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14th International AIDS ConferenceBarcelona, Spain - July 7-12, 2002 |
Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10027)
Aleixo AW, Greco DB, Tanuri A
Immunology and Molecular Laboratory - School of Medicine, Belo Horizonte, Brazil
BACKGROUND: HIV-1 subtypes A, B, C, D and F have been reported in Brazil. We have investigated the subtype prevalence in a HIV-infected cohort on HAART from a Reference Center for AIDS in Belo Horizonte/Brazil using a combination of molecular screening assays and DNA sequencing.
METHODS: 221 patients were segregated in groups of success and therapeutic failure by longitudinal analysis of HIV-1 viral load (VL) and T CD4+ count. The 297bp of viral protease (prt) gene was amplified by nested PCR using cDNA templates from VL. The restriction fragment length polymorphism (RFLP) was used to predict the HIV-1 phylogroups. The non B HIV-1 and potential mixed infection segregated by enzyme Alu-I on RFLP assay were analysed by sequence analysis to confirm the specific phylogroups.
RESULTS: The RFLP analysis segregated restriction patterns predictors for subtype B (n=200), non B (n=6) and dual infection (n=15) on the success (n=101) and failure (n=120) groups. All non B subtypes and 13 of dual infection were in the failure group (p<0,005). Albeit the phylogenetic analysis confirmed only one subtype F and 19 actually belonged to subtype B. Sequencing revealed 71 different polymorphisms in the prt gene with a mean of 3.5/patient and 18 of them were associated with drug resistance. There were transitional (n=4) and transnversional (n=16) nucleotide substitution in theAlu-I restriction site (codons 71, 72 and 94) in all B samples. The transition observed at codon 19 has gained a new site Alu-I restriction in two samples.
CONCLUSIONS: Our molecular data suggest that polimorphisms selected by therapy can change Alu-I restriction sites and although this genetic diversity does not represent distinct subtypes, it can cause misunderstanding in restricion analysis in samples from individuals on HAART.
020707
A10027
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