Cocaine dependence and acute cocaine induce decreases of monocyte proinflammatory cytokine expression across the diurnal period: autonomic mechanisms

Cocaine dependence is associated with an increased risk of infectious diseases. The innate immune system triggers effec-tor pathways to combat microbial pathogens through expres-sion of tumor necrosis factor- (TNF-) and interleukin-6 (IL-6). It is not known whether cocaine alters the capacity of mono-cytes to respond to a bacterial challenge in humans. In co-caine-dependent volunteers and control subjects, we analyzed monocyte TNF- and IL-6 expression at rest and in response to the bacterial ligand, lipopolysaccharide (LPS), over a 24-h pe-riod. In addition, the in vivo effects of cocaine (40 mg) versus placebo on monocyte expression of TNF- and IL-6 were pro-filed over 48 h. Cocaine-dependent volunteers showed a de-crease in the capacity of monocytes to express TNF- and IL-6 compared with control subjects. Moreover, acute infusion o