title: Viral dynamics and CD4+ T cell counts in subtype C human immunodeficiency virus type 1-infected individuals from southern Africa.
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.
authors.affiliation: National Institute for Communicable Diseases, Johannesburg, South Africa. cgray@nicd.ac.za
authors.forename: Clive M
authors.initials: CM
authors.lastname: Gray
authors.forename: Carolyn
authors.initials: C
authors.lastname: Williamson
authors.forename: Helba
authors.initials: H
authors.lastname: Bredell
authors.forename: Adrian
authors.initials: A
authors.lastname: Puren
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Xia
authors.forename: Ruben
authors.initials: R
authors.lastname: Filter
authors.forename: Lynn
authors.initials: L
authors.lastname: Zijenah
authors.forename: Huyen
authors.initials: H
authors.lastname: Cao
authors.forename: Lynn
authors.initials: L
authors.lastname: Morris
authors.forename: Efthyia
authors.initials: E
authors.lastname: Vardas
authors.forename: Mark
authors.initials: M
authors.lastname: Colvin
authors.forename: Glenda
authors.initials: G
authors.lastname: Gray
authors.forename: James
authors.initials: J
authors.lastname: McIntyre
authors.forename: Rosemary
authors.initials: R
authors.lastname: Musonda
authors.forename: Susan
authors.initials: S
authors.lastname: Allen
authors.forename: David
authors.initials: D
authors.lastname: Katzenstein
authors.forename: Mike
authors.initials: M
authors.lastname: Mbizo
authors.forename: Newton
authors.initials: N
authors.lastname: Kumwenda
authors.forename: Taha
authors.initials: T
authors.lastname: Taha
authors.forename: Salim Abdool
authors.initials: SA
authors.lastname: Karim
authors.forename: Jorge
authors.initials: J
authors.lastname: Flores
authors.forename: Haynes W
authors.initials: HW
authors.lastname: Sheppard
mesh_terms: D000353:Africa, Southern; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D015683:Gene Products, gag / Q000235:genetics; D005838:Genotype; D015658:HIV Infections / Q000276:immunology* / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D008297:Male; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D017422:Sequence Analysis, DNA; D013223:Statistics as Topic; D013997:Time Factors; D019562:Viral Load
chemical_list: D015683:Gene Products, gag; D012367:RNA, Viral