[Activation of the macrophage/lymphocyte system in AIDS, ARC and AIDS risk groups].

Elevated neopterin levels are indicative of activation of the cellular immune system. Studies on excretion of neopterin in patients with AIDS and ARC, as well as in members of risk groups have demonstrated repeated or permanent stimulation of the immune system. This stimulation can be observed in all risk groups independent of LAV/HTLV-III infection. Additionally, in vitro replication of LAV/HTLV-III has been observed to be quantitatively greatest in activated CD4+-lymphocytes. Hence, we conclude that activation of the cellular immune system represents the central cofactor for progressive LAV/HTLV-III infection. These findings seem to contrast with most reports in the literature to date, but observations of other authors corroborate them. As consequence of these studies, therapeutic regimens using immunostimulatory strategies should be prevented in AIDS and ARC patients. Immunosuppressive treatment should be considered.