Substantial correlation between HIV type 1 drug-associated resistance mutations in plasma and peripheral blood mononuclear cells in treatment-experienced patients

The correlation of detectable HIV-1 drug resistance mutations in plasma and PBMCs in patients extensively treated with all antiretroviral drug classes has not been fully elucidated. The detection of mutations in PBMCs may reveal resistant HIV-1 associated with past therapies. In addition, these measures in PBMCs may have a practical value when plasma virus is at low levels that are difficult to detect with current assays. The reverse transcriptase (RT) and protease (P) genes were analyzed for drug resistance, using an in-house method carried out on 36 paired samples of plasma and PBMCs from 12 treatment-experienced patients in order to investigate resistance in the two compartments. When viruses in plasma and PBMCs were analyzed by patient, the mean of the Cohen kappa values was 0.728 (substantial agreement). When viruses were analyzed by codon the mean of the Cohen kappa values was 0.715 (substantial agreement). Baseline samples were concordant at 280 of 288 (97%) codons analyzed. This study shows that a minority of mutations associated with previous therapy can be detected in PBMCs and not in plasma. Overall, mutations in plasma and PBMCs showed a substantial correlation in extensively treated patients, suggesting that either compartment is suitable for the detection of mutations as a virological guide for clinical care.