Viral dynamics and CD4+ T cell counts in subtype C human immunodeficiency virus type 1-infected individuals from southern Africa

AIDS Res Hum Retroviruses. 2005 Apr;21(4):285-91. doi: 10.1089/aid.2005.21.285.

Abstract

Defining viral dynamics in natural infection is prognostic of disease progression and could prove to be important for vaccine trial design as viremia may be a likely secondary end point in phase III HIV efficacy trials. There are limited data available on the early course of plasma viral load in subtype C HIV-1 infection in Africa. Plasma viral load and CD4+ T cell counts were monitored in 51 recently infected subjects for 9 months. Individuals were recruited from four southern African countries: Zambia, Malawi, Zimbabwe, and South Africa and the median estimated time from seroconversion was 8.9 months (interquartile range, 5.7-14 months). All were infected with subtype C HIV-1 and median viral loads, measured using branched DNA, ranged from 3.82-4.02 log10 RNA copies/ml from 2-24 months after seroconversion. Viral loads significantly correlated with CD4+ cell counts (r=-0.5, p<0.0001; range, 376-364 cells/mm3) and mathematical modeling defined a median set point of 4.08 log10 (12 143 RNA copies/ml), which was attained approximately 17 months after seroconversion. Comparative measurements using three different viral load platforms (bDNA, Amplicor, and NucliSens) confirmed that viremia in subtype C HIV-1-infected individuals within the first 2 years of infection did not significantly differ from that found in early subtype B infection. In conclusion, the course of plasma viremia, as described in this study, will allow a useful baseline comparator for understanding disease progression in an African setting and may be useful in the design of HIV-1 vaccine trials in southern Africa.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Africa, Southern
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / immunology*
  • Disease Progression
  • Female
  • Gene Products, gag / genetics
  • Genotype
  • HIV Infections / immunology*
  • HIV Infections / virology*
  • HIV Seropositivity
  • HIV-1 / classification*
  • HIV-1 / isolation & purification
  • HIV-1 / physiology*
  • Humans
  • Male
  • Phylogeny
  • RNA, Viral / analysis
  • Sequence Analysis, DNA
  • Statistics as Topic
  • Time Factors
  • Viral Load

Substances

  • Gene Products, gag
  • RNA, Viral