RESISTANCE PROFILES TO ANTIRRETROVIRAL DRUGS IN HIV-1 NAIVE PATIENTS.

G. KIJAK;; S. PAMPURO;; M. GÓMEZ CARRILLO;; M. AVILA;; M. VILLAHERMOSA;; M. CUEVAS;; E. DELGADO;; R. NÁJERA .; H. SALOMÓN

San Francisco, USA

Conferencia; 7th CONFERENCE ON RETROVIRUS AND OPPORTUNISTIC INFECTIONS; 2000

Foundation for Retrovirology and Human Health

Introduction: The emergence of HIV-1 variants resistant to antiretroviral agents is a major cause of treatment failure. Furthermore, transmission of these viral variants has been reported. Objective: Study drug-resistance profiles in naive patients in Argentina. Materials and methods: Thirty-six HIV-1 seropositive asymptomatic drug naive individuals from Buenos Aires City were studied. The median viral load was 19000 copies/ml (Quantiplex HIV RNA 2.0, Chiron Co) and the median CD4– cell count was 316 cells/µl (Coulter XL, Coulter Co., Hialeah, Fl). Proviral DNA was extracted by the proteinase K method from lymphocytes. The viral protease (VP) and reverse transcriptase (RT) coding region of the HIV-1 pol gene were amplified by nested PCR and automatically sequenced (ABI PRISM DNA, Perkin Elmer). The sequences were compared to the HTLV III/LAI reference sequence. Results: Mutations were found in the VP region in 24 patients (70,59%), and in 30 patients (90,91%) in the RT region. Drug-associated mutations that were more frequently found were those on codons 10, 36, 63 and 77 in the VP region, and codons 211 and 214 in the RT region. Discussion and conclusion: Mutations detected in VP and RT regions were secondary mutations. These could have appeared as a result of the natural polymorphism of the virus or could reflect the characteristics of the virus with which the individual was infected. Similar studies have shown frequencies of drug-resistant variants ranging from 8 and 14%. The lower frequency detected in our population may be a result of the delay in beginning the use of antiretroviral drugs in Argentina. The antiretroviral therapy is increasing and the frequency of these variants in the naive population is expected to increase. However, results suggest that resistance studies are, for the moment, not necessary to be performed before antiretroviral therapy is initiated.