Plasmin-alpha 2-antiplasmin Complex Research Articles

Differential Fibrinolysis Profile in COVID-19 Patients Dependent on Immunosuppressive Treatment Regimen: A Nested Case-Control Study

Introduction: Severe coronavirus disease 2019 (COVID-19) is associated with thrombotic complications, despite prophylactic and therapeutic anticoagulation. The disease course of critically ill COVID-19 patients has been characterized by severe hypercoagulability and hypofibrinolysis leading to an increased risk of venous thromboembolism. In COVID-19 (low molecular weight) heparins do not provide sufficient protection against venous thromboembolism. Since the start of the COVID-19 pandemic, several immune modulatory interventions have been introduced to improve outcome, including dexamethasone and tocilizumab. Whether dexamethasone and tocilizumab would alter the course of hypercoagulability by modifying inflammation, is unknown. Tocilizumab, that reduces IL-6 binding to its cellular receptors, has been shown to reduce the plasma plasminogen activator inhibitor-1 (PAI-1). On the other hand, dexamethasone can induce PAI-1 release. Data on the net impact of dexamethasone and tocilizumab on fibrinolysis in critically ill COVID-19 patients is lacking. Therefore, we aimed to characterize the fibrinolytic profile of severe COVID-19 patients on different treatment regimens and to unravel underlying mechanisms of the hypofibrinolytic state of these patients. Methods: A nested case-control study within the Maastricht Intensive Care COVID (MaastrICCht) cohort on mechanically ventilated COVID-19 patients was conducted. Patients receiving tocilizumab and dexamethasone (toci group) were age- and sex-matched with patients receiving only dexamethasone (dexa group) and patients receiving neither tocilizumab nor dexamethasone (control group). Whole blood was collected from these patients at three different time points after intubation (week 1, 2, and 3). The dexa and toci group received dexamethasone treatment before intubation and the toci group received one bolus of tocilizumab before or on the day of intubation. All blood samples were collected thereafter. Whole blood tissue plasminogen activator rotational thromboelastometry (tPA-ROTEM) was performed and subsequently inflammatory markers (c-reactive protein (CRP), ferritin, IL-6, fibrinogen), fibrinolysis parameters (tPA, PAI-1, thrombin activatable fibrinolysis inhibitor (TAFI), plasmin-alpha-2-antiplasmin complex (PAP)) and coagulation biomarkers (D-dimer, prothrombin fragment 1.2 (F1.2)) were measured in plasma samples. All markers were analyzed with linear mixed-effects regression models to estimate the differences between treatment groups over time. Results: Matching showed similar groups (Table 1.) for the baseline characteristics. At week 1 the dexagroup's IL-6 level was significantly lower, whereas the toci group's IL-6 level was significantly higher compared to the control group (difference[95%CI]: -198.37 [-350.86- -45.88], p=0.017 and 269.59 [113.91-425.27], p=0.002, respectively). CRP levels were significantly lower at week 1 in both dexa and toci groups compared to the control group (median [IQR] 60.50 [30.75 - 131.25] and 18.50 [6.00 - 60.00] vs. 296.00 [223.75 - 347.00]) suggesting effective immune suppression. Divergent fibrinolysis was seen at week 1 by tPA-ROTEM showing lower lysis time (LT) in the toci group compared to the control group (difference[95%CI]: -1,759.21 [-2752.05 - -766.34; p=0.002), whereas the dexa group did not differ. Interestingly, LT decreased over time in the control group, while an increase was seen in the toci group (Figure 1.). PAI-1 levels were lower in week 1 in the toci group compared to the control group (difference [95%CI] -7.32 [-14.95 - 0.30], p=0.071) and the tocigroup showed an overall increase in PAI-1 levels, while the control and dexa group showed a decrease over time. High TAFI and tPA levels were observed in all groups at week 1 and over time regardless of the treatment regimens. Coagulation biomarkers D-dimer and prothrombin fragment 1.2 were elevated but did not differ or change over time between groups. Conclusions: The differences and changes over time revealed by tPA-ROTEM and the fibrinolysis markers between the three different treatment regimens show the direct interaction between inflammation and fibrinolysis in these patients. The lower LT and PAI-1 levels upon tocilizumab treatment could be indicative for better fibrinolytic activity in these patients. This study was supported by the Dutch Covid and Thrombosis Coalition (DCTC). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

