Plasminogen Activator Inhibitor Type 1 Antigen Levels Research Articles

Plasminogen Activator Inhibitor Type 1 (PAI-1) and Thrombophilia: A 10 Year Retrospective Review of Clinical Data at a Large Children's Hospital

Introduction: Plasminogen activator inhibitor type 1 (PAI-1) is the most important regulator of fibrinolysis. Elevated PAI-1 levels are reported to be prothrombotic and have been associated with cardiovascular disease, obesity and cancer. PAI-1 synthesis is regulated by insulin, glucocorticoids and cytokines like tumor necrosis factor-α. The single base pair guanine deletion 4G PAI-1 genetic polymorphism has been linked to elevation of PAI-1 antigen and/or activity levels. Genotype frequencies in Caucasian populations have been estimated at 0.25 (5G/5G), 0.49 (4G/5G) and 0.26 (4G/4G). Increased thrombosis risk has been reported in patients with the combination of PAI-1 4G and factor V Leiden (FVL) genetic polymorphisms. Our pediatric specialty laboratory offers PAI-1 genotyping, PAI-1 antigen and PAI-1 activity assays as part of thrombophilia testing. The laboratory at the children's hospital is also a reference lab for the community. We retrospectively reviewed the results of PAI-1 testing over the last 10 years.We hypothesized that the PAI-1 4G polymorphism would be more prevalent in young patients with thrombosis. We also hypothesized that there would be an additive thrombophilia risk from the combination of PAI-1 4G and FVL in young patients with thrombosis.Methods: After IRB approval, using information from Cerner and EPIC, we created a deidentified thrombophilia database of 11,459 unique patients who had thrombophilia testing between March 8, 2007 and June 6, 2017. We identified 1,896 who had PAI-1 genotyping and 2,573 who had antigen and activity testing. Removing those <3 months of age for whom normal ranges for PAI-1 have not been established, we identified 1,418 subjects who had genotype, antigen and activity levels. We also evaluated a subset of 510 pediatric patients with thrombosis, of whom 338 had all three PAI-1 tests and were 3 months or older, and 292 who had both PAI-1 and FVL genotyping. Local genotype frequency was established by the clinical laboratory on 100 controls and was in agreement with published estimates. All comparisons were made using two-sided Fisher's Exact tests. Significance was assessed at the 0.05 level.Results: Ages for subjects tested for PAI-1 ranged from 0.1 - 89.7 years with a mean of 14.3 years, and 41% were male. Compared to the local genotype frequency, PAI-1 4G was not significantly altered in either the thrombophilia cohort or in the subset with pediatric thrombosis (Table 1). This was true even when we re-evaluated by gender or by selecting for those with thrombophilia testing <22 years of age. Among 53 pediatric thrombosis patients with cancer, genotype frequencies for PAI-1 4G did not differ strongly from control group (p=0.14), but numbers were very small. Of the 1,418 thrombophilia testing subjects who had PAI-1 genotype, antigen and activity, correlation between abnormal antigen (p=0.07) or activity (p=0.28) levels and the 4G polymorphism did not reach statistical significance, though it did for those with both abnormal antigen and activity (p=0.05). Among 292 pediatric thrombosis patients with testing (Table 2), there was a suggestion of an effect from the combination of FVL and PAI-1 4G polymorphisms and thrombosis (p=0.06).Conclusions: Abnormal PAI-1 antigen and activity levels are not solely dependent upon the 4G genotype and are likely influenced by other congenital and acquired factors. Among pediatric patients with thrombosis and particularly those with cancer and thrombosis, a possible effect from the PAI-1 4G polymorphism alone or in combination of FVL should be validated in a larger cohort. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Impact of Polytrauma and Acute Respiratory Distress Syndrome on Markers of Fibrinolysis: A Prospective Pilot Study.

Acute respiratory distress syndrome (ARDS), which is associated with major morbidity and high mortality, is commonly developed by polytraumatized patients. Its pathogenesis is complex, and its development is difficult to anticipate, as candidate biomarkers for the prediction of ARDS were found not to be reliable for clinical use. In this prospective study, we assessed the serum antigen levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) of 28 survivors of blunt polytrauma (age ≥18 years; injury severity score ≥16) at admission and on days 1, 3, 5, 7, 10, 14, and 21 of hospitalization. Our results show that these patients presented high mean tPA and PAI-1 antigen levels at admission; despite their decline, these parameters remained elevated for 3 weeks. Over this period, the mean tPA antigen level was higher in polytrauma victims suffering from ARDS than in those without ARDS, whereas the mean PAI-1 level was higher in polytrauma victims sustaining pneumonia than in those without pneumonia. Moreover, in each individual developing ARDS, the polytrauma-related elevated tPA antigen level either continued to rise after admission or suffered a second increase up to the onset of ARDS, declining immediately thereafter. Therefore, our findings support the assessment of serum tPA antigen levels after the initial treatment of polytraumatized patients, as this parameter shows potential as a biomarker for the development of ARDS and for the consequent identification of high-risk individuals.

