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Factor XII dependent fibrinolytic activity is decreased in the acute phase of myocardial or cerebral infarction
Fibrinolysis (1996) 10 Suppl 2, 51-52 © Pearson Professional Ltd 1996
Factor Xll dependent fibrinolytic activity is decreased in the acute phase of myocardial or cerebral ,nfarct,on M. Spannagl', P. Henselmann', M. Weber', J. Gram 2, J. Jespersen 2, C. Kluft 3 'Med. Klinik, Klinikum Innenstadt, Munich, Germany. 2Dept. Clin. Biochemistry, Ribe County University Hospital, Esbjerg, Denmark. 3Gaubius Laboratory, TNO-PG, Leiden, The Netherlands. Summary A factor XII dependent plasminogen activator has been described in human blood. In vitro its activity in plasma is mainly generated via kallikrein. Clinical data suggest long-term depression after myocardial infarction and relation to reinfarction. We were interested in FXII dependent plasminogen activator plasma levels during the acute phase of coronary or cerebral artery occlusion before therapeutic intervention. Plasma was obtained from 41 consecutive patients with myocardial infarction and from 40 patients with cerebral infarction immediately on admission to the hospital. Measurement was performed in dextran sulphate euglobulin fractions in the presence of neutralizing antibodies towards tPA and u-PA. Plasma levels of FXII dependent fibrinolytic activity were found highly significantly reduced both in myocardial (18.3 (8.1-26.3); p=0.003 Blood activator units/ml; median value; (25-75 interpercentile range)) and in cerebral infarction (14.4 (7.6-25.6); p<0.001) as compared to controls (35.3 (27.1-46.2)), but without difference between patient groups. The FXll dependent plasminogen activator plasma levels were neither related to age, gender, smoking or hypertension nor to tPA or PAl-1 plasma levels. Therefore we conclude that FXll dependent fibrinolytic activity plays an independent role in the acute phase of cerebral or coronary artery occlusion.
INTRODUCTION
Besides tissue- and urokinase-type plasminogen activator (t-PA, u-PA) a third pathway of plasminogen activation has been characterised in human blood. ~ In this pathway the generation of activity is dependent on the activation of factor XII (FXII), prekallikrein and an additional proactivator, which up to now is not fully characterised. 2 This activation system can be assessed in the dextran sulphate euglobulin fraction of plasma in the presence of neutralizing antibodies against t-PA and u-PA. Long-term depression has been shown after myocardial infarction.3 We investigated plasma levels of FXII dependent plasminogen activator activity in patients with cerebral or myocardial infarction immediately after onset of clinical
Correspondence to: Dr. M. Spannagl, Medizinische Klinik Innenstadt, Ludwig-Maximillians-Universit&t, Ziemssenstrasse 1, 80336 Munich, Germany. Tel. +49-69-51602226; Fax. +49-89-51602148.
signs of interrupted perfusion before application of any specific diagnostic and therapeutic management. PATIENTS AND METHODS
Plasma samples were obtained from 110 consecutive patients with suspected cerebral or myocardial infarction immediately on admission to the hospital. Diagnosis of cerebral infarction (CI) was confirmed by persisting neurologic deficit and cranial computer tomography in 41 patients. Diagnosis of myocardial infarction (MI) was confirmed by ECG and myocardial enzymes in 40 patients. 19 healthy persons served as controls and were recruted from our hospital staff (median age 48.1; m/f 11/18). All participants gave informed consent and the study protocol was approved by local ethical committee. FXII dependent fibrinolytic activity was determined in the dextran sulphate euglobulin fraction as described previously using excess of neutralizing antibodies against tPA and u-PA. 3 Human normal plasma was used for standardization in blood activator units (BAU/ml) 51
52
Spannagl et al
The protein concentrations in plasma of t-PA and plasminogen activator inhibitor 1 (PAl-l, including free and complexed forms) were analyzed by the use of ELISA, reagents from Chromogenix, MOlndal, Sweden. The PAl activity was determined as the t-PA inhibitory capacity by chromogenic substrate assay from Chromogenix, M61ndal, Sweden. Calibration is performed in arbitrary units (AU). One AU is defined as the amount which inhibits one IU of t-PA/ml plasma under assay conditions. Data are presented as median and 25-75 interpercentile range. Wilcoxon-Mann-Whitney U Test was used for statistical analysis. Table 1 Patient characteristics
