RT mutations patterns associated with cross resistance to NRTI or NNRTI in samples of experienced HIV patients from Buenos Aires

FIGUEROA, MI; SUED, O; LAUFER N; MORETTI F; PAMPURO S,; GOMEZ CARRILLO, M; SALOMÓN H; CAHN P

Mexico DF, Mexico

Congreso; XVII International AIDS Conference; 2008

International Aids Society

Background: Resistance mutations increase with ARV use. Surveillance studies are needed to evaluate potential usefulness of new drugs in experienced patients. Objective: To describe the prevalence of RT mutations associated with cross resistance to NRTI or NNRTI ARVs in one Resistance Database in Buenos Aires. Methods: We used data sequences from 2959 samples of HIV experienced patients collected at the Argentinean National Reference Center for AIDS (2001-2007). Virco®Type was used for genotyping. We analyzed RT mutations patterns associated with cross-resistance to NRTI/NNRTI. MultiNRTI resistance mutations were defined as any of 65R, 69ins, 151M or simultaneous presence of 6 TAMs (41L, 67N, 70R, 210W, 215Y/F, 219Q/E)(IAS 2007). MultiNNRTI resistance was considered when 103N was present. Results: 238 samples (8%;95%CI:7-9.1) were resistant to NRTI. Mutations 65R, T69ins, Q151M and 6TAMs were present in 2.5%, 1.32%, 3.3% and 1.4%., respectively. Significant changes were seen for 65R and 151M, with an increase during 2003-2004 and a tendency to diminish thereafter. For NNRTI 572 (33.2%; 95%CI 31.5-34.9) of the patients presented the mutation 103N, without significant changes over the period. Conclusions: MultiNRTI resistance is prevalent in our database. An 8% of our experienced patients have no NRTI options and one third are resistant to first-generation NNRTIs. Introduction of tenofovir (in 2003) could have prompted the emergency of 65R mutation. Resistance mutations increase with ARV use. Surveillance studies are needed to evaluate potential usefulness of new drugs in experienced patients. Objective: To describe the prevalence of RT mutations associated with cross resistance to NRTI or NNRTI ARVs in one Resistance Database in Buenos Aires. Methods: We used data sequences from 2959 samples of HIV experienced patients collected at the Argentinean National Reference Center for AIDS (2001-2007). Virco®Type was used for genotyping. We analyzed RT mutations patterns associated with cross-resistance to NRTI/NNRTI. MultiNRTI resistance mutations were defined as any of 65R, 69ins, 151M or simultaneous presence of 6 TAMs (41L, 67N, 70R, 210W, 215Y/F, 219Q/E)(IAS 2007). MultiNNRTI resistance was considered when 103N was present. Results: 238 samples (8%;95%CI:7-9.1) were resistant to NRTI. Mutations 65R, T69ins, Q151M and 6TAMs were present in 2.5%, 1.32%, 3.3% and 1.4%., respectively. Significant changes were seen for 65R and 151M, with an increase during 2003-2004 and a tendency to diminish thereafter. For NNRTI 572 (33.2%; 95%CI 31.5-34.9) of the patients presented the mutation 103N, without significant changes over the period. Conclusions: MultiNRTI resistance is prevalent in our database. An 8% of our experienced patients have no NRTI options and one third are resistant to first-generation NNRTIs. Introduction of tenofovir (in 2003) could have prompted the emergency of 65R mutation.