Specific functional and immunologic assay of plasma plasminogen in hereditary angioedema, in hereditary angioedema treated with tranexamic acid, and in normal subjects.

Plasma plasminogen levels were determined by a specific esterolytic assay and a radial immunodiffusion assay, both of which were standardized on a weight basis by using highly purified plasminogen diluted in plasminogen-free plasma. In thirteen normal individuals the functional and antigenic levels were 275 +/- 61 microgram/ml and 285 +/- 61 microgram/ml, respectively (r = 0.95), whereas in 58 plasmas from individuals with hereditary angioedema the levels were 272 +/- 58 microgram/ml and 265 +/- 64 microgram/ml, respectively (r = 0.89). In two patients treated with tranexamic acid either acutely or chronically, both the functional and antigenic plasminogen levels were diminished.