HIV-1 genotype resistance pattern and evolution in patients failing nelfinavir-containing regimens

Clinical and in vitro studies have suggested that nelfinavir (NFV)-containing regimens may not preclude the use of other protease inhibitors (PIs) in treatment sequencing. We have studied the prevalence of 30N mutation in a human immunodeficiency virus-1 (HIV-1)-infected cohort and the virological response to a PI-containing regimen in patients who had previously failed NFV. A total of 335 patients were included in the study; 32 of them were antiretroviral-naive and 303 were antiretroviral-experienced (251 were PI-experienced). Mutations 30N and/or 90M were not detected in sequences obtained either from the antiretroviral naive or non-PI-experienced patients. The 30N mutation was detected in 21/251 (8.3%) of PI-experienced patients and 90M in 103/251 (41%). Moreover, we have observed that the 88D and 77I mutations were present in more than 75% of patients harbouring the 30N HIV-1 variant and the 71T mutation was present in almost 50% of them. Finally, mutations 30N+90M were never detected together in the same HIV-1 strain. The 30N and 90M mutations were not observed together. The presence of mutations at positions 36, 46, 71, 77, and/or 88 in a 30N background, increases the risk of the cross-resistance to other PIs. The use of NFV as a first-line PI, as an application of drug sequencing strategies, may help preserve future PI options.