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

Human pegivirus 1 in Cabo Verde: prevalence and genotypic distribution among HIV-infected individuals

Human pegivirus 1 (HPgV-1) belongs to the genus Pegivirus, family Flaviviridae, and until now has been considered a non-pathogenic agent, despite being considered a risk factor for non-Hodgkin lymphoma. However, a beneficial impact of HPgV-1 on HIV disease progression has been extensively reported. Given the high prevalence of HIV in sub-Saharan Africa and the scarcity of epidemiological data for many countries of West Africa, we conducted the first study of HPgV-1 in HIV-infected individuals from Cabo Verde. To obtain new data regarding prevalence and genetic diversity of HPgV-1 in Africa, serum samples from 102 HIV-infected Cabo Verdeans were tested for the presence of viral RNA, and the circulating genotypes were identified by sequencing of the 5' untranslated region. HPgV-1 RNA was detected in 19.6% (20/102) of the samples. In 72.2% (13/18) of the samples, the virus was identified as genotype 2 (11/13 subtype 2a and 2/13 subtype 2b), and in 27.8% (5/18), it was identified as genotype 1. The estimated substitution rate of HPgV-1 genotype 2 was 5.76 × 10^-4, and Bayesian analysis indicated the existence of inner clusters within subtypes 2a and 2b. The prevalence of HPgV-1 viremia in Cabo Verde agrees with that reported previously in Africa. Genotypes 1 and 2 cocirculate, with genotype 2 being more common, and HIV/HPgV-1 coinfection was not associated with higher CD4 T cell counts in the studied population. This finding contributes for the expansion of the pegivirus research agenda in African countries.

Human pegivirus-1 (HPgV-1) RNA prevalence and genotypes in volunteer blood donors from the Brazilian Amazon

OBJECTIVES

The objectives of this study were to evaluate the prevalence of Human Pegivirus-1 (HPgV-1) viremia and genotype diversity among healthy blood donors from the Eastern Brazilian Amazon (city of Macapá, State of Amapá). There is little information for prevalence and circulation of HPgV-1 in this remote Brazilian region.

MATERIALS AND METHODS

We conducted a study evaluating the HPgV-1 RNA prevalence and circulating genotypes in 431 volunteer blood donors originating from the Eastern Brazilian Amazon. The obtained HPgV-1 positive samples were submitted to sequencing and genotyping analysis in order to examine the genotype diversity of this virus in the Brazilian Amazon.

RESULTS

Our results demonstrated a prevalence of HPgV-1 RNA in 9.5% of the tested blood donors. The phylogenetic analyses of the detected positive samples showed the presence of HPgV-1 genotypes 1, 2 and 3. The most frequently detected genotype was 2 (78.0% of the cases) represented by sub-genotypes 2A (39.0%) and 2B (39.0%). At lower rates, genotypes 1 (14.6%) and 3 (7.4%) were also detected.

CONCLUSION

Our results revealed the presence of genotypes with European, Asiatic and African endemicity in Amazonian blood donors, probably due to the complex miscegenation processes that took place in this Brazilian region. More investigations, including information for the prevalence of HPgV-1 RNA in blood donors from other Latin American countries are needed to estimate the viremic rates and genotype distribution of this virus in a highly diverse continent like South America.

Human pegivirus isolates characterized by deep sequencing from hepatitis C virus-RNA and human immunodeficiency virus-RNA-positive blood donations, France

Human pegivirus (HPgV, formerly GBV-C) is a member of the genus Pegivirus, family Flaviviridae. Despite its identification more than 20 years ago, both natural history and distribution of this viral group in human hosts remain under exploration. Analysis of HPgV genomes characterized up to now points out the scarcity of French pegivirus sequences in databases. To bring new data regarding HPgV genomic diversity, we investigated 16 French isolates obtained from hepatitis C virus-RNA and human immunodeficiency virus-RNA-positive blood donations following deep sequencing and coupled molecular protocols. Initial phylogenetic analysis of 5'-untranslated region (5'-UTR)/E2 partial sequences permitted to assign HPgV isolates to genotypes 2 (n = 15) and 1 (n = 1), with up to 16% genetic diversity observed for both regions considered. Seven nearly full-length representative genomes were characterized subsequently, with complete polyprotein coding sequences exhibiting up to 13% genetic diversity; closest nucleotide (nt) divergence with available HPgV sequences was in the range 7% to 11%. A 36 nts deletion located on the NS4B coding region (N-terminal part, 12 amino acids) of the genotype 1 HPgV genome characterized was identified, along with single nucleotide deletions in two genotype 2, 5'-UTR sequences.

Genotype Distribution and Prevalence of Human Pegivirus among High-Risk Populations in Tunisia

OBJECTIVE

A recently discovered non-A-E hepatitis virus has been designated as human Pegivirus (HPgV). HPgV is prevalent in high-risk groups such as patients with hepatitis C virus (HCV), and it is of interest for patients who are at risk for transmitted infections. The aim of this study was to evaluate the prevalence of HPgV as well as the genotype distribution among patients in the Tunisian population who are infected with HCV and also in multitransfused patients.

