Determining Thrombogenicity: Using a Modified Thrombin Generation Assay to Detect the Level of Thrombotic Event Risk in Lupus Anticoagulant-Positive Patients

The aim of this study was to determine the thrombogenicity of lupus anticoagulant (LA) antibodies using a modified thrombin generation assay (TGA) with the addition of activated protein C (APC) in a group of 85 patients with LA-positive samples. Of these, 58 patients had clinical manifestations of antiphospholipid syndrome (APS) according to the Sydney criteria classification, i.e., each patient had thrombosis or foetal loss, and 27 patients did not show any clinical manifestations of APS. A comparison of the two groups' TGA results revealed statistically significant differences (Fisher's test p = 0.0016). The group of patients exhibiting clinical manifestations of APS showed higher thrombogenicity in 56.9% of patients, while the group of patients not yet exhibiting clinical manifestations of APS showed higher thrombogenicity in 25.9% of patients. There were no significant differences in the specificity of the TGA test between the groups of patients exhibiting similar clinical manifestations. Receiver operating characteristic curve analysis showed a more significant relationship (p = 0.0060) for TGA than for LA titre (p = 0.3387). These data suggest that the determination of LA thrombogenicity with the TGA assay leads to an increased prediction of the manifestation of a thromboembolic event. Our findings appear to be particularly relevant for the prediction of thrombotic events in patients with laboratory-expressed APS and no clinical manifestations.

Evaluation of the Determination of Dabigatran, Rivaroxaban, and Apixaban in Lupus Anticoagulant-Positive Patients

Background: The effect of direct oral anticoagulants (DOAC) on laboratory tests dependent on the production of their targets, factor IIa and factor Xa, is a well-known problem and can cause both false positive and negative results. In particular, the situation in patients who develop lupus anticoagulant (LA) antibodies is highly complex. To evaluate the effectiveness of DOAC therapy in lupus-positive patients, 31 samples were enrolled in this retrospective study. All patient samples were spiked with three types of DOAC (dabigatran, DABI; rivaroxaban, RIVA; and apixaban, API) in a concentration that significantly influenced the screening test for LA and thus can mask the presence of LA. Subsequently, the DOAC was always unbound by the DOAC-Stop procedure. DOAC levels before and after binding were determined by functional assays, followed by liquid chromatography coupled with mass spectrometry (LC-MS) analysis. Methods: The determination of DOAC levels was performed by direct thrombin assay and determination of anti-Xa activity with specific calibration as functional tests for DABI and xabans (API and RIVA). To determine concentration levels of API, DABI, and RIVA, our in-house LC-MS method was used. Results: The results of LA-positive samples show significant differences between functional tests and the LC-MS method both before and after DOAC binding. Conclusions: The acute findings of the presence of LA-type antibodies fundamentally affects the determination of DOAC by functional tests, and in this case, it is necessary to use LC-MS analysis to determine the true value. If patients treated with DOAC develop LA of medium and higher titers, we do not recommend checking DOAC levels with functional tests.

A synergy of liquid chromatography with high-resolution mass spectrometry and coagulation test for determination of direct oral anticoagulants for clinical and toxicological purposes

Direct oral anticoagulants are an alternative to anticoagulants based on vitamin K antagonists. Monitoring of direct oral anticoagulant concentration levels is necessary in specific cases (e.g. in emergency conditions, for determination of the cause of bleeding, adverse effects, risk of drug-direct oral anticoagulants interaction); therefore, a sensitive and specific method is needed. A methanol protein precipitation method followed by liquid chromatography with high-resolution mass spectrometry was developed for simultaneous separation and determination of apixaban, betrixaban, edoxaban, dabigatran, rivaroxaban and ximelagatran. The proposed method was fully validated in terms of linearity, the limits of detection and quantification, intra- and inter-day trueness and precision, recovery, matrix effect, process efficiency and stability. The method shows a strong correlation (Pearson's correlation coefficients > 0.92) with coagulation assays of apixaban, dabigatran and rivaroxaban (dilute thrombin time for gatrans and anti Xa factor (anti-Xa) activity for xabans). In addition, the developed method was applied for the identification and determination of apixaban and dabigatran in post-mortem serum samples. The developed method is a good alternative to coagulation tests which may show various interferences.