Hypofibrinolytic State in Subjects with Type 2 Diabetes Mellitus Aggravated by the Metabolic Syndrome before Clinical Manifestations of Atherothrombotic Disease.

Background. Metabolic and genetic factors induce plasminogen activator inhibitor type-1 (PAI-1) overexpression; higher PAI-1 levels decrease fibrinolysis and promote atherothrombosis. Aim. To assess PAI-1 antigen levels among subjects with type 2 diabetes mellitus (T2DM) plus Metabolic Syndrome (MetS) before clinical manifestations of atherothrombosis and the contribution of metabolic factors and 4G/5G polymorphism of PAI-1 gene on the variability of PAI-1. Methods. We conducted an observational, cross-sectional assay in a hospital in Mexico City from May 2010 to September 2011. MetS was defined by the International Diabetes Federation criteria. PAI-1 levels and 4G/5G polymorphism were determined by ELISA and PCR-RFLP analysis. Results. We enrolled 215 subjects with T2DM plus MetS and 307 controls. Subjects with T2DM plus MetS had higher PAI-1 levels than the reference group (58.4 ± 21 versus 49.9 ± 16 ng/mL, p = 0.026). A model with components of MetS explained only 12% of variability on PAI-1 levels (R2 = 0.12; p = 0.001), with β = 0.18 (p = 0.03) for hypertension, β = −0.16 (p = 0.05) for NL HDL-c, and β = 0.15 (p = 0.05) for NL triglycerides. Conclusion. Subjects with T2DM plus MetS have elevated PAI-1 levels before clinical manifestations of atherothrombotic disease. Metabolic factors have a more important contribution than 4G/5G polymorphism on PAI-1 plasma variability.

Elevated plasminogen activator inhibitor type-1 (PAI-1) as contributing factor in pathogenesis of hypercoagulable state in antiphospholipid syndrome

The aim of this study is to explore the role of plasminogen activator inhibitor type 1 (PAI-1) in primary and secondary antiphospholipid syndrome (APS). Thirty patients of APS (24 primary and 6 secondary) were recruited in the study who fulfilled the revised Sapporo criteria. Control groups comprised of age- and sex-matched 10 healthy volunteers and 10 patients each of systemic lupus erythematosus and rheumatoid arthritis without any antecedent thrombotic event and/or APS-related pregnancy morbidity. Serum samples were tested for PAI-1 antigen levels measured by quantitative ELISA. Positivity rate of PAI-1 in patients of primary, secondary as well as total APS patients was significantly higher in relation to age- and sex-matched healthy volunteers (p = 0.010, p = 0.003 and p < 0.001, respectively). Mean ± SEM levels of PAI-1 in primary and secondary as well as total APS patients were significantly higher (p = 0.006, p < 0.001 and p < 0.001) in relation to healthy controls. Correlation of PAI-1 levels (mean ± SEM) with clinical characteristics, that is, thrombosis and pregnancy morbidity, revealed significantly higher levels of PAI-1 (p < 0.001) in patients having thrombosis and APS-related pregnancy morbidity. Elevated PAI-1 level leading to impaired fibrinolysis plays a significant role in producing hypercoagulable state in primary and secondary APS.

Monitoring PAI-1 and VEGF Levels in 6 Human Squamous Cell Carcinoma Xenografts During Fractionated Irradiation

Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine invivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD(50)). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

P2-11-08: Clinical Value of Combination Assay for Quantitative Determination of Cancer Biomarkers C2P and uPA/PAI-1 for Disease Recurrence Prediction of Early Breast Cancer Patients.

