Search

Background: Dyslipidemia, a metabolic alteration that affects lipoprotein levels, is considered a major risk factor for atherosclerosis and its complications. Dyslipidemia also affects the hemostatic system, especially impairing fibrinolysis, and increased levels of thrombin-activatable fibrinolysis inhibitor (TAFI) have been associated with cardiovascular events., Objectives and Methods: This study evaluated the association of acquired risk factors (hypertension, body mass index - BMI, smoking, sedentary lifestyle, use or not of oral contraceptives and hormone replacement therapy, and post-menopause status), the polymorphisms Thr325Ile (rs1926447), Ala147Thr (rs3742264) and +1542C/G (rs940) in the TAFI gene, and TAFI plasma levels in 109 dyslipidemic and 105 normolipemic individuals. Biochemical analyses and TAFI levels were evaluated by colorimetric/turbidimetric assays and ELISA, respectively. Genotypic and allelic frequencies were determined by polymerase chain reaction (PCR)., Results: Hypertension, increased BMI, and menopause were more common in dyslipidemic individuals, who had higher TAFI levels. The alleles 325Ile, Ala147, and C showed association with lower TAFI levels. The rs3742264 polymorphism was associated with dyslipidemia in males., Conclusions: The results suggest that TAFI levels are independently associated to dyslipidemia and that the polymorphism rs3742264 may be related to cardiovascular risk in male subjects., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Coagulation abnormalities have been reported in familial Mediterranean fever (FMF) patients with amyloidosis and nephrotic syndrome; but there is not enough data about the continuity of the thrombogenic activity in FMF patients in clinical remission. The purpose of this study was to assess thrombin activatable fibrinolysis inhibitor (TAFI) levels and its relationship with fibrinolytic activity and also evaluate relationships between mutations and clinical signs in attack-free patients without amyloidosis., Methods: Seventy-nine FMF patients and 40 healthy adults were included. The study group was divided into five groups as follows: first group, homozygote M694V; second group, homozygote M680I; third group, M694V in one allele, the other allele have other mutations or not; fourth group, other mutations; and fifth group, no mutation., Results: Serum TAFI levels were significantly increased in patients compared with healthy individuals (116.64 ± 21.8 vs. 78.48 ± 19.7 μg/mL, p < 0.001) and a positive correlation was detected between TAFI antigen level and erythrocyte sedimentation rate and C-reactive protein levels (r = 0.247, p = 0.029 and r = 0.252, p = 0.032, respectively). Mean fibrinogen and TAFI levels were significantly higher in Group 1 than the other groups (p = 0.04 and p = 0.001, respectively) and in Group 3 it was higher than Groups 2, 4 and 5 (p = 0.04 and p = 0.001, respectively)., Conclusions: High level of TAFI antigen in attack-free period of FMF disease shows ongoing subclinical inflammation and hypercoagulability. Clinicians should be careful about thrombosis even in patients at clinical remission. Also, genetic tests must be considered to predict clinical outcome and to reduce complications of FMF disease.

Study Objective: Obstructive sleep apnea (OSA) is associated with systemic inflammation and a hypercoagulable state. The current study aim was to investigate whether mandibular advancement splint (MAS) therapy affects inflammatory and hemostatic parameters in patients with mild-to-moderate OSA., Methods: Twenty-two patients with mild-to-moderate OSA and 16 control subjects were studied. OSA subjects were treated with a titratable MAS for 6 months. Baseline plasma C-reactive protein, interleukin-1β, interleukin-10, interleukin-6, P-selectin, fibrinogen, D-dimer, plasminogen activator inhibitor-1 (PAI-1), thrombin-antithrombin complex, activated thrombin-activatable fibrinolysis inhibitor (TAFIa), 6-keto-PGF1α, glucose, and fibrin clot lysis time (CLT) were measured in all subjects. After 3 months of MAS therapy, measurements were repeated for the 22 patients, and after 6 months all measurements were repeated for all study subjects., Results: MAS treatment reduced significantly AHI at 3 months (24 vs 13.1/h) and further improved it at 6 months (13.1 vs 7.05/h). Compared with controls, OSA subjects had a significant higher baseline mean levels of fibrinogen, TAFIa, 6-keto-PGF1α, and glucose. MAS treatment significantly improved levels of IL-1β, D-dimer, TAFIa, and CLT. Despite residual apneas, MAS treatment group presented similar measured homeostatic and inflammatory levels to controls except for glucose., Conclusion: Treatment with MAS in mild-to-moderate OSA subjects improves the inflammatory profile and homeostatic markers., Citation: Niżankowska-Jędrzejczyk A; Almeida FR; Lowe AA; Kania A; Nastałek P; Mejza F; Foley JH; Niżankowska-Mogilnicka E; Undas A. Modulation of inflammatory and hemostatic markers in obstructive sleep apnea patients treated with mandibular advancement splints: a parallel, controlled trial.

Hypercoagulable conditions may determine a hypofibrinolytic state by increasing the activation of thrombin-activatable fibrinolysis inhibitor (TAFI). Factor (F)IX-Padua is a mutated FIX with an eight-fold increased clotting activity and associates with a higher venous thrombotic risk. We evaluated the influence of FIX-Padua on TAFI-mediated regulation of fibrinolysis. A subject hemizygous for FIX-Padua, two family members (heterozygous and normal) and six healthy controls were studied. Clot lysis, TAFI activation and thrombin generation were evaluated in contact-inhibited plasma challenged with low concentrations of tissue factor. Fibrinolysis times were significantly longer in FIX-Padua carriers than controls. The difference disappeared when activated TAFI (TAFIa) was inhibited, when TAFI activation was avoided or when clotting was made independent of FIX. TAFIa generation was markedly enhanced in FIX-Padua carriers as compared to controls, and this could be explained by a greater thrombin generation in the former. Hyperactive FIX, but not wild-type FIX, enhanced fibrinolytic resistance also when the FXI-dependent positive feedback was blocked by a neutralising anti-FXI antibody. This thrombin-mediated, TAFI-dependent down-regulation of fibrinolysis provides new clues for explaining the heightened thrombotic risk in subjects carrying the FIX-Padua mutation.

Objectives: Activated thrombin-activatable fibrinolysis inhibitor is a coagulation factor in some thrombotic diseases. However, available data on whether thrombin-activatable fibrinolysis inhibitor is activated in islet transplant are limited. In this study, changes of plasma-activated thrombin-activatable fibrinolysis inhibitor levels in instant blood-mediated inflammatory reaction after islet transplant were assessed., Materials and Methods: Plasma concentrations of thrombin-antithrombin complex, D-dimer, C-peptide, and activated thrombin-activatable fibrinolysis inhibitor were assessed at 0 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, and 24 hours after an intraportal islet transplant using rats via an enzyme-linked immunosorbent assay, or solid-phase, 2-site chemiluminescent immunometric assay. We recovered the liver at 1 hour after the transplant for histologic examination., Results: Thrombin-antithrombin complex, C-peptide, and activated thrombin-activatable fibrinolysis inhibitor levels increased immediately after we stopped islet infusion, and their peak levels occurred at 1 hour after islet infusion. D-dimer levels increased continually after islet infusion was stopped, and peaked 24 hours after infusion. Histologic examination of the liver 1 hour after islet infusion revealed frequent portal venous thrombi, with entrapped islets. The entrapped islets showed a disrupted morphology., Conclusions: Activated thrombin-activatable fibrinolysis inhibitor was generated and peaked 1 hour after islet transplant according with activating coagulation, indicating that thrombin-activatable fibrinolysis inhibitor is activated and accumulated at levels in instant blood-mediated inflammatory reaction was sufficient to affect fibrinolysis.

