A clinical study on the use of a fluorogenic substrate assay of plasminogen

A fluorogenic substrate assay of plasminogen was compared with acceptable methodologies, i.e., caseinolytic and radial immunodiffusion assays. Reference intervals based on a population of 25 members of the laboratory staff were 2.5-3.8 CTA u/ml (fluorogenic), 2.2-4.0 CTA u/ml (caseinolytic) and 8.7-14.3 mg/dl (RID). Ninety eight determinations were performed on 65 patients. Regression analysis showed linear correlation between the fluorometric and caseinolytic assays (r = 0.8046, p less than 0.03) and between the fluorometric and immunologic assays (r = 0.8572, p less than 0.005). Pre-operative and post-operative determinations were performed on 33 patients undergoing coronary artery bypass surgery and there was a consistent and significant (10%-76%) decrease in the plasminogen levels post-operatively (p less than 0.01). Twenty-five patients with various malignancies were compared with the normal population; no significant difference in the plasminogen levels was observed between the two groups.