Abstract [Background] C2P is an assay measuring specific activities (SA; kinase activity compensated by its protein expression) of cyclin-dependent kinases CDK1 and CDK2 by examining a small piece of fresh-frozen tumor tissue. We reported previously that the C2P risk score given by CDK1SA and CDK2SA is a potent prognostic factor in node-negative breast cancer patients. Likewise, a uPA/PAI-1 ELISA test (FEMTELLE®, American Diagnostica Inc. Stamford, CT) quantitatively determines uPA (urokinase-type plasminogen activator) and PAI-1 (plasminogen activator inhibitor type-1) antigen levels in tumor tissue extracts, to identify patients with high or low risk of disease recurrence of node-negative breast cancer patients. These cancer biomarkers are recommended by the ASCO at the highest level of evidence (LOE-1) for therapy decision making in node-negative breast cancer patients. From the biological point of view, the above two assays can be placed into two categories: tumor cell proliferation for C2P and tumor cell invasion for uPA/PAI-1. This fact led us to examine the concept of combination of the two assays to better select breast cancer patients at risk. [Results] Fifty-nine cases of frozen primary breast cancer tissues were subjected to the C2P assay in a blinded manner. Twenty-one cases (40%) were categorized into “high risk”, 7 cases (14%) into “intermediate risk”, and 24 cases (46%) into “low risk”. Seven cases were judged as “not informative”. The uPA/PAI-1 results and clinical information (26: recurrent cases, 30: non-recurrent cases, 1: stage IV, 2: unknown) were provided by the TUM tumor bank. uPA/PAI-1 risk categories of 36 cases (61%) were classified “high” and 23 cases (39%) categorized “low”. C2P and uPA/PAI-1 showed statistically significant correlation to histological grading (Pearson correlation coefficient; 0.45 and 0.40, respectively). No significant correlation was observed between C2P and uPA/PAI-1. By Kaplan-Meier analysis for disease-free survival, in cases treated with endocrine therapy only, both C2P and uPA/PAI-1 showed a reproducible trend to the respective claimed performances as prognostic factors. In the combination analysis of the two parameters, where low/low was judged as “low” and the others as “high”, 11 cases (24%) were categorized into “low” and 34 cases (76%) into “high”. The sensitivity and negative predictive value for disease recurrence were 90% (19/20) and 91% (10/11), respectively. Strong statistical significance was observed between the risk categories by the log-rank test; p=0.0089, and also by Cox proportional hazards regression analysis; HR=9.18, p=0.032. By multivariate analysis, also including tumor size and nodal status, the CP2 uPA/PAI-1 combination evolved as a significant, statistically independent parameter (HR: 6.51, p&amp;lt;0.01). [Conclusion] In this investigative study, the significance of the combination concept was strongly suggested for early breast cancer patients treated with endocrine therapy only. Yet, prior to implementation in the clinical setting, the practical performance of the combination assay should be validated by investigating an independent patient cohort. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-11-08.

Postprandial hypertriglyceridemia associated with inflammatory response and procoagulant state after a high-fat meal in hypertensive patients

To investigate the changes of inflammatory factors and hemostatic variable in plasma after a high-fat meal in normocholesterolemic patients with essential hypertension. A total of 60 hypertensive patients were randomly assigned to accept a single high-fat meal (group 1, n=40) or not (group 2, n=20) in the morning after an overnight fast, and 20 healthy participants (group 3) consumed a single high-fat meal on the same day. Plasma lipid profiles, high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor alpha (TNFalpha), soluble P-selectin and plasminogen activator inhibitor type 1 (PAI-1) antigen levels were measured at fasting and 4 h after meal ingestion. Postprandial triglyceride levels increased significantly in groups 1 and 3 (P<0.01), whereas levels were higher in group 1 (P<0.001). Postprandial plasma TNFalpha, hsCRP, soluble P-selectin and PAI-1 antigen levels increased in group 1 (P<0.001) but not in group 3. Postprandial plasma triglyceride level was correlated with log(hsCRP) (P<0.001), TNFalpha (P<0.001), soluble P-selectin (P<0.01) and PAI-1 antigen (P<0.05) levels, respectively. Both postprandial plasma level of soluble P-selectin and that of PAI-1 antigen were positively and significantly correlated with those of log(hsCRP) (P<0.01) and TNFalpha (P<0.001), respectively. Postprandial hypertriglyceridemia in hypertensive patients is associated with inflammatory response and procoagulant state.

