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14th Annual Conference of the British HIV Association23–25 April 2008, Belfast |
GENOTYPIC ANTIRETROVIRAL DRUG RESISTANCE TESTING AT LOW PLASMA HIV-1 RNA LOADS IN THE UK
HIV Med 2008; 9(Suppl. 1):36 (abstract no. P96)
P Cane1, S Kaye2, E Smit3, P Tilston4, S Kirk5, J Shepherd6, M Hopkins7, H Zhang8 and AM Geretti9
1Health Protection Agency, London, UK; 2St Mary’s Hospital, London, UK; 3Heartlands Hospital, Birmingham, UK; 4Royal Infirmary, Manchester, UK; 5UCLH, London, UK; 6Royal Infirmary, Edinburgh, UK;
7Royal Liverpool University Hospital, Liverpool, UK; 8Addenbrooke’s Hospital, Cambridge, UK; 9Royal Free Hospital, London, UK
BACKGROUND: Antiretroviral drug resistance testing is recommended in HIV-1 patients failing therapy in order to inform treatment selection. Although guidelines and test manufacturers recommend a plasma HIV-1 RNA load of at least 500–1000 copies/mL for genotypic resistance testing to be performed, prompt management of virological failure could benefit from testing at lower viral load levels.
METHODS: Laboratories undertaking genotypic resistance testing were asked to provide figures for the number of resistance tests undertaken at HIV RNA loads <2000 copies/mL, the success rates of such tests and the extent of resistance detected, all stratified for RNA load levels.
RESULTS: Of the replies received, most laboratories were attempting resistance testing at viral RNA levels below the recommended guidelines, with variable success (e.g. 0–67% of samples for HIV-1 RNA loads of 50–100 copies/mL) and with variable levels of resistance detected.
CONCLUSIONS: This audit of current practice in the UK for undertaking genotypic resistance tests at viral loads <1000 copies/mL highlights the widespread use of such testing outside the BHIVA guidelines. The limitations of results obtained from such testing will be discussed.
2008-04-23
P96
Copyright © 2008 - 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