[Genotypic resistance of human immunodeficiency virus type 1 in patients with therapeutic failure].

Background And Objective: The aim of the present study is to analyse both the frequency of resistances to the different antiretrovirals and the implication of the mayor associated resistance mutations in a group of patients with therapeutic failure.

Patients And Method: He sequence of protease (pr) and retrotranscriptase (rt) of HIV-1 isolated from blood were analysed in 284 patients. The viral load level was between 500 and 106 copies/ml. The genotype was made with TRUGENETM HIV-1 kit, which is based in the synthesis of cDNA by RT-PCR and sequenciation of this cDNA by PCR.

Results: 39,78% of the patients have not associated resistance mutations in the antiretrovirales used in the treatment, including 73 patients who have not associated resistance mutations to antiretrovirales. 60,2% of the patients have associated resistance mutations in the antiretrovirales used in the treatment. In the patients multitreated, 88,2% presented resistance to some and 53% presented genotypic resistance or possible resistance to some of the TARGA treatment.

Conclusions: The prevalence of resistance mutations in patients with therapeutic failure is bigger than 50% with both genes.