Relationship between maternal and cord blood hemostatic disturbances in preeclamptic pregnancies

Endothelial cell activation or damage is believed to play a key role in preeclampsia (PE) and may underlie the hemostatic changes observed in this syndrome. The aim of this study was to evaluate a relationship between maternal and cord blood hemostatic disturbances in preeclamptic pregnancies. We measured the plasma levels of tissue plasminogen activator (tPA) antigen and of plasminogen activator inhibitor type 1 (PAI-1) antigen, both markers of hemostatic and endothelial function, and fibrin fragment D-dimer. Maternal blood from uncomplicated ( n = 42) and PEc pregnancies ( n = 44) were collected before delivery, and umbilical cord blood (UCB) immediately after delivery. In preeclamptic cases, UCB presented significantly higher tPA values and significantly lower PAI-1/tPA ratio. Preeclamptic women also presented significantly higher tPA, as well as PAI-1 values, when compared with normal pregnant women; no significant difference was found for D-dimer. In preeclamptic women, proteinuria (a marker of PE severity) correlated positively and significantly with tPA and PAI-1 antigen levels. An inverse relationship between maternal tPA antigen levels and fetal birth weigh in PE was also observed. Our data show that the hemostatic maternal disturbances observed in preeclamptic women have similarities with the UCB circulation, and that endothelial dysfunction is the most plausible underlying cause. Moreover, maternal hemostatic disturbances seem to be associated with the severity of PE. Further studies are needed to strength the values of tPA and PAI-1 as markers of severity in PE.

Physiological testosterone stimulates tissue plasminogen activator and tissue factor pathway inhibitor and inhibits plasminogen activator inhibitor type 1 release in endothelial cellsThis paper is one of a selection of papers in this Special Issue, entitled International Symposium on Recent Advances in Molecular, Clinical, and Social Medicine, and has undergone the Journal's usual peer-review process.

There is a striking gender difference in atherosclerotic vascular disease. For decades, testosterone was considered detrimental to the cardiovascular system. Recent studies, however, have presented some alternative results. The aim of this study was to evaluate the effect of testosterone, using physiological and supraphysiological concentrations, on antigen and mRNA levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tissue factor pathway inhibitor (TFPI) released by human umbilical vein endothelial cells and to investigate the cellular mechanism. Cells within 2-3 passages were cultured in 25 cm(2) flasks or plated onto 96-well plates with a density of about 1 x 10(5) cells/mL as recommended. The cells were incubated in the presence or absence of testosterone (3, 30, 3 x 10(3), 3 x 10(4) nmol/L) for 48 h. Levels of tPA, PAI-1, and TFPI antigen were assayed with ELISA kits. Reverse transcriptase PCR was carried out to detect tPA, PAI-1, and TFPI mRNA levels. Cells were incubated in androgen-receptor antagonist (flutamide 10 micromol/L) or aromatase inhibitor (aminoglutethimide 50 micromol/L) for 3 h, and then the experiments were repeated. Testosterone at a physiologic concentration (30 nmol/L) increased the antigen levels of tPA and TFPI significantly (P < 0.05). However, tPA and TFPI levels were markedly reduced (P < 0.05) at a larger dose (3 x 10(4) nmol/L). On the other hand, PAI-1 antigen levels decreased significantly at the testosterone concentrations ranging from 3 to 3 x 10(4) nmol/L (P < 0.05). The change in the levels of tPA and TFPI were reflected in the corresponding change in mRNA levels. Flutamide attenuated the effect of testosterone at physiological concentration (30 nmol/L). The results demonstrated that testosterone at physiological concentrations may have a beneficial influence on the haemostatic system through enhancement of anticoagulant activity, resulting from stimulation of TFPI and tPA expression and inhibition of PAI-1 secretion by the endothelium.

Plasminogen activator inhibitor-1 4G/5G polymorphism in breast cancer patients and its association with tissue PAI-1 levels and tumor severity

Background The plasminogen activator inhibitor type 1 (PAI-1) 4G/5G polymorphism may have significance for PAI-1 expression. High levels of PAI-1 in breast cancer patients are associated with a poor prognosis. In this study, we analyzed the influence of the PAI-1 4G/5G polymorphism on tissue PAI-1 levels and its association with tumor severity in women with breast cancer. Material and methods We studied 104 women with breast carcinoma (patient group) and 104 healthy age-matched women (control group). In patients and controls, the PAI-1 4G/5G polymorphism was determined by PCR amplification using allele-specific primers. In patients, PAI-1 levels were quantified in breast cancer tissue by using an ELISA. Results The frequency of the PAI-1 4G allele tended to be higher in patients than in controls ( p = 0.062). The presence of the 4G allele (4G/5G plus 4G/4G genotypes) was significantly higher among patients with histological grade 3 tumors than among those with grade 1 tumors ( p = 0.026). Furthermore, patients with the 4G/4G genotype had significantly higher tissue PAI-1 levels than those with the 5G/5G genotype. Moreover, tissue PAI-1 antigen levels were significantly and positively correlated with tumor severity ( p = 0.003) and tumor size ( p = 0.009). However, no significant differences in PAI-1 level were observed in relation to menopause, hormone receptor or nodal status. Conclusion Tissue PAI-1 antigen levels and tumor severity seem to be associated with the PAI-1 4G/5G polymorphism. Further studies with a larger number of patients are needed to clarify the influence of this polymorphism in breast cancer.