n Age (Median,25-75 percentile) Male / Female (%) Hypertension (%) Smoking (%) Diabetes (%)
Myocardial Infarction 41 67 (58-76)
Cerebral Infarction
70 / 30 39 46 29
52 / 48 65 23 20
40 80 (71-82)
Table 2 FXll dependent plasminogen activator activity (BAU/ml; Median, 25-75 percentile range) Control group BAU/ml
35.3 (27.1-46.2)
Myocardial Infarction 18.3 (8.1-26.3)
Cerebral Infarction 14.4 (7.6-25.6)
RESULTS
Patient groups were significantly different with respect to age (p<0.001), smoking (p<0.01) and hypertension (p<0.01). PAl activity and PAI-1 antigen in plasma were significantly lower in cerebral infarction (5.5 AU/ml; 41 ng/ml) as compared with myocardial infarction (9.0 AU/ml; 56 ng/ml), whereas t-PA antigen plasma levels were not different (11.1 vs. 12.6 ng/ml). DISCUSSION
Long-term depression of FXII dependent plasminogen activator activity has been described after thrombolytic therapy of myocardial infarction. 3 Furthermore the depression has been shown to be related to early reinfarction.4 We were interested in FXII dependent plasminogen activator activity in plasma immediately after clinical manifestation of occlusion of cerebral or coronary arteries, before any acute therapy. Patients receiving antiplatelet or anticoagulant therapy were excluded. Thus FXII dependent plasminogen activator activity in our patients can only be influenced by endogenous
Fibrinolysis (1996) 10 Suppl 2, 51-52
mechanisms. Different pathways of fibrinolytic activation have been proposed in vitro: t-PA release by bradykinin, conversion of single-chain urokinase by kallikrein or plasmin and direct activation of a FXII dependent proactivator by kallikrein. 5'6 Clinical studies suggest a relation of FXII dependent plasminogen activator to systemic plasmin formation or local contact factor activation at the side of injury and subsequent proactivator depletion. 3;4 We found no relation to t-PA or PAI-1 plasma levels in our patients. The significant depression of FXII dependent plasminogen activator activity was similar in both patient groups and not related to age, gender, smoking, diabetes or hypertension. The significantly elevated PAI-1 plasma level in myocardial infarction has been reported in several studies and has been suggested as a prospective risk indicator. 7 In conclusion we found highly significant depression of plasma levels of FXII dependent plasminogen activator in the acute phase of coronary or cerebral artery occlusion. The decreased activity of this pathway of fibrinolysis was not related to arteriosclerotic risk factors and t-PA and PAIl in plasma and suggests an independent role of FXII dependent fibrinolytic activity in arterial vascular events. REFERENCES
1. Kluft C, Trumpi-Kalshoven MM, Jie AFH, Veldhuyzen-Stolk EC. Factor XII-dependent fibrinolysis: A double function of plasma kallikrein and the occurrence of a previously undescribed factor XII- and kallikrein-dependent plasminogen proactivator. Thromb Haemostas 1979; 41:756-773 2. Binnema DJ, Dooijewaard G, van Iersel JJL, Turion PNC, Kluft C. The contact system dependent plasminogen activator from human plasma: Identification and characterization. Thromb Haemostas 1990; 63:390-397 3. Munkvad S, Jespersen J, Gram J, Kluft C. Long-lasting depression of the factor XII-dependent fibrinolytic system in patients with myocardial infarction undergoing thrombolytic therapy with recombinant tissue-type plasminogen activator. J Am Coil Cardiol 1991; 17:957-962 4. Munkvad S, Jespersen J, Gram J, Kluft C. Depression of factor XII dependent fibrinolytic activity characterises patients with early myocardial reinfarction after recombinant tissuetype plasminogen activator therapy. J Am Coil Cardiol 1991; 18:454-458 5. Ichinose A, Fujikawa K, Suyama T. The activation of prourokinase by plasma kallikrein and its inactivation by thrombin. J Biol Chem 1986; 261:3486-3489 6. Kluft C, Jie AFH. Route of activation, in vitro, of the factor XII dependent pathway of fibrinolysis. Fibrinolysis 1994; 8: 172-176 7. Juhan-Vague I, Alessi MC. Plasminogen activator inhibitor 1 and atherothrombosis. Thromb Haemostas 1993; 70:138-143
