Absence of antibodies to tissue-type plasminogen activator in patients with previous deep vein thrombosis.
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Adolescent↗
Biomedical subjects
M Cugno
Publications and source records attributed to M Cugno.
Pathogenetic and clinical aspects of C1 inhibitor deficiency.
People deficient in C1-INH present recurrent angioedema localized to subcutaneous or mucous tissues. The defect can be caused by impaired synthesis, due to a genetic defect (hereditary angioedema), or by increased catabolism (acquired angioedema). In our experience the majority of patients with acquired angioedema (16 of 18) have autoantibodies to C1-INH in their serum. These autoantibodies bind to C1-INH with different and generally low affinity. The vasopermeability mediator responsible for attacks is still undefined: bradykinin (derived from cleavage of high molecular weight kininogen) and a kinin-like peptide (derived from the second component of complement) still remain the two primary candidates. We examined the systems controlled by C1-INH (complement, contact system, fibrinolysis and coagulation) and found that all of them are activated during angioedema attacks. Activation of the coagulation leads to generation of thrombin whose vasoactive effect can thus influence edema formation. Treatment of severe angioedema attacks is satisfactorily performed with C1-INH plasma concentrate although patients with an acquired defect frequently need very high doses. Attenuated androgens effectively prevent attacks in hereditary angioedema, but their safety, on the very long-term, needs to be further assessed. Acquired angioedema generally fail to respond to these drugs, but can be treated prophylactically with antifibrinolytic agents.
Abdomen, Acute↗
Activation of the contact system in cerebrospinal fluid of patients with Alzheimer disease.
Several converging lines of evidence suggest that beta-amyloid and inflammation may be linked in the pathogenesis of Alzheimer disease (AD), but the mechanism of beta-amyloid neurotoxicity is unclear. In this study, by demonstrating that high molecular weight kininogen may be massively cleaved in the cerebrospinal fluid (CSF) of patients with AD, we provide evidence of the potential involvement of the contact system in the inflammatory processes taking place in this disease. In the CSF of patients with neuroimmune inflammatory disease (multiple sclerosis, chronic inflammatory demyelinating polyneuropathy), there was no evidence of increased cleavage of high molecular weight kininogen, suggesting that this finding may be characteristic of the Alzheimer brain. The data obtained from in vitro experiments seem to indicate that the cleavage of high molecular weight kininogen in vivo may be the result of the interaction of beta-amyloid with factor XII and of kallikrein generation. The actual relevance of such a phenomenon remains to be established in vivo. However, the demonstration that the contact system may be activated in the brains of Alzheimer patients points to the potential involvement of the kallikrein-kinin system in the inflammatory process of this disease.
Aged↗
Activation of the coagulation cascade in C1-inhibitor deficiencies.
Activation of the contact and complement systems in C1-inhibitor deficiencies is thought to contribute to the pathogenesis of angioedema attacks by releasing kinins. Trigger stimuli of attacks may also activate coagulation. This is particularly important because experimental data suggest that thrombin, the main enzyme of the coagulation cascade, increases vascular permeability and can thus influence edema formation. We have studied 19 patients with hereditary angioedema (HAE) during remission, 5 HAE patients during acute attacks, and 6 patients with acquired angioedema (AAE) during remission and during seven attacks. Thirty normal subjects, matched for sex and age, served as controls. Generation of thrombin was measured by enzyme-linked immunosorbent assay (ELISA) as plasma levels of the prothrombin fragment 1 + 2 (F1 + 2); the initiators of the tissue factor and contact coagulation pathways were investigated by measuring plasma levels of activated factor VII (FVIIa) coagulometrically and activated factor XII (FXIIa) by ELISA. Cleavage of high molecular weight kininogen (HK) was evaluated by immunoblotting analysis. F1 + 2 was slightly increased during remission and further significantly increased during attacks in both HAE (P = .0115) and AAE. FVIIa and FXIIa, normal during remission, increased strikingly during attacks in both HAE (P = .0022 and P = .0044) and AAE. During remission, cleaved HK was normal in HAE and high in AAE; during attacks it increased in HAE (P = .0008) and remained elevated in AAE. Our data indicate that in C1-inhibitor deficient patients there is increased generation of thrombin during attacks, with signs of activation of both the contact and tissue factor coagulation pathways. In conclusion, C1-inhibitor deficiency, whether hereditary or acquired, has demonstrable activation of the coagulation and kinin-forming cascades during attacks and that thrombin should be considered a possible contributing factor in the pathogenesis of edema in HAE and AAE.
