GB virus C

GB virus C (GBV-C) is a species of virus in the "Flaviviridae" family which has not yet been assigned to a genus, is known to infect humans, but is not known to cause human disease. There have been reports that HIV patients coinfected with GBV-C can survive longer than those without GBV-C, but the patients may be different in other ways. There is current active research into the virus' effects on the immune system in patients coinfected with GBV-C and HIV. [cite journal |author=Mosam A, Sathar MA, Dawood H, Cassol E, Esterhuizen TM, Coovadia HM |title=Effect of GB virus C co-infection on response to generic HAART in African patients with HIV-1 clade C infection |journal= AIDS|volume=21 |issue=10 |pages=1377–1379 |year=2007 |pmid=17545721 |doi=10.1097/QAD.0b013e3281532cb8] [cite journal |author=Jung S, Eichenmüller M, Donhauser N, "et al" |title=HIV entry inhibition by the envelope 2 glycoprotein of GB virus C |journal=AIDS |volume=21 |issue=5 |pages=645–7 |year=2007 |pmid=17314528 |doi=10.1097/QAD.0b013e32803277c7]

History

Hepatitis G virus and GB virus C (GBV-C) are RNA viruses that were independently identified in 1995, and were subsequently found to be two isolates of the same virus. [ [http://cpmcnet.columbia.edu/dept/gi/hepG.html Hepatitis Central] ] [cite journal | author = Birkenmeyer LG, Desai SM, Muerhoff AS, Leary TP, Simons JN, Montes CC, Mushahwar IK | title = Isolation of a GB virus-related genome from a chimpanzee | journal = J. Med. Virol. | volume = 56 | issue = 1 | pages = 44–51 | year = 2010 | pmid = 9700632 | doi = | accessdate = ] Although GBV-C was initially thought to be associated with chronic hepatitis, extensive investigation failed to identify any association between this virus and any clinical illness.

Taxonomy

GBV-C is a member of the "Flaviviridae" family and is phylogenetically related to hepatitis C virus but appears to replicate primarily in lymphocytes, and poorly if at all in hepatocytes. [cite journal | author = Leary TP, Muerhoff AS, Simons JN, Pilot-Matias TJ, Erker JC, Chalmers ML, Schlauder GG, Dawson GJ, Desai SM, Mushahwar IK | title = Sequence and genomic organization of GBV-C: a novel member of the flaviviridae associated with human non-A-E hepatitis | journal = J. Med. Virol. | volume = 48 | issue = 1 | pages = 60–7 | year = 1996 | pmid = 8825712 | doi = 10.1002/(SICI)1096-9071(199601)48:1<60::AID-JMV10>3.0.CO;2-A | accessdate = ] cite journal |author=Thurner C, Witwer C, Hofacker IL, Stadler PF |title=Conserved RNA secondary structures in Flaviviridae genomes |journal=J. Gen. Virol. |volume=85 |issue=Pt 5 |pages=1113–24 |year=2004 |month=May |pmid=15105528 |doi= |url=http://vir.sgmjournals.org/cgi/pmidlookup?view=long&pmid=15105528] GBV-A and GBV-B are probably Tamarin viruses, while GBV-C infects humans. [cite journal | author = Simons JN, Desai SM, Schultz DE, Lemon SM, Mushahwar IK | title = Translation initiation in GB viruses A and C: evidence for internal ribosome entry and implications for genome organization | journal = J. Virol. | volume = 70 | issue = 9 | pages = 6126–35 | year = 1996 | pmid = 8709237 | doi = | accessdate = ]

Human infection

The majority of immune-competent individuals appear to clear GBV-C viraemia within the first few years following infection and although the time interval between GBV-C infection and clearance of viraemia (detection of GBV-C RNA in plasma) is not known, infection may persist for decades in some individuals.

Approximately 2% of healthy US blood donors are viraemic with GBV-C, and up to 13% of blood donors have antibodies to E2 protein, indicating prior infection.

Parenteral, sexual and vertical transmission of GBV-C have all been documented, and because of shared modes of transmission, individuals infected with HIV are commonly co-infected with GBV-C. Among people with HIV infection, the prevalence of GBV-C viraemia ranges from 14 to 43%.cite journal |author=George SL, Varmaz D, Stapleton JT |title=GB virus C replicates in primary T and B lymphocytes |journal=J. Infect. Dis. |volume=193 |issue=3 |pages=451–4 |year=2006 |pmid=16388494 |doi=10.1086/499435]

Some studies have suggested that co-infection with GBV-C will actually slow the progression of HIV disease. [cite journal |author=Zhang W, Chaloner K, Tillmann HL, Williams CF, Stapleton JT |title=Effect of early and late GB virus C viraemia on survival of HIV-infected individuals: a meta-analysis |journal=HIV Med. |volume=7 |issue=3 |pages=173–80 |year=2006 |pmid=16494631 |doi=10.1111/j.1468-1293.2006.00366.x |url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=1464-2662&date=2006&volume=7&issue=3&spage=173]

References

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