GB virus C/hepatitis G virus infection in dialysis patients and kidney transplant recipients in Central Brazil

Target Enrichment Metagenomics Reveals Human Pegivirus-1 in Pediatric Hematopoietic Stem Cell Transplantation Recipients

Human pegivirus-1 (HPgV-1) is a lymphotropic human virus, typically considered nonpathogenic, but its infection can sometimes cause persistent viremia both in immunocompetent and immunosuppressed individuals. In a viral discovery research program in hematopoietic stem cell transplant (HSCT) pediatric patients, HPgV-1 was detected in 3 out of 14 patients (21.4%) using a target enrichment next-generation sequencing method, and the presence of the viruses was confirmed by agent-specific qRT-PCR assays. For the first time in this patient cohort, complete genomes of HPgV-1 were acquired and characterized. Phylogenetic analyses indicated that two patients had HPgV-1 genotype 2 and one had HPgV-1 genotype 3. Intra-host genomic variations were described and discussed. Our results highlight the necessity to screen HSCT patients and blood and stem cell donors to reduce the potential risk of HPgV-1 transmission.

Human pegivirus type 1 infection in kidney transplant recipients: Replication kinetics and clinical correlates

BACKGROUND

Increasing evidence suggests that infection with the nonpathogenic human pegivirus type 1 (HPgV-1) exerts a clinical benefit in human immunodeficiency virus (HIV) patients, which could be attributable to immunomodulatory effects. Whether this impact can be extrapolated to kidney transplantation (KT) remains largely unknown.

METHODS

We measured plasma HPgV-1 RNA by real-time polymerase chain reaction targeting the 5' untranslated region at various points (pretransplantation, day 7, months 1, 3, 6, and 12) in 199 KT recipients. Study outcomes included posttransplant serious infection, immunosuppression-related adverse event (opportunistic infection and/or de novo cancer), and acute graft rejection.

RESULTS

HPgV-1 infection was demonstrated in 52 (26.1%) patients, with rates increasing from 14.7% at baseline to 19.1% by month 12 (p-value = .071). De novo infection occurred in 13.8% of patients with no detectable HPgV-1 RNA before transplantation. Double-organ (liver-kidney or kidney-pancreas) transplantation (odds ratio [OR]: 5.62; 95% confidence interval [CI]: 1.52-20.82) and donation after brain death (OR: 2.21; 95% CI: 1.00-4.88) were associated with posttransplant HPgV-1 infection, whereas pretransplant hypertension was protective (OR: 0.23; 95% CI: 0.09-0.55). There were no significant differences in the incidence of study outcomes according to HPgV-1 status. Plasma HPgV-1 RNA levels at different points did not significantly differ between patients that subsequently developed outcomes and those remaining free from these events. No correlation between HPgV-1 RNA and immune parameters or torque teno virus DNA load was observed either.

CONCLUSION

Unlike patients living with HIV, HPgV-1 infection does not seem to influence patient or graft outcomes after KT.

Deep sequencing applied to the analysis of viromes in patients with beta-thalassemia

To date, blood banks apply routine diagnosis to a specific spectrum of transfusion-transmitted viruses. Even though this measure is considered highly efficient to control their transmission, the threat imposed by emerging viruses is increasing globally, which can impact transfusion safety, especially in the light of the accelerated viral discovery by novel sequencing technologies. One of the most important groups of patients, who may indicate the presence of emerging viruses in the field of blood transfusion, is the group of individuals who receive multiple transfusions due to hereditary hemoglobinopathies. It is possible that they harbor unknown or unsuspected parenterally-transmitted viruses. In order to elucidate this, nucleic acids from 30 patients with beta-thalassemia were analyzed by Illumina next-generation sequencing and bioinformatics analysis. Three major viral families: Anelloviridae, Flaviviridae and Hepadnaviridae were identified. Among them, anelloviruses were the most representative, being detected with high number of reads in all tested samples. Human Pegivirus 1 (HPgV-1, or GBV-C), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) were also identified. HBV and HCV detection was expected due to the high seroprevalence in patients with beta thalassemia. Our results do not confirm the presence of emerging or unsuspected viruses threatening the transfusion safety at present, but can be used to actively search for viruses that threaten blood transfusion safety. We believe that the application of viral metagenomics in multiple-transfused patients is highly useful to monitor possible viral transfusion threats and for the annotation of their virome composition.