Adult↗
Activation of factor XII and cleavage of high molecular weight kininogen during acute attacks in hereditary and acquired C1-inhibitor deficiencies.
Hereditary and acquired C1-inhibitor (C1-INH) deficiencies (hereditary angioedema, HAE and acquired angioedema, AAE) are characterized by episodic increases in vasopermeability due to kinin release. Despite continuously defective C1-INH levels, symptoms only recur occasionally suggesting an episodic generation of pathogenetic factors induced by activation of the protease systems regulated by C1-INH. We evaluated activation of factor XII by measuring plasma levels of FXIIa with a commercial ELISA and cleavage of high molecular weight kininogen by performing SDS PAGE and immunoblotting analysis during 5 attacks in 5 different patients with HAE and during 7 attacks in 3 patients with AAE. The patients were also studied during remission. We confirmed our previous data indicating that during attacks both HAE and AAE patients had very high levels of cleaved HK (p < 0.0001) whereas during remission cleaved HK levels were normal in HAE and significantly increased in AAE (p < 0.0001). Both in HAE and in AAE, plasma levels of FXIIa were normal during remission and significantly increased during acute attacks (p = 0.0126; p = 0.0003). Our data suggest that the activation of a contact system is required to produce clinical symptoms.
Acute Disease↗
Relevance of lymphoproliferative disorders and of anti-C1 inhibitor autoantibodies in acquired angio-oedema.
We looked for autoantibodies to C1 inhibitor (C1-INH) and evaluated the relationship of their presence to the associated lymphoproliferative diseases and to the cleaved form of C1-INH in 13 patients with acquired C1-INH deficiency (acquired angio-oedema (AAE)). At the time of manifestation of angio-oedema symptoms or within a few years the following diseases were diagnosed: liver angioma (n = 1), M-components (n = 7, one of whom also had echinococcal liver cysts), breast cancer (n = 1), chronic lymphocytic leukaemia (CLL; n = 1); three patients had no associated disease. Anti-C1-INH autoantibodies, measured both as immunoglobulin binding to C1-INH immobilized onto microtitre plates (ELISA) and as plasma inhibitory activity of C1-INH function, were found in 12 patients. Binding of C1-INH to paraproteins, transferred to Immobilon after agarose gel electrophoresis, was detectable in five of seven M-components associated with AAE. Immunoblotting analysis of SDS-PAGE-separated plasma demonstrated that C1-INH circulated in the cleaved 96-kD form in the 12 patients with autoantibodies, but not in the one without. In conclusion, the large majority of our patients have autoantibodies to C1-INH. Circulating autoantibodies are necessary for the generation of cleaved C1-INH. The paraproteins associated with AAE are frequently autoantibodies to C1-INH and thus account for its consumption.
Adult↗
Measurement of activated factor XII in health and disease.
