title: Increasing age at HIV seroconversion from 18 to 40 years is associated with favorable virologic and immunologic responses to HAART.
abstract: BACKGROUND
  Studies evaluating the effect of age on response to highly active antiretroviral therapy (HAART) have been limited by their inability to control for duration of human immunodeficiency virus (HIV) infection. We examined the effect of age at HIV seroconversion on response to HAART.
  
  
  METHODS
  A retrospective analysis of a longitudinal US military cohort of HIV-infected subjects. Time to and maintenance of viral suppression, rate of CD4 cell increase, and rate of progression to acquired immunodeficiency syndrome or death were compared across age groups using time-to-event methods.
  
  
  RESULTS
  Five hundred sixty-three HIV-infected adults who seroconverted after January 1, 1996, and started HAART were included. Increasing age at seroconversion was significantly associated with faster time to viral suppression (P = 0.002). Increasing age also correlated with duration of suppression, with a 35% reduction in risk of viral rebound for every 5-year increase in age above 18 years (hazard ratio: 0.65, 95% confidence interval 0.55 to 0.75). The rate of CD4 cell increase from 6 to 84 months post-HAART was significantly greater in those who seroconverted at older ages (P = 0.0002). Rates of progression to acquired immunodeficiency syndrome or death did not differ between groups.
  
  
  CONCLUSIONS
  Increasing age at seroconversion was associated with shorter time to and longer maintenance of viral suppression and a faster increase in CD4 cell count.
authors.affiliation: Uniformed Services University of the Health Sciences, Bethesda, MD, USA. amy.weintrob@na.amedd.army.mil
authors.forename: Amy C
authors.initials: AC
authors.lastname: Weintrob
authors.forename: Ann M
authors.initials: AM
authors.lastname: Fieberg
authors.forename: Brian K
authors.initials: BK
authors.lastname: Agan
authors.forename: Anuradha
authors.initials: A
authors.lastname: Ganesan
authors.forename: Nancy F
authors.initials: NF
authors.lastname: Crum-Cianflone
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Marconi
authors.forename: Mollie
authors.initials: M
authors.lastname: Roediger
authors.forename: Susan L
authors.initials: SL
authors.lastname: Fraser
authors.forename: Scott A
authors.initials: SA
authors.lastname: Wegner
authors.forename: Glenn W
authors.initials: GW
authors.lastname: Wortmann
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D018450:Disease Progression; D006679:HIV Seropositivity / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D008875:Middle Aged; D019562:Viral Load