METHODS

A total of 144 patients were screened using RTPCR/nested PCR of the 5'-untranslated region (UTR); 14 cases were sequenced and phylogenetically analyzed.

RESULTS

Seven (14.9%) subjects from the multitransfused group and 7 (7.2%) patients infected with HCV, respectively, were found positive for HPgV RNA. Sequencing and phylogenetic analysis of the 14 cases revealed that genotype 2a was the main genotype circulating in Tunisian patients. Genotype 2b was found in the amplified samples of 2 HCV-infected patients.

CONCLUSION

This study enriches the limited data on HPgV prevalence in Tunisia, and shows, for the first time, the molecular epidemiology of the circulating strains in this country.

Short communication: Evaluation of GB virus C/hepatitis G viral load among HIV type 1-coinfected patients in São Paulo, Brazil

Recent studies suggest that GB virus C/hepatitis G virus (GBV-C/HGV) infection in HIV-positive individuals is associated with a slower progression to AIDS, leading to a lower HIV viral load and higher counts of CD4(+) T cells, although many studies have failed to demonstrate these beneficial effects. We developed a Real-Time PCR (TaqMan RT qPCR) to quantify the viral load of GBV-C/HGV in 102 HIV-1-infected patients, who were also evaluated for the presence of anti-E2. The prevalence of GBV-C/HGV infection was 21% among infected patients and the mean plasma viral load was 3.62 ± 0.64 log(10) copies/ml. Despite the high prevalence, there was no statistical difference when we compared the mean viral load (p≤0.46) and the average count of CD4(+) (p≤0.29) and CD8(+) (p≤0.64) among patients infected by GBV-C/HGV and HIV and patients infected only by HIV. This fact can be explained by the number of patients included in the study. Nevertheless, compared to other studies, we observed a discrete number of patients with undetectable HIV load and lower median viral load in the group presenting GBV-C/HGV RNA. Our study suggests that there may be an impact on HIV viral load in GBV-C/HGV-coinfected patients. However, further studies are needed to elucidate the molecular and cellular mechanisms involved in this viral interaction, previously reported in other studies, with the aim of contributing to the development of new targets for drugs against HIV.

Evaluation of GBV-C / HVG viremia in HIV-infected women

The present study aimed at standardizing a real-time quantitative polymerase chain reaction assay to evaluate the presence of GBV-C/HGV RNA. A "TaqMan" assay using primers and probe derived from the 5¢ NCR region was developed and validated. Two hundred and fifty-three plasma samples from HIV-infected women were tested for GBV-C viremia and antibody against the envelope protein 2. GBV-C RNA was detected in 22.5% of the patients whereas the antibody was identified in 25.3% of the cohort. Detection of viral RNA and of antibodies was mutually exclusive. Viral loads showed a mean of 1,777 arbitrary units / mL, being 1.1 and 13,625 arbitrary units / mL respectively the lowest and highest values measured. We conclude that the real-time quantitative polymerase chain reaction method developed is appropriate for the investigation of GBV-C RNA since it was shown to be highly specific and sensitive, as well as requiring few steps, preventing contamination and providing additional information as to the relative viremia of carriers, a parameter that must be included in studies evaluating the co-factors influencing the clinical outcome of HIV/AIDS.

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.

The protein kinase IKKepsilon can inhibit HCV expression independently of IFN and its own expression is downregulated in HCV-infected livers

During a viral infection, binding of viral double-stranded RNAs (dsRNAs) to the cytosolic RNA helicase RIG-1 leads to recruitment of the mitochondria-associated Cardif protein, involved in activation of the IRF3-phosphorylating IKKepsilon/TBK1 kinases, interferon (IFN) induction, and development of the innate immune response. The hepatitis C virus (HCV) NS3/4A protease cleaves Cardif and abrogates both IKKepsilon/TBK1 activation and IFN induction. By using an HCV replicon model, we previously showed that ectopic overexpression of IKKepsilon can inhibit HCV expression. Here, analysis of the IKKepsilon transcriptome profile in these HCV replicon cells showed induction of several genes associated with the antiviral action of IFN. Interestingly, IKKepsilon still inhibits HCV expression in the presence of neutralizing antibodies to IFN receptors or in the presence of a dominant negative STAT1alpha mutant. This suggests that good IKKepsilon expression levels are important for rapid activation of the cellular antiviral response in HCV-infected cells, in addition to provoking IFN induction. To determine the physiological importance of IKKepsilon in HCV infection, we then analyzed its expression levels in liver biopsy specimens from HCV-infected patients. This analysis also included genes of the IFN induction pathway (RIG-I, MDA5, LGP2, Cardif, TBK1), and three IKKepsilon-induced genes (IFN-beta, CCL3, and ISG15). The results show significant inhibition of expression of IKKepsilon and of the RNA helicases RIG-I/MDA5/LGP2 in the HCV-infected patients, whereas expression of TBK1 and Cardif was not significantly altered. In conclusion, given the antiviral potential of IKKepsilon and of the RNA helicases, these in vivo data strongly support an important role for these genes in the control of HCV infection.