title: Long-term persistence of AZT-resistance mutations in the plasma HIV-1 of patients removed from AZT therapy.
abstract: Zidovudine (3'-azido-2',3'-dideoxythymidine) resistant isolates of human immunodeficiency virus type I (HIV-1) were previously demonstrated in zidovudine-treated AIDS patients. The genetic linkage of multiple mutations characteristic of zidovudine-resistance as well as dideoxyinosine-resistance were demonstrated by examining clones of viral reverse transcriptase after polymerase chain reaction (PCR) amplification of plasma culture DNA. The zidovudine-resistance mutations persisted in seven timepoints from four patients for 5 to 22 months despite cessation of zidovudine therapy (and while patients underwent ddI therapy). One patient's plasma virus isolate at 14 months possessed a genotype doubly resistant to ZDV and ddI. Virus recovered from four timepoints showed Intermediate to high levels of zidovudine-resistance. As these genotypes were mainly derived from plasma culture, the zidovudine resistant virus appears to persist and replicate well in vivo after cessation of zidovudine therapy.
authors.affiliation: University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill.
authors.forename: M S
authors.initials: MS
authors.lastname: Smith
authors.forename: K L
authors.initials: KL
authors.lastname: Koerber
authors.forename: J S
authors.initials: JS
authors.lastname: Pagano
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000188:drug therapy*; D004351:Drug Resistance / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D009154:Mutation; D013997:Time Factors; D015215:Zidovudine / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D015215:Zidovudine