We investigated a new ELISA for measuring activated factor XII (FXIIa) in plasma. The intra-assay coefficient of variation was 3.5% and 5.1% for plasma containing 2.5 and 8.2 ng/ml FXIIa. The inter-assay coefficient of variation was 6.2% and 6.6%. FXIIa correlated with age in women older than 55 years (r = 0.55, P = 0.0003). Mean levels in the whole population of 160 healthy individuals included in this study were not different between men and women, but women younger than 55 years had lower levels than older women and men of the corresponding age. In a group of 25 healthy centenarians FXIIa was significantly higher (3.2 ng/ ml, 95% CI 2.3-3.6) than in controls (2.1 ng/ml, 95% CI 1.8-2.4). Increased levels were also found in pregnancy, with higher levels in the third trimester (4.7 ng/ml, 95% CI 3.9-5.5) than in the first trimester (2.9 ng/ml, 95% CI 2.2-3.9). FXIIa was unmeasurable in patients with FXII deficiency, but normal in patients with FXI deficiency and C1-inhibitor deficiency. FXIIa was significantly higher than in normal controls in patients with severe sepsis (3.9 ng/ml, 95% CI 2.8-5.4) and septic shock (5.4 ng/ml, 95% CI 3.7-7.7). After treatment with thrombolytic agents, a marked increase of FXIIa was found in patients with myocardial infarction. In conclusion, the immunoassay of FXIIa permits to study more directly the contact phase of blood coagulation in situations in which the involvement of this system may play a pathophysiological role.
Adult↗
Non neutralizing antibodies to tissue type plasminogen activator in the serum of acute myocardial infarction patients treated with the recombinant protein.
Recombinant tissue-type plasminogen activator (rt PA) is currently used as a thrombolytic agent in the management of acute myocardial infarction (AMI). Since it is known that other recombinant proteins induce antibody formation when administered to humans, we determined the presence of anti-rt-PA antibodies in serial blood samples from 60 AMI patients (43 treated with and 17 without rt-PA). Blood samples were taken upon hospital admission, 15 days and 1, 3, 6 months thereafter. A blood sample was also collected from 200 healthy subjects. Using an ELISA, anti-rt-PA antibodies were detected as serum immunoglobulins specifically binding immobilized rt-PA, AMI patients before treatment and normal subjects exhibited negligible levels of anti-rt-PA antibodies; both groups had only one outlier value. Fifteen days after rt-PA treatment, 2 AMI patients showed an increase in antibody titer beyond the highest normal value. This titer progressively decreased during the following 6 months. The antibodies from these two patients bound rt-PA both in a solid and fluid phase. They bound melanoma t-PA to a lower degree and did not bind urokinase type plasminogen activator at all, indicating specificity for t-PA. The marked temporal relationship between rt-PA infusion and antibody appearance indicated that antibody formation had been elicited by the infusion of rt-PA. Nevertheless, the lack of anti-rt-PA antibody interference with rt-PA function in vitro, along with the favourable clinical outcome of those patients having such antibodies would indicate that the appearance of anti-rt-PA antibodies does not interfere with the physiological fibrinolytic activity.
Adult↗
Cardioprotective effect of C1-inhibitor.
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Animals↗
Cleavage of high molecular weight kininogen in ascites and plasma of patients with cirrhosis.
The vasoactive peptide bradykinin may be involved in the pathogenesis of vasodilation, which has been considered the initiating event of ascites formation in cirrhotic patents. Since bradykinin is generated through the cleavage of high molecular weight kininogen (HK) by kallikrein, we looked for the cleavage of HK by an immunoblotting technique in plasma and ascitic fluid of 28 patients with cirrhosis of different etiology. The majority of patients showed massive cleavage of HK in ascitic fluid (median 50% of total HK; range 23-100%). Patients with severe ascites had more cleaved HK in plasma (29%; range 8-38%) than normal subjects (22%; range 11-32) (P = 0.02). Patients with high levels of plasma renin activity (5-60 ng/ml/hour), which is considered a consequence of peripheral vasodilation, had more plasma cleaved HK (31%; range 18-38)(p = 0.0097) than normals. Thus, our data support the view that cleavage of HK could play a role in the pathogenesis of vasodilation and ascites formation in patients with decompensated cirrhosis.
Adult↗
Infusion of C1-inhibitor plasma concentrate prevents hyperamylasemia induced by endoscopic sphincterotomy.
