title: Rates and determinants of virologic and immunological response to HAART resumption after treatment interruption in HIV-1 clinical practice.
abstract: OBJECTIVE
  To describe CD4 and HIV RNA changes during treatment resumption (TR) after treatment interruption (TI) compared with response to first highly active antiretroviral therapy (HAART) and to investigate predictors.
  
  
  METHODS
  Using Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) data, we identified subjects who interrupted first HAART, not initiated during primary infection. We estimated rate of CD4 change during TR and time from TR to HIV RNA<500 copies per milliliter and subsequent rebound and factors associated with these outcomes.
  
  
  RESULTS
  Of 281 persons treated for median 18.4 months before interrupting, 259 resumed HAART. CD4 increases in the first 3 months on HAART were similar pre-TI and post-TI but after 3 months were significantly higher during pre-TI HAART, with median +106 and +172 cells per microliter at 3 and 18 months, respectively, during initial HAART compared with +99 and +142 cells per microliter during post-TI HAART, respectively. Subjects with lower CD4 counts at TI, aged older than 40 years, and those resuming the same HAART as their pre-TI regimen had lower CD4 increases during the first 3 months of TR. The majority (86%) of individuals reinitiating therapy achieved HIV RNA<500 copies per milliliter.
  
  
  CONCLUSIONS
  Immune reconstitution after TI is generally poorer than after first HAART, particularly for patients aged older than 40 years at TI and those with poorer immunological responses to pre-TI HAART. Reinitiation of the same HAART regimen as pre-TI also seems to have unfavorable outcomes.
authors.affiliation: Department of Hygiene, Epidemiology, and Medical Statistics, Athens University Medical School, Athens, Greece. gtouloum@med.uoa.gr
authors.forename: Giota
authors.initials: G
authors.lastname: Touloumi
authors.forename: Nikos
authors.initials: N
authors.lastname: Pantazis
authors.forename: Heide A
authors.initials: HA
authors.lastname: Stirnadel
authors.forename: A Sarah
authors.initials: AS
authors.lastname: Walker
authors.forename: Faroudy
authors.initials: F
authors.lastname: Boufassa
authors.forename: Philippe
authors.initials: P
authors.lastname: Vanhems
authors.forename: Kholoud
authors.initials: K
authors.lastname: Porter
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology*; D015497:HIV-1; D006801:Humans; D008297:Male; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents