AEGiS-14IAC: Molecular evidence that polymorphisms in HIV-1 protease selected in patients on HAART can cause misunderstanding in the subtype caracterization by restriction analysis assay.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Molecular evidence that polymorphisms in HIV-1 protease selected in patients on HAART can cause misunderstanding in the subtype caracterization by restriction analysis assay.

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.

Keywords: AEGIS, HIV Protease, Antiretroviral Therapy, Highly Active, HIV-1, Polymorphism (Genetics), HIV Infections, Variation (Genetics), Polymorphism, Restriction Fragment Length, HIV Protease Inhibitors, Prevalence, HIV-1 Reverse Transcriptase, Polymerase Chain Reaction, CD4 Lymphocyte Count, Codon, Brazil, Human, analysis, genetics

020707
A10027