The plasminogen activator inhibitor (PAI-1) 4G/5G promoter polymorphism and PAI-1 levels in ischemic stroke

High levels of plasminogen activator inhibitor type 1 (PAI-1) have been implicated as a risk factor for cardiovascular disease, but its precise role remains controversial. The 4G allele of the PAI-1 4G/5G promoter polymorphism is associated with higher levels of PAI-1. We studied the relationship between ischemic stroke and the PAI-1 4G/5G polymorphism and PAI-1 antigen levels. We performed a case-control study among patients aged 18-75 years with first ischemic stroke, confirmed by CT. All patients were screened for cardiovascular risk factors, cardiac disorders and large vessel disease. We excluded patients with a definite non-atherosclerotic cause of the stroke and patients using oral anticoagulants. Population-controls were age -and sex-matched, without a history of stroke, and of the Caucasian race. Venous blood samples were taken for PAI-1 4G/5G polymorphism and PAI-1 level one week after stroke. We included 124 patients and 125 controls. Mean age was 56 yrs (range 18 to 75 yrs). Sixty one patients (50%) and 58 (47%) controls were heterozygous for the PAI-1 4G/5G polymorphism. The homozygous 4G/4G genotype was found in 33 patients (27%) and in 36 controls (29%). The odds ratio of ischemic stroke associated with 4G-carriers versus 5G/5G homozygotes was 1.0 (95% CI: 0.6-1.8). The relative risk of ischemic stroke associated with the level of PAI-1 in the upper quartile was 0.73 (95%CI: 0.4 to 1.4). Neither the PAI-1 4G/5G polymorphism nor the PAI-1 antigen level is a strong risk factor for ischemic stroke.

Angiotensin II type 1 receptor blockers reduce tissue factor activity and plasminogen activator inhibitor type-1 antigen in hypertensive patients: a randomized, double-blind, placebo-controlled study

Angiotensin II stimulates the expression of tissue factor (TF) and plasminogen activator inhibitor type-1 (PAI-1), and AT1 receptor blockade (ARB) reduces PAI-1 and TF activities in experimental studies. We investigated the effects of ARBs on TF activity, tissue plasminogen activator (tPA), PAI-1 antigen levels, plasma renin activity (PRA) and aldosterone levels in hypertensive patients. Placebo, losartan 100 mg, irbesartan 300 mg, and candesartan 16 mg daily were administered to 122 patients for 2 months. Compared with placebo, ARBs significantly reduced TF activity ( P < 0.001 by ANOVA), and candesartan was the most potent. Compared with placebo or losartan, irbesartan and candesartan significantly lowered plasma levels of PAI-1 antigen ( P < 0.001 by ANOVA) with no differences between the two. Compared with placebo, all ARBs lowered plasma levels of aldosterone ( P = 0.012 by ANOVA) and increased PRA ( P = 0.005 by ANOVA). There were significant correlations between the degree of change in TF activity and PAI-1 antigen levels ( r = 0.458, P < 0.0001) and between the change in TF activity and PRA ( r = −0.296, P = 0.006), but not with the magnitude of reduction in blood pressure following ARB therapy. ARBs significantly reduced TF activity, PAI-1 antigen levels, and aldosterone levels in hypertensive patients. The clinical significance of the varying potency of some ARBs needs to be further investigated.

