Inhibition of HIV-1 disease progression by contemporaneous HIV-2 infection.
BACKGROUND
Progressive immune dysfunction and the acquired immunodeficiency syndrome (AIDS) develop in most persons with untreated infection with human immunodeficiency virus type 1 (HIV-1) but in only approximately 20 to 30% of persons infected with HIV type 2 (HIV-2); among persons infected with both types, the natural history of disease progression is poorly understood.


METHODS
We analyzed data from 223 participants who were infected with HIV-1 after enrollment (with either HIV-1 infection alone or HIV-1 and HIV-2 infection) in a cohort with a long follow-up duration (approximately 20 years), according to whether HIV-2 infection occurred first, the time to the development of AIDS (time to AIDS), CD4+ and CD8+ T-cell counts, and measures of viral evolution.


RESULTS
The median time to AIDS was 104 months (95% confidence interval [CI], 75 to 133) in participants with dual infection and 68 months (95% CI, 60 to 76) in participants infected with HIV-1 only (P=0.003). CD4+ T-cell levels were higher and CD8+ T-cell levels increased at a lower rate among participants with dual infection, reflecting slower disease progression. Participants with dual infection with HIV-2 infection preceding HIV-1 infection had the longest time to AIDS and highest levels of CD4+ T-cell counts. HIV-1 genetic diversity was significantly lower in participants with dual infections than in those with HIV-1 infection alone at similar time points after infection.


CONCLUSIONS
Our results suggest that HIV-1 disease progression is inhibited by concomitant HIV-2 infection and that dual infection is associated with slower disease progression. The slower rate of disease progression was most evident in participants with dual infection in whom HIV-2 infection preceded HIV-1 infection. These findings could have implications for the development of HIV-1 vaccines and therapeutics. (Funded by the Swedish International Development Cooperation Agency-Swedish Agency for Research Cooperation with Developing Countries and others.).
Department of Experimental Medical Science, Section of Molecular Virology, Lund University, Lund, Sweden. joakim.esbjornsson@med.lu.se
Joakim
J
Esbjörnsson
Fredrik
F
Månsson
Anders
A
Kvist
Per-Erik
PE
Isberg
Salma
S
Nowroozalizadeh
Antonio J
AJ
Biague
Zacarias J
ZJ
da Silva
Marianne
M
Jansson
Eva Maria
EM
Fenyö
Hans
H
Norrgren
Patrik
P
Medstrand
D000163:Acquired Immunodeficiency Syndrome; D000328:Adult; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes; D015331:Cohort Studies; D060085:Coinfection; D018450:Disease Progression; D019143:Evolution, Molecular; D005260:Female; D014644:Genetic Variation; D015658:HIV Infections / Q000276:immunology / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D015498:HIV-2; D006801:Humans; D053208:Kaplan-Meier Estimate; D016013:Likelihood Functions; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D019562:Viral Load