title: Highly sensitive plasma RNA quantification by real-time PCR in HIV-2 group A and group B infection.
abstract: Plasma HIV-2 viral load has been reported as predictive of AIDS in HIV-2 infected patient but the lack of sensitivity of the current HIV2 viral load assay is a limitation for the monitoring of the HIV-2-infected patients.
  
  
  OBJECTIVE
  To validate a new quantification assay based on a synthetic HIV-2 RNA transcript and real-time PCR with primers and probes selected in the LTR region, together with high-performance reagents and a protective RNA carrier.
  
  
  METHODS
  We quantified 23 HIV-2 group A and B supernatants and 58 plasma samples with our TAQMAN-PCR assay and compared the results to those of our previously published in a real time reference PCR performed onto Light Cycler technology, the LC-PCR with a detection of 2.0 log10 copies/ml.
  
  
  RESULTS
  The performance of TAQMAN-PCR was significantly improved, yielding a detection limit of 17 RNA copies/ml. There was a major difference (1-5 log10 copies/ml) between LC-PCR and TAQMAN-PCR values for HIV-2 group B supernatants. Twenty-six of 27 plasma samples with levels higher than 2.0 log10 copies/ml in LC-PCR were positive by TAQMAN-PCR. Ten of the 31 plasma samples below the LC-PCR detection limit were quantifiable with the TAQMAN-PCR.
  
  
  CONCLUSIONS
  The new primers and probe in the LTR region can circumvent HIV-2 diversity, making our method suitable for use in HIV-2 group B-infected patients. Use of a high-performance RT enzyme and RNA carrier protection contributed to improving the detection limit. This study confirms that plasma viral load is lower than 17 copies/ml in a large number of HIV-2-infected patients.
authors.affiliation: Service de virologie, CHU Saint Louis, Faculté de Médecine Paris - Diderot, INSERM U 941 Paris, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Delarue
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Didier
authors.forename: Florence
authors.initials: F
authors.lastname: Damond
authors.forename: Diane
authors.initials: D
authors.lastname: Ponscarme
authors.forename: Karen
authors.initials: K
authors.lastname: Brengle-Pesce
authors.forename: Matthieu
authors.initials: M
authors.lastname: Resche-Rigon
authors.forename: Muriel
authors.initials: M
authors.lastname: Vray
authors.forename: Marie
authors.initials: M
authors.lastname: Gueudin
authors.forename: François
authors.initials: F
authors.lastname: Simon
mesh_terms: D017931:DNA Primers / Q000235:genetics; D015658:HIV Infections / Q000821:virology*; D016325:HIV Long Terminal Repeat / Q000235:genetics; D015498:HIV-2 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D015345:Oligonucleotide Probes / Q000235:genetics; D010949:Plasma / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D019562:Viral Load / Q000379:methods*
chemical_list: D017931:DNA Primers; D015345:Oligonucleotide Probes; D012367:RNA, Viral
keywords: HIV-2; Natural history; Viral load