© Pearson Professional Ltd 1996
Factor Xll dependent fibrinolytic activity is decreased in the acute phase of myocardial or cerebral ,nfarct,on M. Spannagl', P. Henselmann', M. Weber', J. Gram 2, J. Jespersen 2, C. Kluft 3 'Med. Klinik, Klinikum Innenstadt, Munich, Germany. 2Dept. Clin. Biochemistry, Ribe County University Hospital, Esbjerg, Denmark. 3Gaubius Laboratory, TNO-PG, Leiden, The Netherlands. Summary A factor XII dependent plasminogen activator has been described in human blood. In vitro its activity in plasma is mainly generated via kallikrein. Clinical data suggest long-term depression after myocardial infarction and relation to reinfarction. We were interested in FXII dependent plasminogen activator plasma levels during the acute phase of coronary or cerebral artery occlusion before therapeutic intervention. Plasma was obtained from 41 consecutive patients with myocardial infarction and from 40 patients with cerebral infarction immediately on admission to the hospital. Measurement was performed in dextran sulphate euglobulin fractions in the presence of neutralizing antibodies towards tPA and u-PA. Plasma levels of FXII dependent fibrinolytic activity were found highly significantly reduced both in myocardial (18.3 (8.1-26.3); p=0.003 Blood activator units/ml; median value; (25-75 interpercentile range)) and in cerebral infarction (14.4 (7.6-25.6); p<0.001) as compared to controls (35.3 (27.1-46.2)), but without difference between patient groups. The FXll dependent plasminogen activator plasma levels were neither related to age, gender, smoking or hypertension nor to tPA or PAl-1 plasma levels. Therefore we conclude that FXll dependent fibrinolytic activity plays an independent role in the acute phase of cerebral or coronary artery occlusion.
INTRODUCTION
Besides tissue- and urokinase-type plasminogen activator (t-PA, u-PA) a third pathway of plasminogen activation has been characterised in human blood. ~ In this pathway the generation of activity is dependent on the activation of factor XII (FXII), prekallikrein and an additional proactivator, which up to now is not fully characterised. 2 This activation system can be assessed in the dextran sulphate euglobulin fraction of plasma in the presence of neutralizing antibodies against t-PA and u-PA. Long-term depression has been shown after myocardial infarction.3 We investigated plasma levels of FXII dependent plasminogen activator activity in patients with cerebral or myocardial infarction immediately after onset of clinical
Correspondence to: Dr. M. Spannagl, Medizinische Klinik Innenstadt, Ludwig-Maximillians-Universit&t, Ziemssenstrasse 1, 80336 Munich, Germany. Tel. +49-69-51602226; Fax. +49-89-51602148.
signs of interrupted perfusion before application of any specific diagnostic and therapeutic management. PATIENTS AND METHODS
Plasma samples were obtained from 110 consecutive patients with suspected cerebral or myocardial infarction immediately on admission to the hospital. Diagnosis of cerebral infarction (CI) was confirmed by persisting neurologic deficit and cranial computer tomography in 41 patients. Diagnosis of myocardial infarction (MI) was confirmed by ECG and myocardial enzymes in 40 patients. 19 healthy persons served as controls and were recruted from our hospital staff (median age 48.1; m/f 11/18). All participants gave informed consent and the study protocol was approved by local ethical committee. FXII dependent fibrinolytic activity was determined in the dextran sulphate euglobulin fraction as described previously using excess of neutralizing antibodies against tPA and u-PA. 3 Human normal plasma was used for standardization in blood activator units (BAU/ml) 51
52
Spannagl et al
The protein concentrations in plasma of t-PA and plasminogen activator inhibitor 1 (PAl-l, including free and complexed forms) were analyzed by the use of ELISA, reagents from Chromogenix, MOlndal, Sweden. The PAl activity was determined as the t-PA inhibitory capacity by chromogenic substrate assay from Chromogenix, M61ndal, Sweden. Calibration is performed in arbitrary units (AU). One AU is defined as the amount which inhibits one IU of t-PA/ml plasma under assay conditions. Data are presented as median and 25-75 interpercentile range. Wilcoxon-Mann-Whitney U Test was used for statistical analysis. Table 1 Patient characteristics