DYNAMICS OF THE TISSUE SYSTEM OF PLASMINOGEN REGULATORS IN CUTANEOUS MELANOMA WITH CHRONIC PAIN IN FEMALE MICE

Background. Chronic pain is a pathologic process changing the whole body metabolism. Objective: determination of plasminogen regulators in tissues of cutaneous melanoma and in the skin tissues not associated with the tumor in female mice in the dynamics of the growth of experimental melanoma with chronic neurogenic pain. Design and methods . в16/F10 melanoma with chronic pain was reproduced in female С57вL/6 mice. Plasmin-alpha2-antiplasmin complex (PAP), urokinase (pro-uPA and uPA) and tissue (pro-tPA and tPA) plasminogen activators, the uPA (uPAR) receptor and serpin-1 (PAI-1) were determined by ELISA using standard test systems. Results were analyzed using the Statistica 10 program. Results. Chronic neurogenic pain was accompanied by significant changes in the fibrinolysis components in the skin of female С57вL/6 mice. After the в16/ F10 melanoma transplantation (1-3 weeks), skin and tumor tissues showed higher levels of рар and the uPAR receptor (p<0.05), decreased levels of pro-uPA and uPA, pro-tPA and tPA, and PAI-1 (p<0.05), compared to the comparison group (standard melanoma model). Conclusion. Analysis of the state of the tissue fibrinolysis in the skin and tumors of female С57вL/6 mice demonstrated that during the tumor formation with chronic neurogenic pain, plasmin, tPA, uPA, uPAR and PAI-1 play a leading role in the rapid growth and increased malignancy of melanoma. The study of the proposed model will make it possible to clarify many questions of carcinogenesis and the generalization of the malignant process. Studying the model can clarify many issues of the carcinogenesis and progression of the malignant process.

The influence of corticosteroids on hemostasis in healthy subjects

Corticosteroids have been associated with an increased risk of venous thromboembolism in patients treated for inflammatory diseases. It is unclear whether the thrombotic risk is induced by the inflammation of the underlying inflammatory diseases or whether corticosteroids are prothrombotic as well. Considering the widespread use of corticosteroids in clinical practise, it is critical to know whether corticosteroids enhance coagulation. To investigate whether a 10-day prednisolone burst therapy activates hemostasis in healthy individuals. Healthy subjects received either 0.5 mg kg(-1) day(-1) of oral prednisolone or placebo. Venous blood was collected at baseline, day 1 and day 10 and tested for thrombin-antithrombin complexes (TATc), D-dimer, plasmin-alpha2-antiplasmin complexes (PAPc), plasminogen-activator inhibitor type-1 (PAI-1), von Willebrand factor (VWF) and thrombin generation (peak thrombin, velocity index and endogenous thrombin potential [ETP]). Fifteen subjects received prednisolone and 16 placebo (median age 29 vs. 22 years, female subjects 33% vs. 56%, respectively). Peak thrombin and velocity index were higher in the placebo group at baseline. After 10 days of treatment, peak thrombin, velocity index, PAI-1 and VWF increased in the oral prednisolone group as compared with the placebo group (15.8 [SD 16.3] vs. -0.1 [SD 16.1], 41.2 [SD 41.3] vs. -2.3 [SD 42.7], 18.0 [IQR 8.0-37.0] vs. 0.5 [IQR -18.5-13.0], 4.0 [IQR -1.0-12.0] vs. 0.0 [IQR -2.5-1.5], respectively). No changes were observed for TATc, ETP, PAPc and D-dimer. Oral prednisolone induces a procoagulant state in healthy subjects, suggesting that corticosteroid treatment may increase the thromboembolic risk in patients with inflammatory diseases.

