An anti-plasminogen antibody preparation that inhibits the activation of human plasminogen but enhances the activator activity of the B-chain-streptokinase complex.

An anti-Glu-plasminogen (GLU-PLG) polyclonal antibody antiserum was prepared in the goat, and specific IgG anti-GLU-PLG antibodies were purified by affinity chromatography using a sepharose-GLU-PLG column. In chromogenic assay studies, the anti-GLU-PLG antibody preparation was found to be an effective inhibitor of the activation of PLG, and it produced different inhibition curves with four different PLG activators. 80% inhibition of streptokinase (SK) activation of GLU-PLG occurred with an anti-GLU-PLG antibody/GLU-PLG molar ratio of 1:1, whereas at this ratio only 28% and 36% inhibition of the plasmin-streptokinase (PLN-SK) and the B-chain-streptokinase (B-SK) complexes occurred. At a 1:1 molar ratio of antibody to PLN, no inhibition of PLN activity occurred. When the anti-GLU-PLG antibody preparation was incubated with each PLG activator, an enhancement in the activator activity of the B-SK complex, but not the other activators was observed with mini-plasminogen (MINI-PLG). Enhancement occurred at a molar ratio of 1:1 and reached a peak of 97% enhancement at a molar ratio of 10:1. Enhanced activator activity of the B-SK complex of 49% occurred at a molar ratio of 1:1 when GLU-PLG was the substrate. At higher molar ratios inhibition of activator activity on GLU-PLG was observed, but not on MINI-PLG. These results indicate that there are multiple activator binding sites on PLG, that these four activators all bind differently to GLU-PLG and MINI-PLG, that some antibody populations that are specific for the PLN B-chain can stimulate activator activity, while other antibody populations that are specific for either the PLN A-chain or the B-chain are inhibitory.

Relationship between postsurgical fibrinolytic parameters and deep vein thrombosis in surgical patients treated with compression devices.

This study consisted of 52 patients admitted for orthopedic surgery and 28 patients admitted for general surgery, who were treated with Sequential Compression Devices (SCD) and Thromboembolic Deterrent Stockings (TEDS) and monitored for the development of deep vein thrombosis (DVT). Coagulation and fibrinolytic profiles were carried out on these patients preoperatively, and on days one, three, and six postoperatively. All patients were followed by I-125-Fibrinogen scanning, Venous Doppler, and Impedance Plethysmography studies for clot detection. In the orthopedic surgery group, six (11.5%) developed DVT, and in the general surgery group, one (3.6%) developed DVT. No patients developed pulmonary embolism. The combined incidence of DVT was 8.8 per cent. A variety of parameters was measured in order to determine whether compression devices prevent a fibrinolytic shut-down commonly seen in the postsurgical patient. A combination of three assays was found to be significant in demonstrating a fibrinolytic response. These parameters were a post-surgical decrease in the plasminogen level, an increase in the level of free protease activity postoperatively, and an increase in the level of tissue plasminogen activator after surgery. 56.3 per cent of all patients treated with SCD and TEDS showed a fibrinolytic response on postoperative day one by a combination of all three of these parameters. In the group of patients that developed DVT none showed an increase in free protease activity, and five of seven showed no significant decrease in plasminogen and no increase in tissue plasminogen activator. Patients who developed thrombosis had measurable differences in their fibrinolytic system compared to those without postoperative thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased platelet number and function and increased fibrinolysis contribute to postoperative bleeding in cardiopulmonary bypass patients.

We simultaneously evaluated platelet and fibrinolytic parameters to assess their individual and combined contributions to postoperative blood loss in cardiopulmonary (CP) bypass patients. Platelet count, platelet aggregability, hematocrit, plasminogen (PLG) concentration, alpha 2-antiplasmin (AP) concentration, free protease activity (fPA), and antithrombin-III (AT-III) were measured in nine patients undergoing surgery using cardiopulmonary bypass. Chest tube drainage was used as the measure of postoperative blood loss. Hematocrit, platelet count, PLG, AP, and AT-III all decreased during CP bypass, with PLG and AT-III decreasing much more than dilution. During CP bypass, platelet aggregability to ADP did not change significantly from pre-bypass, but aggregability to arachidonic acid (AA) decreased significantly. Following protamine administration there was a large increase (83%) in fPA, the platelet count showed a further drop (from 61% to 50% of pre-bypass levels), and platelet aggregability decreased significantly (from 95% to 34% of pre-bypass levels for ADP, and from 55% to 11.9% for AA). Chest tube drainage during the first four postoperative hours correlated positively (p less than 0.05) with the combination of increase in free protease activity and decrease in platelet count. The total chest tube drainage correlated significantly with the combination of decrease in platelet count and the decrease in platelet aggregability. These combinations of changes correlated significantly with postoperative blood loss whereas the individual changes did not.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro comparison of fibrinolytic activity of plasminogen activators using a thrombelastographic method: in vivo evaluation of the B-chain-streptokinase complex in the dog model using pre-titered doses.

Thrombelastography was used to quantitatively compare the clot-lysing efficiency of 6 different plasminogen activators, using human whole blood, pooled normal plasma, and platelet rich plasma. The activators compared were the B-chain-streptokinase complex, the plasmin-streptokinase complex, the mini-plasminogen-streptokinase complex, tissue plasminogen activator, streptokinase, and urokinase. The most efficient activator found was the B-chain-streptokinase complex. This complex was 4.0 times more effective than streptokinase, 3.0 times more effective than the plasmin-streptokinase complex, 1.3 times more effective than the mini-plasminogen-streptokinase complex, 2.3 times more effective than tissue plasminogen activator, and 16.0 times more effective than urokinase. Although there were differences in both the coagulation and fibrinolysis thrombelastographic patterns between plasma and whole blood, the comparative efficiencies of each activator were the same with either plasma or blood. The B-chain-streptokinase complex was evaluated as a thrombolytic agent in clot-lysis experiments in the jugular vein in the dog model, using a thrombelastographic method to determine the minimum dose of activator necessary for clot-lysis. With 6 dogs infused locally with 0.25 mg (8000 I.U.) of the plasmin-streptokinase complex, the cumulative clot-lysis was 18.0 +/- 3.0% with the first dose, 33.0 +/- 2.1% with the second dose, and 55.2 +/- 8.6% with the third dose. With 6 dogs infused locally with 0.03 mg (2000 I.U.) of the B-chain-streptokinase complex, the cumulative clot-lysis was 30.6 +/- 6.4% with the first dose, 54.4 +/- 9.6% with the second dose, and 80.2 +/- 9.0% with the third dose.