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.

Human pegivirus (HPgV, GBV-C) RNA in volunteer blood donors from a public hemotherapy service in Northern Brazil

BACKGROUND

Human pegivirus (HPgV)-formerly known as GBV-C-is a member of the Flaviviridae family and belongs to the species Pegivirus C. It is a non-pathogenic virus and is transmitted among humans mainly through the exposure to contaminated blood and is often associated with human immunodeficiency virus (HIV) infection, among other viruses. This study aimed to determine the prevalence of HPgV viremia, its association with HIV and clinical epidemiological factors, as well as the full-length sequencing and genome characterization of HPgV recovered from blood donors of the HEMOPA Foundation in Belém-PA-Brazil.

METHODS

Plasma samples were obtained from 459 donors, tested for the presence of HPgV RNA by the RT-qPCR. From these, a total of 26 RT-qPCR positive samples were submitted to the NGS sequencing approach in order to obtain the full genome. Genome characterization and phylogenetic analysis were conducted.

RESULTS

The prevalence of HPgV was 12.42%. We observed the highest prevalences among donors aged between 18 and 30 years old (16.5%), with brown skin color (13.2%) and men (15.8%). The newly diagnosed HIV-1 prevalence was 26.67%. The HPgV genotype 2 (2a and 2b) was identified. No data on viral load value was found to corroborate the protective effect of HPgV on HIV evolution.

CONCLUSIONS

This study provided information regarding the HPgV infection among blood donors from HEMOPA Foundation. Furthermore, we genetically characterized the HPgV circulating strains and described by the first time nearly complete genomes of genotype 2 in Brazilian Amazon.

Beyond Cytomegalovirus and Epstein-Barr Virus: a Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients

Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians' radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.

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.

Evaluation of prevalence and risk factors of hepatitis g virus infection among hemodialysis patients referred to Iranian army hospitals in tehran during 2012-2013

BACKGROUND

GB virus C (GBV-C) or hepatitis G virus (HGV) is a newly discovered and enveloped RNA positive-stranded flavivirus-like particle, which has not yet been proven to have major negative effects on liver.

OBJECTIVES

Increasing the risk of blood-borne infections in hemodialysis patients is a main health care concern in different countries. Therefore, it is important to estimate the prevalence and risk factors of hepatitis G virus infection in Iranian hemodialysis patients to design standard prevention and treatment plans.

PATIENTS AND METHODS

In this multicenter observational or epidemiologic study, 138 patients who underwent hemodialysis in Iranian Army hospitals in Tehran were included. Serum HIV antibody (Ab), HCV antibody and HBS antigen (Ag) were assessed. Demographic data such as gender, age, blood group, cause of renal failure, dialysis onset and duration were collected from medical files. GBV-C/HGV was evaluated by nested reverse transcription polymerase chain reaction (RT-PCR) method. Then, all data were analyzed by SPSS ver. 13.

RESULTS

In total, 81 males and 57 females were included. The mean age of patients was 62.16 ± 14.86 years. Six (4.3%) had positive results for GBV-C/HGV by RT-PCR. Except gender (P = 0.045) and duration of dialysis in a week (P < 0.001), other demographic factors revealed no significant difference (P > 0.05). All patients had negative results for HIV Ab, HCV Ab and HBS Ag.

CONCLUSIONS

Overall, 4.3% of patients had positive results for GBV-C/HGV and all negative for HIV, HCV and HBV. Further studies are needed to elucidate real prevalence, risk factors and characteristics of HGV infection in Iranian hemodialysis patients.

GB virus C Viremia and Anti-E2 Antibody Response Among Hemodialysis Patients in Gorgan, Iran

Background:

GB Virus C is a blood-borne virus and a member of Flaviviridae, like hepatitis C that is distributed globally and puts hemodialysis patients at high risk of developing liver disease. The clinical significance of GBV-C in this population remains unclear.

Objectives:

The current study aimed to evaluate GBV-C infection among hemodialysis patients.

Patients and Methods:

Totally, 149 patients receiving hemodialysis were included in the study. The detection of GBV-C sequences in plasma was done by the nested Reverse transcription polymerase chain reaction (RT-PCR) using specific primers selected from highly conserved regions of 5' UTR of GBV-C and antibodies to the envelope protein of GBV-C (anti-E2 GBV-C antibody) were analyzed by also serological methods. In addition, Hepatitis B surface antigen (HBsAg), Hepatitis B core antibody (HBcAb) IgM, anti- Hepatitis C virus (HCV) and anti- hepatitis E virus (HEV) Ab was determined in patients who were GBV-C RNA and anti-E2 GBV-C antibody positive.