Protein expression of MMP-13, uPA, and PAI-1 in pseudocapsular and interface tissue around implants of loose artificial hip joints and in osteoarthritis

Matrix metalloproteinase 13 (MMP-13), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1) have been reported to be involved in aseptic loosening of artificial hip joints. This study for the first time presents the protein levels of all of these factors in synovial-like interfaces between bone and prosthesis and in pseudocapsular tissues surrounding the artificial joint in patients with aseptic loosening (n=17) measured by ELISA. No differences were observed in the antigen expression of MMP-13, uPA, and PAI-1, comparing interface and pseudocapsular tissue. Also, no significant correlation between the protein expression of these factors and years from arthroplasty to revision or to type of fixation (cemented vs. cementless) was observed. As control, MMP-13, uPA, and PAI-1 antigen levels were also determined in the synovium of patients with osteoarthritis (n=10). Yet, the antigen levels of MMP-13, uPA, and PAI-1 in tissue specimens from patients with aseptic loosening of artificial hip joints were significantly higher compared to their expression in synovial capsular tissues obtained from patients with osteoarthritis. In conclusion, this study shows that elevated protein levels of uPA, PAI-1, and MMP-13 in periprosthetic pseudocapsular and interface tissues from patients after total hip replacement due to aseptic loosening seem not to be associated with the patient outcome.

The Tissue Factor and Plasminogen Activator Inhibitor Type-1 Response in Pediatric Sepsis-induced Multiple Organ Failure

Cytokines increase endothelial tissue factor (TF) and tissue plasminogen activator inhibitor type-1 (PAI-1) expression in vitro. Tissue factor interacts with factor VII to facilitate thrombosis and PAI-1 inhibits fibrinolysis by endogenous plasminogen activators. Because cytokine release is increased in children with sepsis-induced multiple organ failure (MOF), we hypothesized a cytokine associated increase in circulating TF and PAI-1 antigen release, and systemic activity in these patients. One hundred and seven consecutive children, who met the criteria for sepsis, and 10 critically ill children without sepsis, were enrolled in the study. Plasma TF and PAI-1 antigen and activity levels, Interleukin-6 antigen levels (IL-6), nitrite + nitrate levels (marker of nitric oxide production) and number of organs failing were measured on days 1-3 of sepsis. Increased TF and PAI-1 antigen, and PAI-1 activity levels were associated with increasing IL-6 and nitrite + nitrate levels (p <0.05), the development of MOF (p <0.05), and mortality (p <0.05). Increased systemic PAI-1 activity was associated with cardiovascular, renal. and hepatic failure (p <0.05). Increased systemic TF activity was associated with the development of coagulopathy (p <0.05) and tended to be associated with mortality (p = 0.06, power .77) A shift to an anti-fibrinolytic endothelium phenotype characterizes children who develop sepsis-induced MOF and mortality. Children with coagulopathy have a shift to a pro-coagulant phenotype. These findings support potential therapeutic roles for PAI-1 and TF pathway inhibitors in reversal of this devastating pathophysiologic process.

Differential effects of ACE-inhibition and angiotensin II antagonism on fibrinolysis and insulin sensitivity in hypertensive postmenopausal women

The aim of this study was to compare the effects of trandolapril and losartan on plasminogen activator inhibitor type 1 (PAI-1) levels and insulin sensitivity in hypertensive postmenopausal women. We studied 89 hypertensive (diastolic blood pressure >90 and <110 mm Hg) postmenopausal women, aged 51 to 60 years not taking any hormone replacement therapy. Diabetic, obese, and smoking patients were excluded. After a 4-week placebo period, they were randomized to receive 2 mg of oral trandolapril ( n = 45) or 50 mg of oral losartan ( n = 44) for 12 weeks according to a double-blind, parallel group design. At the end of the placebo and active treatment periods, blood pressure (BP) was measured, plasma samples were drawn to evaluate PAI-1 antigen levels, and insulin sensitivity was assessed. Both trandolapril and losartan reduced systolic BP (by a mean of 16.9 mm Hg and 15.2 mm Hg, respectively, P < .01 v placebo) and diastolic BP (by a mean of 13.1 mm Hg and 11.9 mm Hg, respectively, P < .01 v placebo) with no difference between the two treatments. The PAI-1 antigen levels were significantly decreased by trandolapril (from 36.9 ± 21 ng/dL to 27.2 ± 17 ng/dL, P < .05), but not by losartan (from 35.3 ± 22 ng/dL to 37.1 ± 23 ng/dL, P = not significant). Glucose infusion rate was significantly increased by trandolapril (from 6.67 ± 0.56 mg/min/kg to 7.9 ± 0.65 mg/min/kg, P < .05), but was not significantly modified by losartan (from 6.7 ± 0.47 mg/min/kg to 6.9 ± 0.50 mg/min/kg, P = not significant). In the trandolapril group the PAI-1 decrease correlated with glucose infusion rate increase (r = 0. 36, P = .045) These results provide evidence of different effects of angiotensin converting enzyme inhibitors and AT 1 antagonists on fibrinolysis and suggest that the PAI-1 decrease induced by angiotensin converting enzyme inhibitors is related to their action on insulin sensitivity and is not dependent on angiotensin II antagonism but rather on other mechanisms. It remains to be seen whether these findings apply to other patient populations than postmenopausal women.

