title: Evaluation of HIV-1 resistance to antiretroviral drugs among 150 patients after six months of therapeutic interruption.
abstract: Most of the antiretroviral (ARV) studies in Brazil have been reported in treatment-experienced and naive patients rather than in the setting of treatment interruption (TI). In this study, we analysed reasons given for TI and resistance mutations occurring in 150 HIV-1-infected patients who underwent TI. Of the patients analysed, 110 (73.3%) experienced TI following medical advice, while the remaining patients stopped antiretroviral therapy (ART) of their own accord. The main justifications for TI were: ARV-related toxicities (38.7%), good laboratory parameters (30%) and poor adherence (20%). DNA sequencing of the partial pol gene was successful in 137 (91.3%) patients, of whom 38 (27.7%) presented mutations conferring ARV resistance. A higher viral load prior to TI correlated with drug resistance (P < 0.05). Our results demonstrate that there are diverse rationales for TI and that detection of resistant strains during TI most likely indicates a fitter virus than the wild type. High viral loads coupled with unprotected sex in this group could increase the likelihood of transmission of drug-resistant virus. Thus, treating physicians should be alerted to this problem when the use of ARVs is interrupted.
authors.affiliation: Department of Infectious Disease, Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: E M N
authors.initials: EM
authors.lastname: Kalmar
authors.forename: S S
authors.initials: SS
authors.lastname: Sanabani
authors.forename: A
authors.initials: A
authors.lastname: Charlys da Costa
authors.forename: S
authors.initials: S
authors.lastname: Ferreira
authors.forename: C C
authors.initials: CC
authors.lastname: Barreto
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: E C
authors.initials: EC
authors.lastname: Sabino
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000008:administration & dosage*; D001938:Brazil; D018791:CD4 Lymphocyte Count; D004334:Drug Administration Schedule; D024882:Drug Resistance, Viral; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D019562:Viral Load; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D044966:Anti-Retroviral Agents; D012367:RNA, Viral; D054302:pol Gene Products, Human Immunodeficiency Virus