Results:

The total prevalence of GBV-C infection was 14.7% (95%CI: 0.09-0.21) among patients receiving hemodialysis. The rate of GBV-C viremia and anti-E2 antibody positivity were 6.04% and 10.73%, respectively. Among the subjects who were positive for GBV-C, 27.27% (95% CI: 0.02-0.09), 45.45% (95% CI: 0.03-0.11), 59.9% (95% CI: 0.06-0.16) and 0% (95% CI: 0.01-0.07) were positive for anti-HCV, anti-HBsAg, anti-HBc IgM and anti-(HEV) Ab, respectively. In addition, the rate of both anti-HBc IgM /anti-HCV/ HBsAg and anti-HBc IgM /anti-HCV positivity in GBV-C infected cases were 9.09%. The liver enzymes were normal in all of them. There was significant difference between GBV-C exposures with viral hepatitis co-infection, but there was no correlation between GBV-C exposure with gender, age, ethnicity, time on dialysis and history of blood transfusions. A relatively high frequency of positivity GBV-C-exposure among hemodialysis patients suggested that the transmission route for GBV-C may be nosocomial transmission, and via transfusions.

Conclusions:

The current study found a relatively high frequency of positivity GBV-C-exposure among the patients receiving hemodialysis in the area understudy. Nosocomial transmission seems to be the main route of GBV-C infection in the area.

Emerging viral diseases in kidney transplant recipients

Viruses are the most important cause of infections and a major source of mortality in Kidney Transplant Recipients (KTRs). These patients may acquire viral infections through exogenous routes including community exposure, donor organs, and blood products or by endogenous reactivation of latent viruses. Beside major opportunistic infections due to CMV and EBV and viral hepatitis B and C, several viral diseases have recently emerged in KTRs. New medical practices or technologies, implementation of new diagnostic tools, and improved medical information have contributed to the emergence of these viral diseases in this special population. The purpose of this review is to summarize the current knowledge on emerging viral diseases and newly discovered viruses in KTRs over the last two decades. We identified viruses in the field of KT that had shown the greatest increase in numbers of citations in the NCBI PubMed database. BKV was the most cited in the literature and linked to an emerging disease that represents a great clinical concern in KTRs. HHV-8, PVB19, WNV, JCV, H1N1 influenza virus A, HEV, and GB virus were the main other emerging viruses. Excluding HHV8, newly discovered viruses have been infrequently linked to clinical diseases in KTRs. Nonetheless, pathogenicity can emerge long after the discovery of the causative agent, as has been the case for BKV. Overall, antiviral treatments are very limited, and reducing immunosuppressive therapy remains the cornerstone of management.

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, 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.

Hepatitis G virus exposure in dialysis patients

BACKGROUND

Hepatitis G virus (HGV) is a blood-borne virus. The predominant route of its transmission is parenteral. The aim of this study was to assess the frequency of HGV exposure in haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients in Iran.

METHODS

This study was performed in a major dialysis centre in Tehran, Iran. The study cohort consisted of 77 patients on HD and 13 patients on CAPD. The presence of anti-HGV envelope protein E2 (anti-E2) in the blood serum, as determined by means of an ELISA assay, indicated HGV exposure. All patients were also screened for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis C antibody (anti-HCV). In patients who tested positive for anti-E2, HGV RNA was detected by RT-PCR using primers derived from the NS5A region of the viral genome.

RESULTS

In total, 3.89% of the HD patients and none of the CAPD patients tested positive for anti-E2. None of the patients tested positive for HGV RNA. The mean age of the anti-E2-positive patients was 53.3 +/- 26.5 years, with 66.66% having previously received blood transfusion. The mean duration of dialysis of the anti-E2-positive patients was 68 +/- 64 months. Co-infection with HCV or HBV was not observed in the anti-E2 positive patients.

CONCLUSION

The rate of exposure to HGV was low among the dialysis patients in our study. The appearance of anti-E2 was accompanied by clearance of serum HGV-RNA. No relationship was noted between HGV exposure and age, sex, history of blood transfusion, time on dialysis and HCV or HBV markers.