The Modern Pneumatic Tube System Transports with Reduced Speed Does Not Affect Special Coagulation Tests

Pneumatic tube transport systems (PTS) for delivery of patient samples to a hemostasis laboratory are often used to reduce turnaround time for vital analyses. PTS in our hospital has the ability to regulate the transport speed in the range of 3-6 m/s with acceleration control technology. We evaluated the effects of PTS transport for routine coagulation tests, platelet function tests and special global coagulation tests. Duplicate samples were collected from 29 patients and 40 healthy individuals. One sample was sent using PTS and the other was carried by personnel to the lab for determination of protrombin time, activated partial thromboplastin time, trombin time, fibrinogen, antitrombin and thrombin generation test. Platelet function was measured by means of a Apact 4004® analyzer using the inductors (ADP, Arachidonic acid and Epinephrine). Samples transported using PTS with normal transport speed 6 m/s does not affect basic coagulation tests (PT, aPTT, FIB, TT and AT), but TGT has significantly altered. The use of PTS with controlled acceleration regulated the increase in thrombin generation from 10% to 3%, which is not statistically signifiant. The use of PTS with controlled acceleration did not show a significant difference even with the highly sensitive method of platelet aggregation. We conclude that PTS with acceleration control with transport speed from 3 to 6 m/s does not affect to platelet activity as measured by LTA and also global coagulation test - TGT. The advantage of PTS transport is very rapid assessment laboratory testing. From the above validation study, it is clear that PTS should always be validated for specialized laboratory methods and appropriately adapted to specific transport conditions.

Searching for genetic variants associated with thrombophilia

Thrombotic states are inherited or acquired predisposition for thrombosis in the human vascular system. Nowadays Leiden mutation and mutation in prothrombin G20210A contributing to congenital thrombophilia are routinely tested. These mutations have a high prevalence in the population. Congenital deficiencies of protein S, protein C and antithrombin III are rare thrombophilia with lower population frequency, but higher risk of thromboembolic event. The genetic causes are mutations in the genes, which encode these proteins. The choice of proper molecular genetic testing depends on the difference in the detection of well-known single nucleotide polymorphism or unknown/rare variant. For the detection of causative variant FV Leiden and prothrombin G20210A are mostly used PCR-RFLP, reverse Strip Assay®, allele-specific PCR, TaqMan real-time PCR and SNaPshot®. Precise patient selection should precede the genetic testing of rare variants in anticoagulant proteins. It is appropriate to use methodology of massive parallel sequencing supplemented by a methodology for the detection of larger gene rearrangements - MLPA. We are successfully employing this approach in our institute. This methodology is faster with larger analytic capacity compared to commonly used direct sequencing by Sanger method.

Hypertriglyceridemic waist - a simple clinical tool to detect cardiometabolic risk: comparison with harmonized definition of metabolic syndrome

With the increasing prevalence of obesity and especially abdominal obesity, a simple clinical tool is needed that identifies the cardiometabolic risk for cardiovascular disease and type 2 diabetes. The aim of our study was to evaluate a broad spectrum of metabolic variables and IMT in subjects with and without hypertriglyceridemic waist (HTGW) and compare it with the harmonized definition of metabolic syndrome (MS) with both a higher (MS-I) and lower waist circumference (MS-II) for Europids. We enrolled 607 asymptomatic dyslipidemic subjects (295 men and 312 women) into our cross-sectional study. The subjects with HTGW had an atherogenic lipid profile (significantly higher triglycerides, AIP, non-HDL-C, lower HDL-C and ApoA-1, and the women also higher TC and ApoB), increased markers of insulin resistance (insulin, HOMA, C-peptide, proinsulin), inflammation (hsCRP), thrombosis (fibrinogen, PAI-1), SBP and DBP, and lower adiponectin (p<0.05-0.001 for all). These risk factors were entirely similar in HTGW, MS-I and MS-II. Age-adjusted IMT was significantly higher only in the women with HTGW but this significance disappeared after further adjustment for TC, SBP, and smoking. Our results support the routine use of HTGW as a simple and inexpensive screening tool to detect subjects at increased cardiometabolic risk in clinical practice.

[Occurence, etiology and clinical significance of trombocytopenia in pregnancy]

OBJECTIVE

The principal objective of the study is to compare results from the experimental group of pregnant women suffering from thrombocytopenia in pregnancy with results from the control group of pregnant women with normal physiologic blood platelet count.

