOGY/PRINCIPAL FINDINGS

The study population included 233 patients from a cohort primarily comprised of homosexual men recently infected with HIV-1 in São Paulo, Brazil. The presence of GBV-C RNA was determined in plasma samples by reverse transcriptase-nested polymerase chain reaction and quantified by real-time PCR. GBV-C genotypes were determined by direct sequencing. HIV viral load, CD4+ T lymphocyte and CD8+ T lymphocyte count were also tested in all patients. The overall prevalence of GBV-C infection was 0.23 (95% CI: 0.18 to 0.29) in the study group. There was no significant difference between patients with and without GBV-C infection and Glycoprotein E2 antibody presence regarding age, sex, HIV-1 viral load, CD4+ and CD8+T cell counts and treatment with antiretroviral drugs. An inverse correlation was observed between GBV-C and HIV-1 loads at enrollment and after one year. Also, a positive but not significant correlation was observed between GBV-C load and CD4+ T lymphocyte. Phylogenetic analysis of the GBV-C isolates revealed the presence of genotype 1 and genotype 2, these sub classified into subtype 2a and 2b.

CONCLUSION/SIGNIFICANCE

GBV-C infection is common in recently HIV -1 infected patients in Sao Paulo, Brazil and the predominant genotype is 2b. This study provides the first report of the GBV-C prevalence at the time of diagnosis of HIV-1 and the incidence density of GBV-C infection in one year.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

Prevalence and distribution of the GBV-C/HGV among HIV-1-infected patients under anti-retroviral therapy

Infection with GB virus C (GBV-C) or hepatitis G virus (HGV) is highly prevalent among HIV/AIDS patients. GBV-C/HGV viremia has not been associated with liver disease and seems to slow HIV disease progression. To study the GBV-C/HGV genotypes prevalence among HIV/AIDS patients and its association with HIV viral load (VL) and CD4+ lymphocyte counts. From February 2003 to February 2004, we analyzed 210 HIV-1-infected subjects who were on anti-retroviral therapy (ART). For 63 of them a PCR-nested to the non-coding 5' (5'NCR) region of the GBV-C/HGV was done, and for 49 a DNA direct sequencing was done. A phylogenetic analysis was performed by PHYLIP program. 63 (30%) of the HIV-1-infected patients were co-infected with GBV-C/HGV. The phylogenetic analysis revealed the following genotypes (and respective relative frequencies): 1 (10%), 2a (41%), 2b (43%), and 3 (6%). Co-infected patients presented lower HIV-1 VL and higher T CD4+ lymphocyte cells counts as compared with patients negative for GBV-C/HGV sequences (log=4.52 vs. 4.71, p=0.036), and T CD4+ lymphocyte counts (cells/mm(3)=322.6 vs. 273.5, p=0.081, respectively). T CD4+ cells counts equal to, or higher than, 200/mm(3) were significantly more common among co-infected patients than among HIV-infected-only patients (p=0.042). The lowest T CD4+ cells counts were associated with genotype 1 and the highest with genotype 2b (p=0.05). The GBV-C/HGV infection prevalence was 30% among HIV-1-infected subjects, and was associated with lower VL and higher CD4+ lymphocyte counts. GBV-C/HGV genotype 2b may be associated with better immunological response.

Epidemiological characteristics and clinical manifestations of acute non-A-E hepatitis