Kinetics of coagulation in ST-elevation myocardial infarction following successful primary percutaneous coronary intervention

IntroductionST-elevated myocardial infarction (STEMI) is most frequently caused by coronary occlusion due to formation of an intracoronary thrombus in reaction to rupture of atherosclerotic plaques. Little is known about kinetics of coagulation markers after STEMI in patients treated according to current guidelines. We aimed to investigate kinetics of important coagulation markers in percutaneous coronary intervention (PCI)-treated STEMI patients. Materials and methods60 consecutive PCI-treated STEMI patients were prospectively included. Blood samples were collected immediately after as well as 1, 4 and 7days following PCI. Samples collected 90days after PCI served as baseline values. ADAMTS13 activity, VWF (von Willebrand factor) activity, VWF antigen, VWF propeptide, fibrinogen antigen, D-dimer, alpha2-antiplasmin (α2AP), plasmin-alpha2-antiplasmin complex (PAP), prothrombin fragment F1+2 (F1+2), prothrombin time (PT), activated partial thromboplastin time (aPTT), and anti-factor Xa (anti-Xa) were measured. Cardiac magnetic resonance (CMR) was performed at 4–6 and 90days after PCI in 49 patients and left ventricular ejection fraction (LVEF), infarct size and microvascular injury (MVI) were determined. ResultsImmediately after PCI, ADAMTS13 activity, fibrinogen antigen and α2AP levels were significantly decreased and VWF activity, VWF antigen and VWF propeptide levels were significantly elevated, compared to baseline. Individual coagulation markers and different combinations thereof were not related to LVEF or infarct size at 90days, or the occurrence of MVI at 4–6days after PCI. ConclusionCoagulation parameters show a very dynamic profile in the early days after STEMI. However, individual coagulation parameters or combinations thereof do not predict CMR-defined LVEF, infarct size or MVI.

Effects of steroids on thrombogenic markers in patients undergoing unilateral total knee arthroplasty: a prospective, double-blind, randomized controlled trial.

Venous thromboembolism (VTE) remains an important complication after total knee arthroplasty (TKA). Systemic thrombin generation starts perioperatively. Inflammation, characterized by a rise in interleukin-6 (IL6), initiates the coagulation cascade, but low-dose steroids can reduce post-TKA IL6 levels. This double-blinded, randomized, placebo-controlled study enrolled 30 patients undergoing unilateral TKA to assess the effect of perioperative steroids on serum prothrombin fragment (PF1.2), a marker of thrombin generation, and plasmin-alpha-2-antiplasmin complex (PAP), a marker of fibrinolysis. Study patients received 100 mg of intravenous hydrocortisone 2 h prior to surgery, and controls received normal saline. Blood samples, drawn pre-incision and at 4 h post tourniquet release, were assayed for PF1.2 and PAP. The study group had significantly lower mean PF1.2 at 4 h compared to controls (616 ± 358 pMol/L vs. 936 ± 332 pMol/L, p = 0.037). The mean rise in PF1.2 in the control group was significantly greater compared to the study group (672 ± 173 pMol/L vs. 350 ± 211 pMol/L, p < 0.001). Mean PAP was higher in the study group at 4 h (1639 ± 823 µg/L vs. 1087 ± 536 µg/L), but did not reach statistical significance (p = 0.07). These results may have clinical implications in terms of postoperative VTE risk and management.

Treatment related changes in antifibrinolytic activity in patients with polycythemia vera

Polycythemia vera (PV) is a clonal myeloproliferative disorder characterized by predominantly excessive erythrocyte production. During the course of the disease, bleeding or thrombosis may be observed. In PV patients, the influence of antifibrinolytic activities on development of thrombohemorrhagic complications remains to be elucidated. In the present study, alterations in antifibrinolytic activity of PV patients and the effects of treatments on these alterations were investigated. Newly diagnosed and therapy-naive 22 PV patients were included. Thrombomodulin (TM), plasmin-alpha 2-antiplasmin complex (PAP), plasminogen activator inhibitor-1 (PAI-1) and thrombin activable fibrinolysis inhibitor antigen (TAFIa) levels were measured in all individuals and after phlebotomy and 5-hydroxyurea (5-HU) therapy in PV patients. TM, PAP, PAI-1 and TAFIa values of the patient group were higher than those of the controls. After phlebotomy, no changes were detected in TM, PAI-1 and TAFIa values, but PAP values decreased. On the contrary, 5-HU treatment resulted in a marked decrease in TM, PAI-1, PAP and TAFIa levels. These findings suggested that the changes in antifibrinolytic activity and endothelial dysfunction might be contributed to formation of intravascular thrombosis in PV patients, even though not clinically overt. 5-HU in addition to phlebotomy affects antifibrinolytic activity and may have an influence on diminishing predisposition of thrombosis.