SETTING

Department of Obstetrics and Gynaecology of the Tomas Bata Regional Hospital Zlín, Obstetrics and Gynaecology Clinic, Haematology and Oncology Clinic of the Palacky University Teaching Hospital and Medical School in Olomouc, Obstetrics and Gynaecology Clinic of the Ostrava Teaching Hospital.

METHODOLOGY

A group of 200 pregnant women suffering from thrombocytopenia underwent thorough medical tests. The level of platelets, presence of anti-platelets agents, liver function (LFT), anti-phospholipid antibodies, complete blood count with differential, specific antibodies for hepatitis B and C, Lyme borreliosis and cytomegalovirus were determined from venous blood using the EIA, ELISA methods.

RESULTS

Medical articles and books about thrombocytopenia divide the causes for thrombocytopenia as follows: 79.5% benign gestational thrombocytopenia, 16% preeclampsia, 2.5% HELLP syndrome, 1% immune thrombocytopenia, 1% HVC. The number of women who developed physiological anaemia in pregnancy and were overweight is identical in the experimental group of pregnant women suffering from thrombocytopenia and in the control group of pregnant women with normal physiologic blood platelet count, and the proportion of the different age groups in the two groups of pregnant women is also identical.

CONCLUSION

32% of pregnancies in the experimental group ended in a caesarean section, of which 13.5% in a group of 127 pregnant women suffering from mild thrombocytopenia, 17.5% in a group of 71 pregnant women suffering from moderate thrombocytopenia and 1% in a group of 2 pregnant women suffering from severe thrombocytopenia. 20.5% pregnancies in the control group ended in caesarean section.

[Preeclampsia and thrombin generation test]

OBJECTIVE

Acquiring new information to allow prediction of the development of diseases associated with impaired coagulation. Design effective preventive measures most serious diseases (TEN) in the fields of gynecology and obstetrics. For pregnant women with preeclampsia, hypertension compared with women with normal pregnancies could lead to increased thrombin generation due to the synergistic effect of thrombotic risk factors. Based on the results and found statistically significant differences between the groups among pregnant can select for a higher risk of developing deep vein thrombosis. This risk group could then greatly benefit from more stringent follow-up and possible preventive treatment prophylactic doses of LMWH in reducing maternal and perinatal morbidity and mortality.

DESIGN

Prospective study.

SETTING

Department of Obstetrics and Gynecology, University Hospital Olomouc.

METHODS

In early pregnancy - during pregnancy standard samples (up to the end of the first trimester) patients venous blood was sampled and they completed information questionnaire. A second sampling was carried out between 24 to 28 week, the third sample and between 36th to 40th week. Obtained blood samples were subsequently processed in the coagulation laboratory Hemato-Oncology Clinic and Olomouc. The blood samples were investigated protein C and S, antithrombin, FVIII level, FII, Leiden, and plasma endothelial microparticles, and lupus anticoagulant and APC resistance standardized methodologies. Thrombin generation was determined thrombin generation test. Thrombin generation was measured fully automatically using a kit (Technothrombin TGA, Technoclone, Vienna, Austria) and analyzer Ceveron Alpha (Technoclone, Vienna, Austria) with fully automatic analysis software. As the main parameter is evaluated by the maximum thrombin generation, at the same time, however, was also detected in the total amount of thrombin and the time until the beginning of the formation of thrombin.

RESULTS

In the period 2008-2011 were analyzed blood samples of 303 healthy pregnant women. 215 women, ie 71% were nuliparas, 60 women, ie 19.8% were primiparas, 28 women, 9,2% were secundiparas. The average age of pregnant women was 28.6 years(± 3.8 years). The average maternal weight at the beginning of pregnancy was 63.6 kg (± 7.8 kg). Of the 303 women in 18 (6%) developed slight to moderate degree of preeclampsia or HELLP syndrome with varying severity of clinical manifestations. 20 mothers (6.6%) gave birth prematurely terminated before 37 week of pregnancy. 3 pregnancies (0.9%) were discontinued due to genetic indication for fetal birth defect. The complete study protocol (sampling in all three trimesters) thus completed 280 pregnancies. Of the three evaluated, parameter Lag time, ETP and peak we observed significant differences when comparing physiological pregnancies and pregnancies with preeclampsia (Table 3 and Figure 5-7), the statistical level of p < 0.01. In pregnancies with chronic hypertension, these differences were not significant. Comparison of 18 pregnancies, in which the III. trimester developed preeclampsia with other pregnant with physiological pregnancy did not show statistically significant differences in I. and II. trimester. The results suggest the activation of coagulation through the late stages of pregnancy. Results are influenced by strong clinical variability of disease. In severe and early preeclampsia this activation and significant differences begin much earlier.

