PAI-2 levels in plasma of patients with HAE-N and control subjects. PAI-2 levels in plasma of patients and control subjects were measured by means of ELISA. A, Each bar represents individual subjects (HAE-N) expressed as nanograms per milliliter. B, Means ± SEs of 23 control samples, 11 samples from patients with HAE-N without the Factor XII mutation and 12 samples from patients with HAE-N with the Factor XII mutation, and 23 samples from patients with HAE type I. C, Individual values for patients with HAE type I. Values that exceeded the detection limit of 100 are shown as 100. *Significant difference at P < .01 and **significant difference at P < .001. FXII, Factor II.