Hyperamylasemia after endoscopic sphincterotomy is a common event, occurring in about 70% of cases. Clinical acute pancreatitis may also develop in 1% to 6% of cases. Previous attempts to prevent this reaction with inhibitors of exocrine pancreatic secretion (somatostatin and octreotide) provided conflicting and often disappointing results. Kallikrein is one of the proteases that sustain the inflammatory process in acute pancreatitis; the C1 inhibitor is the only physiologic inhibitor of the first component of the human complement cascade and is a major inactivator of kallikrein and Factor XII. Therefore, we tested the C1 inhibitor in the prevention of hyperamylasemia in 40 consecutive patients undergoing endoscopic sphincterotomy for common bile duct stones or benign papillary stenosis. They were given either C1 inhibitor (20 cases) or placebo (20 cases) before the procedure. Serum amylase levels were determined at baseline and 2, 4, 8, and 24 hours thereafter. Significant differences in serum amylase levels between groups were observed at 2 hours (p < .01), 4 hours (p < .0005), and 8 hours (p < .005) after sphincterotomy. The differences in amylase levels were also significant among the 24 subjects with pancreatic ductal filling (2 hours, p < .05; 4 hours, p < .005; 8 hours, p < .01) and the 9 patients with previous episodes of acute pancreatitis (4 hours, p < .05; 8 hours, p < .05; 24 hours, p < .05). The infusion of C1-inhibitor plasma concentrate resulted in a 50% increase in functional levels of C1 inhibitor (in the 8 cases for whom they were assayed), which persisted throughout the observation period.
Acute Disease↗
Activation of the contact system and fibrinolysis in autoimmune acquired angioedema: a rationale for prophylactic use of tranexamic acid.
C1-inhibitor deficiency results in bouts of mucocutaneous edema and may be inherited (hereditary angioedema) or acquired (acquired angioedema [AAE]). The two forms have the same clinical picture but differ in the response to treatment. Prophylaxis with antifibrinolytic agents produces better results in the acquired form than in the inherited form, in which androgen derivatives are more effective. It is hypothesized that activation of the contact and fibrinolytic systems is involved in the pathogenesis of attacks. We evaluated these two systems in plasma from eight patients with AAE and anti-C1-inhibitor autoantibodies (autoimmune AAE) by measuring the cleavage of high molecular weight kininogen and the complexes formed by plasmin and its inhibitor alpha 2-antiplasmin. We also measured complement parameters, autoantibody titer, and cleaved C1-inhibitor (relative molecular mass = 96,000), because autoantibodies to C1-inhibitor are known to facilitate its cleavage by proteases. Plasma was obtained from patients in remission, during prophylactic treatment with the antifibrinolytic agent tranexamic acid (2 to 4.5 gm/day) and also from two patients during acute attacks of edema. Levels of cleaved high molecular weight kininogen and antiplasmin-plasmin complexes in patients with AAE were both higher in basal conditions, during treatment, and during acute attacks than those in normal subjects (p < 0.001). The cleaved inactive form of C1-inhibitor was also present in all patients in all three conditions. Therapy with antifibrinolytic agents reduced the frequency and intensity of symptoms without significantly changing any of the biochemical parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute Disease↗
Activation of complement and kinin systems after thrombolytic therapy in patients with acute myocardial infarction. A comparison between streptokinase and recombinant tissue-type plasminogen activator.