Background/Aim. Acute non-A, non-B, non-C, non-D, non-E hepatitis (non-A-E AH) is an acute disease of the liver of unknown etiology for which one or more new, so far undetected, hepatotropic viruses may be responsible. The frequency of non-A-E AH ranges from 3.8% to 33.9%, and therefore it has a significant place within current infectology and hepatology. The aim of our study was to establish the frequency, clinical and biochemical characteristics, natural course and outcome of non-A-E AH and compare them with control groups affected by acute viral hepatitis A, B and C. Methods. This descriptive-analytic prospective study included 31 patients with non-A-E AH treated at the Institute of Infectious and Tropical Diseases, Clinical Center of Serbia, Belgrade, from 2003 to 2008. They were followed up during the period not less than 6 months. The controls involved randomly selected patients, treated at the same time with a definite diagnosis of acute viral hepatitis A, B and C. Statistical data analysis used Mann-Whitney Utest, Student's t-test and variance analysis. The value of p < 0.05 was considered statistically significant. Results. The frequency of non-A-E AH was 7.6%. Almost no difference was found between sexes (male/female ratio was 1 : 1.07); it was developed in all age groups, with the highest incidence in the middle age (mean age was 38.32 ? 15.3 years). It appeared equally throughout the whole year. Out of risk factors, inoculation risk was predominant (before all, dental interventions), mostly involving urban population living in comfortable conditions. The duration of incubation varied much ranging from 20 to 180 days (median 60 days). By clinical course, moderate and icteric forms were most common, mostly corresponding to acute hepatitis A and C. On the other hand, by duration of the disease (mean duration was 67.1 ? 27.1) and chronic transformation, non-A-E AH resembled to acute hepatitis B. Progression to chronicity was recorded in 9.68% of the patients. There was no fulminant neither cholestatic form of the disease. Conclusion. Based on the results obtained in this study, it is probable that there are some so far undetected primary hepatotropic viruses in our environment.

GB virus type C infection modulates T-cell activation independently of HIV-1 viral load

BACKGROUND

Many clinical studies have suggested a beneficial effect of GB virus type C (GBV-C) on the course of HIV-1 infection, but the mechanisms involved in such amelioration are not clear. As recent evidence has implicated cellular activation in HIV-1 pathogenesis, we investigated the effect of GBV-C viremia on T-cell activation in early HIV-1 infection.

METHODS

Forty-eight recently infected HIV-1 patients (23 GBV-C viremic) were evaluated for T-cell counts, expanded immunophenotyping GBV-C RNA detection, and HIV-1 viral load. Nonparametric univariate and multivariate analyses were carried out to identify variables associated with cellular activation, including GBV-C status, HIV-1 viral load, T lymphocyte counts, and CD38 and chemokine (C-C motif) receptor 5 (CCR5) surface expression.

FINDING

We not only confirmed the positive correlation between HIV-1 viral load and the percentage of T cells positive for CD38(+)CD8(+) but also observed that GBV-C viremic patients had a lower percentage of T cells positive for CD38(+)CD4(+), CD38(+)CD8(+), CCR5(+)CD4(+), and CCR5(+)CD8(+) compared with HIV-1-infected patients who were not GBV-C viremic. In regression models, GBV-C RNA(+) status was associated with a reduction in the CD38 on CD4(+) or CD8(+) T cells and CCR5(+) on CD8(+) T cells, independent of the HIV-1 viral load or CD4(+) and CD8(+) T-cell counts. These results were also supported by the lower expression of CD69 and CD25 in GBV-C viremic patients.

INTERPRETATION

The association between GBV-C replication and lower T-cell activation may be a key mechanism involved in the protection conferred by this virus against HIV-1 disease progression to immunodeficiency in HIV-1-infected patients.

Hepatitis G virus

A number of new hepatitis viruses (G, TT, SEN) were discovered late in the past century. We review the data available in the literature and our own findings suggesting that the new hepatitis G virus (HGV), disclosed in the late 1990s, has been rather well studied. Analysis of many studies dealing with HGV mainly suggests the lymphotropicity of this virus. HGV or GBV-C has been ascertained to influence course and prognosis in the HIV-infected patient. Until now, the frequent presence of GBV-C in coinfections, hematological diseases, and biliary pathology gives no grounds to determine it as an "accidental tourist" that is of no significance. The similarity in properties of GBV-C and hepatitis C virus (HCV) offers the possibility of using HGV, and its induced experimental infection, as a model to study hepatitis C and to develop a hepatitis C vaccine.

