BACKGROUND: Human pegivirus-1 (HPgV-1) influences the pathogenesis and outcome of viral infections. We investigated the prevalence and impact of HPgV-1 due to the paucity of studies on Indian people living with HIV (PLHIV).
METHODS: Samples were collected from 347 treatment-naïve PLHIV; and 100 blood donors negative for HIV, HBV, and HCV. CD4+ T-cell and HIV-1 viral load were measured using flow-cytometry and quantitative polymerase chain reaction (qPCR), respectively. HPgV-1 was quantified and genotyped by qPCR and Sanger sequencing, respectively.
RESULTS: HPgV-1 viremia in PLHIV and controls was 11% (38/347) and 1% (1/100), respectively. We found HPgV-1 genotype-2a in PLHIV and genotype-2b in controls. Male preponderance was seen in HIV-1 mono-infection and co-infection groups (166 vs. 143 and 33 vs. 5; p < 0.0001). The peak prevalence of HPgV-1 was at 31-50 years (p = 0.02). CD4+ T-cell count (245.5 vs. 240; p = 0.59) and HIV-1 log viral load (4.7 vs. 4.9; p = 0.50) were not significantly different between the HIV-1 mono-infected and coinfected individuals. However, a direct correlation existed between HpgV-1 viral load and CD4+ T-cell count (r = 0.27, p = 0.05) and an inverse correlation with HIV-1 viral load (r = -0.21, p = 0.10).
CONCLUSIONS: This is the first study in India to estimate the HPgV-1 prevalence in PLHIV with the predominance of genotype-2a. HPgV-1 viremia had a moderate impact on CD4+ T-cells and HIV-1 viral load, which requires a longitudinal study to identify the beneficial influence on HIV-1 disease progression and outcome.

Coinfections with human pegivirus 1 (HPgV-1) are common in chronic hepatitis C virus (HCV) patients. However, little is known about whether HPgV-1 is affected by direct-acting antivirals during HCV treatment. Metagenomic analysis and reverse transcriptase-quantitative PCR (RT-qPCR) were performed on RNA from the plasma of 88 selected chronic HCV patients undergoing medical treatment. Twenty (23%) of these HCV patients had HPgV-1 coinfections and were followed by RT-qPCR during treatment and follow-up to investigate HPgV-1 RNA titers. Recovered sequences could be assembled to complete HPgV-1 genomes, and most formed a genotype 2 subclade. All HPgV-1 viral genomic regions were under negative purifying selection. Glecaprevir/pibrentasvir treatment in five patients did not consistently lower the genome titers of HPgV-1. In contrast, a one log10 drop of HPgV-1 titers at week 2 was observed in 10 patients during treatment with sofosbuvir-containing regimens, sustained to the end of treatment (EOT) and in two cases decreasing to below the detection limit of the assay. For the five patients treated with ledipasvir/sofosbuvir with the inclusion of pegylated interferon, titers decreased to below the detection limit at week 2 and remained undetectable to EOT. Subsequently, the HPgV-1 titer rebounded to pretreatment levels for all patients. In conclusion, we found that HCV treatment regimens that included the polymerase inhibitor sofosbuvir resulted in decreases in HPgV-1 titers, and the addition of pegylated interferon increased the effect on patients with coinfections. This points to the high specificity of protease and NS5A inhibitors toward HCV and the more broad-spectrum activity of sofosbuvir and especially pegylated interferon.
OBJECTIVE: Human pegivirus 1 coinfections are common in hepatitis C virus (HCV) patients, persisting for years. However, little is known about how pegivirus coinfections are affected by treatment with pangenotypic direct-acting antivirals (DAAs) against HCV. We identified human pegivirus by metagenomic analysis of chronic HCV patients undergoing protease, NS5A, and polymerase inhibitor treatment, in some patients with the addition of pegylated interferon, and followed viral kinetics of both viruses to investigate treatment effects. Only during HCV DAA treatment regimens that included the more broad-spectrum drug sofosbuvir could we detect a consistent decline in pegivirus titers that, however, rebounded to pretreatment levels after treatment cessation. The addition of pegylated interferon gave the highest effect with pegivirus titers decreasing to below the assay detection limit, but without clearance. These results reveal the limited effect of frontline HCV drugs on the closest related human virus, but sofosbuvir appeared to have the potential to be repurposed for other viral diseases.