CONCLUSION

We demonstrated significantly higher activation of thrombin generation in women with preeclampsia [10]. Changes in preeclampsia are characterized by increased generation of thrombin in plasma. This fact may explain the partial success of the clinical use of aspirin in preeclampsia. In the third trimester, during the manifestation of the disease, patients with preeclampsia have significantly higher ETP compared to patients with a normal pregnancies. Pregnant women with chronic hypertension also show a slight increase in the activation of thrombin. However, these results are not statistically significant. Examination of coagulation in the first and second trimester in women who later developed preeclampsia, showed no statistically significant differences and thus can not be used in this case as predictive, but only as a diagnostic test.

[Endothelial dysfunction in pregnancies with chronic hypertension]

AIM OF THE STUDY

To establish endothelial activation markers which could uncover endothelial damage during hysiological pregnancy and pregnacies with chronic hypertension.

SETTINGS

Department of Hemato-oncology, Obstetrics and Gynecology and Department of Medical Genetics and Fetal Medicine Medical Faculty of Palacký University Olomouc, Department of Obstetrics and Gynecology Medical Faculty Ostrava.

METHODS

We examined 298 pregnant women with a physiological pregnancy. Venous blood samples were collected from the women in both arms at the beginning of the pregnancy, a second sample was collected in the interval 24-28 weeks gestation, the third sample was colected about the 36 weeks of gestation. Parameters were examined using methods: t-PA - ELISA, PAI-1 - ELISA, vWF - EIA, ePCR - ELISA, MMP-2,9 - ELISA with fluorogenic detection, TIMP-2 - ELISA, endothelial microparticles - flow cytometry.

RESULTS

In accordance with the literature, we have observed in our study significantly increased endothelial activatition in hypertensive pregnancies compared with women with physiological pregnancy, as evidenced by significant increases in vWF activity and antigen, thrombomodulin and PAI-1 in all trimesters. In the other investigated parameters statistically significant changes were not observed.

CONCLUSION

We have found significant signs of endothelial dysfunction in the group of women with pre-existing hypertension, a wide range of parameters examined markers indicating an significantly increased endothelial activation pregnant women with pre-existing hypertension, confirming the need for strict follow-up of pregnant women with hypertensive disease.

[The occurence of genetic trombophilic markers in patients evaluated for infertility]

OBJECTIVE

To assess and compare the frequency of selected gene mutations of thrombophilic markers (FV Leiden, FII prothrombin G20210A and MTHFR C677T) in patients with primary and secondary infertility.

DESIGN

Retrospective study.

SETTING

Institute of normal anatomy, Faculty of Medicine and Dentistry, Palacky University Olomouc.

METHODS

The study included 92 patients with primary infertility and 89 patients with secondary infertility. Indications for examination of these mutations were following: a positive family or personal history, a positive obstetrical history or a repeated failure of assisted reproduction treatment.

RESULTS

According to our anticipation, women with the secondary infertility were significantly older(p < 0.0005) than those with primary infertility. No mutations of genes of examined thrombophilic markers (FV, FII and MTHFR), either alone or in combination, were found in only 8.7 % patients with primary infertility and in 5.6 % patients with secondary infertility. Significantly higher frequency of factor Leiden(p < 0.02) was observed in women with secondary infertility. There were no significant differences in the frequency of detected mutations of the remaining factors.

CONCLUSION

Based on our findings we suggest that the assessment of selected gene mutations of thrombophilic markers should be a part of the diagnostic algorithm in patients with positive history for thrombophilic disorders.

[Monitoring of endothelial activation markers during physiological pregnancy]

AIM OF THE STUDY

To establish endothelial activation markers which could uncover endothelial damage during physiological pregnancy.

TYPE OF STUDY

Prospective study.