In vitro effects of detergent sclerosants on fibrinolytic enzymes and inhibitors

Objective To investigate the effects of Sodium Tetradecyl Sulphate (STS) and Polidocanol (POL) on fibrinolytic mechanisms. Materials and methods Measurements were done with serial dilutions of sclerosants in whole blood (WB), platelet rich (PRP) and platelet poor plasma (PPP). Control experiments were done in 5% bovine serum albumin (BSA), spiked with the enzyme/inhibitor. Plasminogen was measured with a chromogenic assay. Alpha-2-antiplasmin (AP) activity, plasmin-alpha-2-antiplasmin (PAP) complexes, plasminogen activator inhibitor-1 (PAI-1) activity, tissue plasminogen activator (t-PA) total antigen, t-PA activity, t-PA/PAI-1 complexes, thrombin activatable fibrinolysis inhibitor (TAFI) antigen and activated TAFI (TAFIa) were measured by ELISA. Results At high concentrations (> 0.3%), STS destroyed plasminogen, PAI-1, t-PA/PAI-1 complexes and total t-PA antigen but increased t-PA activity. At low concentrations (< 0.3%), both agents reduced PAP complexes while increasing AP activity. Low concentration STS increased PAI-1 activity, t-PA/PAI-1 complexes, TAFI and TAFIa. Low concentration POL mildly increased the total t-PA antigen and TAFI. Conclusion At low concentrations, both agents demonstrated a prothrombotic, antifibrinolytic (increase in PAI-1, total t-PA antigen, AP, TAFI and TAFIa) activity. At high concentrations, STS demonstrated non-prothrombotic (destruction of PAI-1, t-PA/PAI-1 complexes), antifibrinolytic (destruction of plasminogen, increase in AP) activity while POL had minimal effect.

Hyperglycemia modulates plasminogen activator inhibitor-1 expression and aortic diameter in experimental aortic aneurysm disease

Extracellular matrix degradation is a sentinel pathologic feature of abdominal aortic aneurysm (AAA) disease. Diabetes mellitus, a negative risk factor for AAA, may impair aneurysm progression through its influence on the fibrinolytic system. We hypothesize that hyperglycemia limits AAA progression through effects on endogenous plasminogen activator inhibitor-1 (PAI-1) levels and subsequent reductions in plasmin generation. Experimental AAAs were induced in diabetic and control mice via the intra-aortic elastase infusion method. Serial transabdominal high-frequency ultrasound examinations were performed to monitor aortic diameter following elastase infusion. Circulating PAI-1 and plasmin alpha2-antiplasmin (PAP) complex concentrations were determined by ELISA and local expression of PAI-1 levels was examined by RT-PCR and immunohistochemistry. Hyperglycemia was associated with reduced AAA diameter, increased plasma PAI-1 concentration and reduced plasmin generation. Aneurysmal aortic PAI-1 gene expression increased in parallel with plasma concentration, with peak expression occurring early after aneurysm initiation. Hyperglycemia increases PAI-1 expression and attenuates AAA diameter in experimental AAA disease. These results emphasize the role of the fibrinolytic pathway in AAA pathophysiology, and suggest a candidate mechanism for hyperglycemic inhibition of AAA disease.

