title: Sequence clusters in human immunodeficiency virus type 1 reverse transcriptase are associated with subsequent virological response to antiretroviral therapy.
abstract: Many amino acid (aa) sites in reverse transcriptase (RT) have been implicated in resistance to nucleoside (NRTI) and nonnucleoside antiretrovirals. Interactions between these in response to combination therapy remain poorly understood. In a trial (ACTG 241) of zidovudine/didanosine (ddI) versus zidovudine/ddI/nevirapine in nucleoside-experienced patients, baseline sequence data from the RT coding region was analyzed from 55 individuals. Sequences were clustered by use of a parsimony method and the virological responses (ratio of baseline viral load to viral load after of therapy) for each cluster were analyzed at week 8 and week 48. Both clusters and genotype at aa 215 were significantly associated with virological response at both time points, whereas viral load showed a stronger association with sequence clusters. Sequence clusters identified one group of patients who never developed high-level resistance to NRTIs despite prior nucleoside exposure and poor suppression of viral replication.
authors.affiliation: Centre for HIV Research, University of Edinburgh, Edinburgh EH9 3JN, Scotland. A.Leigh-Brown@ed.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Brown
authors.forename: H F
authors.initials: HF
authors.lastname: Günthard
authors.forename: J K
authors.initials: JK
authors.lastname: Wong
authors.forename: R T
authors.initials: RT
authors.lastname: D'Aquila
authors.forename: V A
authors.initials: VA
authors.lastname: Johnson
authors.forename: D R
authors.initials: DR
authors.lastname: Kuritzkes
authors.forename: D D
authors.initials: DD
authors.lastname: Richman
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000188:drug therapy*; D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D016049:Didanosine; D004359:Drug Therapy, Combination; D019143:Evolution, Molecular; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D019829:Nevirapine / Q000627:therapeutic use; D016415:Sequence Alignment; D013997:Time Factors; D019562:Viral Load; D015215:Zidovudine
chemical_list: D019380:Anti-HIV Agents; D015215:Zidovudine; D019829:Nevirapine; D054303:HIV Reverse Transcriptase; D016049:Didanosine