Inhibition of lipopolysaccharide stimulated interleukin-1βproduction after subarachnoid hemorrhage

PURPOSE: To identify the characteristics of cytokine production from peripheral blood mononuclear cells (PBMCs) in response to lipopolysaccharide (LPS) in patients with subarachnoid hemorrhage (SAH). METHODS: Blood samples were collected on the first day and 3 days after SAH (n = 12) to measure plasma concentrations of catecholamines, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-10. PBMCs from SAH patients or healthy volunteers were incubated with LPS (1 microg) for 24 hours. In the second phase, PBMCs from healthy volunteers (n = 6) were incubated with or without catecholamine (10 micromol/1) for 6 hours. After pre-treatment, the cells were treated with LPS (1 microg) for 18 hours. Supernatants were extracted and subjected to measurement by enzyme-linked immunosorbent assay. RESULTS: Plasma concentrations of epinephrine or dopamine prolong increased significantly 3 days after SAH, involved in elevation of plasma IL-10. In the PBMCs from the SAH patients, LPS-stimulated IL- 10 production was inhibited significantly. Pre-treatment with epinephrine or dopamine inhibited LPS-stimulated IL-1beta production significantly in the PBMCs from the healthy volunteers. CONCLUSIONS: The initial SAH involved in an impaired production of pro-inflammatory cytokines in response to LPS with an elevation of plasma epinephrine, dopamine and IL-10 after acute stressful conditions. This phenomenon may play an important role of an early immnosupression in patients with poor grade SAH.