Background: Since thrombolysis is the only approved intervention for ischemic stroke, improving its efficacy and safety is a therapeutic aim of considerable interest. The activated form of thrombin activatable fibrinolysis inhibitor (TAFI) has antifibrinolytic effects, and inhibition of TAFI might thus favor recanalization. The present study compared efficacy between TAFI inhibition alone and TAFI inhibition in combination with rtPA at a suboptimal dose, in a murine model of thromboembolic stroke., Methods: Focal ischemia was induced in mice by thrombin injection in the middle cerebral artery. Animals were placed within the magnet immediately after surgery for baseline MRI (H0). MRI examination comprised diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), and T2-weighted imaging (T2-WI). Animals were randomly assigned to 1 of 5 treatment groups: saline, rtPA 5 mg/kg (tPA(5): suboptimal or low dose), rtPA 10 mg/kg (tPA(10): standard dose), TAFI-I 100 mg/kg (TAFI-I), and rtPA 5 mg/kg + TAFI-I 100 mg/kg (tPA(5) + TAFI-I). Treatments were administered inside the magnet, via a catheter placed in the tail vein, using a power injector, as 10% bolus and 90% infusion over a period of 20 min. MRI examination was repeated at 3 h (H3) and 24 h (H24) after surgery. Therapeutic benefit was evaluated by: (1) improvement of reperfusion and (2) reduction in final lesion size. Microhemorrhages were assessed as black spots on T2-WI at H24. Animals were sacrificed after the last MR examination. The surgeon and all investigators were blinded to treatment allocation., Results: A total of 104 mice were operated on. Forty four of these were excluded from the study and 27 from the analysis, according to a priori defined criteria (no lesion or no mismatch), leading to the following distribution: saline (n = 6), tPA(5) (n = 8), tPA(10) (n = 7), TAFI-I (n = 7), and TAFI-I + tPA(5) (n = 5). Standard-dose rtPA treatment (tPA(10)) significantly improved lesion regression between H0 and H24 compared to saline (-57 ± 18% vs. -36 ± 21%, p = 0.03), which treatment with rtPA(5) or TAFI-I alone did not. On the other hand, combined treatment with tPA(5) + TAFI-I showed only a trend toward lesion regression (-49 ± 26%), similarly to treatment with tPA(10), but not significantly different from saline (p = 0.46). Nine animals showed microhemorrhage on T2-WI at H24. These animals were evenly distributed between groups., Conclusions: The present study showed that the combination of TAFI-I with a suboptimal dose of rtPA is not as effective as the standard dose of rtPA, while TAFI inhibition alone is not effective at all. The thromboembolic model is of particular interest in assessing rtPA association to improve thrombolysis, especially when coupled with longitudinal MRI assessment., (© 2014 S. Karger AG, Basel.)

Thrombin activatable fibrinolysis inhibitor (TAFI) is an important procoagulant factor. Patients with metabolic syndrome (MetS) also have an elevated procoagulant status. However, TAFI and its association with MetS are still not well known. We aimed to investigate TAFI in type 2 diabetes mellitus patients with MetS. We enrolled a total of 55 patients who had MetS (n = 30) and 25 healthy controls. MetS was diagnosed using National Cholesterol Education Program Adult Treatment Panel III criteria. We measured activated and inactivated TAFI (TAFIa/ai) antigen in plasma samples using a commercially available ELISA kit (Imubind TAFIa/ai antigen ELISA; American Diagnostica Inc., Stamford, Connecticut, USA). TAFIa/ai levels were then evaluated for links to MetS parameters. Mean TAFIa/ai levels were 156.6 ± 66.9 ng/dl in patients with MetS and 104.1 ± 60.3 ng/dl in the control group (P = 0.005). None of the MetS parameters, including blood pressure, fasting plasma glucose, waist circumference, triglycerides or high-density lipoprotein cholesterol (HDL-C) levels were correlated with TAFIa/ai levels. However, TAFIa/ai level had a strong correlation with the number of metabolic risk components, which increased proportionally when MetS parameters were over three. When there were increased numbers of MetS risk components, we detected a rise in TAFIa/ai levels. TAFIa/ai levels could be an indicator of atherosclerotic tendency in patients with MetS.

Impairment of fibrinolytic function plays an important role in the mechanism of thrombotic disorders in cancer patients. Thrombin-activatable fibrinolysis inhibitor (TAFI) has an antifibrinolytic effect as it can remove partially degraded fibrin C-terminal lysine residues and reduce plasmin formation. The purpose of this study was to investigate whether blood TAFI levels and TAFI Thr325Ile polymorphism could be a risk marker of breast cancer. The plasma TAFI antigen (Ag) level was determined using ELISA assay in 256 patients with breast cancer and 192 healthy controls. TAFI Thr325Ile (rs1926447) polymorphism was genotyped in both patients and control groups using PCR-restriction fragment length polymorphism (PCR-RFLP) and sequencing. The results showed that TAFI Ag levels were significantly higher in breast cancer patients than those in controls (100.6 ± 15.2 and 82.7 ± 11.2%, P < 0.001). TAFI Ag levels were correlated with metastasis of breast cancer (P < 0.001). The Thr/Ile (CT) and Ile/Ile (TT) genotypes were found more frequently in patients group compared with the control group [odds ratio (OR) 2.106; (95% confidence interval, CI 1.379-3.217); P < 0.001]. The high-risk T alleles frequency was also higher in patients compared with healthy controls [OR 1.718; (95% CI 1.316-2.243); P < 0.001]. The polymorphism was significantly correlated with TAFI Ag levels in either group (P < 0.001). The Ile/Ile (TT) genotype had the lowest TAFI Ag level, whereas the Thr/Thr (CC) had the highest one. In conclusion, the plasma TAFI levels and TAFI Thr325Ile genotypes were associated with breast cancer patients in Chinese Han populations and could be considered as the risk indicators of breast cancer.

Background: Infectious complications frequently occur after major trauma, leading to increased morbidity and mortality. Thrombin-activatable fibrinolysis inhibitor (TAFI), a procarboxypeptidase in plasma, plays a dual role in regulating both coagulation and inflammation. Activated TAFI (TAFIa) has broad anti-inflammatory properties due to its inactivation of active inflammatory mediators (anaphylatoxins C3a and C5a, bradykinin, osteopontin)., Objectives: The purpose of this study was to determine if TAFI plays a role in the development of inflammatory complications after major trauma., Patients/methods: Upon arrival at the emergency department (ED), plasma levels of TAFI and TAFIa were measured in 26 multiple traumatized patients for 10 consecutive days. Systemic levels of inflammatory mediators, including interleukin-6 (IL-6), procalcitonin (PCT), C-reactive protein (CRP) and leukocytes were determined., Results: Fifteen patients developed pneumonia and/or sepsis (compl) and 11 had no complications (wo compl). Overall injury severity and age were comparable in both groups. Complications occurred approximately 5 days after trauma. IL-6 increased on day 5, whereas CRP, PCT and leukocytes started to increase on day 6 in the compl-group. Upon arrival at the ED and on days 1 and 4, TAFI levels were significantly lower in the compl-group compared to the wo compl-group (p=0.0215). Similarly, TAFIa was significantly lower on day 4 in the compl-group than in the wo compl-group (p=0.049)., Conclusions: This pilot study shows that TAFI levels are inversely correlated with inflammation-associated development of complications after major trauma., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a procarboxypeptidase, which is synthesised in liver and activated by thrombin and the thrombin-thrombomodulin complex. TAFI suppresses fibrinolysis by removing carboxy-terminal lysine residues from partially degraded fibrin. In this study we aimed to assess the circulating levels of TAFI antigen, 'a fibrinolytic parameter' in women with gestational diabetes (GDM). Thirty-four pregnant women with GDM and 50 pregnant women with normal glucose tolerance were included in the study. Plasma TAFI antigen levels were significantly higher in pregnant women with GDM when compared with controls. Increased TAFI levels may contribute to the decreased fibrinolytic potency, causing a thrombophilic state. GDM is regarded as a specific form of diabetes, and it could in addition be a predictor of type 2 diabetes mellitus in the future and the risk of complications due to hypercoagulability increases in this disease. Increased TAFI levels may also have a role in increased risk of hypercoagulability.