Significance of factors of coagulation and fibrinolysis in progression of lung cancer

To clarify the significance of factors of coagulation and fibrinolysis in tumor progression, we measured levels of D-Dimer, Thrombin-Anti-Thrombin III complex (TAT), and Plasmin-alpha 2-Anti-Plasmin complex (PAP) in 55 patients with primary lung cancer, and studied the relationship between these parameters and clinical TNM stage. D-Dimer, TAT and PAP increased in parallel with progression of primary tumor and distant metastasis, whereas there was no significant relationship between the progression of nodal involvement and these factors. In 19 patients, we investigated changes of D-Dimer, PAP and TAT during chemotherapy. These parameters decreased in the partial response group and minor response group, whereas they increased in the progressive disease group. These data suggest that D-Dimer, PAP and TAT determination is useful for evaluation of disorders of coagulation and fibrinolysis related to tumor progression or remission in patients with lung cancer.

Activation of coagulation with concurrent impairment of anticoagulant mechanisms correlates with a poor outcome in severe melioidosis.

Melioidosis, which is caused by infection with the Gram-negative bacterium Burkholderia pseudomallei, is an important cause of sepsis in South-East Asia with a mortality of up to 40%. Knowledge of the involvement of coagulation and fibrinolysis in the pathogenesis of melioidosis is highly limited. To define the involvement of the coagulation and fibrinolytic systems in patients with severe melioidosis. Parameters of coagulation and fibrinolysis were measured in 34 patients with culture proven septic melioidosis and 32 healthy controls. Patients demonstrated strong activation of the coagulation system, as reflected by high plasma levels of soluble tissue factor, the prothrombin fragment F(1+2) and thrombin-antithrombin complexes (TATc), and consumption of coagulation factors resulting in a prolonged prothrombin time and activated partial thromboplastin time. Concurrently, anticoagulant pathways were downregulated in patients: protein C, protein S, and antithrombin levels were all decreased when compared to controls. Patients also demonstrated evidence of activation and inhibition of fibrinolysis, as reflected by elevated concentrations of tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1, plasmin-alpha2-antiplasmin complexes (PAPc) and D-dimer. High TATc/PAPc ratios in patients pointed to a predominance of the prothrombotic pathway in melioidosis. Furthermore, soluble thrombomodulin levels were increased. The extent of coagulation activation correlated with mortality; patients who went on to die had higher TATc, F(1+2), tPA and PAPc and lower protein C and antithrombin levels on admission than patients who survived. The coagulation system is strongly activated during melioidosis. A high degree of activation of the coagulation system is an indicator of poor outcome in patients with melioidosis.

ASSOCIATION BETWEEN THE SEVERITY OF SEPSIS AND THE CHANGES IN HEMOSTATIC MOLECULAR MARKERS AND VASCULAR ENDOTHELIAL DAMAGE MARKERS

It is well known that disorders of coagulation and fibrinolysis play a major role in the development of organ dysfunction during sepsis. Furthermore, the importance of the early initiation of anticoagulation therapy for severe cases has been emphasized based on the success of recent clinical trials. The purpose of this study is to search for useful markers for predicting organ dysfunction. Plasma samples were prospectively collected from 78 patients within 48 h after the onset of sepsis. Hemostatic markers and endothelial damage markers were compared between the patients with and without organ dysfunction. The WBC and platelet counts were not different between the groups. In contrast, fibrin/fibrinogen degradation products, D-dimer, thrombin-antithrombin complex, plasmin alpha2-antiplasmin complex, soluble fibrin, and total plasminogen activator inhibitor-1 were significantly higher, and the antithrombin activity and protein C levels were lower in the patients with organ dysfunction. Thus, the changes in the hemostatic molecular markers were associated with organ dysfunction from an early stage of sepsis, and antithrombin and protein C activities were found to be the most reliable markers.

Blood coagulation and fibrinolysis after long-duration treadmill exercise controlled by individual anaerobic threshold.

