Equal Plasma Viral Loads Predict a Similar Rate of CD4⁺T Cell Decline in Human Immunodeficiency Virus (HIV) Type 1– and HIV‐2–Infected Individuals from Senegal, West Africa

Abstract

Human immunodeficiency virus (HIV) type 2 infection is characterized by slower disease progression to acquired immunodeficiency syndrome than results from HIV-1 infection. To better understand the biological factors underlying the different natural histories of infection with these 2 retroviruses, we examined the relationship between HIV RNA and DNA levels and the rate of CD4(+) T cell decline among 472 HIV-1- and 114 HIV-2-infected individuals from Senegal. The annual rate of CD4(+) T cell decline in the HIV-2 cohort was approximately one-fourth that seen in the HIV-1 cohort. However, when the analysis was adjusted for baseline plasma HIV RNA level, the rates of CD4(+) T cell decline per year for the HIV-1 and HIV-2 cohorts were similar (a rate increase of approximately 4% per year for each increase in viral load of 1 log(10) copies/mL). Therefore, plasma HIV load is predictive of the rate of CD4(+) T cell decline over time, and the correlation between viral load and the rate of decline appears to be similar among all HIV-infected individuals, regardless of whether they harbor HIV-1 or HIV-2.

Improved Sensitivity of Human Immunodeficiency Virus Type 2 Subtype B Plasma Viral Load Assay

“…Two longitudinal studies of patients living in West Africa reported a link between HIV-2 viral load and the CD4 cell count decline and death (2,11). In the French Agence Nationale de Recherche sur le SIDA HIV-2 cohort study, we confirmed the very slow progression of HIV-2 disease and showed that, as in HIV-1 infection, plasma RNA quantification was predictive of the risk of clinical progression (14).…”

Broad and Potent Neutralizing Antibody Responses Elicited in Natural HIV-2 Infection

“…Plasma or serum samples were obtained from 64 antiretrovirus therapy-naive subjects chronically infected with HIV-2 (see Table S1 in the supplemental material). These included samples from 52 Senegalese subjects enrolled between 1994 and 2004 (22,63), 1 Ivory Coast subject (samples 7312Apl1992 and 7312Apl2003) (20), 6 source plasma donors whose country of origin was unknown (samples 8704Apl2006 and 8704Apl2007, 7810Apl1993, 7924Apl, 60667Kpl, 10849pl1995, and SLRHCNo.10pl1995), and 5 subjects from the NIH AIDS Research and Reference Reagent Program (1026se, Ivory Coast; 1030se, Senegal; 1032se, Ivory Coast; 1495se, Senegal; and 3660se, Guinea Bissau). HIV-1 clade B-infected plasma samples (SHROpl, BELIpl, FAROpl, PUMApl, and YOALpl) from chronically infected patients were obtained from the University of Alabama at Birmingham Center for AIDS Research HIV/ AIDS tissue repository (39).…”

“…Plasma HIV-2 vRNA levels were determined by a modified Amplicor Monitor test method previously described (22) and by a validated real-time PCR assay (9,17).…”

CCR5, GPR15, and CXCR6 Are Major Coreceptors of Human Immunodeficiency Virus Type 2 Variants Isolated from Individuals with and without Plasma Viremia

“…Indeed, a broader in vitro tropism for human and animal cell lines has been observed (14,36). The observed broad coreceptor usage and tropism seem to conflict with the lower pathogenicity of HIV-2 (3,17,28,44). Many HIV-2-infected individuals remain AIDS free for prolonged periods and have low or no detectable levels of viral RNA in their plasma (35).…”