Genotypic resistance in plasma and peripheral blood lymphocytes in a group of naive HIV-1 patients

Background: Since HIV infection cannot be completely eliminated due to the establishment of latently infected CD4+ T cell reservoirs, there is an urgent need for a clearer understanding of comparative resistance profiles between plasma and PBMC in HIV-1 patients. Objectives: To assess the prevalence of mutations associated with drug resistance and to compare cell free and cell-associated strains. Study design: Genotypic resistance analysis on viral DNA and plasma was performed in 31 therapy naive patients with chronic infection to check reverse transcriptase (RT) and protease resistance associated mutations before beginning antiretroviral therapy. Results: Direct sequencing of DNA provirus disclosed key mutations (such as G190A/S, V106A, K103N and T215F) to RT inhibitors more frequently (7 patients out 31) than in plasma RNA (2 out of 31). In addition, major mutations (D30N, M46I, I50V, I84V) associated with drug resistance in the PR region were only found in PBMCs. Conclusions: Despite the small number of patients, our results show a different resistance profile between plasma and PBMC compartments and may yield additional information for first-line antiretroviral regimens. Further investigations on larger series followed-up for a longer period of time are required to obtain in-depth information on the meaning of the mutations detectable in plasma and/or in PBMCs.