Viral dynamics and CD4+ T cell counts in subtype C human immunodeficiency virus type 1-infected individuals from southern Africa.
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.
Gray
Clive M
CM
National Institute for Communicable Diseases, Johannesburg, South Africa. cgray@nicd.ac.za
Williamson
Carolyn
C
Bredell
Helba
H
Puren
Adrian
A
Xia
Xiaohua
X
Filter
Ruben
R
Zijenah
Lynn
L
Cao
Huyen
H
Morris
Lynn
L
Vardas
Efthyia
E
Colvin
Mark
M
Gray
Glenda
G
McIntyre
James
J
Musonda
Rosemary
R
Allen
Susan
S
Katzenstein
David
D
Mbizo
Mike
M
Kumwenda
Newton
N
Taha
Taha
T
Karim
Salim Abdool
SA
Flores
Jorge
J
Sheppard
Haynes W
HW
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
D015683:Gene Products, gag; D012367:RNA, Viral