Cellular HIV-1 DNA levels in drug sensitive strains are equivalent to those in drug resistant strains in newly-diagnosed patients in Europe.
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.
Demetriou
Victoria L
VL
Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
van de Vijver
David A M C
DA
Kousiappa
Ioanna
I
Balotta
Claudia
C
Clotet
Bonaventura
B
Grossman
Zehava
Z
Jørgensen
Louise B
LB
Lepej
Snjezana Z
SZ
Levy
Itzchak
I
Nielsen
Claus
C
Paraskevis
Dimitrios
D
Poljak
Mario
M
Roman
Francois
F
Ruiz
Lidia
L
Schmidt
Jean-Claude
JC
Vandamme
Anne-Mieke
AM
Van Laethem
Kristel
K
Vercauteren
Jurgen
J
Kostrikis
Leondios G
LG
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
D017931:DNA Primers; D004279:DNA, Viral; D019713:Receptors, CCR5