Endocrine disorders affect both the coagulation and fibrinolytic systems, and have been associated with the development of cardiovascular diseases. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a link between coagulation and the fibrinolytic system. The aim of this study was to determine the effect of thyroid hormone excess and deficiency on TAFI levels and function. The effect of hyperthyroxinemia on TAFI was studied in healthy volunteers who were randomised to receive levothyroxine or no medication for 14 days in a crossover design. The effect of hypothyroidism on TAFI was studied in a multicentre observational cohort study. Blood was drawn before treatment of patients with newly diagnosed hypothyroidism and when euthyroidism was achieved. Plasma clot-lysis times, activated TAFI (TAFIa)-dependent prolongation of clot-lysis and TAFI levels were measured. Thyroid hormone excess resulted in a hypofibrinolytic condition and in an enhanced TAFIa-dependent prolongation of clot lysis. A trend towards decreased plasma TAFI levels was observed in healthy volunteers who used levothyroxine. Hypothyroidism resulted in hyperfibrinolysis and a reduced TAFIa-dependent prolongation of clot lysis. In conclusion, alterations of TAFIa-dependent prolongation of clot lysis in patients with thyroid disorders may cause an impaired haemostatic balance. The disturbed haemostatic balance in patients with hyperthyroidism might make them prone to thrombosis, while the risk for bleeding may increase in patients with hypothyroidism.

Background: Severe clotting deficiencies are associated with enhanced in vitro fibrinolysis due to insufficient thrombin activatable fibrinolysis inhibitor (TAFI) activation. Because oral anticoagulant therapy (OAT) with warfarin causes a partial deficiency of vitamin K-dependent factors, its effect on clot lysability remains unclear., Objectives: To evaluate plasma and blood fibrinolytic capacity in patients under stable OAT (n = 221) as compared with controls (n = 132)., Methods: Fibrinolysis resistance of plasma (turbidimetry) and blood (thromboelastography) clots was calculated as the lysis time of tissue factor-induced clots exposed to 30 and 100 ng mL(-1) t-PA, respectively., Results: Plasma PAI-1 was similar in the two groups, whereas TAFI was slightly lower in patients. OAT plasma clots lysed faster than controls (P = 0.001). The addition of the TAFIa inhibitor PTCI reduced lysis time by 14% in OAT and 34% in controls, and the difference between the groups disappeared. Similar data were obtained with blood clots. Thrombin and TAFIa generation in OAT plasma amounted to roughly 50% of controls, supporting a reduced thrombin-dependent TAFI activation. Clot resistance of OAT plasma was normalized by Ba-citrate plasma eluate or prothrombin but not by BaSO(4) serum eluate, rFVIIa or FX. Surprisingly, circulating levels of TAFIa and its inactive derivative TAFIai were higher in warfarin patients (P < 0.0001) and correlated with plasmin-antiplasmin (P = 0.0001) but not with prothrombin F(1) (+) (2) ., Conclusions: OAT enhances both plasma and blood fibrinolysis by reducing thrombin-dependent TAFI activation, a phenomenon largely determined by low prothrombin levels. At variance with in vitro data, 'basal' in vivo TAFIa/ai levels seem related to plasmin rather than thrombin generation., (© 2012 International Society on Thrombosis and Haemostasis.)

Introduction: The thrombin-activatable fibrinolysis inhibitor (TAFI) is a potent inhibitor of fibrinolysis. However, the time course of TAFI and its activated form (TAFIa) following trauma, in particular in patients suffering trauma-induced coagulopathy, has been poorly examined., Methods: A total of 26 severely injured trauma patients were prospectively enrolled. TAFI and TAFIa levels were measured upon arrival and through hospital days one to 10. Trauma-induced coagulopathy was defined as elevated international normalized ratio (INR), and/or prolonged activated partial thromboplastin time (aPTT) and/or thrombocytopenia within one day of admission., Results: TAFIa and TAFI levels showed the largest decrease on days one and two, respectively, with a progressive increase thereafter. Overall, 11 patients developed coagulopathy. No statistically significant differences were found for TAFI levels between the two groups. For TAFIa, however, coagulopathic patients experienced significantly lower levels on admission and on days six to eight (all p<0.05). Statistically significant correlations were found between TAFIa level on admission and the amount of packed red blood cells (p=0.011; Spearman's correlation coefficient=-0.5) and fresh frozen plasma (p=0.044; Spearman's correlation coefficient=-0.405) transfused within the initial 24hours., Conclusion: Depletion of TAFIa may contribute to the development of trauma-induced coagulopathy., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Hypertension is associated with fibrinolysis abnormality. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a novel molecule-linking coagulation and fibrinolysis. The aim of this study was to investigate the levels of TAFI in primary hypertensive patients and to compare the effects of amlodipine and ramipril on TAFI levels. The study was performed with 58 hypertensive subjects and 27 healthy volunteers. Biochemical and hematological parameters and TAFI levels were measured at baseline and after 1-month follow-up. TAFI concentrations increased in hypertensive patients compared with the controls (P = .030). Additionally, TAFI levels decreased with blood pressure control at 1-month follow-up (P = .026). There was no significant difference between TAFI levels in the amlodipine and ramipril groups at baseline. However, after 1-month follow-up, TAFI levels were decreased in the amlodipine group (P = .037) but not in the ramipril group. Our study is the first in the literature to determine increased TAFI levels in primary hypertension patients. In addition, we determined a decrease in TAFI levels in the amlodipine group after 1 month, but none in the ramipril group.

Introduction: We hypothesized that thrombin activatable fibrinolysis inhibitor (TAFI) and the activation of fibrinolysis by both plasmin and neutrophil elastase is insufficient to overcome fibrinolytic shutdown, contributing to multiple organ dysfunction syndrome (MODS) in sepsis-induced disseminated intravascular coagulation (DIC)., Materials and Methods: Fifty patients with sepsis were prospectively enrolled. The DIC was diagnosed based on the Japanese Association for Acute Medicine (JAAM) DIC and the International Society on Thrombosis and Haemostasis (ISTH) overt DIC criteria., Results: The JAAM DIC scores were independent predictors of patient death and MODS. The JAAM DIC patients, especially those who met the ISTH overt DIC criteria, showed lower TAFI activity, and higher levels of soluble fibrin, neutrophil elastase, fibrin degradation product by neutrophil elastase (EXDP), plasmin-alpha2 plasmin inhibitor complex (PPIC), tissue plasminogen activator-plasminogen activator inhibitor-1 complex (tPAIC) and D-dimer in comparison with non-DIC patients. There were differences in the levels of soluble fibrin, tPAIC, TAFI activity, and neutrophil elastase between the patients with and without MODS. However, no differences were observed in the levels of PPIC, D-dimer, or EXDP. Soluble fibrin negatively correlated with the TAFI activity. High neutrophil elastase, low TAFI activity and PPIC are independent predictors of patient death and MODS. tPAIC is an independent predictor of elevation of EXDP in DIC patients., Conclusions: Activation of fibrinolysis both by plasmin and neutrophil elastase cannot overcome fibrinolytic shutdown, leading to MODS and a poor outcome in sepsis-induced DIC. The systemic activation of neutrophils and a low TAFI activity are also involved in the pathogenesis of MODS., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The aim of this study was to examine the contribution of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS) and a novel marker of vascular endothelial dysfunction, and thrombin-activatable fibrinolysis inhibitor (TAFI), a risk factor for venous thrombosis, to the predisposition of coronary restenosis following stent implantation in coronary artery disease (CAD) patients. Thirty-seven patients with CAD were recruited from the Kobry El Obba Military Hospital, Cairo, Egypt. The patients were hospitalized for coronary angiography and coronary stenting (CS). Overnight fasting blood samples were collected from patients prior to CS and four months later for the determination of plasma ADMA and TAFI levels. The patients underwent follow-up coronary angiography to reveal in-stent restenosis. The results showed that plasma ADMA levels in CAD patients were significantly higher than those reported for healthy subjects. ADMA levels were significantly increased by 30% in CAD patients four months following CS. CAD patients who developed in-stent restenosis had a 35% increase in ADMA levels following CS. TAFI levels were not significantly changed after CS in CAD patients or in any of the subgroups. In conclusion, ADMA, but not TAFI, is linked to the predisposition of in-stent restenosis following CS.

