Alteration of Macrophage Functions by Cocaine

Although immunomodulation by cocaine has been reported by a number of investigators, it is not consistently associated with immunosuppression, and reports have described a reduction or alteration in the production of certain cytokines.

Abstract

Studies elucidating the effects of cocaine on immune cells and immune function are relatively recent. Although immunomodulation by cocaine has been reported by a number of investigators, it is not consistently associated with immunosuppression. A review sum­marized many of the earlier studies of cocaine on the immune system (1). Another study (2) describes a number of immune abnormalities in mice exposed to cocaine including an enhancement of neutrophil phagocytosis, a reduction of T-cell responses to the mitogen phytohemagglutinin, and cytotoxic activity of immune spleen cells. Other reports have described alteration of spleen cell subsets following injection with cocaine (3,4). A number of reports have described a reduction or alteration in the production of certain cytokines (5–7). In a series of publications, Peterson et al. (8–10) have reported an enhancement of HIV replication in cultures of human monocytes via the induction of transforming growth factor β (TGFβ) and tumor necrosis factor (TNFα). An increase in p24, one of the internal viral proteins, was used to quantify viral replication. A recent study (11) reported that Me culture supernatants from cells exposed to cocaine, modulate mesangial cell proliferation in vitro altering TGFβ, as well as IL-6.