Increased von Willebrand factor levels in patients with systemic lupus erythematosus reflect inflammation rather than increased propensity for platelet activation.

In this SLE cohort, VWF:Ag behaved similarly to acute-phase reactants, but VWF:Ag increases were not matched by increases in functional activity per unit of VWF. Thus, more VWF did not increase the propensity for platelet aggregation in SLE.