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen that is activated by thrombin in plasma. In fibrinolytic processes, carboxy-terminal lysine (Lys) residues in partially degraded fibrin are important sites for plasminogen binding and activation, and an active form of TAFI (TAFIa) inhibits fibrinolysis by eliminating these residues proteolytically. We synthesized DD2 [7-Amino-2-(sulfanylmethyl)heptanoic acid], a Lys analogue containing sulfur, as an inhibitor of TAFIa and investigated its pharmacological profile and pathophysiological role in thrombolysis via in vitro and in vivo studies. DD2 specifically inhibited plasma TAFIa activity with an apparent IC(50) (50% inhibitory concentration) value of 3.4×10(-8)M under the present experimental condition and enhanced tissue plasminogen activator-mediated clot lysis in a concentration-dependent manner. In order to study tissue factor (TF)-induced microthrombosis in an animal model, rats were given intravenous injection (2.5mg/kg and higher) or oral administration (10mg/kg and higher) of DD2. This attenuated TF-induced glomerular fibrin deposition and increased the plasma levels of fibrin degradation products and D-dimer in a dose-dependent manner. A DD2 dose approximately 4X higher than the dose used in intravenous injections was required to achieve an equivalent thrombolytic effect to that seen following oral administration. Moreover, the oral absorption efficiency of DD2 into the vasculature was 29.8%. These results indicate that both intravenous and oral administration of DD2 enhanced endogenous fibrinolysis and reduced thrombi in a TF-induced microthrombosis model., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Aim: In addition to suppressing fibrinolysis, thrombin activatable fibrinolysis inhibitor (TAFI) was suggested to be involved in inflammation. To date, no study has been published that reports the role of TAFI in acute pancreatitis (AP). Therefore, the objective of the present study was to investigate the role of plasma TAFI as an indicator of inflammation in AP, and its association with disease severity., Methods: Plasma TAFI antigen levels quantitatively determined by using ELISA kits in 21 AP patients at onset and remission and 17 healthy controls. Associations of TAFI with inflammatory markers to determine AP and disease severity were assessed. To predict the severity of AP, modified Glasgow prognostic score (mGPS) and computerized tomography severity index (CTSI) were used for each subject., Results: Plasma TAFI levels was higher in AP patients at onset of the disease compared with healthy controls. The disease severity according to mGPS was significantly correlated with TAFI levels. Overall, accuracy of TAFI in determining AP was 83.3% with a sensitivity, specificity, NPV and PPV of 80.9%, 85.7%, 81.8%, and 85% respectively (AUC: 0.915)., Conclusions: The present study for the first time demonstrated that TAFI is elevated in AP. The appraisal of TAFI levels in patients with AP in conjunction with other markers of inflammation may provide additional information in estimating AP severity., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

The relation between cancer and coagulation is the subject of investigation since a relation between tumor and thrombosis has been determined. Antithrombin III is an important thrombin inhibitor, and increased thrombin-antithrombin (TAT) complex levels activate coagulation. Activated thrombin activatable fibrinolysis inhibitor (TAFI) inhibits the conversion of plasminogen to plasmin. In addition, it directly inactivates plasmin. Defective fibrinolysis increases the risk of thrombosis. In this study, we evaluated homeostatic parameters, TAFI, and TAT levels in patients with gastric cancer applying to the medical oncology outpatient clinic. Fifty-two patients and 35 healthy controls were included. ELISA was used to measure TAFI and TAT complex levels. These were statistically higher in the patient group (p < 0.05 and p = 0.001, respectively). D-dimer levels were higher in stage IV (p = 0.05). Correlations between lymph nodes and TAFI and TAT levels were examined. Weak but positive correlation between lymph nodes and TAFI was detected (R = 0.452, p = 0.027). TAFI and TAT levels were evaluated using relative operating characteristic analysis to differentiate the disease. TAT was more specific than TAFI according to this analysis (TAFI area under curve (AUC), 0.676; TAT AUC, 0.874). Thrombotic events and bleeding disorders need to be borne in mind in gastric cancer. This situation is due to the impairment of the balance between coagulation and fibrinolysis. Further studies are now needed to evaluate the effects of TAFI and TAT on survey and prognosis as well as the potential of these parameters as tumor markers for gastric cancer.

Objective: We determined the profile of coagulation/fibrinolytic and vascular endothelial cell function parameters including plasminogen activator inhibitor (PAI) and thrombin-activatable fibrinolysis inhibitor (TAFI), tissue factor pathway inhibitor (TFPI), thrombomodulin (TM), and tissue plasminogen activator (tPA) levels in children with hypothyroidism., Methods: Forty children with hypothyroidism aged 0-16 months who presented for the first time to our hospital and 29 age-and sex-matched healthy controls were enrolled in the study. All coagulation tests were performed with ELISA method. One year after Na-L-thyroxine treatment, the study parameters were re-evaluated in 25 euthyroid children out of the 40 patients diagnosed with hypothyroidism., Results: Although no significant effect was detected regarding PAI antigen (Ag) and tPA Ag, the levels of TAFI, TM, and TFPI were consistent with subclinical hypercoagulability and hypofibrinolysis. There was a significant increase in TAFI Ag levels and a significant decrease in TFPI Ag and TM Ag levels in hypothyroid patients compared to healthy controls. As a result of correlation tests, the largest impact of hypothyroidism on coagulation system was on TFPI. In accordance with these findings, TAFI Ag levels decreased and TFPI Ag and TM Ag levels increased with hormonal replacement therapy., Conclusions: Increased TAFI and decreased TFPI and TM in patients with hypothyroidism may indicate a potential hypercoagulable and hypofibrinolytic state as well as possible endothelial dysfunction, which may increase the risk of atherosclerotic and atherothrombotic complications. Thyroid hormone levels should also be checked in patients with a predisposition to coagulation, and thyroid replacement therapy should be initiated.

