title: High drug resistance prevalence among vertically HIV-infected patients transferred from pediatric care to adult units in Spain.
abstract: BACKGROUND
  Antiretroviral treatment (ART) has contributed to increased life expectancy of HIV-1 infected children. In developed countries, an increasing number of children reaching adulthood are transferred to adult units. The objectives were to describe the demographic and clinical features, ART history, antiviral drug resistance and drug susceptibility in HIV-1 perinatally infected adolescents transferred to adult care units in Spain from the Madrid Cohort of HIV-1 infected children.
  
  
  METHODS
  Clinical, virological and immunological features of HIV-1 vertically infected patients in the Madrid Cohort of HIV-infected children were analyzed at the time of transfer. Pol sequences from each patient were recovered before transfer. Resistance mutations according to the InternationaI AIDS Society 2011 list were identified and interpreted using the Stanford algorithm. Results were compared to the non-transferred HIV-1 infected pediatric cohort from Madrid.
  
  
  RESULTS
  One hundred twelve infected patients were transferred to adult units between 1997 and 2011. They were mainly perinatally infected (93.7%), with a mean nadir CD4+-T-cells count of 10% and presented moderate or severe clinical symptoms (75%). By the time of transfer, the mean age was 18.9 years, the mean CD4+T-cells count was 627.5 cells/ml, 64.2% presented more than 350 CD4+T-cells/ml and 47.3% had ≤ 200 RNA-copies/ml. Most (97.3%) were ART experienced receiving Highly Active ART (HAART) (84.8%). Resistance prevalence among pretreated was 50.9%, 76.9% and 36.5% for Protease Inhibitors (PI), Nucleoside Reverse Transcriptase Inhibitors (NRTI) and Non-NRTI (NNRTI), respectively. Resistance mutations were significantly higher among transferred patients compared to non-transferred for the PI+NRTI combination (19% vs. 8.4%). Triple resistance was similar to non-transferred pediatric patients (17.3% vs. 17.6%).
  
  
  CONCLUSIONS
  Despite a good immunological and virological control before transfer, we found high levels of resistance to PI, NRTI and triple drug resistance in HIV-1 infected adolescents transferred to adult units.
authors.affiliation: HIV-1 Molecular Epidemiology Laboratory, Microbiology and Parasitology Department, Hospital Universitario Ramón y Cajal, IRYCIS and CIBER-ESP, Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: de Mulder
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Yebra
authors.forename: Adriana
authors.initials: A
authors.lastname: Navas
authors.forename: María Isabel
authors.initials: MI
authors.lastname: de José
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Gurbindo
authors.forename: María Isabel
authors.initials: MI
authors.lastname: González-Tomé
authors.forename: María José
authors.initials: MJ
authors.lastname: Mellado
authors.forename: Jesús
authors.initials: J
authors.lastname: Saavedra-Lozano
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Muñoz-Fernández
authors.forename: Santiago Jiménez
authors.initials: SJ
authors.lastname: de Ory
authors.forename: José Tomás
authors.initials: JT
authors.lastname: Ramos
authors.forename: Africa
authors.initials: A
authors.lastname: Holguín
mesh_terms: D000293:Adolescent; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D024882:Drug Resistance, Viral / Q000235:genetics; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D013030:Spain; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors