Combination immunotherapy with soluble tumor necrosis factor receptors plus interleukin 1 receptor antagonist decreases sepsis mortality.

OBJECTIVE: Inhibition of tumor necrosis factor (TNF) or interleukin 1 (IL-1) alone has not improved sepsis survival in human clinical trials; therefore, it has been suggested that blockade of both may be successful. We tested whether combination immunotherapy would improve survival in mice subjected to a lethal lipopolysaccharide (LPS) challenge or the sepsis model of cecal ligation and puncture. DESIGN: Mice were treated with the combination immunotherapy and challenged with either a lethal dose of lipopolysaccharide or a septic challenge induced by cecal ligation and puncture. SETTING: University research laboratory. SUBJECTS: Adult, female Balb/c mice. INTERVENTIONS: Mice were treated with the combination of the IL-1 receptor antagonist plus a polyethylene glycol-linked dimer of the TNF soluble receptor. MEASUREMENTS AND MAIN RESULTS: LPS lethality was reduced in the treated mice with a decrease in biologically active TNF in the plasma and peritoneal fluid. In the cecal ligation and puncture (CLP) model of sepsis, this combination immunotherapy for 1 day decreased plasma and peritoneal levels of IL-6 and the murine chemokines KC and MIP-2. However, treatment did not result in a reduction in the hypothermia or peripheral blood alterations that occur after CLP, and the 1-day therapy did not result in an improvement in survival. In contrast, when combination immunotherapy was extended to 3 days there was a significant improvement in survival. CONCLUSIONS: These data demonstrate that inhibition of both TNF and IL-1 will decrease the lethality of sepsis initiated by CLP if the combination immunotherapy is provided for a sufficient amount of time.