Comparison of GB virus C, HIV, and HCV infection markers in hemophiliacs exposed to non-inactivated or inactivated factor concentrates

BACKGROUND

Until the mandatory introduction of viral inactivation techniques of blood plasma products in the early 1980s many recipients of these products were infected with various viral pathogens.

OBJECTIVES

To determine the rate of transmission of GB virus C/hepatitis G virus (GBV-C/HGV) HCV, and HIV through non-virus-inactivated clotting factor concentrates in hemophiliacs, as well as the relation between amount of administered clotting factor and risk for GBV-C/HGV infection.

STUDY DESIGN

In this cross-sectional study, we determined retrospectively the rates of infection markers for GBV-C/HGV, HCV, and HIV in a German cohort of hemophiliacs treated with documented amounts of non-virus-inactivated clotting factor concentrates (group A) and in a second group of hemophiliacs who were treated exclusively with virus-inactivated clotting factor (group B). The presence of anti-virus antibodies was determined by ELISA. Viral RNA was detected by RT-PCR. Markers for viral infections were compared to amounts of administered non-virus-inactivated clotting factor.

RESULTS

Among hemophiliacs treated with documented amounts of non-virus-inactivated clotting factor the prevalence for GBV-C/HGV, HCV, and HIV was 40.3%, 98.6%, and 56.3%, respectively. In contrast to HIV, the rate of GBV-C/HGV infections did not increase with increasing amounts of consumed non-inactivated clotting factor. Even in the subgroup of heavily treated hemophiliacs the rate of GBV-C/HGV infection markers did not exceed 45%.

CONCLUSIONS

The amount of non-virus-inactivated clotting factor is not predictive for the risk of GBV-C/HGV infection in hemophiliacs. Despite repeated parenteral exposure more than 55% of hemophiliacs were not infected with GBV-C/HGV. Our findings indicate a high frequency of host factors preventing parenteral transmission of GBV-C/HGV.

Effectiveness in controlling haemorrhage after dental scaling in people with haemophilia by using tranexamic acid mouthwash

AIMS

To compare the effectiveness of tranexamic acid mouthwash (TAMW) in controlling gingival haemorrhage after dental scaling with that of using factor replacement therapy (FRT) prior to dental scaling in people with haemophilia.

DESIGN

Double-blind cross-over randomised control trial.

SETTING

Dedicated hospital dental practice for patients with inherited bleeding disorders.

METHOD

Sixteen patients with haemophilia who required dental scaling participated in this pilot study. The experimental treatment regime (ETR) involved transfusing each patient with saline before scaling both quadrants on one side of the mouth followed by oral rinsing with TAMW four times daily for up to eight days. The control regime (CR) involved giving each patient FRT before scaling the opposite side of the mouth followed by use of a placebo TAMW. Each patient underwent both treatments in a random-ised sequence. Both the operator and the patients were unaware of which were the ETR and CR episodes. On both occasions the patient kept a log book of the rinsing regime and any post-operative bleeding. Additionally, a structured post-treatment telephone interview was conducted to assess the effectiveness and the patient acceptability of the ETR.

RESULTS

Thirteen patients completed the study. No statistically significant difference was found in gingival bleeding and mouthwashing frequencies between the ETR and the CR (p > 0.05). Five patients reported no gingival bleeding with either the ETR or the CR. No patient, using either regime, required extra FRT due to gingival haemorrhage. All subjects found the ETR acceptable and easy and reported feeling safe in using TAMW alone to control gingival bleeding after dental scaling.

CONCLUSION

TAMW use after dental scaling was as effective as using FRT beforehand in controlling gingival haemorrhage for people with haemophilia.

Evaluation of Three Molecular Biology-Based Assays for the Detection of GB Virus C/Hepatitis G Virus in Clinical Specimens

OBJECTIVE

The present study was performed to evaluate the reliability of three reverse transcription-polymerase chain reaction (RT-PCR) assays, one commercial and two 'homebrew', for GB virus C (GBV-C)/hepatitis G virus (HGV) RNA detection in clinical specimens. We, therefore, investigated the virus prevalence with the method that gave us the best performances.