METHOD

We examined 403 pregnant women with a physiological pregnancy. Venous blood samples were collected from the women at the beginning of the pregnancy, a second sample was collected in the interval 24-28 weeks gestation. Parameters were examined using methods: t-PA--ELISA, PAI-1--ELISA, vWF Ag--EIA ePCR--ELISA, MMP-2,9--ELISA with fluorogenic detection, TIMP-2--ELISA, endothelial microparticles - flow cytometry.

RESULTS

The level of vWF antigen increased during the entire course of pregnancy (in the I. trimester the average level was 152.32%, in the II. and III. trimester 173.34% and 216.20% respectively). At the same time, vWf activity also increased (I. trimester average level 130.20%, II. and III. trimester 150.09% and 181.91% respectively). The level of thrombomodulin significantly increased during pregnancy (I. trimester average level 19.05 ng/ml, II. and III. trimester 28.47 ng/ml and 39.86 ng/ml respectively). The level of soluble form of EPCR increased during pregnancy (I. trimester average level 201.76 ng/ml, II. and III. trimester 274.68 ng/ml and 324.07 ng/ml respectively). The level of PAI-1 increased during the entire course of pregnancy (I. trimester average level 36.14 ng/ml, II. and III. trimester 50.07 ng/ml and 60.12 ng/ml respectively). The level of t- PA did not change significantly during the course of pregnancy (I. trimester average level 2.48 ng/ml, II. and III. trimester 2.97 and 3.34 ng/ml respectively). The levels of MMP-2 (I. trimester average level 9043.76 RFU, II. and III. trimester 9315.38 and 8800.27 RFU respectively), MMP-9 (I. trimester average level 8371.90, II. and III. trimester 8290.81 and 7470.50 respectively), TIMP-2 (I. trimester average level 92.5 ng/ml, II. and III. trimester 98.5 and 96.5 ng/ml respectively) or endothelial microparticles (I. trimester average level 3838.38 particles/microl, II. and III. trimester 3836.59 and 3650.59 particles/microl respectively) did not change significantly throughout the individual trimesters.

CONCLUSION

We confirmed the hypothesis regarding the significant influence pregnancy has on changes in levels of these markers.

[Antithrombotic therapy in pregnancy]

Despite the fact of low prevalence of maternal death, deep venous thrombosis remains one of the most serious complication in pregnancy and puerperium. Virchows triad--vascular stasis, hypercoagulability, and vascular trauma plays the main role in the pathogenesis of deep vein thrombosis in pregnancy. Low molecular weight heparins and unfractionated heparins are the best treatment option. The aim of the treatment is to be effective in extension of thrombus and prevention of the postthrombotic syndrome and pulmonary embolism. Management of pregnant women with increased risk of venous thromboembolism can be stratified by determining whether the prior episode VTE was unprovoked or associated with a transient risk factor and the presence or absence of an inherited thrombophilia.

[Molecular methods in thrombophilic states diagnostics]

Molecular genetic methods passed into the field of investigation of thrombophilic states in 90th years of last century, along with the first discoveries of coagulation inhibitors (AT III, protein C and protein S). They have acquired a widespread use above all with the detection of the molecular basis of activated protein C (APC) resistance in 1994 by prof. Bertina. At the present time, a wide range of molecular genetic markers, linked with a clearly documented increased risk of thrombophilia are adapted. They include mutations of factor V Leiden 506R/Q, of protrombin 20210G/A, MTHFR 677C/T in homozygous form, mutation of PAI-1 4G/5G, mutations of different coagulation inhibitors and finally a range of polymorphisms with still not precisely defined increased risk for thrombophilia (F XIII Val34leu, platelets glycopeproteins, endothelial protein C receptor and trombomodulin). From the methodological viewpoint, all these techniques are based on the principle polymerase chain reaction (PCR). In the last period of time, however there was a rapid evolution, allowing a significant improvement in their laboriousness. Nowadays, splitting with the aid of restriction endonucleases, real time PCR or allel specific primers for PCR. The second, where molecular genetic methods are currently under use, is pathophysiological investigation of the single coagulation processes. Here, in a fact, most significant progress has been in the field of APC resistance made elucidation. Although still in the 90th years of the past century the genetical cause of these coagulation disturbance was unequivocally documented its clinically heterozygous appears not yet fully understood at the moment. Similarly, in prothrombin mutation, only the latest investigations have outlined the probable mechanism of expression. Concerning the future evolution of molecular genetic methods, there can be observed a clear cut tendency to better understanding the pathophysiologic cause of thrombophilia in comparison with the searching for new coagulation defects which consecutively bear lesser a relative risk of thrombosis.