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.

Anelloviridae and Human Pegivirus 1 (HPgV-1) blood burden have been postulated to behave as surrogate markers for immunosuppression in transplant recipients. Here, we assessed the potential utility plasma Torque teno virus (TTV), total Anelloviridae (TAV), and HPgV-1 load monitoring for the identification of allogeneic hematopoietic stem cell transplantation recipients (allo-HSCT) at increased risk of infectious events or acute graft versus host disease (aGvHD). In this single-center, observational study, plasma TTV DNA, TAV DNA, and HPgV-1 RNA loads were monitored in 75 nonconsecutive allo-HSCT recipients (median age, 54 years). Monitoring was conducted before at baseline or by days +30, +60, +90, +120, and +180 after transplantation. Pneumonia due to different viruses or Pneumocystis jirovecii, BK polyomavirus-associated haemorrhagic cystitis (BKPyV-HC), and Cytomegalovirus DNAemia were the infectious events considered in the current study. Kinetics of plasma TTV, TAV DNA, and HPgV-1 RNA load was comparable, with though and peak levels measured by days +30 and day +90 (+120 for HPgV-1). Forty patients (53%) developed one or more infectious events during the first 180 days after allo-HSCT, whereas 29 patients (39%) had aGvHD (grade II-IV in 18). Neither, TTV, TAV, nor HPgV-1 loads were predictive of overall infection or CMV DNAemia. A TTV DNA load cut-off ≥4.40 log10 (pretransplant) and ≥4.58 log10 (baseline) copies/mL predicted the occurrence of BKPyV-HC (sensitivity ≥89%, negative predictive value, ≥96%). TTV DNA loads ≥3.38 log10 by day +30 anticipated the occurrence of aGvHD (sensitivity, 90%; negative predictive value, 97%). Pretransplant HPgV-1 loads were significantly lower (p = 0.03) in patients who had aGvHD than in those who did not. Monitoring of TTV DNA or HPgV-1 RNA plasma levels either before or early after transplantation may be ancillary to identify allo-HSCT recipients at increased risk of BKPyV-HC or aGvHD.

Metagenomics revealed novel and routinely overlooked viruses, representing sources of unrecognized infections after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aim to describe DNA and RNA virus prevalence and kinetics in allo-HSCT recipients\' plasma for one year post HSCT. We included 109 adult patients with first allo-HSCT from 1 March 2017 to 31 January 2019 in this observational cohort study. Seventeen DNA and three RNA viral species were screened with qualitative and/or quantitative r(RT)-PCR assays using plasma samples collected at 0, 1, 3, 6, and 12 months post HSCT. TTV infected 97% of patients, followed by HPgV-1 (prevalence: 26-36%). TTV (median 3.29 × 105 copies/mL) and HPgV-1 (median 1.18 × 106 copies/mL) viral loads peaked at month 3. At least one Polyomaviridae virus (BKPyV, JCPyV, MCPyV, HPyV6/7) was detected in >10% of patients. HPyV6 and HPyV7 prevalence reached 27% and 12% at month 3; CMV prevalence reached 27%. HSV, VZV, EBV, HHV-7, HAdV and B19V prevalence remained <5%. HPyV9, TSPyV, HBoV, EV and HPg-V2 were never detected. At month 3, 72% of patients had co-infections. TTV and HPgV-1 infections were highly prevalent. BKPyV, MCPyV and HPyV6/7 were frequently detected relative to classical culprits. Further investigation is needed into associations between these viral infections and immune reconstitution or clinical outcomes.

