Clinical and molecular aspects of human pegiviruses in the interaction host and infectious agent

Background

Human pegivirus 1 (HPgV-1) is a Positive-sense single-stranded RNA (+ ssRNA) virus, discovered in 1995 as a Flaviviridae member, and the closest human virus linked to HCV. In comparison to HCV, HPgV-1 seems to be lymphotropic and connected to the viral group that infects T and B lymphocytes. HPgV-1 infection is not persuasively correlated to any known human disease; nevertheless, multiple studies have reported a connection between chronic HPgV-1 infection and improved survival in HPgV-1/HIV co-infected patients with a delayed and favorable impact on HIV infection development. While the process has not been thoroughly clarified, different mechanisms for these observations have been proposed. HPgV-1 is categorized into seven genotypes and various subtypes. Infection with HPgV-1 is relatively common globally. It can be transferred parenterally, sexually, and through vertical ways, and thereby its co-infection with HIV and HCV is common. In most cases, the clearance of HPgV-1 from the body can be achieved by developing E2 antibodies after infection.

Main body

In this review, we thoroughly discuss the current knowledge and recent advances in understanding distinct epidemiological, molecular, and clinical aspects of HPgV-1.

Conclusion

Due to the unique characteristics of the HPgV-1, so advanced research on HPgV-1, particularly in light of HIV co-infection and other diseases, should be conducted to explore the essential mechanisms of HIV clearance and other viruses and thereby suggest novel strategies for viral therapy in the future.

Clinical practice guideline management of blood borne viruses within the haemodialysis unit

Some people who are receiving dialysis treatment have virus infection such as hepatitis B, hepatitis C and/or HIV that is present in their blood. These infections can be transmitted to other patients if blood is contaminated by the blood of another with a viral infection. Haemodialysis is performed by passing blood from a patient through a dialysis machine, and multiple patients receive dialysis within a dialysis unit. Therefore, there is a risk that these viruses may be transmitted around the dialysis session. This documents sets out recommendations for minimising this risk.There are sections describing how machines and equipment should be cleaned between patients. There are also recommendations for dialysing patients with hepatitis B away from patients who do not have hepatitis B. Patients should be immunised against hepatitis B, ideally before starting dialysis if this is possible. There are guidelines on how and when to do this, for checking whether immunisation is effective, and for administering booster doses of vaccine. Finally there is a section on the measures that should be taken if a patient receiving dialysis is identified as having a new infection of hepatitis B, hepatitis C or HIV.

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.

Assessment of synthetic chimeric multiple antigenic peptides for diagnosis of GB virus C infection

The use of synthetic peptides of both structural and nonstructural proteins of GB virus C (GBV-C) has been studied for the development of new systems to diagnose infection caused by this virus. In an attempt to increase the antigenicity of linear peptide sequences, chimeric multiple antigenic peptides (MAPs) containing epitopes from E2, NS4, and NS5 GBV-C proteins have been synthesized. The synthetic constructs were evaluated by ELISA to establish whether the epitopes in chimeric branched peptides are more efficiently recognized by the specific antibodies compared to the monomeric linear sequences. Moreover, we have investigated the application of a commercial biosensor instrument for the detection of antibodies against the GBV-C in human serum samples. The results of the immunoassays reported in this work highlight the usefulness of synthetic tetrameric branched peptides containing sequences from envelope and nonstructural GBV-C proteins for the diagnosis of GBV-C infection. The potential clinical value of the MAP(4)(E2-NS5a) for the serodiagnosis of GBV-C infection was demonstrated, thus providing the basis for performing prevalence studies of the infection among the hemodialyzed and hepatitis C virus (HCV)-infected population.