['Von Willebrand factor antigen (vWf) is an essential hemostatic protein. Increased plasma levels have been documented in patients suffering from the systemic inflammatory response syndrome (SIRS) and resulted presumably from endothelial cell damage specific to the site of injury. We hypothesize that increased plasma levels result from systemic endothelial cell activation and degranulation.', 'We compared immunohistochemical vWf staining in dermal biopsy specimens from patients with SIRS to healthy control subjects in the presence and absence of recombinant human tumor necrosis factor (rhTNF)-alpha. Also, we quantified plasma levels of vWf in these groups using a newly available antibody.', 'A tertiary care surgical intensive care unit in a university teaching hospital.', 'Patients with SIRS and healthy controls.', 'Biopsies and blood samples were obtained from study groups.', 'Decreased baseline vWf staining was noted in SIRS patients. The rhTNF-alpha caused a statistically significant decrease in vWf staining in control subjects but not in SIRS patients. Plasma vWf levels were increased an average of 11-fold in SIRS patients compared with control subjects.'] Is increased plasma von Willebrand factor in the systemic inflammatory response syndrome derived from generalized endothelial cell activation?