Human pegivirus (HPgV) is a single-stranded RNA virus​ that is closely related to hepatitis C virus (HCV)​. HPgV has also been shown to infect patients with human immunodeficiency virus (HIV). The mechanisms and disease outcomes of HPgV infections are largely unknown, although it has been implicated in both cancer and neurological diseases. There are no established therapies for HPgV.
To estimate the prevalence of HPgV in a cohort of HCV/HIV co-infected patients undergoing treatment for HCV with direct acting antivirals (DAA) and investigate the effect of DAA therapy on HPgV infection.
RNA was extracted from plasma samples collected at time points before, during, and after DAA. HPgV RNA abundance was quantified by droplet digital PCR assays targeting the NS5A and 5\'UTR domains and confirmed by RT-qPCR. Clinical, demographic and treatment data were analysed.
HPgV RNA was detected and quantified in 26 of 100 patients\' plasma (26%) before starting DAA. Patients with detectable HPgV were more likely to be male, had higher peak HIV plasma levels, and a history of injection drug use. Patients receiving sofosbuvir/ledipasvir (n = 9) displayed significantly lower HPgV levels at time of DAA completion and had lower post-DAA HPgV rebound​ levels compared to patients receiving sofosbuvir/velpatasvir (n = 11) although both regimens significantly reduced viremia directly following DAA completion. Sustained suppression of HPgV was ​also observed among patients (n = 2) receiving pegylated-interferon.
HPgV RNA ​was frequently detected in HCV/HIV co-infected patients and ​was​ supressed by DAA and pegylated interferon therapies with sofosbuvir-ledipasvir showing greatest antiviral activity. These findings suggest potential treatment strategies for HPgV infections​.

Human pegivirus-1 (HPgV-1) is known for its protective role in HIV co-infected individuals. This immunomodulatory effect raised questions concerning the possible role of HPgV-1 infection and the risk of rejection in liver transplanted patients. We aimed to evaluate the possible protective effect of HPgV-1 on graft outcome of liver transplanted patients. A total of 283 patients were recruited. Formalin-fixed paraffin-embedded tissue samples were collected from the explanted liver. HBV-DNA, HCV-RNA, and HPgV-1-RNA were determined using PCR and multiplex RT-PCR assays. The clinical course of patients including the occurrence of acute cellular rejection was compared between HPgV-1-infected vs. uninfected patients. HBV-DNA, HCV-RNA and HPgV-1-RNA were detected in 42.6%, 4.9%, and 7.8% of samples, respectively. None of the HPgV-1-infected patients experienced graft rejection. Group LASSO logistic regression revealed that HPgV-1 infection was the only factor which significantly reduced the odds of graft rejection (OR = 0.5, 95% CI = 0.29-0.89). No significant association was found between the presence of HPgV-1 with HBV and HCV infections. The lack of graft rejection in HPgV-1-infected liver transplanted patients might indicate a possible role of this virus for graft surveillance. Since these are still preliminary findings, prospective studies should further elucidate the role of HPgV-1 in liver transplantation outcomes.

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 (HPgV-1), previously known as GB virus C (GBV-C) or hepatitis G virus (HGV), is a single-stranded positive RNA virus belonging to the genus Pegivirus of the Flaviviridae family. It is transmitted by percutaneous injuries (PIs), contaminated blood and/or blood products, sexual contact, and vertical mother-to-child transmission. It is widely prevalent in general population, especially in high-risk groups. HPgV-1 viremia is typically cleared within the first 1-2 years of infection in most healthy individuals, but may persist for longer periods of time in immunocompromised individuals and/or those co-infected by other viruses. A large body of evidences indicate that HPgV-1 persistent infection has a beneficial clinical effect on many infectious diseases, such as acquired immunodeficiency syndrome (AIDS) and hepatitis C. The beneficial effects seem to be related to a significant reduction of immune activation, and/or the inhabitation of co-infected viruses (e.g. HIV-1). HPgV-1 has a broad cellular tropism for lymphoid and myeloid cells, and preferentially replicates in bone marrow and spleen without cytopathic effect, implying a therapeutic potential. The paper aims to summarize the natural history, prevalence and distribution characteristics, and pathogenesis of HPgV-1, and discuss its association with other human viral diseases, and potential use in therapy as a biovaccine or viral vector.

The microbiome\'s role in transplantation has received growing interest, but the role of virome remains understudied. Pegiviruses are single-stranded positive-sense RNA viruses, historically associated with liver disease, but their path-ogenicity is controversial. In the transplantation setting, pegivirus infection does not seem to have a negative impact on the outcomes of solid-organ and hematopoietic stem cell transplant recipients. However, the role of pegiviruses as proxies in immunosuppression monitoring brings novelty to the field of virome research in immunocompromised individuals. The possible immunomodulatory effect of pegivirus infections remains to be elucidated in further trials.