Detection of residual human immunodeficiency virus type 1 reverse transcriptase K103N minority species in plasma RNA and peripheral blood mononuclear cell DNA following discontinuation of non-nucleoside therapy

Non-nucleoside reverse transcriptase inhibitor (NNRTI) therapy failed in 30 patients with the typical human immunodeficiency virus type 1 reverse transcriptase K103N mutation, detected using standard genotyping. Following discontinuation of NNRTI therapy for a median of 55.9 weeks and a decrease of K103N mutant species to undetectable levels in plasma RNA, minority K103N species remained detectable, by allele-specific PCR, for longer periods of time and at higher frequency, in peripheral blood mononuclear cell (PBMC) DNA than in plasma RNA (76.7% and 46.7% of samples with residual K103N species detected at median frequencies of 18.0% and 3.8%, respectively). Analysis of PBMC DNA should be considered when searching for residual K103N mutant species in patients previously exposed to NNRTIs.