Frequency and diversity of human immunodeficiency virus type 1 mutations associated with antiretroviral resistance among patients from Southern Brazil failing highly active antiretroviral therapy (HAART)

The human immunodeficiency virus type 1 (HIV-1) epidemic in Brazil is spreading to small municipalities as well as the innermost parts of the country and scarce information has been reported on the frequency of HIV-1 resistance-associated mutations in these areas. To determine the frequency and diversity of the HIV-1 antiretroviral resistance-associated mutations among patients failing highly active antiretroviral therapy from Londrina in Southern Brazil, 127 HIV-1 genotyping tests that were assayed during January 2000 to July 2008 from 108 patients were evaluated. Sixty-nine patients (63.9%) were male and 39 (36.1%) were female and the age ranged from 10 to 68 years (mean, 40.8±9.2). All of them showed at least one HIV-1 antiretroviral resistance-associated mutation and in 72 (56.7%) genotyping tests, mutations for the three antiretroviral classes were detected simultaneously. Mutations associated with resistance to protease inhibitor (PI) were detected in 124 tests (97.6%), the main ones were L90M in 28 (22.0%), V82A in 27 (21.2%), M46I in 26 (20.5%), and I54V in 23 (18.1%). The main mutations associated with nucleoside reverse transcriptase inhibitor (NRTI) resistance were M184V in 82 (64.6%), and the thymidine analog mutations were D67N in 51 (40.1%) tests, K70R in 45 (35.4%), T215Y in 40 (31.5%), and M41L in 38 (30.0%). The most frequent major mutations associated with resistance to non-nucleoside RT inhibitors (NNRTI) were K103N in 47 (37.0%), G190A in 11 (8.7%), and G190S in 2 (2.6%) tests. Mutations associated with reduced susceptibility to NRTI and IP simultaneously were observed in 46 (36.2%) tests. The results obtained may contribute to the improvement of the treatment strategies and the management of the antiretroviral drug therapy of HIV-1-infected patients from this Brazilian region, reducing public costs for antiretroviral drugs which have not been efficient in therapy.