Browsing by Author "Kovac, Mirjana (7102654168)"

Changes in the hemostatic system during COVID infection lead to hypercoagulability. Numerous studies have evaluated hemostatic abnormalities in COVID patients during acute infection, in the period of hospitalization. However, the hemostatic status following hospital discharge has not been sufficiently assessed. Considering the importance of FVIII and D-dimer levels as markers for the assessment of thrombosis, our study aimed to evaluate changes in these markers, as well as the influence of patient’s age and clinical presentation of COVID infection on those hemostatic markers in the post-COVID phase. This prospective study (July 2020 to December 2022) included 115 COVID patients, 68 (59%) with asymptomatic/mild and 47 (41%) with moderate/severe clinical presentation. Patient follow-up included laboratory evaluation of FVIII and D-dimer levels at 1, 3, and 6 months following the COVID infection. Three months after the COVID infection, elevated FVIII was recorded in 44% of younger versus 65% of older individuals, p ¼ 0.05, respectively, and 30 versus 57% (p ¼ 0.008) 6 months post–COVID infection. With a focus on clinical presentation, a higher number of patients with moderate/severe COVID had elevated FVIII activity, but a statistically significant difference was observed only for the 6 months (32% mild vs. 53% moderate/severe, p ¼ 0.041) post-infection time point. Following a COVID infection, an increase in FVIII activity suggests a continued hypercoagulable state in the post-COVID period and correlates with elevated D-dimer levels. This increase in FVIII is more pronounced in patients with moderate/severe clinical picture and those patients older than 50 years. © 2024. Thieme. All rights reserved.

Objectives: A considerable number of patients do not achieve an adequate response to clopidogrel. Our study aimed to evaluate genetic and non-genetic factors as possible risks for clopidogrel high on-treatment platelet reactivity (HTPR) in patients (n=112) with carotid artery stenosis undergoing endarterectomy (CEA). Methods: Using multiple-electrode impedance aggregometry (MEA) the antiplatelet effectiveness of clopidogrel was measured after 24 h, 7 and 30 days of clopidogrel treatment, which was introduced after elective CEA at a dose of 75 mg daily, for at least 30 days. Results: HTPR was observed among 25% patients after clopidogrel therapy for 30 days. Further analysis showed that 53.3% of patients carrying the CYP2C19*2 gene variant had clopidogrel-HTPR, while in the wild type group there were 14.6% (p<0.001). Multivariate logistic regression analysis identified the CYP2C19*2 variant allele (OR 4.384; 95% CI 1.296-14.833, p=0.017) and high total cholesterol level (OR 2.090; 95% CI 1.263-3.459, p=0.004) as the only independent risk factors for clopidogrel-HTPR. Conclusion: The CYP2C19*2 gene variant and high total cholesterol level were major factors for clopidogrel-HTPR in patients with carotid artery stenosis undergoing CEA. © 2016 Bentham Science Publishers.

Objectives: A considerable number of patients do not achieve an adequate response to clopidogrel. Our study aimed to evaluate genetic and non-genetic factors as possible risks for clopidogrel high on-treatment platelet reactivity (HTPR) in patients (n=112) with carotid artery stenosis undergoing endarterectomy (CEA). Methods: Using multiple-electrode impedance aggregometry (MEA) the antiplatelet effectiveness of clopidogrel was measured after 24 h, 7 and 30 days of clopidogrel treatment, which was introduced after elective CEA at a dose of 75 mg daily, for at least 30 days. Results: HTPR was observed among 25% patients after clopidogrel therapy for 30 days. Further analysis showed that 53.3% of patients carrying the CYP2C19*2 gene variant had clopidogrel-HTPR, while in the wild type group there were 14.6% (p<0.001). Multivariate logistic regression analysis identified the CYP2C19*2 variant allele (OR 4.384; 95% CI 1.296-14.833, p=0.017) and high total cholesterol level (OR 2.090; 95% CI 1.263-3.459, p=0.004) as the only independent risk factors for clopidogrel-HTPR. Conclusion: The CYP2C19*2 gene variant and high total cholesterol level were major factors for clopidogrel-HTPR in patients with carotid artery stenosis undergoing CEA. © 2016 Bentham Science Publishers.