For rehabilitation training it is recommended that the intensity of exercise should be clearly below the individual anaerobic threshold (IAT). We investigated blood coagulation, particularly endogenous thrombin potential (ETP) and fibrinolysis following a standardized treadmill (TR) ergometer test at 90% IAT for 60-120 min. Sixteen healthy male non-smokers underwent the TR test. Blood samples were taken after a 30-min rest, immediately after exercise, and 2 h after exercise completion. Extrinsic and intrinsic total (TTP(ex+in)) and endogenous (ETP(ex+in)) thrombin potential, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), plasmin-alpha2-antiplasmin complex (PAP), D-dimer, tissue plasminogen activator antigen and activity (tPA-AG and tPA-ACT) and plasminogen activator inhibitor type 1 antigen and activity (PAI-1-AG and PAI-1-ACT) were measured. Immediately after TR, F1+2, TAT and TTP(ex+in) were increased ( P<0.05) while ETP(ex+in) remained unchanged. In contrast, PAP, D-dimer, tPA-AG, tPA-ACT ( P<0.05) were distinctly enhanced while PAI-1-ACT was decreased ( P<0.05) immediately after exercise. The changes in tPA-AG, tPA-ACT, and PAI-1-ACT were reversed to nearly baseline while the enhancement in PAP and D-dimer was prolonged by more than 2 h after exercise. Long-duration exercise between 60 and 120 min controlled by IAT (90%) on a TR ergometer only implicates a small increase in thrombin generation markers and total (free and alpha(2)-macroglubulin-bound thrombin), but not in endogenous (free) thrombin potential alone. In contrast, fibrinolysis is distinctly increased after this type of exercise. Endurance exercise with an intensity below 90% IAT and a duration below 2 h generates a more favourable condition for fibrinolysis than for blood coagulation in healthy young subjects. Data are given as mean (SD).

The prognostic value of the soluble urokinase-type plasminogen activator receptor (s-uPAR) in plasma of breast cancer patients with and without metastatic disease

Elevated levels of soluble uPAR (s-uPAR) and other fibrinolytic parameters functionally related to the urokinase-type plasminogen activator system might indicate the presence of cancer cells. In 25 breast cancer patients with metastases s-uPAR was significantly increased compared with 25 patients without metastases and with 25 healthy controls: 420 pg mL-1 vs. 145 pg mL-1 (P = 0.005) and 190 pg mL-1 (P = 0.003). Plasmin-alpha2-antiplasmin (PAP) complexes and d-dimers were significantly increased in breast cancer patients with metastases compared with patients without metastases and with healthy controls. The levels of plasminogen activator inhibitor (PAI)-1 activity, uPA antigen and factor (F)XIIa did not significantly differ between the patient groups and healthy controls. PAP complexes (529 microg L-1 vs. 420 microg L-1; P = 0.03), d-dimers (278.5 ng mL-1 vs. 79.0 ng mL-1; P = 0.005) and FXIIa (1.64 ng mL-1 vs. 1.19 ng mL-1; P = 0.01) were significantly higher in patients with metastases not surviving compared with patients with metastases surviving the 3-year follow-up period. Plasma s-uPAR levels in the patients with metastases did not discriminate between patients surviving and patients not surviving after 3-year follow-up. No significant differences in s-uPAR or any of the other parameters were found in the five patients developing metastases during follow-up. A single value of s-uPAR is of limited value in the follow-up of breast cancer patients with and without metastatic disease and does not predict survival or future metastases.

Platelet activation through triathlon competition in ultra-endurance trained athletes: impact of thrombin and plasmin generation and catecholamine release.

The aims of this study were to evaluate whether platelets are activated during strenuous exercise in healthy athletes. Also, to determine the impact of plasmin and thrombin activity and catecholamine release. Previous studies have shown activation of the hemostatic system after competitive exercise, but platelet activation was thought to be absent in trained athletes. The impact of thrombin and other potent platelet activators is still a matter for debate. We examined 30 healthy triathletes during a triathlon competition. Flow cytometric detection of CD62p (P-selectin) was used to measure in vivo activation of platelets. Platelet-leukocyte aggregates were also determined. Thrombin concentration was assessed by the thrombin-antithrombin III complex (TAT) and the fibrinolytic state was characterised by the plasmin-alpha2-antiplasmin complex (PAP). Catecholamines were measured by means of high-pressure liquid chromatography. CD62p rose from baseline (2.3%) to 3.4% and was still elevated after 2 hours (3.1%, p = 0.0133). Platelet-leukocyte aggregates were elevated 30 min after exercise (4.3 % vs 3.6%) and decreased significantly after 60 min (2.9 %, p = 0.008). TAT increased from 3.9 microg/l to 8.3 microg/l after competition and to 5.4 microg/l 2 hours later (p < 0.001). PAP increased 10-fold from 350 microg/l to 3,267 microg/l after the triathlon and was still elevated after 2 hours (1,074 microg/l, p<0.001). No linear correlation was found between the hemostatic markers, catecholamines and platelet activation. Platelets, coagulation and fibrinolysis are activated by competitive exercise in athletes, whereby fibrinolytic changes are pronounced. Mechanisms of platelet activation during exercise include phenomena other than plasmatic hemostatic factors and catecholamines.

