Plasminogen San Antonio: an abnormal plasminogen with a more cathodic migration, decreased activation and associated thrombosis.

An abnormal plasminogen (San Antonio) has been isolated from a patient with axillary vein thrombosis. A decreased level of fibrinolytic activity was detected in both plasma and a purified system. The molecular abnormalities were investigated with both functional and immunological tests. Slightly decreased antigen concentration was noted in plasma. By crossed immunoelectrophoresis, the patient and his two children had a second small arc and the primary arc migrated more cathodically. A distinct isozyme was detected in the abnormal plasminogen. Functionally, this abnormal plasminogen is characterized by failure to enhance maximal conversion to plasmin, especially by plasminogen activators, which are enhanced by fibrin or fibrin degradation products. The proband and his children are heterozygous for this abnormal plasminogen.