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Antiretroviral resistance patterns and factors associated with resistance in adult patients failing NNRTI‐based regimens in the western cape, South Africa
Author(s) -
van Zyl Gert U.,
van der Merwe Lize,
Claassen Mathilda,
Zeier Michele,
Preiser Wolfgang
Publication year - 2011
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.22189
Subject(s) - nevirapine , etravirine , efavirenz , regimen , viral load , drug resistance , virology , resistance mutation , medicine , reverse transcriptase inhibitor , lentivirus , immunology , oncology , human immunodeficiency virus (hiv) , reverse transcriptase , antiretroviral therapy , biology , viral disease , microbiology and biotechnology , polymerase chain reaction , biochemistry , gene
Antiretroviral drug resistance in patients failing non‐nucleoside reverse transcriptase inhibitor (NNRTI)‐based first‐line combination antiretroviral treatment (ART) is influenced by: regimen choice, HIV‐1 subtype, detection of and response to therapy failure. In order to describe resistance patterns by genotypic testing, at the time of first‐line ART failure and to describe associations with having M184I/V, K65R, three or more thymidine analog mutations (TAMs) and etravirine (ETV) resistance, the prevalence of antiretroviral drug resistance associated mutations in a cross‐sectional study, at two South African public health clinic settings, at the time of virologic failure (HIV‐1 RNA load >400 copies/ml) are described. Also reported are associations of therapy choice, prolonged virologic failure, and concurrent HIV viral load and CD4 count with the presence of M184I/V, TAMs, K65R, and resistance to ETV. Of 167 adult patients with virologic failure on first‐line ART, 28 (17%) had no resistance, 137 (82%) had NNRTI resistance, 101 (60%) M184I/V, 20 (12%) TAMs, of which 4 had 3 or more TAMs, and 7 (4%) had K65R, of which 6 were on D4T and one on AZT. A prolonged estimated period of failure was associated with having ≥3 TAMs. Patients treated with nevirapine (NVP) were more likely to have ETV resistance than those treated with efavirenz (EFV). Major protease inhibitor mutations were not detected. A delayed response to ART failure may risk accumulation of TAMs in patients on an NNRTI‐based regimen. The use of NVP rather than EFV was associated with ETV resistance. J. Med. Virol. 83:1764–1769, 2011. © 2011 Wiley‐Liss, Inc.