Clinical studies on alpha 2 plasmin inhibitor.

Plasma levels of alpha 2 plasmin inhibitor (alpha 2 PI) were measured by both an immunological and a functional assay, and a good correlation (r = 0.793; p less than 0.001) was found between the two methods. When compared to values recorded in 17 control subjects (69.55 micrograms/ml +/- 2.04) alpha 2 PI antigen levels were found to be obviously decreased in the 10 patients with decompensated cirrhosis of the liver (41.06 micrograms/ml +/- 4.66) and slightly increased in the 13 nephrotic patients (79.73 micrograms/ml +/- 2.35) and in the 23 hypertriglyceridemic and obese patients (78.59 micrograms/ml +/- 2.23). In spite of similar plasma levels of alpha 2 PI, dilute blood clot lysis was rather accelerated in patients with the nephrotic syndrome (240 min +/- 12) and obviously delayed in patients with endogenous hypertriglyceridemia (739 min +/- 131). Apparently the rate of clot lysis is mainly determined at an earlier stage of the fibrinolytic process, represented by the balance between tissue plasminogen activator and its inhibitor. Severe decrease of alpha 2 PI may nevertheless contribute to accelerated clot lysis as noted in a patient with familial heterozygous alpha 2 PI deficiency. On the other hand increased level of factor XIII and alpha 2 PI associated to an impaired plasminogen activation would render the fibrin network more resistant to fibrinolysis.