[Disturbances of the plasma coagulation defects in retinal venous occlusions]

Occlusions of retinal veins (central and branch) represent multifactorialy-conditioned disease involving presumably older patients, in whom the changes of retinal vessels caused by hypertension and atherosclerosis present the most important pathophysiological factors for development of this disease. In last years, the intensive scientific research is focused to the explanation of the role of the defects of the coagulations cascade. Especially in younger patients, the most often mentioned defect of the coagulations cascade is called as APC-resistance. Up to 95% of all patients with APC-resistance are carriers of so called Leiden mutation. The aim of our study was to establish the prevalence of the ACP-resistance in 92 patients with central or branch occlusion of the retinal vein verified by means of angiography treated at the Department of Ophthalmology, Faculty Hospital, Olomouc, Czech Republic, EU, during the period 1999-2005. The control group consisted of 40 patients without any vascular, eye-related disease. In the group of patients with occlusion of the retinal vein, the prevalence of the APC-resistance was 10.9% and in the control group 5%. In the group of patients 55 years old and younger the prevalence of the ACP-resistance was 14.3%, in patients older than 55 years it was 5.6%. According to the relatively small groups of patients, the established difference did not reach the level of statistical evidence. Results of our study confirmed the conclusions of previously published papers that the prevalence of the APC-resistance is not significantly higher in patients with retinal vein occlusion according to the prevalence in controls.

[Coagulation factor VIII in the early postpartum period]

OBJECTIVE

Pregnancy is accompanied by changes in the coagulation and fibrinolytic systems. There is a marked increase in some of the coagulation factors, particularly fibrinogen and factor VIII. A high plasma levels of coagulation factor VIII is an important risk factor for thrombotic complications during pregnancy and puerperium. The aim of the study was to determine changes of the VIII:C in the early postpartum period.

SETTING

Dept. of Obstetrics and Gynaecology, Medical Faculty of Palacký University, Olomouc.

DESIGN

A longitudinal prospective study of 197 healthy women. Primi or multigravidas whose pervious pregnancies had been uncomplicated, aged 18-41 years. All of the deliveries were spontaneous and vaginal. First samples were taken between 24-72 hours postpartum. Women whose factor VIII plasma levels were higher than 150 (percentage of standard) were tested again after 6 weeks. Factor VIII:C was investigated by the one-step coagulation method. Statistical evaluation was done by Statsoft, Inc. (2001) Statistika Cz (Software system data analysis), version 6.

RESULTS

Pregnancy is associated with increased levels of VIII:C. Mean value was 194.09 percentage of standards. 119 (60.4 %) of the tested women had VIII:C higher than 150%. The post-puerperal tests were done in 59 women and showed values similar to those from formerly published data in age-matched non-pregnant group. Mean value was 139.76%.

CONCLUSION

Normal pregnancy is connected with increased levels of factor VIII. However elevated plasma levels of VIII:C is not associated with poor pregnancy outcome. The highest level of the clotting factor VIII was associated with patient's blood group A. Post-puerperal data showed distinct decrease of factor VIII. There is a necessity to rule out thrombophilia, in the case of the outlasting elevation of the factor VIII.

[Endothelial injury and activation of the coagulation cascade during radiofrequency catheter ablation]

GOAL OF STUDY

To identify the extent of systemic activation of the coagulation cascade and to evaluate thrombogenic effect of the radiofrequency catheter ablation.

