Genomic characterization of a Brazilian TT Virus isolate closely related to SEN virus-F

Diniz-Mendes, Leonardo; Devalle, Sylvie; Niel, Christian

doi:10.1590/s0074-02762004000300011

Cited by 15 publications

(15 citation statements)

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“…TTV was originally isolated from a patient with cryptogenic hepatitis and assumed that TTV may associated with hepatitis, although to date a causative effect has not been established [14]. in order to clear pathology of TTV infection, further studies should be performed to evaluate prevalence, genotyping, and pathogenicity of TTV infection.…”

Section: Discussionmentioning

confidence: 99%

“…Several researches showed the presence of this virus in patients infected by HCV and believed that TTV titer is correlated with severity of carcinoma attributed to HCV and therefore it can be used as a prognostic predictor for the outcome of chronic HCV infection [12][13]. In recent years, several studies performed to determine the prevalence, modes of transmission, and clinical relevance of TT virus [14]. However, no data are available in regards to circulating TTV genotypes in Iran.…”

Section: Introductionmentioning

confidence: 99%

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Phylogenetic Analysis of Torque Teno Virus in Hepatitis C Virus Infected Patients in Shiraz

Koohi

Ravanshad²,

Falahi

et al. 2012

Hepat Mon

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BackgroundTorque teno virus (TTV) was the first human Circoviridae detected in a Japanese patient with unknown hepatitis in 1997. Subsequently, several studies performed to evaluate different aspects of Torque teno virus pathogenesis.ObjectivesThe present study aimed to determine dominant genotype of Torque teno virus in chronic hepatitis disease using 5΄-UTR sequence among patients infected by hepatitis C virus in Shiraz – Iran.Patients and MethodsThe study conducted in 240 patients with chronic hepatitis C from Prof. Alborzi Clinical Microbiology Research Center. The presence of Torque teno virus DNA and its genotype in plasma was assessed by nested polymerase chain reaction using two primer sets for 5΄-UTR and N22 regions. Phylogenetic analysis was performed based on 5΄-UTR region.ResultsDNA of Torque teno virus was detected in 220 out of 240 (92 %) patients with chronic hepatitis C by the use of 5΄-UTR primer based PCR method and in 12 out of 240 (5%) by the use of N22 primer. Based on phylogenetic analysis it was shown that the Dominant genotype in this study was 11. Genotypes 1, 3, 17, and 22 were also detected. Some sequences could not be classified to a specific genotype.ConclusionsThe prevalence of Torque teno virus DNA in patients with chronic hepatitis C disease by the use of 5΄-UTR primer appeared to be higher compared to that revealed by N22 primer. We observed five genotypes among hepatitis C chronic patients in our study.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phylogenetic Analysis of Torque Teno Virus in Hepatitis C Virus Infected Patients in Shiraz

Koohi

Ravanshad²,

Falahi

et al. 2012

Hepat Mon

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“…The ORF2 coding sequences were amplified from plasmids containing TTV genomic DNA. The study included five strains of different species from four genogroups: Gr1 TTV3 HEL32, Gr2 TTV6 LTT6, Gr3a TTV13 3h, Gr3b TTV15 5A and Gr4 TTV29 ViPi08 (Diniz-Mendes et al, 2004;Kakkola et al, 2002;Niel et al, 2005). The details of each strain are depicted in Table S2; the primers used to amplify the ORF2 fragments are shown in Table S3.…”

Section: Methodsmentioning

confidence: 99%

Antigenic diversity and seroprevalences of Torque teno viruses in children and adults by ORF2-based immunoassays

Chen

Väisänen

Mattila

et al. 2013

Journal of General Virology

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Torque teno viruses (TTVs) circulate widely among humans, causing persistent viraemia in healthy individuals. Numerous TTV isolates with high genetic variability have been identified and segregated into 29 species of five major phylogenetic groups. To date, the diversity of TTV sequences, challenges in protein expression and the subsequent lack of serological assays have hampered TTV seroprevalence studies. Moreover, the antigenic relationships of different TTVs and their specific seroprevalences in humans remain unknown. For five TTV strains -belonging to different species of four genogroups -we developed, using recombinant glutathione Stransferase (GST)-fused TTV ORF2 proteins, glutathione-GST capture enzyme immunoassays (EIAs) detecting antibodies towards conformational epitopes. We then analysed serum samples from 178 healthy adults and 108 children; IgG reactivities were observed either towards a single strain or towards multiple strains, which pointed to antigenic distinction of TTV species. The overall seroprevalence for the five TTVs peaked at 43 % (18 of 42) in children 2-4 years of age, subsequently declined, and again reached 42 % (74 of 178) among adults. TTV6 species-specific IgG predominated in children, whereas that for TTV13 predominated in adults. During a 3 year follow-up of the same children, both species-specific seroconversions and seroreversions occurred. This is the first EIA-based study of different TTVs, providing a new approach for seroepidemiology and diagnosis of TTV infections. Our data suggest that different TTVs in humans may differ in antiviral antibody profiles, infection patterns and epidemiology.

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“…The TT virus has been detected in the serum of patients with non-A-C fulminant hepatitis, chronic hepatitis, cirrhosis and HCC [52,70,73,[78][79][80][81][82][83][84]. The virus is often present in the serum of individuals at high risk of infection with bloodborne viruses, such as intravenous drug abusers, and in patients with thalassaemia, haemophilia, receiving blood transfusions for any reason, or on chronic haemodialysis [79,82,83,85,86].…”

Section: Tt Virusmentioning

confidence: 99%

Hepatitis viruses (other than hepatitis B and C viruses) as causes of hepatocellular carcinoma: an update

Kew

2012

Journal of Viral Hepatitis

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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.

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Genomic characterization of a Brazilian TT Virus isolate closely related to SEN virus-F

Abstract: SEN virus (SENV) is a circular

Cited by 15 publications

References 32 publications

Phylogenetic Analysis of Torque Teno Virus in Hepatitis C Virus Infected Patients in Shiraz

Phylogenetic Analysis of Torque Teno Virus in Hepatitis C Virus Infected Patients in Shiraz

Antigenic diversity and seroprevalences of Torque teno viruses in children and adults by ORF2-based immunoassays

Hepatitis viruses (other than hepatitis B and C viruses) as causes of hepatocellular carcinoma: an update

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