Prognostic value of fibrinolytic tests for hospital outcome in patients with acute upper gastrointestinal hemorrhage.

We assessed the predictive value of fibrinolytic tests for hospital outcome in a prospective study of 84 nonconsecutive patients with acute upper gastrointestinal hemorrhage. Six readily available parameters of activated fibrinolysis (fibrinogen, D-dimer, tissue plasminogen activator [TPA], plasminogen activator inhibitor type 1 [PAI-1], TPA--PAI-1 complexes, and plasmin-alpha 2-antiplasmin complexes) were tested for association with hospital outcome. Patients were divided into the following three groups: patients who survived and did not require transfusion or surgery, those who survived without surgery but required transfusion, and those who required surgery or died. Patients with adverse outcome (surgery and/or death) showed significantly higher plasma levels of D-dimer than patients with favorable outcome (p = 0.01). Plasma concentrations of D-dimer >300 ng/mL showed a 20.5% positive predictive value of adverse outcome, with a relative risk of 7.5 (95% CI: 1--57%). Patients who required transfusion showed significantly higher plasma levels of TPA (p = 0.01). A positive correlation between endoscopic bleeding stigmata and D-dimer in the subgroup of patients without liver cirrhosis was found (p = 0.02); however, in the multivariate logistic regression analysis the concentration of D-dimer did not appear as an independent predictor of adverse outcome. These findings are consistent with the role of increased local fibrinolysis in the digestive tract, particularly of D-dimer, in patients with upper gastrointestinal hemorrhage and adverse outcome. Accordingly, plasma fibrinolytic tests may constitute an appropriate prognostic marker in upper gastrointestinal bleeding.

Hemostatic and fibrinolytic parameters in survivors of myocardial infarction: a low plasma level of plasmin-alpha2-antiplasmin complex is an independent predictor of coronary re-events.

Abnormalities of coagulation or fibrinolysis play a role in the pathogenesis of coronary artery disease (CAD). Elevated plasma levels of fibrinogen, von Willebrand factor antigen, plasminogen activator inhibitor-1 and tissue-type plasminogen activator were reported to be predictive for reinfarction and death in patients with CAD. We investigated the risk for coronary re-events associated with 18 hemostatic and fibrinolytic parameters in a prospective study including 200 survivors of myocardial infarction (MI). During a 2-year follow-up, 37 patients suffered one of the following predefined re-events: fatal MI (n = 2), non-fatal MI (n = 5), percutaneous transluminal coronary angioplasty (n = 17) or coronary artery bypass grafting (n = 13). Low plasmin-alpha2-antiplasmin complex (PAP) plasma levels were associated with an up to fivefold (95% confidence interval, 1.6-15.3) increase in relative risk. The association between decreasing PAP levels and coronary re-events remained significant (P = 0.004) after correction for possible confounders using multiple logistic regression analysis. Our data indicate low PAP plasma levels to be associated with subsequent coronary events in patients with a history of MI.

In vitro fertilization. Do short-term changes in estrogen levels produce increased fibrinolysis?