METHODS

The commercial assay amplified sequences from the viral 5'-untranslated region (5'UTR) and non-structural 3 (NS3) region. The non-commercial assays 1 and 2 were based on different primers for the 5'UTR consensus sequence.

RESULTS

The percentage of overall concordance by the three methods was 91.7%, raising to 93.0% when only the two non-commercial methods were compared. Assay 1 showed low sensitivity (57.1% vs. the commercial assay, 58.8% vs. assay 2), with 100% specificity. The commercial assay gave 18 of 54 (33.3%) 'false-negative' results, concordantly negative by the other assays. The prevalence of GBV-C/HGV RNA among the HIV+ patients was 27.0 and 32.6% in HIV/HCV co-infected patients.

CONCLUSION

These data suggest that assay 2 has higher reliability as compared to the other two methods and may be used for an accurate GBV-C/HGV RNA detection in clinical and epidemiological studies.

GB virus C/hepatitis G virus infection in Indian blood donors and high-risk groups

The hepatitis G virus (HGV) or GB virus C (GBV-C) was discovered in 1995 as a putative agent of post-transfusion, non-A-E hepatitis. The present study was carried out with the aim to find the prevalence of this virus among various subject groups at risk for parenteral transmission as well as in healthy control subjects both individually and along with other parenterally transmitted hepatitis viruses. Of the 402 subjects tested, 6.22% were positive for the HBsAg surface antigen, 7.21% were positive for HCV RNA while only 2.24% were seen to be carriers of the HGV/GBV-C RNA. All the HGV/GBV-C positive cases were either multi-transfused thalassaemic subjects or hemodialysis patients. None of the healthy control subjects showed presence of the virus. Seven of the HGV/GBV-C positive subjects showed co-infection with one or more additional virological markers. Also, of the 9 HGV/GBV-C positive subjects, 5 showed elevated ALT levels while 4 showed elevated alkaline phosphatase levels. Overall our findings seem to indicate that HGV infections generally are asymptomatic, transient and self-limiting and the virus does not seem to show a very high prevalence among the Indian population.

Clinical, histologic and serologic evaluation of patients with acute non-A-E hepatitis in north-eastern Brazil: is it an infectious disease?

Non-A-E hepatitis and acute cryptogenic hepatitis are the names given to the disease of patients with clinical hepatitis, but in whom serologic evidence of A-E hepatitis has not been found. Over a period of 8 years, we evaluated in Brazil 32 patients who fulfilled the criteria for this diagnosis in order to determine patterns of the clinical illness, laboratory parameters, or histologic features. Each patient was subjected to virologic tests to exclude A-E hepatitis and cytomegalovirus/Epstein-Barr virus infection. Drug-induced hepatitis and autoimmune disease were also excluded. Wilson's disease was excluded in young patients. The course of the disease was clinical/biochemical recovery in 3 months in 25 patients and persistent alanine aminotransferase (ALT) elevation in 7 patients. Three of these had chronic hepatitis, and one had severe fibrosis on liver biopsy. During the acute illness, mean peak ALT was 1267 IU/L, bilirubin was 4.0 mg/dL, and ferritin was 1393 IU/mL. GB virus type C (GBV-C) was found in six patients, and TT virus (TTV) in five patients. We conclude that, in Brazil, non-A-E hepatitis probably originates from still unidentified viruses. The course of the disease and the histologic patterns are similar to those recorded for known viruses. Continuous survey for the specific etiologic agents is needed.