Effects of four angiotensin II-receptor antagonists on fibrinolysis in postmenopausal women with hypertension

Background: Reduced fibrinolysis due to increased concentrations of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of endogenous fibrinolysis, is associated with an increased risk for cardiovascular events. Objective: This study was undertaken to compare the effects of 4 angiotensin II (AII)-receptor antagonists with different pharmacokinetic properties—losartan, valsartan, irbesartan, and candesartan—on levels of PAI-1 antigen in postmenopausal women with hypertension. Methods: Postmenopausal women aged 51 to 60 years with mild to moderate hypertension (diastolic blood pressure [DBP] > 90 mm Hg and ≤105 mm Hg) who were not taking any hormone replacement therapy were studied. Patients with diabetes or obesity and patients who smoked were excluded. After a 2-week placebo washout period, patients were assigned to receive losartan 50 mg, valsartan 80 mg, irbesartan 150 mg, candesartan 8 mg, or placebo for 12 weeks according to a double-blind, randomized, parallel-group design, with a titration for nonresponders after 6 weeks. At the end of the placebo period and 6 and 12 weeks after active treatment, blood pressure, PAI-1 antigen levels, heart rate, and body mass index were measured. Results: A total of 156 patients were randomized to receive losartan (n = 31), valsartan (n = 32), irbesartan (n = 31), candesartan (n = 32), or placebo (n = 30); of these, 140 completed the study. All 4 active treatments significantly reduced DBP and systolic blood pressure, with no significant differences in efficacy between groups. Plasma PAI-1 levels decreased slightly after treatment with losartan (−0.9%) and valsartan (−3.8%) and increased slightly with irbesartan (+10.1%), but these values were not significantly different from placebo. In contrast, candesartan significantly increased PAI-1 values by 33.3% ( P < 0.05 vs placebo). There were no significant changes in heart rate or body mass index in any group. Conclusions: These findings suggest that, despite a comparable antihypertensive efficacy, candesartan differs from the other AII-receptor antagonists studied in that it significantly increases PAI-1 antigen levels. This might be related to its specific pharmacologic characteristics, particularly its insurmountable antagonism of the AII AT1 receptor.

Plasma PAI-1 Levels in Obese Children – Effect of Weight Loss and Influence of PAI-1 Promoter 4G/5G Genotype

An association between an increase in plasminogen activator inhibitor type 1 (PAI-1) and obesity, and also between elevated levels of PAI-1 and the presence of PAI-1 promoter 4G allele has been described in adults and can contribute to increased risk of cardiovascular disease. It has also been suggested that in adults a decrease in adiposity has beneficial effects on the haemostatic system. However, less information is available regarding adiposity and fibrinolysis in children. The aim of the present study is to evaluate the effect of weight loss and the influence of the PAI-1 promoter 4G/5G genotype on the fibrinolytic system and lipid parameters in obese children. The clinical groups included 102 obese children and 105 controls of similar age and sex distribution. A significant decrease in fibrinolytic activity due to a significant increase in PAI-1 antigen and activity levels was observed in the obese children in comparison with the control group. In obese children, no significant differences in PAI-1 levels between the PAI-1 4G/5G genotypes were obtained. A significant correlation was observed between PAI-1 antigenic and functional levels and body mass index (BMI), as well as between PAI-1 levels and both triglyceride and insulin levels. No correlation between PAI-1 levels and either cholesterol or glucose levels was observed. After a three-month period of treatment to reduce weight, an increase in fibrinolytic activity due to a decrease in PAI- levels was observed in the obese children who had reduced their BMI in comparison with the group of obese children who did not show a decrease in their BMI. No significant differences between the two groups with respect to the variations in tissue type plasminogen activator and fibrinogen levels were obtained after three months of intervention to reduce weight. A significant correlation was observed between variations in BMI and variations in PAI-1 levels, and a significant inverse correlation was also observed between previous PAI-1 levels and variation in PAI-1 levels. Therefore, the largest decrease in PAI-1 levels was observed in the obese children with the highest previous PAI-1 levels. In conclusion, a decrease in BMI in obese children shows a favourable effect on the fibrinolytic system due to a decrease in PAI-1 levels. However, no influence of 4G/5G genotype on PAI-1 levels was observed.