Introduction: Though thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to hypercoagulability during pregnancy, limited data are available on the role of TAFI in women with recurrent fetal loss., Material/methods: We performed a case-control study aimed at evaluating any possible association between TAFI levels and early recurrent fetal loss (≥ 3, or 2 with at least one normal fetal karyotype, before the 10th week of gestation). 140 women with early recurrent fetal loss and 140 age-matched healthy controls with at least one normal pregnancy were included. The number of miscarriages was 2.59 and occurred at gestational age 6.89 weeks. TAFI levels were determined by a chromogenic assay measuring total potential activatable TAFI., Results: TAFI levels were significantly lower in early recurrent fetal loss women (12.2 ± 2.3 μg/ml vs 13.2 ± 2.6 μg/ml in healthy controls, p=0.001). ORs of early recurrent fetal loss (crude and adjusted for possible confounding variables) were calculated after stratification of TAFI levels into quartiles. 25/140 (17.8%) early recurrent fetal loss women had TAFI levels above 14.0 μg/ml (4th quartile) vs 44/140 (31.3%) in healthy women (p=0.014). Crude and adjusted ORs of early recurrent fetal loss in women with TAFI levels in the 4th quartile vs those in the reference category (1st quartile=below 11.0 μg/ml) were 0.42 (95%CI: 0.22-0.82) and 0.39 (95%CI: 0.19-0.80), respectively., Conclusions: Our study provides evidence that high TAFI levels are associated with reduced risk of early recurrent fetal loss. Further studies are needed to better understand the actual role of TAFI in recurrent fetal loss., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Limited data are available on the role of innate fibrinolysis in acute coronary syndromes (ACS). In the present study we evaluated the dynamic alterations of fibrinolytic markers in patients presenting with ACS. Tissue-type-(tPA) and urokinase type-(uPA) plasminogen activators, plasminogen activator inhibitor (PAI-1) antigen and activity and thrombin activatable fibrinolysis inhibitor (TAFI) were analysed in 50 patients with ST elevation myocardial infarction (STEMI), 47 non-STEMI patients (NSTEMI), 40 patients with stable coronary artery disease (CAD) and 39 controls. The parameters were measured on day 1 and days 3, 7 and 30. Counts of monocyte subsets, monocyte-platelet aggregates and plasma inflammatory cytokines were assessed on admission. On day 1, TAFI was higher in NSTEMI vs. STEMI (p<0.001) while PAI-1 activity was higher in STEMI (p<0.001). In STEMI, uPA activity levels was low on day 1 but significantly increased on day 30 (p<0.001). TAFI levels were increased in NSTEMI on day 1 and gradually reduced by day 30 (p<0.05). In STEMI, TAFI levels peaked at day 7 (p<0.05) and dropped significantly by day 30 (p<0.05). CD14++CD16+ monocytes were independently associated with PAI-1 activity in ACS (p=0.03). Monocyte-platelet aggregates rather than platelet-free monocytes were an independent determinant of tPA, PAI-1 antigen and TAFI on a multivariate analysis (p<0.05). There are significant differences in fibrinolytic activity between patients with STEMI and NSTEMI. These changes could reflect the role of these factors in post-MI myocardial healing. Monocyte-platelet interactions are independently associated with the regulation of the fibrinolytic status in ACS.

Activated thrombin-activatable fibrinolysis inhibitor (TAFIa or CPU) is a carboxypeptidase that is able to attenuate fibrinolysis. Although its role in fibrinolysis and inflammation has been studied extensively in vitro, its levels and subsequent effect in vivo has not been studied to the same extent. Using our recently developed assay that is specific for TAFIa, we were able to quantify its levels in plasma samples obtained from an Escherichia coli (E. coli) challenged baboon sepsis model. TAFIa levels accumulated appeared to be E. coli dose dependent, where the lethal dose of 10(10) CFU/kg generated a peak TAFIa level of 24 nM by 2 h, which represents almost 32% of total plasma level of its precursor, thrombin-activatable fibrinolysis inhibitor (TAFI or proCPU). Furthermore, our data suggest that there is continual TAFI activation under lethal level of E. coli as the apparent half-life of TAFIa is increased from 8 min to 2.2 h. Two sublethal doses of 10(8) and 10(6) CFU/kg generated peak TAFIa levels of 1.1 and 0.4 nM, respectively, both by 6 h. Taken together, our data show that TAFIa is generated at systemic levels, in a dose-dependent manner, that can substantially affect both fibrinolysis and inflammatory response in the E. coli challenged baboon sepsis model.

TAFI (thrombin activatable fibrinolysis inhibitor) is the precursor of a basic carboxypeptidase (TAFIa) with strong antifibrinolytic and anti-inflammatory activity. Compelling evidence indicates that thrombin, either alone or in complex with thrombomodulin, is the main physiological activator of TAFI. For this reason derangements of thrombin formation, whatever the cause, may influence the fibrinolytic process too. Experimental models of thrombosis suggest that TAFI may participate in thrombus development and persistence under certain circumstances. In several models of pharmacological thrombolysis, the administration of TAFI inhibitors along with the fibrinolytic agent leads to a marked improvement of thrombus lysis, underscoring the potential of TAFI inhibitors as adjuvants for thrombolytic therapy. The role of TAFI in inflammatory diseases is more complex as it may serve as a defense mechanism, exacerbate the disease, or have no influence, depending on the nature of the model and the role played by the mediators controlled by TAFIa. Finally, the numerous clinical studies in patients with thrombotic disease support the idea that increased levels of TAFI and/or the enhancement of TAFI activation may represent a new risk factor for venous and arterial thrombosis., (Copyright © 2011. Published by Elsevier Ltd.)

Introduction: Thrombin activatable fibrinolysis inhibitor (TAFI) down-regulates fibrinolysis after activation by thrombin/thrombomodulin. We investigated the effect of treatment with FVIII concentrate on plasma levels of pro-TAFI and activated TAFI in haemophilia A patients., Methods: Samples were collected pre and posttreatment from patients treated prophylactically or on-demand. Pro-TAFI, TAFI/TAFIi and FVIII levels were measured in all samples., Results: Treatment had no effect on pro-TAFI levels. Pro-TAFI was similar in both patient groups but higher than in controls. Patients from the prophylactic treatment group had measurable FVIII levels pretreatment while in the treatment-on-demand group FVIII levels were ≤0.01 IU/mL. In the prophylactic treatment group, the levels of TAFI/TAFIi were significantly lower pre- and posttreatment (4.31 ± 3.14 and 3.48 ± 2.65 ng/mL respectively) than in the on-demand group (13.02 ± 3.47 and 14.87 ± 3.47 ng/mL respectively). This difference may be due to release of tissue factor at the injury site in the on-demand group. This could induce thrombin and TAFI activation within the clot counterbalancing fibrinolysis in these patients. In the prophylactic group, no injury existed, thus there was insufficient thrombin generation within the clot to activate TAFI., Conclusion: These findings suggest that in patients to whom FVIII is administered on demand the fibrinolysis activity is more down regulated than in patients following a prophylactic treatment regime., (© 2011 Blackwell Publishing Ltd.)

Background: Thrombin activatable fibrinolysis inhibitor (TAFI) has been reported to be involved in the pathogenesis and progression of inflammatory bowel disease (IBD). Activated TAFI (TAFIa) attenuates fibrinolysis by cleaving C-terminal lysine residues thus down-regulating plasminogen activation. To date, no reports on TAFIa in IBD have been published., Methods: Plasma levels of TAFIa were measured using a functional assay in 55 consecutive patients with ulcerative colitis (UC) and 50 with Crohn's disease (CD). Associations of TAFIa with disease activity, hemostatic variables and inflammatory markers were assessed., Results: Plasma TAFIa was higher in CD patients than in those with UC. The disease activity correlated positively with TAFIa levels in the UC group, but not in the CD group. In UC patients, there were positive correlations of TAFIa with white blood cells, C-reactive protein and fibrinogen and an inverse correlation with albumin. In the CD group, a positive correlation was shown for C-reactive protein, fibrinogen and platelet count, while a negative correlation was noted for albumin., Conclusions: This study is the first to show that TAFIa is increased in CD patients compared with UC and its levels are associated with inflammatory markers in both forms of IBD. These findings fit in the hypothesis that TAFIa may be a marker of active IBD, and in particular of active UC., (Copyright © 2011 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.)

We aimed to determine plasma thrombin-activatable fibrinolysis inhibitor (TAFI) antigen levels in women with previous gestational diabetes mellitus (GDM) and to evaluate the possible association of plasma TAFI with glucose intolerance and markers of subclinical atherosclerosis. This cross-sectional study was performed in 111 women with previous GDM and 60 controls. Glucose intolerance was evaluated. Homeostasis model assessment score was calculated. Circulating lipids, interleukin-6, matrix metalloproteinase-1, fibrinogen, plasminogen activator inhibitor-1, and TAFI antigen levels were assayed. Carotid intima media thickness (IMT) was measured. Women with previous GDM had increased levels of atherosclerosis markers and carotid IMT. On the other hand, plasma TAFI antigen levels were similar (P = .395). Thrombin-activatable fibrinolysis inhibitor was not associated with the indices of insulin resistance, glucose intolerance, markers of atherosclerosis, and carotid IMT. Our data demonstrated that plasma TAFI was not altered in women with previous GDM. TAFI was not associated with glucose intolerance and subclinical atherosclerosis.