Epidemiological and quantitative study of GBV-C infection in french polytransfused children

From 1999 to 2002, 246 serum samples taken from polytransfused children were tested for the presence of GB virus C (GBV-C) RNA using a real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. This assay was based on the TaqMan technology and allowed viral load determination in infected children with a dynamic range from 10(3) to 10(7) genome equivalent (gEq) copies/ml. The limit of detection was estimated to 619 gEq copies/ml with a > or = 95% probability of a positive result. Thirty five sera were found to be GBV-C RNA positive, corresponding to a prevalence of GBV-C of 14.2%. The mean viral load was high, i.e., 6 +/- 1.4 log (range 3.22-7.42) gEq copies/ml, but low viral loads were also detected. Sequencing of the 5'-untranslated region (UTR) identified a majority of genotype 2 strains (82%) distributed into two subtypes, 88.5% genotype 2a and 11.5% genotype 2b. In conclusion, GBV-C active infection is very frequent in exposed populations such as polytransfused children. GBV-C RNA quantitation using real-time assay may be useful for diagnosis and follow-up of the natural history of GBV-C infection.

[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.

HGV/GB virus C transmission by blood components in patients undergoing open-heart surgery

BACKGROUND

To establish the rate of HGV/GB virus C (GBV-C) transmission by blood components in open-heart surgery patients.

STUDY DESIGN AND METHODS

From 55 patients receiving blood components, sera were collected before and 2, 4, 6, 8, 10, 12, 16, 20, 26, and 32 weeks after heart surgery. Serum samples from patients and implicated blood donations were tested for HGV/GBV-C RNA by PCR. Recipients of RNA-positive blood components were also tested for the presence of E2 antibodies (E2Ab) by ELISA.

RESULTS

Of 55 recipients, 18 received RNA-positive blood components. Of 14 recipients of RNA-positive blood components, who were negative for RNA or E2Ab before transfusion, 8 became RNA positive and one developed E2Ab after transfusion. Three recipients of RNA-positive blood components had E2Ab before transfusion, and none of these became RNA positive after transfusion. One of 18 recipients was RNA positive before and after transfusion. Of 55 recipients, 37 received RNA-negative blood components: 34 were RNA negative before and after transfusion. Of 37 recipients, 3 were RNA positive before and after transfusion.

CONCLUSION

Of susceptible patients, 64 percent became infected with HGV/GVC-C when transfused with RNA-positive blood components. E2Ab-positive patients were protected against HGV/GBV-C infection.

Prevalence of GBV-C infection among dental personnel

Healthcare workers who carry out exposure-prone procedures are theoretically at increased risk of acquiring blood-borne virus infections. GB virus C (GBV-C) is a recently described blood-borne virus that is related distantly to hepatitis C virus. The occupational risk of GBV-C infection to healthcare workers is unknown. This study collected detailed occupational and personal risk data in parallel with a blood specimen, to establish the prevalence and determinants of GBV-C infection among dental healthcare workers. The presence of GBV-C antibodies was detected using commercially available ELISA; GBV-C RNA was detected by nested PCR using primers from the conserved 5' noncoding region. The overall prevalence of GBV-C antibodies among the study population was 11.1% (98/880, 95% confidence interval [CI], 9.1-13.4%) and 4.6% were positive for GBV-C RNA (46/879, 95% CI, 2.5-5.1%), resulting in a cumulative prevalence of 15.7%. These figures are similar to those described in other populations. There was no significant difference in lifetime exposure to GBV-C between dentists (17.7%) and dental nurses/hygienists (14.3%). Significantly more dental nurses/hygienists aged 16-30 years had been exposed to GBV-C compared to dentists of the same age (chi(2) = 13.75; P < 0.001). Conversely, significantly more dentists 46 years or older had evidence of exposure to GBV-C compared to dental nurses/hygienists (chi(2) = 6.79; P = 0.009). The high prevalence of GBV-C infection did not seem to be related to past parenteral exposure, and the data suggest that sexual transmission, rather than occupational transmission, was a more important route for GBV-C infection among this population.

