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10th Anniversary Conference Of The British HIV Association [BHIVA]15 – 17 April 2004, City Hall, Cardiff, UK |
[AUTHOR(S):] NE Mackie1, C Sabin2, S Dustan1, JR Clarke1, JN Weber1
1 St Mary's Hospital, Jefferiss Wing Laboratories, Imperial College London, 2 Royal Free and University College Medical School, London, UK
BHIVA Conf 2004 Apr 15-17;10:O14
BACKGROUND: Resistance to antiretroviral drugs is a major factor contributing to failure of therapy.
METHODS: Genotyping of 795 samples from antiretroviral therapy (ART)-experienced adults submitted from July 1999 to end 2003 was analysed. Frequency of mutations was compared year on year by χ2-tests.
RESULTS: Key mutations associated with reduced ART sensitivity were most common in 1999 (85.9%), but declined to 74% in 2003 (P= 0.06). The prevalence of nucleoside analogue reverse transcriptase inhibitor (NRTI) resistance mutations was relatively constant (average 68.2%). Non-NRTI mutation frequencies (range 45.3–56%) did not change significantly. Mutations associated with protease inhibitor (PI) resistance declined from 56.3% to 17.2% (P=0.0001). There were significant declines in two-class (NRTI plus PI) (P=0.0001) and three-class resistance (P=0.001), while non-B clade HIV and recombinants become increasingly prevalent (21.6%–33.5%, P=0.004).
CONCLUSIONS: Despite some reduction, mutations in HIV pol remain common. NRTI-associated mutations are still most common. The reduction in PI-associated mutations may reflect decreased first-line use of PIs, shifts to using more potent boosted-PI regimens and introduction of new agents with less well described mutation pathways. Increasing uptake of resistance testing and alterations in clinic demographics may contribute to some of the changes.
PRESENTING AUTHOR: NE Mackie
040415
O14
Copyright © 2004 - British HIV Association (BHIVA) Reproduction of this abstract (other than one copy for personal reference) must be cleared through the BHIVA Organising Secretariat 1 Mountview Court, 310 Friern Barnet Lane, London N20 0LD