BACKGROUND: We have previously shown that treatment with streptokinase induces abrupt complement activation and transient neutropenia in patients with acute myocardial infarction (AMI). The purpose of this study was to compare the effects of two different thrombolytic agents--streptokinase (SK) and recombinant tissue-type plasminogen activator (rTPA)--on activation of the complement and kinin systems in plasma of patients with AMI. METHODS AND RESULTS: Forty-one patients with AMI who were eligible for thrombolytic therapy were studied. Twenty-three patients were treated with streptokinase (1.5 million IU IV over 60 minutes) and 18 were treated with rTPA (8 with bolus of 10 mg IV, followed by 50 mg infused over 60 minutes and then 40 mg infused over 120 minutes; 10 patients were administered rTPA and heparin according to the accelerated infusion protocol indicated by the GUSTO study). C4a and C3a were measured by radioimmunoassay, soluble terminal complement components (SC5b-9) and anti-SK IgG antibodies were measured by ELISA. Cleaved high molecular weight kininogen (HK) was quantitated in plasma by SDS-PAGE and immunoblotting analysis. C4a levels were significantly and similarly increased in both groups, whereas the levels of C3a and SC5b-9 after rTPA infusion were only slightly elevated and were significantly lower than after SK. No differences were observed between patients treated with slow or accelerated rTPA regimens. The titer of antibodies to SK was highly correlated with the levels of C3a and SC5b-9, whereas a lesser correlation was observed with C4a. Treatment with rTPA did not induce the transient neutropenia observed after SK infusion. The cleavage products of HK were significantly greater after SK than after rTPA infusion. CONCLUSIONS: Our results show that both thrombolytic agents activate the classic complement pathway and that plasmin could be the common trigger for this phenomenon. A significant activation of the complement common pathway (from C3 to terminal components) was observed only with SK infusion and is attributable to the rapid formation of immunocomplexes between SK and anti-SK antibodies present in plasma as a consequence of previous streptococcal infections. The minimal activation of C5 component of the common pathway explains the absence of leukopenia in patients treated with rTPA. Cleavage of HK, larger after SK than after rTPA infusion, represents a condition enhancing the generation of bradykinin by kallikrein. The recent experimental data that indicate a damaging effect of complement activation on the infarcted zone and the contrasting favorable effect consequent to bradykinin formation raise some questions about the clinical importance of the different biological consequences of SK versus rTPA.
Adult↗
Autoimmune C1 inhibitor deficiency: report of eight patients.
PURPOSE: In this study, we investigated the clinical and biochemical features and the responses to treatment of eight patients with auto-antibody-mediated C1 inhibitor (C1-INH) deficiency and symptoms of angioedema. PATIENTS AND METHODS: In addition to the 8 patients with acquired angioedema (AAE), we also studied 36 subjects with hereditary angioedema (HAE), 15 of them treated with C1-INH plasma concentrate, and 26 patients with different autoantibodies in their plasma (10 with systemic lupus erythematosus, 6 with lupus-like anticoagulant, and 10 with chronic liver disease). Functional C1-INH was measured with the reagent kit of Immuno (Vienna, Austria); C1-INH, C4, and C1q antigen were determined by radial immunodiffusion; and autoantibodies to C1-INH were detected by an enzyme-linked immunosorbent assay method. RESULTS: Four patients with AAE had no other diseases, one had breast cancer, one liver hydatidosis, one Waldenström's disease, and one a benign M component. Functional C1-INH levels were below 30% of normal, and C1q plasma levels were low in seven patients but normal in one. Autoantibodies to C1-INH were detectable in all eight AAE patients but in none of the others. Prophylactic treatment with attenuated androgens was successful in one of four patients, and with antifibrinolytic agents (tranexamic acid) in six of seven patients. Laryngeal attacks in five patients were treated with C1-INH plasma concentrate; two patients had marked clinical and biochemical responses. In three, the symptoms resolved only with high doses, and the biochemical parameters did not significantly increase. CONCLUSIONS: Our results suggest that patients with autoimmune AAE are clinically and biochemically heterogeneous. They have different responses to treatment that seem to be related to variable C1-INH consumption.
Aged↗
Clinical problems in the C1-inhibitor deficient patient.