Relationship between fibrinolytic and metabolic variables: a study in patients attending a lipid clinic

We investigated the relationship between plasma levels of metabolic and fibrinolytic variables in 163 fasted patients attending a lipid clinic. Of these patients, 118 had hypertriglyceridaemia (HTG) and 45 had normotriglyceridaemia (NTG). In HTG, basal fibrinolytic activity, ie tissue plasminogen activator (t-PA) activity, was impaired as a result of high plasminogen activator inhibitor type 1 (PAI-1) antigen and activity. Multiple stepwise regression analysis identified insulin and triglyceride levels as independent determinants of plasma PAI-1 levels (R2 = 0.18; P = 0.0001). When the patients were stratified into tertiles according to their levels of triglyceride and insulin, PAI-1 antigen levels were found to increase with rising levels of triglyceride in each insulin tertile. In contrast, the increase of PAI-1 with rising insulin levels was evident in the highest triglyceride tertile. In addition, subjects in the lowest tertile of both triglyceride and insulin had the lowest PAI-1 antigen levels, and subjects in the highest tertile of both triglyceride and insulin had the highest levels of PAI-1. Both basal and stimulated levels of t-PA antigen were significantly higher in HTG than in NTG. Multiple stepwise regression analysis identified triglyceride level as the sole major determinant of t-PA antigen levels (R2 = 0.13; P = 0.00003). The observation that both insulin and triglycerides correlate with PAI-1, whereas triglycerides were involved only in the increased secretion of t-PA, suggests that these two proteins are regulated by different mechanisms.

Effects of Hormone-Replacement Therapy on Fibrinolysis in Postmenopausal Women

Background Plasma levels of plasminogen-activator inhibitor type 1 (PAI-1), an essential inhibitor of fibrinolysis in humans, increase in women after menopause, and this may contribute to the risk of cardiovascular disease. We studied the effects of hormone-replacement therapy on PAI-1 levels. Methods In a randomized, crossover study, we investigated the effects of oral conjugated estrogen (0.625 mg per day) in 30 postmenopausal women and transdermal estradiol (0.1 mg per day) in 20 postmenopausal women, either alone or in combination with medroxyprogesterone acetate (2.5 mg daily) for one month, on plasma PAI-1 antigen levels. Degradation products of cross-linked fibrin (D-dimer) were measured in serum as an index of fibrinolysis. Results PAI-1 levels were inversely associated with D-dimer levels at base line (r = -0.540, P = 0.002). Conjugated estrogen, both alone and in combination with medroxyprogesterone acetate, reduced mean (±SD) plasma levels of PAI-1 from 32±34 ng per milliliter to 14±10 ng per m...

406 Abnormal expression of plasminogen activator inhibitors in patients with gestational trophoblastic disease

We previously reported significantly elevated levels of plasminogen activator inhibitor type 1 (PAI-1) in plasma and placenta from pregnant women with severe pre-eclampsia, and pre-eclampsia is a frequent problem in molar pregnancies. As increases in PAI-1 may contribute to the placental alterations that occur in pre-eclampsia, we have begun to investigate changes in PAI-1 as well as PAI-2 and several other components of the fibrinolytic system in patients with trophoblastic disease. Significant increases in plasma PAI-1 and decreases in plasma PAI-2 levels were observed in molar pregnancies when compared with the levels in normal pregnant women of similar gestational age. PAI-1 antigen levels also were increased, and PAI-2 levels were decreased in placenta from women with molar pregnancies compared with placenta obtained by spontaneous abortion. Immunohistochemical analysis revealed strong positive and specific staining of PAI-1 in trophoblastic epithelium in molar pregnancies and relatively weak staining of PAI-2. No association between the distribution of PAI-1 and vitronectin was found, and no specific signal for tissue type PA, urokinase type PA, tumor necrosis factor-alpha, or interleukin-1 was detected. In situ hybridization revealed an increase in PAI-1 but not PAI-2 mRNAs in placenta from molar pregnancies in comparison with placenta from abortions. These results demonstrate increased PAI-1 protein and mRNA in trophoblastic disease and suggest that localized elevated levels of PAI-1 may contribute to the hemostatic problems associated with this disorder.