The risk of hospital-acquired GB virus C infection: a pilot case-control study

The risk of hospital-acquired infection with GB virus C (GBV-C) was explored among 42 patients. The factors independently associated with detection of GBV-C RNA in serum were bronchoscopic examination [adjusted odds ratio (OR)=18.1 (95% confidence interval 1.3-255.3), P=0.03] and a history of illicit drug use [OR=14.5 (1.0-218.7), P=0.05]. In this cohort of patients, invasive procedures appear to be associated with GBV-C infection but not with hepatitis C virus (HCV) infection.

Interactions Between GB Virus Type C and HIV

GB virus C (GBV-C, also known as hepatitis G virus) commonly causes human infection. Genetically, it is closely related to hepatitis C virus, but GBV-C appears to grow primarily in lymphocytes, not hepatocytes. Although it causes persistent infection in about 25% to 50% of infected individuals, numerous studies have failed to connect GBV-C with any disease process. GBV-C is transmitted sexually, parenterally, and vertically, and due to these shared modes of transmission, coinfection is common among HIV-infected individuals. Of 10 studies done of HIV-GBV-C coinfection, eight found a beneficial effect of GBV-C viremia on HIV-related mortality or response to therapy. The mechanism by which GBV-C may improve survival of HIV-positive people is not known; however, in vitro studies suggest that GBV-C inhibits HIV replication, and preliminary data also point toward alterations in cytokine and/or chemokine expression by GBV-C-infected cells.

High prevalence of GB virus C/hepatitis G virus genotype 3 among autochthonous Venezuelan populations

GB virus C or hepatitis G virus (GBV-C/HGV) is highly prevalent among population groups at risk of parenterally transmitted viral agents, but it has also a worldwide distribution in other non-risk population groups. GBV-C/HGV RNA and antibodies against its envelope protein (anti-E2 Abs) were found in 3/86 (3%) and 7/89 (8%) of biomedical science personnel (BSP), in 31/453 (7%) and 37/200 (19%) of blood donors (BD), and in 6/64 (9%) and 26/59 (44%) of hemodialysis patients (HD) from Caracas, Venezuela. A significant gradient of GBV-C/HGV exposure (anti-E2 Abs and/or GBV-C/HGV RNA) was found between BSP (lowest prevalence), BD, and HD (P < 0.001). GBV-C/HGV RNA and anti-E2 Abs were also found in 2/69 (2.9%) and 2/44 (4.5%) of individuals from a rural community, in 9/162 (5.5%) and 2/40 (5%) of West Amerindians, and in 14/56 (25%) and 4/53 (7.5%) of South Amerindians. Socioeconomic and cultural factors may have contributed to the relatively high risk of exposure to GBV-C/HGV in BD and Amerindians. Whereas GBV-C/HGV genotypes 1 (n = 1), 2 (n = 6), and 3 (n = 22) were present in Venezuela, only the Asiatic genotype 3 was found infecting Amerindians and rural populations (n = 16). Genotype assignment based on the 5' noncoding region of the GBV- C/HGV genome was corroborated in some isolates by genetic analysis of the E2 region. This report confirms the circulation of the Asiatic genotype of GBV-C/HGV among Amerindians, suggesting an old origin of GBV-C/HGV. This might be associated with the apparently low pathogenesis of this virus.

Hepatitis G virus genotypes in a tertiary care centre in southern India

BACKGROUND

The association of GBV-C/HGV in patients at high risk of parenteral infection and those with chronic liver disease in southern India is unknown.

OBJECTIVES

To study the occurrence of GBV-C/HGV in three patient groups attending a tertiary care centre in Vellore and identify the prevailing genotype(s).

STUDY DESIGN

Two hundred and twenty-seven individuals were studied using an RT-PCR assay with primers specific for the 5'NCR and the NS5a-coding regions. Ten randomly selected samples were sequenced in the 5'NCR region of the GBV-C/HGV genome.

