title: Cellular HIV-1 DNA levels in drug sensitive strains are equivalent to those in drug resistant strains in newly-diagnosed patients in Europe.
abstract: BACKGROUND
  HIV-1 genotypic drug resistance is an important threat to the success of antiretroviral therapy and transmitted resistance has reached 9% prevalence in Europe. Studies have demonstrated that HIV-1 DNA load in peripheral blood mononuclear cells (PBMC) have a predictive value for disease progression, independently of CD4 counts and plasma viral load.
  
  
  RESULTS
  Molecular-beacon-based real-time PCR was used to measure HIV-1 second template switch (STS) DNA in PBMC in newly-diagnosed HIV-1 patients across Europe. These patients were representative for the HIV-1 epidemic in the participating countries and were carrying either drug-resistant or sensitive viral strains. The assay design was improved from a previous version to specifically detect M-group HIV-1 and human CCR5 alleles. The findings resulted in a median of 3.32 log(10) HIV-1 copies/10(6) PBMC and demonstrated for the first time no correlation between cellular HIV-1 DNA load and transmitted drug-resistance. A weak association between cellular HIV-1 DNA levels with plasma viral RNA load and CD4(+) T-cell counts was also reconfirmed. Co-receptor tropism for 91% of samples, whether or not they conferred resistance, was CCR5. A comparison of pol sequences derived from RNA and DNA, resulted in a high similarity between the two.
  
  
  CONCLUSIONS
  An improved molecular-beacon-based real-time PCR assay is reported for the measurement of HIV-1 DNA in PBMC and has investigated the association between cellular HIV-1 DNA levels and transmitted resistance to antiretroviral therapy in newly-diagnosed patients from across Europe. The findings show no correlation between these two parameters, suggesting that transmitted resistance does not impact disease progression in HIV-1 infected individuals. The CCR5 co-receptor tropism predominance implies that both resistant and non-resistant strains behave similarly in early infection. Furthermore, a correlation found between RNA- and DNA-derived sequences in the pol region suggests that genotypic drug-resistance testing could be carried out on either template.
authors.affiliation: Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Demetriou
authors.forename: David A M C
authors.initials: DA
authors.lastname: van de Vijver
authors.forename: Ioanna
authors.initials: I
authors.lastname: Kousiappa
authors.forename: Claudia
authors.initials: C
authors.lastname: Balotta
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Clotet
authors.forename: Zehava
authors.initials: Z
authors.lastname: Grossman
authors.forename: Louise B
authors.initials: LB
authors.lastname: Jørgensen
authors.forename: Snjezana Z
authors.initials: SZ
authors.lastname: Lepej
authors.forename: Itzchak
authors.initials: I
authors.lastname: Levy
authors.forename: Claus
authors.initials: C
authors.lastname: Nielsen
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Paraskevis
authors.forename: Mario
authors.initials: M
authors.lastname: Poljak
authors.forename: Francois
authors.initials: F
authors.lastname: Roman
authors.forename: Lidia
authors.initials: L
authors.lastname: Ruiz
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Schmidt
authors.forename: Anne-Mieke
authors.initials: AM
authors.lastname: Vandamme
authors.forename: Kristel
authors.initials: K
authors.lastname: Van Laethem
authors.forename: Jurgen
authors.initials: J
authors.lastname: Vercauteren
authors.forename: Leondios G
authors.initials: LG
authors.lastname: Kostrikis
mesh_terms: D000328:Adult; D000483:Alleles; D001483:Base Sequence; D017931:DNA Primers; D004279:DNA, Viral / Q000235:genetics*; D024882:Drug Resistance, Viral; D005060:Europe; D005260:Female; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D019713:Receptors, CCR5 / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D019562:Viral Load; D056189:Viral Tropism
chemical_list: D017931:DNA Primers; D004279:DNA, Viral; D019713:Receptors, CCR5