The clinical course of C1-INH deficiency is presently well established. There is an inherited form (Hereditary Angioedema) characterized by recurrence of cutaneous and mucous swellings appearing early in life and usually accompanied by substantial family history, and an acquired form (Acquired Angioedema) where identical symptoms start after the fourth decade of life without family history. The acquired form can be associated with other diseases, mainly B cell disorders, and/or with autoantibodies to C1-INH. The biochemical characteristic is the functional deficiency of C1-INH and of C4 and C2. Moreover a marked deficiency of C1 is present in most acquired forms, but never in the inherited ones. C1-INH deficiency can be corrected by attenuated androgens that increase C1-INH levels in a few days and are effective in the prophylaxis of attacks, or by substitutive therapy with C1-INH plasma concentrate that is the life-saving drug in laryngeal edema. Patients with the inherited form have a uniformly good response to both these treatments which are otherwise effective only in a minority of patients with the acquired deficiency. In these subjects C1-INH concentrate needs to be given in higher doses and prevention of attacks is obtained with antifibrinolytic agents (Tranexamic acid).
Adolescent↗
Generation of plasmin during acute attacks of hereditary angioedema.
Hereditary angioedema is caused by a genetic deficiency of C1-inhibitor, a serine protease inhibitor that regulates activation of complement, contact, and fibrinolytic systems. Symptoms (bouts of subcutaneous and mucous swelling) depend on the release of a vasoactive mediator, probably through activation of these three systems. We studied the interrelationship among complement, contact, and fibrinolytic activation in 23 patients with hereditary angiodema, 18 during remission and five during an attack, by measuring plasma levels of C1-C1 inhibitor, factor XIIa-C1 inhibitor, kallikrein-C1 inhibitor, and plasmin-alpha 2-antiplasmin complexes, tissue plasminogen activator, and urokinase plasminogen activator. In addition, cleavage of high-molecular weight kininogen was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and quantified by densitometry. During remission, plasma levels of C1-C1 inhibitor complexes were elevated (p = 0.0002), whereas the other parameters were within the normal range. During acute attacks, not only plasma levels of C1-C1 inhibitor complexes but also those of plasmin-alpha 2-antiplasmin complexes (P = 0.0009) and cleaved high-molecular weight kininogen were elevated. A positive correlation between plasmin-alpha 2-antiplasmin complexes and cleaved high-molecular weight kininogen was observed (r = 0.75, p < 0.001). This article presents the first in vivo evidence that supports the concept that release of vasoactive mediators in hereditary angiodema attacks is associated with the activation of the fibrinolytic system.
Acute Disease↗
DDAVP infusion does not affect plasma levels of endothelin-1 in four normal subjects.
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Adult↗
Tissue-type plasminogen activator and von Willebrand factor plasma levels as markers of endothelial involvement in patients with Raynaud's phenomenon.
In order to investigate the significance of high circulating levels of von Willebrand factor (vWF), recently observed in patients with vascular diseases, we compared the plasma levels of vWF with those of tissue-type plasminogen activator (t-PA) and the platelet content of serotonin (5-HT) in 40 patients with Raynaud's phenomenon (RP), primary or associated to systemic sclerosis (SSc), and in 14 patients with chronic peripheral obstructive disease due to arteriosclerosis (PAOD). VWF and t-PA plasma levels were significantly increased (p < 0.001) in SSc (vWF: 158.2, range 116.3-305.0%; t-PA: 10.2, range 6.4-17.8 ng/ml). By contrast, normal plasma levels of both vWF (85.3, range 53.5-157.0%) and t-PA (6.5, range 2.7-9.3 ng/ml) were observed in primary RP. VWF and t-PA were normal in PAOD patients, compared with age-matched healthy controls (vWF: 143.0, range 57.0-204.0%; t-PA: 7.5, range 3.4-13.6, ng/ml). The platelet content of 5-HT was within the normal range (37.3-99.7 ng/10(8) platelets) in RP patients, but significantly reduced (P < 0.05) in PAOD patients (39.0, range 14.7-91.4). Our data suggest that the different pattern of circulating vWF and t-PA between SSc and arteriosclerotic patients may be related to a different endothelial cell involvement. Whether this increase may reflect active attempts of regeneration and repair, indicating endothelial cell viability rather than damage is a matter of speculation.
Adult↗