Neutrophils express tissue factor in a monkey model of sepsis

Background. Although tissue factor (TF) is involved in hemostasis, thrombog enesis, inflammation, and cellular immune response, its source in sepsis re mains controversial. Recently, we found that, in addition to monocytes and endothelial cells, neutrophils may express TF in a rabbit model. The purpos e of this study was to determine whether neutrophils could be a source of T F in a monkey model of sepsis. Methods. TF messenger RNA (mRNA) and protein in neutrophils were assayed by in situ hybridization and immunohistochemistry in tissues obtained from mo nkeys after injection of lipopolysaccharide (LPS) (n = 3) and after injecti on of saline as a control (n = 2). Coagulation Parameters were measured bef ore and at 1.5 and 3 hours after injections. Results, In LPS-treated monkeys, TF mRNA and Protein were induced not only in monocytes and endothelial cells, but also in neutrophils accumulating in the Liver 3 hours after LPS injection. Thrombin-antithrombin III complex a nd fibrin degradation Products D-dimer levels were significantly Increased at 3 and 1.5 hours after LPS injection compared with controls. Conclusions, Neutrophils are a source of TF and are implicated in direct ac tivation of the coagulation cascade in the early phases of sepsis in the mo nkey. These results give important information for the treatment of sepsis.