n Age (Median,25-75 percentile) Male / Female (%) Hypertension (%) Smoking (%) Diabetes (%)
Myocardial Infarction 41 67 (58-76)
Cerebral Infarction
70 / 30 39 46 29
52 / 48 65 23 20
40 80 (71-82)
Table 2 FXll dependent plasminogen activator activity (BAU/ml; Median, 25-75 percentile range) Control group BAU/ml
35.3 (27.1-46.2)
Myocardial Infarction 18.3 (8.1-26.3)
Cerebral Infarction 14.4 (7.6-25.6)
RESULTS
Patient groups were significantly different with respect to age (p<0.001), smoking (p<0.01) and hypertension (p<0.01). PAl activity and PAI-1 antigen in plasma were significantly lower in cerebral infarction (5.5 AU/ml; 41 ng/ml) as compared with myocardial infarction (9.0 AU/ml; 56 ng/ml), whereas t-PA antigen plasma levels were not different (11.1 vs. 12.6 ng/ml). DISCUSSION
Long-term depression of FXII dependent plasminogen activator activity has been described after thrombolytic therapy of myocardial infarction. 3 Furthermore the depression has been shown to be related to early reinfarction.4 We were interested in FXII dependent plasminogen activator activity in plasma immediately after clinical manifestation of occlusion of cerebral or coronary arteries, before any acute therapy. Patients receiving antiplatelet or anticoagulant therapy were excluded. Thus FXII dependent plasminogen activator activity in our patients can only be influenced by endogenous
Fibrinolysis (1996) 10 Suppl 2, 51-52
mechanisms. Different pathways of fibrinolytic activation have been proposed in vitro: t-PA release by bradykinin, conversion of single-chain urokinase by kallikrein or plasmin and direct activation of a FXII dependent proactivator by kallikrein. 5'6 Clinical studies suggest a relation of FXII dependent plasminogen activator to systemic plasmin formation or local contact factor activation at the side of injury and subsequent proactivator depletion. 3;4 We found no relation to t-PA or PAI-1 plasma levels in our patients. The significant depression of FXII dependent plasminogen activator activity was similar in both patient groups and not related to age, gender, smoking, diabetes or hypertension. The significantly elevated PAI-1 plasma level in myocardial infarction has been reported in several studies and has been suggested as a prospective risk indicator. 7 In conclusion we found highly significant depression of plasma levels of FXII dependent plasminogen activator in the acute phase of coronary or cerebral artery occlusion. The decreased activity of this pathway of fibrinolysis was not related to arteriosclerotic risk factors and t-PA and PAIl in plasma and suggests an independent role of FXII dependent fibrinolytic activity in arterial vascular events. REFERENCES
1. Kluft C, Trumpi-Kalshoven MM, Jie AFH, Veldhuyzen-Stolk EC. Factor XII-dependent fibrinolysis: A double function of plasma kallikrein and the occurrence of a previously undescribed factor XII- and kallikrein-dependent plasminogen proactivator. Thromb Haemostas 1979; 41:756-773 2. Binnema DJ, Dooijewaard G, van Iersel JJL, Turion PNC, Kluft C. The contact system dependent plasminogen activator from human plasma: Identification and characterization. Thromb Haemostas 1990; 63:390-397 3. Munkvad S, Jespersen J, Gram J, Kluft C. Long-lasting depression of the factor XII-dependent fibrinolytic system in patients with myocardial infarction undergoing thrombolytic therapy with recombinant tissue-type plasminogen activator. J Am Coil Cardiol 1991; 17:957-962 4. Munkvad S, Jespersen J, Gram J, Kluft C. Depression of factor XII dependent fibrinolytic activity characterises patients with early myocardial reinfarction after recombinant tissuetype plasminogen activator therapy. J Am Coil Cardiol 1991; 18:454-458 5. Ichinose A, Fujikawa K, Suyama T. The activation of prourokinase by plasma kallikrein and its inactivation by thrombin. J Biol Chem 1986; 261:3486-3489 6. Kluft C, Jie AFH. Route of activation, in vitro, of the factor XII dependent pathway of fibrinolysis. Fibrinolysis 1994; 8: 172-176 7. Juhan-Vague I, Alessi MC. Plasminogen activator inhibitor 1 and atherothrombosis. Thromb Haemostas 1993; 70:138-143
© Pearson Professional Ltd 1996