Introduction: Atrial fibrillation (AF) is associated with a prothrombotic state., Objectives: We evaluated associations of previous thromboembolic events with fibrinolytic parameters in patients with AF., Patients and Methods: We studied 62 consecutive patients with permanent AF (27 men, 35 women, aged 46-89 years [median, 78 years]). Patients receiving warfarin or acenocoumarol on a long-term basis were eligible. We determined plasma fibrin clot lysis time (CLT), plasminogen activator inhibitor-1 (PAI-1) antigen, thrombin-activatable fibrinolysis inhibitor (TAFI) activity and antigen, plasminogen, α2-antiplasmin (α2AP), and soluble thrombomodulin (sTM)., Results: There were 19 subjects (30.6%) with a history of thrombotic events (stroke in 11, myocardial infarction in 8, and pulmonary embolism in 3 patients). They had longer CLT (P = 0.0035 for patients with previous stroke and P = 0.001 for patients with any previous thrombotic event), together with higher PAI-1 (P = 0.025 and P = 0.016, respectively), TAFI activity (P = 0.002 and P = 0.011, respectively), sTM (P = 0.0023 and P = 0.012, respectively), and α2AP (P = 0.007 and P = 0.0006, respectively) than the remaining subjects. AF patients with previous stroke had also higher TAFI antigen than the remainder (P = 0.04). CLT (P = 0.024), PAI-1 (P = 0.022), TAFI activity (P = 0.048), and sTM (P = 0.032, all P for trend) increased with higher CHA2DS2-VASc scores. CLT was not associated with time from thrombotic event to enrollment. Patients taking oral anticoagulants (n = 46) had only slightly higher sTM levels (3.6 [2.9-6.3] vs. 2.9 [2.2-4.1] ng/ml, P = 0.049) than the remaining subjects., Conclusions: Stroke or other thromboembolic event in AF patients is associated with impaired lysability of fibrin clots combined with elevated PAI-1, TAFI, sTM, and α2AP.

Interferon (IFN) interacts with endothelial cells and modulates the functions of these cells. In our study, we aimed to determine the effects of treatment with pegylated IFN-α (peg-IFN-α) on fibrinolytic parameters in patients with chronic hepatitis C. Fifteen patients with chronic hepatitis C were treated with peg-IFN-α once per week plus daily oral ribavirin. Euglobulin lysis time (ELT), plasma levels of D-dimer, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), and thrombin activatable fibrinolysis inhibitor (TAFI) were determined before treatment, 2 weeks, 1 month, and 3 months after the initiation of the treatment. Plasma levels of t-PA increased significantly 1 month and 3 months after the treatment (P < .05). The PAI-1 and TAFI levels in 2 weeks, 1 month and 3 months after treatment were not statistically different as compared with pretreatment levels (P > .05) No significant difference in plasma D-dimer levels was observed during peg-IFN-α treatment (P > .05). There was a significant decrease in ELT 1 month and 3 months after the treatment (P < .05). Our results indicated that treatment with peg-IFN-α may be associated with enhanced fibrinolysis.

Introduction: The objective was to evaluate if thrombin-activated fibrinolysis inhibitor (TAFI) polymorphisms (G505A, C1040T, and G-438A), and TAFIa plasma levels are associated with preeclampsia., Materials and Methods: In a case-control study design, we evaluated preeclampsia patients and women with uncomplicated pregnancies. The TAFI polymorphisms were determined by real-time PCR method, and TAFIa plasma levels were established with a chromogenic assay., Results: We included 87 women in each group. The TAFIa levels in the preeclampsia group were 20.4 μg/mL (CI 95% 17.3-23.5), while in the control group, they were significantly lower: 13.3 μg/mL (12.0-14.5, p 0.003). There were no differences in the genotype distribution or allelic frequency of TAFI polymorphisms between the two groups. In preeclampsia patients and controls heterozygous for the G505A polymorphism, the TAFIa values were 22.8 (16.7-28.9 μg/mL) and 13.2 (11.3-15.0 μg/mL, p 0.019), respectively. In G505A homozygous polymorphism the TAFIa values were 25.7 (18.7-32.6 μg/mL) and 13.5 (1.6-21.9 μg/mL, p 0.041), respectively. In the C1040T and G-438A TAFI wild type polymorphisms, the TAFIa values were 18.3 (12.5-23.9 μg/mL) and 11.5 (9.9-35.0, p 0.033), and 19.4 (10.9-27.9 μg/mL) and 12.5 (10.8-14.2 μg/mL, p 0.006), respectively, without differences in other genotypes., Conclusions: Preeclampsia by itself may be responsible for the increase in TAFIa values rather than the presence of polymorphisms., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Disturbances of coagulation and fibrinolysis in type 2 diabetes mellitus (DM2) contribute to increased rates of macrovascular complications such as myocardial infarction and ischemic stroke. The aim of the study was to investigate the relationship among plasminogen activator inhibitor 1 (PAI-1), thrombin-activable fibrinolysis inhibitor (TAFI), tissue plasminogen activator (t-PA), prothrombin fragments 1+2 (F1+2), glycemic control, hypertension, sex and body mass index (BMI) in DM2 patients with normoalbuminuria and microalbuminuria. Forty-two normoalbuminuric (NAU), 42 microalbuminuric (MAU) patients with DM2 and 42 blood donors as control group were enrolled. TAFI, PAI-1, t-PA and F1+2 were assessed by enzyme-linked immunosorbent assay (ELISA) in all patients. TAFI was significantly increased in the MAU group, PAI-1 and F1+2 were increased in both groups and t-PA was not elevated in either group compared to controls. We found positive correlations in the NAU: TAFI and fibrinogen (r=0.65, P=0.02), PAI-1 and triglycerides (r=0.67, P=0.01), in the MAU: TAFI and F1+2 (r=0.48, P=0.02), TAFI and systolic blood pressure (r=0.53, P=0.01), PAI-1 and BMI (r=0.43, P<0.05). We found decreased fibrinolysis in DM2 patients presented with increased PAI-1 in both NAU and MAU. Hypofibrinolysis in MAU is further accented by the elevation of TAFI. TAFI-mediated inhibition of fibrinolysis in DM2 is regulated independently from PAI-1. Patient[Combining Acute Accent]s sex does not affect diabetes-related changes in hemostasis and fibrinolysis.

Objective: The objective of this study was to investigate whether thrombin activatable fibrinolytic inhibitor (TAFI) Thr325Ile polymorphism and TAFI antigen (Ag) levels could constitute a risk marker of myocardial infarction (MI) in Egyptian patients., Study Population and Results: The study included forty-six patients with acute MI (mean age 55.7 +/- 8.1 years, 33 men, 13 women) compared with age and sex-matched healthy volunteers (n = 54) as a control group. Clinical examination, laboratory investigations, electrocardiography (ECG) and/or echocardiography were done. TAFI Thr325Ile (reference sequence: rs1926447) polymorphism was genotyped in both studied groups using TaqMan SNP (single nucleotide polymorphism) genotyping assay. The genotypes of the high-risk allele [Thr/Ile (CT) and Ile/Ile (TT)] were significantly more frequent in patients compared with the control group (54.4% and 32.6% vs. 51.8% and 5.6%, respectively) and were also associated with an increased risk of MI [OR = 4.95, (95% CI: 1.80 - 13.63); P = 0.0001]. Ile325 allele carriers were more frequent in cases than in control subjects (60.0% vs. 31.5%) [OR = 3.26, (95% CI = 1.82 - 5.83), P = 0.001]. The Thr325Ile SNP significantly correlated with TAFI antigen levels with the C/C genotype corresponding with the highest and the T/T genotype with the lowest TAFI antigen levels (P < 0.001). No statistically significant relation was found between TAFI Thr325Ile polymorphism and either the type or the site of MI., Conclusions: TAFI Thr325Ile and its respective plasma protein level could have a contribution to MI risk in the Egyptian population.This could be helpful in refining a risk profile for coronary heart disease (CHD) patients.

