AEGiS-14IAC: Phenotypic resistance testing for RT inhibitors with a biochemical method - problems and potential solutions.

14th International AIDS Conference


Barcelona, Spain - July 7-12, 2002

DonateNow
Print this article

Phenotypic resistance testing for RT inhibitors with a biochemical method - problems and potential solutions.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. B10184)

Obermeier MJ, Opgen-Rhein MH, Huber C, Eberle J
Max von Pettenkofer Institut LMU Muenchen, Munich, Germany

BACKGROUND: Viral resistance to ART is a common cause for therapy failure. Different types of assays have been developed to prove susceptibility of HIV strains to various drugs: Genotypic, phenotypic cell culture based, and biochemical resistance tests.

METHODS: The ultra-sensitive RT assay of H. Pyra et al. (PNAS 91: 1544-1548) was modified. To improve sensitivity for inhibitors the reverse transcribed sequence was lengthened and now this assay is very susceptible to NRTIs. However unspecific inhibitors of reverse transcription in plasma decrease the sensitivity of the assay about 1000 fold. To remove unspecific inhibitors, affinity binding of virions to magnetic beads was applied. Beads were coated with monoclonal antibodies against HLA-DR,DP, and DQ. In a second step virions were trapped on the beads via HLA molecules on the surface of the virions. Removal of the inhibitors was achieved by consecutive washing.

RESULTS: With this method we could measure resistance against AZT and 3TC of a strain with the following mutations: A62V, K65R, T69I, V75I, F77L, K101E, Y115F, F116Y, V118I, Q151M, Y181C, G190A, K219Q. (see figure 1) This is the first report for a biochemical assay to analyse AZT resistance without further modifications (Lennerstrand et al. 7th conference on retroviruses, Abstract 734). By introduction of this purification step it was possible to remove about 90% of the inhibitors. Discussion: Further experience with this method has to be collected. Still a problem is resistance testing directly out of patients' plasma, as even the introduced removal of unspecific inhibitors seems to be not potent enough. [Image not included]

Keywords: AEGIS, Zidovudine, Lamivudine, HIV Infections, Research Design, Mutation, Virion, Human, antagonists & inhibitors, genetics, methodsKWDaegis,zidovudine,lamivudine,hivinfections,researchdesign,mutation,virion,human,antagonists&inhibitors,genetics,methods

020707
B10184

Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.