METHODS AND RESULTS

Markers of activation of the coagulation cascade (D-dimers [DD]), markers of activation of the fibrinolytic system (tissue plasminogen activator [t-PA] and its inhibitor [PAI-1]), and markers of endothelial damage (von Willebrand factor [vWf]) were monitored in 50 patients undergoing catheter ablation. Levels of these substances were identified in time T0--at the beginning of the examination, T1--after finishing diagnostic part of the electrophysiological study, T2--after finishing all applications of radiofrequency energy, and T3--24 hours after T2. Levels of vWf were significantly elevated in time T1 compared to values in T0 (p < 0.001) and were further elevating after finishing the procedure in time T2 (p < 0.05). Levels of t-PA were also elevated in time T1, however after application of the radiofrequency energy, further increase in T2 was nonsignificant. Concentrations of PAI-1 were in time T2 significantly lower compared to T1 values (p < 0.001). Levels of DD were significantly elevated during entire procedure and elevated levels persisted even 24 hours later (p < 0.001). Levels of vWf a t-PA in time T2 correlated with total time of application of radiofrequency energy. Significantly higher activation of the coagulation cascade was identified, in patients undergoing isolation of pulmonary veins compared to patients undergoing catheter ablation of other arrhythmias. In the subgroup of patients treated with anticoagulation before the intervention elevation of DD levels in times T1 and T2 was lower compared to patients who did not undergo any treatment (p < 0.05).

CONCLUSION

The radiofrequency catheter ablations activate the coagulation cascade. Moreover, application of the radio frequency energy increases systemic thrombogenic state and this effect "depends on the dose". A risk group make patients undergoing catheter isolation of pulmonary veins.

[Endothelial dysfunction in a family with familial combined hyperlipidemia]

Familial Combined Hyperlipidemia is the most frequent familial hyperlipidemia with a high risk a early manifestation of arteriosclerosis. Endothelial dysfunction is the first step in the development of arteriosclerosis. The aim of our investigation was to examine selected markers of endothelial dysfunction in hyperlipidemic members of families with familial combined hyperlipidemia and their normolipidemia first-line relatives and to compare them with healthy individuals. The study includes non-smoking members of the affected families (probands and first-line relatives), who have not suffered from clinical manifestations of arteriosclerosis and/or hypertension during the start of the study. The cohort was divided into hyperlipidemic individuals (N = 25) and normolipidemic individuals (N = 21). Both groups were compared with control groups of healthy individuals (two groups, N = 17 each), who were adjusted by age and sex. The following markers of endothelial dysfunction were examined: 1. ultrasound--flow mediated dilatation of brachial artery and 2. humoral--serum levels of von Willebrand factor, inhibitor of activator of plasminogen-1 and vasoadhesive molecules (vascular cell adhesion molecule-1, intercellular adhesion molecule-1). The members of families with familial combined hyperlipidemia displayed symptoms of endothelial dysfunction. In comparison with healthy controls the endothelial dysfunction was more expressed in hyperlipidemic individuals. They displayed a significantly lower flow-mediated dilatation of brachial artery (3.6 +/- 3.3% versus 6.6 +/- 2.8%, P < 0.01), higher levels of von Willebrand factor (152.8% +/- 79.1% versus 110.4% +/- 24.8%, P < 0.05), inhibitor of activator of plasminogen-1 (94.6 +/- 30.8 ng/ml versus 60.4 +/- 38.0 ng/ml, P < 0.01) and vasoadhesive molecules: vascular cell adhesion molecule-1 (927.0 +/- 167.7 ng/ml versus 814.7 +/- 171.1 ng/ml, P < 0.05), intercellular adhesion molecule-1 (601.7 +/- 89.5 ng/ml versus 544.8 +/- 59.8 ng/ml, P < 0.05). The normolipidemic individuals displayed only a significantly lower flow-mediated dilatation of brachial artery (5.6 +/- 2.6% versus 7.5 +/- 2.8%, P < 0.05) and higher levels of von Willebrand factor (136.8 +/- 40.32% versus 104.1 +/- 24.9%, P < 0.05). No significant difference was found in the levels of inhibitor of activator of plasminogen-1 and vasoadhesive molecules. The results indicated that members of families with familial combined hyperlipidemia represent a high-risk group from the standpoint of early manifestation of arteriosclerosis.

[Occurrence of gene mutations in factor V Leiden, prothrombin and methylenetetrahydrofolate reductase in patients with pre-eclampsia]

OBJECTIVE

The aim of the study was to detect the incidence of thrombophilia FV Leiden, prothrombin G20210A, MTHFR C677T, resistance to activated protein C, and deficiency of protein C and S in pregnant or puerperal women with preeclampsia and control group.

DESIGN

Case-control study.

SETTING

Department of Obstetrics and Gynecology, Department of Hemato-oncology, Medical Faculty, Palacký University, Olomouc.