Depending on type, duration, and intensity of the exercise, changes occur in hemostasis. In this study, we evaluated the changes in the parameters of coagulation and fibrinolytic systems that happened after the submaximal aerobic exercises by bicycle ergomater. Twelve healthy male participants whose ages were between 21 and 28 have been included. The venous samples have been drawn before the exercise as well as at the 0 th, 15th, and 60th minutes after the submaximal exercise. The values of prothrombin time (PT), active partial thromboplastin time (aPTT), D-dimer, fibrinogen, plasminogen activator inhibitor 1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) have been measured. Plasminogen activator inhibitor 1 values have shown an insignificant increase after exercise (P = .328), whereas, it has decreased significantly during the resting period (P = .033) Postexercise 15th and 60th minutes TAFI values have decreased significantly comparing to basal and postexercise (0 th minute) values (P = .001). Fibrinolytic system activation is observed after acute submaximal aerobic exercise of sedentary healthy participants.

The fibrinolytic system is often the target for pathogenic bacteria, resulting in increased fibrinolysis, bacterial dissemination, and inflammation. The purpose of this study was to explore whether proteases NprB and InhA secreted by Bacillus anthracis could activate the host's fibrinolytic system. NprB efficiently activated human pro-urokinase plasminogen activator (pro-uPA), a key protein in the fibrinolytic cascade. Conversely, InhA had little effect on pro-uPA. Plasminogen activator inhibitors (PAI)-1, 2 and the uPA receptor were also targets for NprB in vitro. InhA efficiently degraded the thrombin-activatable fibrinolysis inhibitor (TAFI) in vitro. Mice infected with B. anthracis showed a significant decrease in blood TAFI levels. In another mouse experiment, animals infected with isogenic inhA deletion mutants restored TAFI levels, while the levels in the parent strain decreased. We propose that NprB and InhA may contribute to the activation of the fibrinolytic system in anthrax infection., (© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

Since its discovery more than 20 years ago, a lot has been revealed about the biochemistry and physiological behaviour of carboxypeptidase U (CPU). Recent advances in CPU research include the unravelling of the crystal structure of proCPU and revealing the molecular mechanisms for the marked instability of the active enzyme, CPU. The recent development of two highly sensitive assays has cleared the path toward the direct measurement of CPU in circulation or the determination of CPU generation, rather than the measurement of total proCPU concentration in plasma. Finally, since CPU is known to have a prominent bridging function between coagulation and fibrinolysis, the development of CPU inhibitors as profibrinolytic agents is an attractive new concept and has gained a lot of interest from several research groups and from the pharmaceutical industry. These recent advances in CPU research are reviewed in this literature update.

Multiple myeloma has been associated with the development of thromboembolic events. Thrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme, which potently inhibits fibrinolysis. The purpose of the present study was to assess the TAFI levels in patients with newly diagnosed multiple myeloma. Twenty-seven newly diagnosed multiple myeloma patients (16 women and 11 men) and 27 age-matched healthy individuals (14 women and 13 men) were included in the study. Serum TAFI levels were significantly increased in patients with multiple myeloma (46 ± 13. 3 vs. 36. 6 ± 9.7 μg/ml) compared with healthy individuals. Serum TAFI levels were negatively correlated with serum albumin (CC: -0.453, P < 0.05) and hemoglobin levels (CC: -0.392, P < 0.05) and positively correlated with the β-2 microglobulin levels (CC: 0.524, P < 0.05). In this study, we observed significantly elevated TAFI levels in patients with multiple myeloma and higher serum TAFI levels were suggested to be associated with higher disease stage. With these results, a possible role of elevated TAFI levels in thromboembolic manifestations in the course of multiple myeloma can be suggested.

Background: Recurrent implantation failure (RIF) following embryo transfer (ET) is a major continuing problem in IVF. Women with haemostatic defects may be at increased risk of miscarriage and preclinical pregnancy loss. The fibrinolytic system is considered, at present, the key to new thrombotic pathogenic mechanisms. Patients with unexplained recurrent miscarriage have an impairment of fibrinolysis, as demonstrated by prolonged clot lysis time (CLT) in association with increased plasma levels of thrombin-activatable fibrinolysis inhibitor (TAFI). In this study, we investigated fibrinolytic potential in patients with RIF., Methods: Three groups of patients were studied: 30 women with RIF (RIF group), 60 patients undergoing a first successful IVF-ET cycle (IVF group) and 60 healthy fertile women (FER group). Plasma CLT was measured using a global fibrinolysis assay. TAFI antigen plasma levels and polymorphisms in the TAFI gene (+505A/G and +1542C/G) were analysed using enzyme-linked immunosorbent assay and allele-specific PCR, respectively., Results: CLT was significantly longer (P < 0.0001 and P < 0.0009, respectively) and TAFI antigen levels were significantly higher (both P < 0.0001) in the RIF versus the IVF and FER groups. A direct relationship between CLT and TAFI antigen levels (r = 0.40; P = 0.001) was detected in the whole study population. There were no differences in distribution of TAFI polymorphisms between groups., Conclusions: Patients with RIF have reduced plasma fibrinolytic potential, as shown by a prolonged CLT, and this may be explained, at least in part, by increased TAFI antigen levels.

Background: Previous studies suggested that hypofibrinolysis is associated with increased risk of peripheral arterial disease. Thrombin activatable fibrinolysis inhibitor (TAFI) has been identified as an important inhibitor of fibrinolysis. The aim of our study was to assess the role of TAFI in young patients with peripheral arterial disease., Methods: In a single-center case-control study we measured plasma TAFI antigen levels and functional TAFI in consecutive young patients (men 18-45 years and women 18-55 years) with a first manifestation of peripheral arterial disease and compared these with a population-based control group., Results: A total of 47 peripheral arterial disease patients and 141 controls (mean age 43) were included. Intact TAFI antigen levels were significantly higher in patients with peripheral arterial disease (112.4±21.1%) than in controls (104.9±19.9%, p=0.03). The risk of peripheral arterial disease increased with 18% (OR 1.18; CI 1.01-1.34) per 10% increase of TAFI antigen. Functional TAFI levels were slightly higher in patients compared to controls, however this difference was not significant. For individuals with the highest functional TAFI levels, above the 90th percentile, the increased risk for peripheral arterial disease was most pronounced (OR 3.1; CI 1.02-9.41)., Conclusion: High TAFI levels are associated with increased risk of premature peripheral arterial disease., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Objective: To compare components of the fibrinolytic cascade in newborns of gestational age ranging from extreme prematurity to full term, at birth and for the next 10 days, and in their mothers at delivery., Study Design: We studied 10 extremely preterm neonates, 10 very preterm neonates, 10 moderately preterm neonates, 10 full-term neonates, and their mothers (n = 40). We measured the antigen levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitors 1 (PAI-1) and 2 (PAI-2), and thrombin-activatable fibrinolysis inhibitor, as well as PAI-1 activity, in neonates at birth and on postnatal days 3 and 10 and in mothers at delivery., Results: On day 10, both PAI-1 antigen and activity were higher in extremely preterm neonates than in full-term neonates (P = .004 and <.0006, respectively), and the t-PA/PAI-1 activity ratio was lower in the extremely preterm and very preterm neonates compared with the full-term neonates (P = .002 and .017, respectively). No significant differences in the fibrinolytic system components were seen among the 4 groups of mothers., Conclusions: The development of fibrinolysis suppression in extremely preterm infants within 10 days after birth may contribute to the increased risk of periventricular hemorrhagic infarction in these infants., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: The resistance of platelet-rich thrombi to fibrinolysis is generally attributed to clot retraction and platelet PAI-1 release. The role of TAFI in platelet-mediated resistance to lysis is unclear., Objective: We investigated the contribution of TAFI to the antifibrinolytic effect of platelets in whole blood by thromboelastography., Methods: Platelet-poor (PP-WB, < 40 × 10(3) μL(-1) ) and platelet-rich (PR-WB, > 400 × 10(3) μL(-1) ) blood samples were obtained from normal human blood (N-WB, 150-220 × 10(3) μL(-1) ). Clot lysis time was measured by thromboelastography in recalcified blood supplemented with t-PA (100 ng mL(-1) ) and tissue factor (1:1000 Recombiplastin)., Results: t-PA-induced lysis time increased in parallel with platelet concentration (up to 3-fold). Neutralization of TAFI, but not of PAI-1, shortened the lysis time by ∼ 50% in PR-WB and by < 10% in PP-WB. Accordingly, prothrombin F1+2 and TAFIa accumulation was greater in PR-WB than in PP-WB. A similar TAFI-dependent inhibition of fibrinolysis was observed when clot retraction was prevented by cytochalasin D or abciximab, or when platelet membranes were tested. Moreover, in blood with an intact contact system, platelet-mediated fibrinolysis resistance was attenuated by an anti-FXI but not by an anti F-XII antibody. Finally, platelets made the clots resistant to the profibrinolytic effect of heparin concentrations displaying a strong anticoagulant activity., Conclusions: Our data indicate that TAFI activation is one major mechanism whereby platelets make clots resistant to fibrinolysis and underscore the importance of TAFI inhibitors as new antithrombotic agents., (© 2010 International Society on Thrombosis and Haemostasis.)

