title: Age- and time-related changes in extracellular viral load in children vertically infected by human immunodeficiency virus.
abstract: BACKGROUND
  It is known that plasma or serum viral load is high in vertically HIV-infected children during the first year of life, but the changes in these titers after the first birthday have not been described. Information on the natural history of circulating extracellular virus will be useful in elucidating the pathogenesis of pediatric HIV infection and in using viral load measurement to guide prognosis and therapy.
  
  
  METHODS
  We measured serum RNA by reverse transcriptase-polymerase chain reaction and immune complex-dissociated p24 antigen enzyme-linked immunosorbent assay over time in 48 unselected children followed in our clinics and analyzed the findings in relation to age and clinical outcome.
  
  
  RESULTS
  In first-available samples from the 48 children there was a gradual reduction in HIV RNA values with increasing age, with a slope of -0.21 log copy/ml/year (P < 0.001, R2 = 0.6022). This downward trend was seen in subsets of children with all degrees of immunodeficiency. The mean slope of repeated HIV RNA measurements in individual children was similarly in a downward direction (slope -0.11 (P = 0.007 for difference from zero)). The slope was more negative in children who were younger at baseline. Immune complex-dissociated p24 antigen values were much less predictable and predictive.
  
  
  CONCLUSIONS
  Viral load in vertically infected children, measured by reverse transcriptase-polymerase chain reaction, falls very gradually over time, descending from very high titers at the end of the first year, and reaching values seen in horizontally infected adults at approximately 5 years of age.
authors.affiliation: Division of Infectious Diseases, Children's Hospital, Boston MA 02115, USA. mcintosh@al.tch.harvard.edu
authors.forename: K
authors.initials: K
authors.lastname: McIntosh
authors.forename: A
authors.initials: A
authors.lastname: Shevitz
authors.forename: D
authors.initials: D
authors.lastname: Zaknun
authors.forename: J
authors.initials: J
authors.lastname: Kornegay
authors.forename: P
authors.initials: P
authors.lastname: Chatis
authors.forename: N
authors.initials: N
authors.lastname: Karthas
authors.forename: S K
authors.initials: SK
authors.lastname: Burchett
mesh_terms: D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006678:HIV / Q000276:immunology* / Q000472:pathogenicity; D016655:HIV Core Protein p24 / Q000032:analysis* / Q000097:blood; D015658:HIV Infections / Q000276:immunology / Q000635:transmission; D006679:HIV Seropositivity / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D016014:Linear Models; D008297:Male; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012367:RNA, Viral / Q000032:analysis* / Q000097:blood; D012189:Retrospective Studies; D012494:Sampling Studies; D015996:Survival Rate; D013997:Time Factors
chemical_list: D016655:HIV Core Protein p24; D012367:RNA, Viral