High estrogen levels have been implicated as a cause of thrombosis. Patients undergoing in vitro fertilization (IVF) present an opportunity to study isolated estrogen effects on the coagulation system, since hormonal manipulation is used to achieve varying estrogen concentrations. We evaluated the effect of estrogen levels on the fibrinolytic and clotting systems of 32 patients undergoing IVF from whom venous samples were obtained during a period of several weeks at baseline and retrieval times. Flow cytometric studies were performed to assay platelet activation. Hemostasis markers measured thrombin-antithrombin complexes (TAT), fibrinogen, plasmin-alpha 2-antiplasmin complexes (PAP), plasminogen activator inhibitor (PAI-1), and D-dimer. A significant decrease in PAI-1 and an increase in PAP were observed at high estrogen levels, suggesting an increase in fibrinolytic potential. However, the products of fibrinolysis, as measured by D-dimer levels, decreased at high estrogen levels. No changes were seen in platelet activation indicators or TAT levels. The fact that a decrease in products of fibrinolysis was seen at high estrogen levels despite concurrent changes in PAI-1 and PAP that normally accompany increased fibrinolysis may be due to alterations in the overall balance of the fibrinolytic system or to a delay in onset of fibrinolysis.

The imbalance between coagulation and fibrinolysis is related to the severity of the illness and the prognosis in sepsis.

ObjectivesThe coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation(DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis.MethodsPlasma thrombin-antithrombin III (TAT) and plasmin-α2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients.ResultsPlasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT(21.7±22.3ng/mL) and lower levels of PAP(628.4±378.1ng/mL) than survivors (TAT: 11.1±11.2ng/mL; PAP: 857.1±364.1ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis(r=0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors(34.4±21.4 vs. 14.4±13.8).ConclusionIn sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.

Intraperitoneal hypercoagulation and hypofibrinolysis is present in childhood peritonitis

An increased rate of obstruction of peritoneal dialysis catheters is observed during peritonitis. Hypercoagulation and hypofibrinolysis may explain this increased occurrence. We studied plasminogen activator inhibitor type 1 antigen (PAI-1), tissue-type plasminogen activator antigen (t-PA), D-dimer (DD), plasmin-alpha2-antiplasmin complexes (PAP), and thrombin-antithrombin III complexes (TAT) in 7 children with peritonitis (group A) and 12 children during stable peritoneal dialysis (group B). Albumin, beta2-microglobulin, IgG, and alpha2-macroglobulin were measured for baseline transperitoneal protein transport. After a dwell of 6 h with 1.36% Dianeal, dialysate and serum samples were collected. Dialysate to plasma ratios of all proteins were calculated. During peritonitis (group A) TAT was higher: 34.7 versus 22.0 (P=0.01). PAI-1 was increased in group A: 76.5 versus 22.9 (P=0.004). PAP was decreased during peritonitis (group A): 24.9 versus 39.3 (P=0.01). In group A, DD were decreased. 10.8 versus 26.7 (P=0.002). t-PA was similar in both groups (23.7 in group A vs. 27.7 in group B; P=0.26). In both groups TAT, PAI-1, t-PA, PAP, and DD were significantly higher than in baseline transperitoneal transport, suggesting intraperitoneal production. Hypercoagulability and hypofibrinolysis were present during peritonitis compared with the control situation.

Plasma proteolytic activity in liver transplant rejection.

In this study, we evaluated the role of proteolytic enzymes belonging to the coagulation, fibrinolytic, and plasma contact systems in the early postoperative phase after orthotopic liver transplantation (OLT). Twenty-nine patients were studied at the time of OLT and during the first 2 postoperative weeks. Blood samples were collected daily after OLT and analyzed for kallikrein-like activity (KK), functional kallikrein inhibition (KKI), plasmin-like activity (PL), and alpha2-antiplasmin (AP). In addition, prekallikrein (PKK), prothrombin (PTH), antithrombin III (AT III), plasminogen (PLG), prothrombin/antithrombin III complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), and plasmin/alpha2-antiplasmin complexes (PAP) were measured. Nineteen patients experienced biopsy-verified acute rejections (AR) and ten patients had uneventful courses and served as controls. Plasma analyses showed that the contact, coagulation, and fibrinolytic systems were activated during OLT. Following OLT, continuous thrombin and plasmin generation was observed, and these effects were more pronounced in the group having an uneventful course than in patients with AR. Factors that could possibly affect plasma proteolytic activity, such as blood product usage during and after OLT and cold ischemia time of the liver graft, did not differ between the groups, nor did the routine liver function tests, alanine aminotransferase (ALT) and aspartate aminotransferase (AST).