METHODS

The group of 38 women with confirmed diagnosis of preeclampsia were examined for resistance to activated C protein. (Coatest, APC resistence Chromogenix), levels of C and S protein. For the detection of FV:Q506, prothrombin G20210A and MTHFR C677T allels was done by PCR test. The control group had 50 women, chosen randomly. The statistical evaluation was performed by the STATISTICA program. For the analyzing of the continuous variables the Student's T-test was used. Values below p < 0.01 were considered to be statistically significant.

RESULTS

Women who suffered from preeclampsia came to mean age of 32.8 +/- 4.3 (years), mean gestational age 33.6 +/- 2.8 (weeks), mean systolic pressure 163 +/- 21 mmHg, diastolic pressure 108 +/- 8 mmHg. All of the results were rendered to be statistically significant in comparison the control group. On the other hand, the results in observed haematologic parameters were not significant (Preeclampsia/controls). FV Leiden--heterozygous subjects 4/3, prothrombin G20210A 1/0, C677T heterozygous subjects 12P10, C677T 2/0, protein C and S deficiency 2(0. Resistance to activated C protein was found in 14 (37%) patients, in comparison to 6 (12%) in the control group (p = 0.0073).

CONCLUSION

We didn't find any difference in the prevalence of genetic mutations in patients with preeclampsia compared to the control group. The prevalence of APC resistance was statistically higher in preeclamptic patients compared to the control group.

[Activated protein C resistance and deep venous thrombosis in pregnancy]

OBJECTIVE

The aim of the study was to detect the incidence of resistance to activated protein C in pregnant or puerperal women with confirmed diagnosis of deep venous thrombosis or pulmonary embolism.

DESIGN

Case-control study.

SETTING

Dept. of Obstetrics and Gynaecology, Dept. of Haemato-oncology, Medical Faculty, Palacky University, Olomouc.

METHODS

The group of 33 women with confirmed deep venous thrombosis were examined for resistance to activated C protein. The levels of C and S proteins, antithrombin III., prothrombin, heparin II cofactor and plasminogen were measured. Patient with APC ratio below 1.86, were tested by PCR analysis for the detection of the FV:Q506 allele. The control group had 51 pregnant women, chosen randomly. The statistical evaluation was performed by STATISTICA program. For the analyzing of the continuous variables the Students' T-test was used. For the categorical variables the chi 2 test was used (for comparison of 2 relative values). Values below P < 0.01 were considered to be statistically significant.

RESULTS

Women who have shown to suffer from deep venous thrombosis (DVT) came to the mean age of 31 +/- 3.1 years, weight 75.3 +/- 7.9 kg and BMI 28.7 +/- 4.3. All of the results above were rendered to be statistically significant. 54.5% of thrombosis occurred in the 3rd trimester, 61% were localised to the left iliofemoral vein. APC resistance appeared in 17 (51%) women with DVT, in comparison to 5 (9.8%) women in the control group (i.e. statistically significant). Factor V appeared in II (33.3%) women, in comparison to 3 (5.9%) women in the control group.

CONCLUSION

APC resistance and factor V. Leiden represent as important factors in the aetiology of deep venous thrombosis in pregnancy.

Comparison of kinetic properties between plant and fungal amine oxidases

Kinetic properties of novel amine oxidases isolated from a mold Aspergillus niger AKU 3302 were compared to those of typical plant amine oxidase from pea seedling (EC 1.4.3.6). Pea amine oxidase showed highest affinity with diamines, such as putrescine and cadaverine, while fungal enzymes oxidized preferably n-hexylamine and tyramine. All enzymes were inhibited by carbonyl reagents, copper chelating agents, some substrate analogs and alkaloids, but there were quite significant differences in the sensitivity and inhibition modes. Aminoguanidine, which strongly inhibited pea amine oxidases showed only little effect on fungal enzymes. Substrate analogs such as 1.5-diamino-3-pentanone and 1-amino-3-phenyl-3-propanone, which were potent competitive inhibitors of pea amine oxidases, inhibited fungal enzymes much more weakly and non competitively. Also various alkaloids behaving as competitive inhibitors of pea amine oxidase inhibited the fungal enzymes non competitively. Very surprising was the potent inhibition of fungal enzymes by artificial substrates of pea amine oxidases, E- and Z-1,4-diamino-2-butene. The relationships between the different inhibition modes and possible binding at the active site are discussed.