[HLA-B*5701 and hypersensitivity reactions to abacavir. Study methods and clinical relevance].

Hypersensitivity reactions to abacavir occur in 5-8% of patients starting treatment with this drug and limits future treatment. Some host genetic factors, especially the HLA-B*5701 allele, have been identified as risk factors for hypersensitivity reaction in Caucasians. Consequently, the possibility of routine implementation of a genetic test to rule out the presence of this allele has been proposed to achieve a personalized therapeutic profile.

Risk of selecting de novo drug-resistance mutations during structured treatment interruptions in patients with chronic HIV infection.

Background: Structured treatment interruption (STI) may allow viral replication in the presence of decreased plasma drug levels, with risk of selection of resistance mutations.

Methods: For patients recruited for an STI study, genotypic resistance testing was performed at baseline (before receipt of any treatment), immediately before the STI, and 2 weeks after each interuption of therapy.

Results: During 20 (18%) of 112 STI cycles (95% CI, 11%-26%), resistance mutations were selected; 6% of the mutations were de novo (i.

Similar HIV-1 evolution and immunological responses at 10 years despite several therapeutic strategies and host HLA Types.

Two sexual partners infected with related HIV-1 viruses and enrolled in different therapeutic strategies including structured treatment interruptions (STI) provided us an opportunity to compare long term (10 years) viral genetic evolution for closely related isolates in different hosts. HLA loci were molecularly typed and different genetic markers were studied. The viral genetic evolution was studied by sequencing pol and env genes.