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Prevalence of Resistance to at Least 1 Drug in Treated HIV-infected Patients with Viral Load >1000 Copies/mL in 2004: A French Nationwide Study
Dominique Costagliola*1, L Morand-Joubert2, L Assoumou1, V Brodard3, J C Plantier4, C Delaugerre5, V Mackiewicz6, S Saidi1, F Brun-Vezinet7, B Masquelier8, and the ANRS AC11 Resistance Study Group
1U720 INSERM and Univ Pierre et Marie Curie, Paris, France; 2Hosp St Antoine, Paris, France; 3Univ Hosp, Reims, France; 4Univ Hosp, Rouen, France; 5Necker Univ Hosp, Paris, France; 6Univ Hosp Paul Brousse, Villejuif, France; 7Hosp Bichat, Paris, France; and 8Univ Hosp Bordeaux, France
Background: Surveillance of resistance in treated patients with detectable viral
load is important both because of the risk of spreading resistant viruses and
to evaluate proportion of patients for which new drugs with minimal
cross-resistance are needed
Methods: Resistance mutations were systematically sought
in samples from 481 consecutive treated HIV-infected patients with viral load
>1000 copies/mL seen in 27 specialized centers
throughout metropolitan France and 1 in Switzerland with a prescription for
viral load in June 2004. The protease, reverse transcriptase (RT), and gp41
genes of plasma virions were sequenced. Primary and secondary protease, RT, and
gp41 gene mutations were identified from the International AIDS Society
resistance testing USA panel. The genotype results
were interpreted for each drug by using the ANRS algorithm (July 2005 version
13). Weighted analyses were used to derive representative estimates of the
percentage of patients with resistance mutations and resistance to a drug with
the weight base on the number of patients followed in each center. Results are
expressed with median and interquartile range or percentage.
Results: Known duration of HIV infection was 12 years (8.0 to 16.0), patients had
been exposed to 9 ART (6 to 12), 12.3% had received enfuvirtide
(T20). The viral load was 4.0 (3.5 to 4.7) copies/mL
and the CD4 cell count 265 (145 to 430)/mm3. In
terms of resistance mutations, 4 (1 to 6) mutations to nucleoside reverse
transcriptase inhibitors (NRTI) were detected, 3 (2 to 6) to protease inhibitors (PI) and 0 (0 to 1) to non-NRTI (NNRTI).
Resistance to at least 1 ART was observed in 88.8% of patients, to at least 1
NRTI in 77.2%, 1 PI in 66.5%, and 1 NNRTI in 50.3%. The number of drugs to
which the viruses were not sensitive was 3 NRTI (1 to 5), 1 PI (0 to 5), and 1
NNRTI (0 to 2). The percentage of patients with viruses with no sensitive drugs
in the NRTI family was 18.3%; 6.5% in the PI family; 49.1% in the NNRTI family;
and 6.6% for T20. Overall 19.8% of patients had viruses with no sensitive drugs
in at least 2 families of drugs.
Conclusions: In France, 80.3 % of patients followed in hospital were receiving ART in
2004 and only 21.3% had a viral load >1000 copies/mL.
Therefore, although resistance to at least 1 ART was frequent in treated
patients with a viral load >1000 copies/mL, only
18.9% of treated patients could contribute to the transmission of resistant
viruses and among those in care, only 3.4% of patients with complete resistance
to at least 2 families of drugs are in urgent need of new drugs with limited
cross-resistance.
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