RESULTS

GBV-C/HGV RNA was detected in 37/70 (52.9%) of renal transplant recipients, 18/70 (25.7%) of patients with haematological disorders and in 9/87 (10.3%) patients with chronic liver disease. Nine of the ten sequences could be assigned to genotype 2a while the remaining sequence could not be assigned.

CONCLUSIONS

In this centre, GBV-C/HGV is widely prevalent in patients with high parenteral risk and in those with chronic liver disease. The predominantly circulating genotype among study patients is genotype 2a.

Effects of co-infection with hepatitis C virus and GB virus C on CD4 cell count and HIV-RNA level among HIV-infected patients treated with highly active antiretroviral therapy

The effects of co-infection with hepatitis C virus (HCV) and GB virus C (GBV-C) on CD4 cell counts and plasma HIV-RNA levels has been investigated in HIV-infected patients treated with highly active antiretroviral therapy (HAART). Patients co-infected with HCV and GBV-C experienced a CD4 cell increase during 4 years of HAART, whereas the increase stopped after 2 years in the other groups.

Infectious hepatitis C, hepatitis G, and TT virus: review and implications for dentists

In the past 10 years, hepatitis C and G viruses have been identified, and in the last two years a further parenterally transmitted agent, termed TT virus (TTV), has been discovered. These viruses have a worldwide distribution and frequently cause chronic infection. The purpose of this article was to promote an understanding of these viral agents and their relevance in dental practice. Infected patients may develop a chronic carrier state without clinical disease or may develop liver disease, and may have related oral conditions. Dental providers will see a growing number of patients with HCV/HGV and possibly TTV infection. All of these patients require appropriate infection control measures during dental treatment.

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.

Epidemiology and prophylaxis of viral hepatitis: a global perspective

BACKGROUND

Viral hepatitis with various forms of acute and chronic liver disease as potential and ultimately fatal sequelae presents a public health problem worldwide.

METHODS

Recent published reports on the global epidemiology and prophylaxis of viral hepatitis were reviewed.

RESULTS

With the advances in novel technologies, eight distinct types of hepatitis virus have been described: Hepatitis A, B, C, D, E, G, TT and SEN viruses. Hepatitis A and E viruses are transmitted by the fecal-oral route and do not induce a chronic carrier state. Due to major changes in epidemiology of hepatitis A virus their significance is more pronounced in areas of intermediate endemicity. Since the available hepatitis A vaccine is rather expensive, cost-benefit studies should be performed with emphasis on the area under consideration or specialized vulnerable groups. Parenterally transmitted hepatitis B and C viruses are major causes of chronic liver disease, including cirrhosis, hepatocellular carcinoma and end-stage liver failure. Hepatitis D virus is unable to replicate on its own, it requires an established hepatitis B virus infection to be able to replicate. Since its introduction, hepatitis B vaccine has been widely used leading to a significant decrease in HBV infection in countries with universal vaccination. Hepatitis G and TT viruses have been characterized within the latter part of the past decade but their significance as to the causation of human liver disease has yet to be elucidated. Likewise, the precise impact of the most recently described SEN virus isolated from patients with post-transfusion hepatitis awaits further studies.

CONCLUSIONS

In the course of this review, we present the situation and focus on research activities emphasizing epidemiology and prevention of the various forms of viral hepatitis.

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.

High incidence of hepatitis B infections among chronic hepatitis cases of unknown aetiology

BACKGROUND/AIMS

In approximately 5% of chronic liver disease cases, no aetiology can be identified. We selected sera from 50 patients with chronic hepatitis of unknown aetiology who were enrolled in this follow-up study whose aim is to gain insight into the possible role of viruses and to define potential clinical outcomes.

METHODS

Patients' sera were screened with highly sensitive polymerase chain reaction assays for hepatitis B (HBV), C, D, and G viruses and TT virus. Sera were also retested for antibodies against the core antigen of HBV.

