Objective: To determine whether blood plasma levels of HIV-2 RNA viral loads and immune activation markers differ between persons infected with HIV-2 only and those dually infected with HIV-1 and HIV-2.
Methods: Between September 1996 and February 2000, we collected, analyzed and compared levels of HIV-2 RNA in plasma and immune activation markers among 52 persons infected with HIV-2 alone and 75 with confirmed dual infection. We also compared viral load and immune activation in patients who were infected with HIV-1 only and those who were dually infected.
Results: When we conducted a CD4 T-cell count-stratified multivariate analysis of HIV-2 viral load, controlling for difference in CD4 T-cell counts, age and sex: at < 200 × 106 CD4 T cells/l, HIV-2 viral load was 2.0 log10 copies/ml lower in dually infected patients than in HIV-2 only patients (P < 0.0001). At CD4 T-cell counts between 200 × 106 and 500 × 106/l, HIV-2 viral load was 0.3 log10 copies/ml lower in dually infected patients (P = 0.45). However, at CD4 T-cells counts > 500 × 106/l, HIV-2 viral load was 0.9 log10 copies/ml higher in dually infected patients (P < 0.0001). Dually infected persons with undetectable HIV-2 viral loads had significantly higher median levels of CD8 T cells expressing CD38 (P < 0.001) and HLA-DR (P = 0.01) than HIV-2 only infected patients.
Conclusion: These results suggest that in dual infection, the level of HIV-2 replication depends on the immune status of the patients, with HIV-1 out-replicating HIV-2 as disease progress.
From the aProjet RETRO-CI, Abidjan, Côte d'Ivoire, the bInstitute of Tropical Medicine, Antwerp, Belgium, the cDivision of HIV/AIDS Prevention, Surveillance and Epidemiology, National Center for HIV, STD, and TB prevention, the dDivision of HIV/AIDS, STD, TB Laboratory Research, National Center for Infectious Diseases, and the eGlobal AIDS Program, National Center for HIV, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Correspondence to J. N. Nkengasong, Division of HIV/AIDS Prevention, National Center for HIV, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Received: 14 November 2002; revised: 27 June 2003; accepted: 1 July 2003.