Proviral load and immune function in blood and lymph node during HIV-1 andHIV-2 infection

Proviral load as well as lymphocyte phenotype and function were compared in peripheral blood and lymph node compartments of 17 HIV-1, 12 HIV-2 and thr ee dually infected patients with lymphadenopathy. The mean percentage (95% confidence interval (CI)) of CD4(+) cells was higher in lymph node mononucl ear cells (LNMC) than in peripheral blood mononuclear cells (PBMC) in both infections, being 26.7% (21.1%, 32.3%) and 15.3% (10.4%, 20.2%), respective ly, for HIV-1-infected patients (P = 0.0001) and 32.3% (22.7%, 41.9%) and 2 2.1% (13.6%, 30.6%), respectively, for HIV-2-infected patients (P = 0.02). In both types of infection, proviral load adjusted for number of CD4(+) cel ls was higher in LNMC than in PBMC: the geometric mean (95% CI) was 8937 (4 991; 16 003) and 4384 (2260; 8503), respectively, for HIV-1 patients (P = 0 .02) and 1624 (382; 6898) and 551 (147; 2058) DNA copies, respectively, for HIV-2 patients (P = 0.05). Proviral load in both compartments was closely correlated (HIV-1, r = 0.60, P = 0.01; and HIV-2, r = 0.83, P = 0.0003). In both infections, proliferation and interferon-gamma (IFN-gamma) production in response to purified protein derivative (PPD) was lower in LNMC than in PBMC, both of which, in turn, were lower than in healthy controls. These r esults indicate that in HIV-2 as in HIV-1 infection, infected cells have a tropism for the lymph nodes resulting in higher viral load in this compartm ent and lower lymphocyte responses to the recall antigen PPD which may incr ease susceptibility to tuberculosis.