Objective: To evaluate the levels of thrombin-activatable fibrinolysis inhibitor (TAFI) activity and also its relationship with other homeostasis markers in breast cancer patients., Subjects and Methods: Forty-two female patients with breast cancer and 24 healthy women (controls) were enrolled in the study and fasting blood samples of all cases were drawn from a large antecubital vein for assay of TAFI and other homeostasis tests., Results: The TAFI levels were 79.5 ± 15.5 and 39.3 ± 12.1 in patients and controls, respectively, and the difference was statistically significant (p < 0.001). In the patient group, the serum fibrinogen level was 504.9 ± 224.8, while in the control group it was 393.9 ± 100.5, and the difference was also statistically significant (p < 0.001)., Conclusion: The data showed that increased levels of TAFI are a contributing factor of thrombotic disorders in breast cancer patients., (Copyright © 2011 S. Karger AG, Basel.)

Objective: The aim of this prospective study was to investigate the effect of LT4 suppression therapy on plasma thrombin activatable fibrinolysis inhibitor (TAFI) antigen and plasminogen activator inhibitor-1 (PAI-1) levels in benign thyroid nodules. We also compared hyperthyroid patients and healthy controls., Subjects and Methods: Twenty premenopausal women with benign thyroid nodules were given LT4 suppression therapy for 1 year. Plasma TAFI and PAI-1 antigen levels were measured at baseline and after LT4 suppression treatment. The endogenous hyperthyroid group was composed of 19 premenopausal females with newly diagnosed endogenous hyperthyroidism. Eighteen age-matched euthyroid healthy premenopausal women were enrolled as the control group., Results: TAFI antigen levels decreased after LT4 suppression treatment; however, the difference was not statistically significant (p = 0.057). LT4 treatment resulted in a nonsignificant increase in PAI-1 levels. Patients with endogenous hyperthyroidism had decreased levels of TAFI antigen and increased levels of PAI-1 antigen (p < 0.05). There was a negative correlation between the FT(4) and TAFI antigen levels. Serum TSH was positively correlated with the plasma levels of TAFI antigen., Conclusion: LT4 suppression therapy for benign thyroid nodules did not result in a significant decrease in TAFI antigen levels in premenopausal women, but endogenous hyperthyroidism was associated with significantly decreased levels of TAFI antigen., (Copyright © 2010 S. Karger AG, Basel.)

Objective: To determine the role of the fibrinolytic and antifibrinolytic systems in HELLP syndrome., Methods: This study consisted of patients with HELLP Syndrome (study group, n = 17), women who were admitted for routine prenatal care (pregnant control group, n = 21) and those presenting for routine gynecologic examination (non-pregnant control group, n = 21). Plasma tissue-type plasminogen activator (tPA), thrombin-activatable fibrinolysis inhibitor (TAFI), plasminogen activator inhibitor-1 (PAI-1), thrombin-antithrombin complex (TAT) and thrombomodulin (TM) were measured at admission for all groups. They were again measured after 7 days of biochemical improvement in HELLP Syndrome group., Results: The mean ages of women in the study, pregnant, and non-pregnant control groups were 29.82 ± 4.98, 29.71 ± 5.64, and 27.60 ± 4.21, respectively. Demographically, the patients in all three groups were similar with regard to maternal age, race, and body mass index. Compared to the control groups, the mean tPA, PAI-1, TAFI, TAT, and TM levels were significantly increased in HELLP Syndrome. The mean plasma TAFI antigen concentration 7 days after delivery was significantly lower compared to the baseline (5.84 ± 7.14 % change, p < 0.01). Significant decreases in the mean plasma concentrations were also found in tPA (21.78 ± 20.93 ng/mL mean difference, p < 0.01), PAI-1 (14.22 ± 10.38 ng/mL mean difference, p < 0.001), TAT (0.93 ± 1.19 ng/mL mean difference, p < 0.01), and TM (0.54 ± 0.94 ng/mL mean difference, p < 0.05)., Conclusion: It is likely that the impaired fibrinolytic and antifibrinolytic systems, in response to thrombus formation, affect the pathophysiology of HELLP syndrome.

Aim: To study effects of thrombin-activated fibrinolysis inhibitor (TAFI) on efficacy and safety of long-term anti-coagulant treatment in patients with venous thromboembolic complications (VTEC)., Material and Methods: A total of 111 patients with a history of an episode of deep vein thrombosis (DVT) and/or pulmonary artery thromboembolism (PATE) entered the study. All the patients received unfractionated or low-molecular heparin for at least 5 days than switch on warfarin (target values of INR 2.0-3.0). Baseline blood levels of TAFI were measured. The patients were followed up for 18 months. Recurrent (DVT/TAFI and hemorrhagic complications (HC) were endpoints. Also, frequency of complete lysis of deep vein thrombi was assessed after 12 months of treatment., Results: A TAFI level varied from 50 to 217% (median 106%, interquartile rage 90-133%). TAFI concentration positively correlated with fibrinogen and thromb size. The patients were divided into two groups depending on TAFI content: group 1 patients had low TAFI (under 25th percentile; < 90%); patients of group 2 had high TAFI (above 25th percentile; > 90%). Group 1 patients were characterized by less stable anticoagulation. This association did not depend on genetic characteristics which determine sensitivity to warfarin (CYP2C9 and VKORC1). Low TAFI was associated with reduced risk of DVT for 18 months and higher probability of complete lysis of the thrombi after 12 months of anticoagulant therapy compared to VTEC patients with high TAFI. No differences were found by TAFI level in patients with HC and without HC, but in HC patients low TAFI was associated with spontaneous hemorrhages and bleeding in therapeutic INR values., Conclusion: The results of this pilot study evidence that a TAFI level can be one of the factors influencing efficacy and safety of long-term anticoagulant therapy in patients with VTEC on warfarin treatment.

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.