RESULTS

Surprisingly, HBV DNA was detected in both serum and liver in 15/50 (30%) patients. Immunostaining for HBV antigens on biopsies from patients positive for HBV DNA showed HBcAg and/or HBsAg expression at low levels in 9/15 samples. Eleven of the fifteen patients were anti-HBc positive. With one exception, all patients carried HBV genomes at low levels (10(4) copies/ml or less). Histological signs of chronic liver disease were observed in all patients.

CONCLUSION

Unrecognised HBV infections may account for a high proportion of chronic hepatitis cases of unknown aetiology. Improved HBV detection tests, which appear mandatory for the diagnosis and management of non-A non-E hepatitis as well as for improved safety of transfusions and transplantations are needed.

New hepatitis viruses: contenders and pretenders

Following the development of tests for hepatitis C virus and hepatitis E virus infection, it became clear that there remained cases of hepatitis that were non-A-E. Such cases provided impetus for the search for additional hepatitis viruses and, by using molecular techniques, several candidates were identified. An enteric agent responsible for sporadic non-A and non-E hepatitis was tentatively called hepatitis F virus. However, the lack of any corroborating reports has cast doubt on its status as a true hepatitis virus. Two groups independently reported the isolation of a blood-borne virus, designated as hepatitis G virus (HGV) and GB virus C (GBV-C) by their respective discoverers. They were later shown to be isolates of the same virus. While the virus has a high prevalence in cases of non-A-E hepatitis, it also has a high prevalence in the appropriate control groups and convincing evidence for its replication in the liver is lacking. Another possible hepatitis virus, TT virus, was discovered in the blood of a patient with post-transfusion non-A-E hepatitis. By using PCR primers designed to overcome the high nucleotide sequence divergence, TT virus was found to be ubiquitous with a worldwide distribution. A disease association is thus unlikely. Most recently, a DNA virus designated as SEN-V has been announced as a major cause of non-A-E hepatitis. Based on limited data available to researchers, SEN-V is the most convincing contender for the new hepatitis virus title. However, the lessons learnt from the hepatitis virus pretenders will need to be applied to SEN-V and any future contenders.

A high frequency of GBV-C/HGV coinfection in hepatitis C patients in Germany

AIM: To detect infection rate of GBV-C/HGV in hepatitis C patients, to determine the methods of higher sensitivity and the primers of higher efficiency for GBV-C/HGV RNA detection and to study the dominant subtype and mutation of GBV-C/HGV.

METHODS: Quantitative RT-PCR for detection pf HCV RNA concentration in serum samples, RT-nested PCR with two sets of primers for detection of GBV-CRNA, RT-PCR ELISA with two sets of primers for detection of HGV RNA, nucleotide sequence and putative amino acid sequence analysis.

RESULTS: The positive rates of GBV-C RNA at the 5’-NCR and NS3 region in 211 serums amples from the patients with HCV infection were 31.8% and 22.8% respectively. The positive rates of HGV RNA at the 5’-NCR and NS5 region in the same samples were 47.9% and 31.8% respectively. The total positive rate of GBV-C/HGV RNA was as high as 55.5%. HCV copy numbers in the patients without GBV-C/HGV coinfection were statistically higher than that in the patients with GBV-C/HGV coinfection (P < 0.01). Frequent mutation of nucleotide residue was present in the amplification products. Frameshift mutation was found in two samples with GBV-C NS3 region nucleotide sequences. All nucleotide sequences from amplification products showed higher homology to HGV genome than to GBV-C genome even though part of the sequences were amplified with GBV-C primers.

CONCLUSION: A high frequency of GBV-C/HGV coinfection existed in the hepatitis C patients. RT-PCR ELISA was more sensitive than RT-nested PCR for detection of GBV-C/HGV RNA. The primers derived from the 5’-NCR was more efficient than those derived from the NS3 and NS5 regions. A reverse relationship was found to exist between HCV RNA concentration and GBV-C/HGV infection frequency. HGV was the dominant subtype of the virus in the local area. The major mutations of GBV-C/HGV genomes were random mutation of nucleotide residue.