The objective of this study was to analyse the effect of d-dexfenfluramine
(d-FEN) on the human lymphocyte response, in vitro. Experiments were design
ed to determine whether d-FEN augments specific human immune parameters ass
ociated with protection from opportunistic microbial pathogens and particul
arly focuses on d-FEN as a means by which to augment the function of CD8(+)
and CD4(+) lymphocytes. Lymphocytes were examined for three reasons: (1) f
or their ability to inhibit the growth of Candida albicans; (2) for their a
bility to proliferate in response to a mitogen; and, (3) their cytokine pro
file (vis., production of IL-2, IFN-gamma and TNF-alpha). Peripheral blood
mononuclear cells (PBMC) were obtained from 20 HIV+ patients. The patients
were diagnosed as HIV+ within the past 0.5-9 years, d-FEN was found to augm
ent the capacity of CD8(+) lymphocytes to inhibit the growth of the opportu
nistic microbial pathogen, C. albicans. d-FEN enhanced the capacity of CD4(
+) lymphocytes to proliferate in response to the mitogen, Concanavalin A, a
nd to increase the amount of IL-2 produced by CD4(+) and CD8(+) lymphocytes
from AIDS patients, d-FEN increased the number of CD4(+) and CD8(+) lympho
cytes that produced IFN-gamma from either non-AIDS or AIDS patients and inc
reased the number of AIDS patient's CD8(+) lymphocytes that produce TNF-alp
ha. These in vitro data suggest that d-FEN may be effective in enhancing im
mune function in immunocompromised individuals. (C) 1998 International Soci
ety for Immunopharmacology. Published by Elsevier Science Ltd.