Introduction: The lesser pathogenicity of HIV-2 relative to HIV-1 is generally attributed to its slower replication. To compare the amounts of total HIV DNA during human HIV-1 and HIV-2 infection, we developed a quantitative real-time PCR method with a unique external quantification standard based on a single plasmid harboring both the HIV-1 and the HIV-2 LTR.
Methods: Viral DNA load was compared between 40 HIV-1-infected and 42 HIV-2-infected antiretroviral-naive patients.
Results: The difference between HIV-1 and HIV-2 proviral DNA load was highly significant in patients with CD4 cell counts > 500 cells/μl [HIV-1: n = 14; median, 2.5; interquartile range (IQR), 2.1–2.7; HIV-2: n = 22, median, 1.6; IQR, 1.0–2.0] and in patients with CD4 cell counts between 300 cells/μl and 500 cells/μl (HIV-1: n = 12; median, 2.7; IQR, 2.3–2.8; HIV-2: n = 11; median, 2.0; IQR, 1.0–2.4). Too few HIV-2-infected patients had CD4 cell counts < 300 cells/μl to detect a significant difference but DNA values were again lower in HIV-2-infected patients (HIV-1: n = 14; median, 2.9; IQR, 2.2–3.2; HIV-2: n = 9; median, 2.7; IQR, 2.2–3.3).
Conclusions: These differences are in line with the natural histories of the two infections and show that HIV-2 infection is a valid model for studying the pathophysiology of HIV infection in general.
From the aLaboratoire de Virologie, CHU Charles Nicolle Rouen, France
bLaboratoire de Virologie, Hôpital Bichat, Paris, France
cINSERM U593 Bordeaux, France
dService de Microbiologie, CHU Saint Louis, Paris, France.
Correspondence to M. Gueudin, Laboratoire de Virologie, CHU Charles Nicolle, 1 rue de Germont, 76031 Rouen Cedex, France. Tel: +33 (0)2 32 88 82 36; fax: +33 (0)2 32 88 04 30; e-mail: Marie.Gueudin@chu-rouen.fr