The study was conducted to evaluate the effect of anticoagulant therapy in women with thrombophilia and to detect the possible differences among carriers of mutations (factor V [FV] Leiden and FIIG20210) and those with natural anticoagulant deficiency. The 4-year prospective investigation included 85 pregnant women, with a history of recurrent fetal loss (RFL). They were treated with prophylactic doses of low-molecular-weight heparin (nadroparin) starting from 6 to 8 weeks of gestation. Pregnancy outcomes were evaluated based on the thrombophilia type. Carriers of thrombophilic mutations had a live birth rate of 93%, compared to 41.6% for women with natural anticoagulant deficiencies. Significant differences between the groups were also observed for intrauterine fetal death, intrauterine growth restriction, and postpartum thrombosis. The optimal therapy for women with natural anticoagulant deficiency and RFL remains unclear and future prospective study with a large number of patients is required to determine the best treatment for these severe thrombophilic conditions. © The Author(s) 2013.

The overall incidence of thromboembolic events in the neonatal period is 5 per 100 000 births, wherein more than 40% of all such manifestations are symptomatic renal vein thromboses. We describe the case of a newborn female who developed extensive thrombosis, which filled the inferior vena cava and renal vein and was diagnosed in the first weeks of life. A homozygous type II heparin-binding site antithrombin deficiency (c. 391C>T, p. Leu131Phe) was detected in the background. Despite the timely diagnosis and appropriate treatment, clinical signs of renal insufficiency, because of left kidney atrophy and arterial hypertension, were observed. Our case demonstrates the seriousness of the consequences arising after early onset of venous thrombosis caused by homozygous type II heparin-binding site antithrombin deficiency. In addition to prompt diagnosis, of huge importance is the determination of inherited thrombophilia, as it significantly affects therapeutic treatment and indicates that long-term follow-up is mandatory. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.

[No abstract available]

Introduction: Haemostatic balance shifted towards hypercoagulability in normal pregnancy is even more pronounced in pre-eclampsia (P-EC). The aim of this study was to analyse haemostatic disturbances and fibrin clot properties in women with pre-eclampsia and to investigate their association with maternal and foetal outcomes. Methods: Forty-six pregnant women diagnosed with pre-eclampsia were included in the study, with blood sampling done on the morning following admission to hospital, as well as after delivery (mean duration 4.8 days). Two global haemostatic assays—endogenous thrombin potential (ETP) and assay of overall haemostatic potential (OHP)—were employed, including fibrin clot turbidity measurements and scanning electron microscopy (SEM) of representative samples. Results: Three thrombin generation parameters (ETP, t_lag and peak height) and OHP were significantly increased in pre-eclampsia compared with controls, whereas overall fibrinolytic potential (OFP—determined as a parameter of the OHP assay) had significantly lower values. Clot lysis time was significantly prolonged in patients with pre-eclampsia. In the pre-eclamptic group after delivery, we observed a significant elevation in the peak height and a reduction in the time to peak and OFP compared with values before delivery. Pre-eclamptic patients with renal complications had significantly higher values for ETP, peak height and D-dimer. Turbidity measurements and SEM revealed dense fibrin structure in patients with pre-eclampsia. Conclusion: Patients with pre-eclampsia have enhanced coagulation and impaired fibrinolysis before, and even after, delivery. In particular, the presence of multi-organ dysfunction, such as renal dysfunction, may be associated with increased thrombin generation in pre-eclampsia. © 2020 John Wiley & Sons Ltd

Introduction: Haemostatic balance shifted towards hypercoagulability in normal pregnancy is even more pronounced in pre-eclampsia (P-EC). The aim of this study was to analyse haemostatic disturbances and fibrin clot properties in women with pre-eclampsia and to investigate their association with maternal and foetal outcomes. Methods: Forty-six pregnant women diagnosed with pre-eclampsia were included in the study, with blood sampling done on the morning following admission to hospital, as well as after delivery (mean duration 4.8 days). Two global haemostatic assays—endogenous thrombin potential (ETP) and assay of overall haemostatic potential (OHP)—were employed, including fibrin clot turbidity measurements and scanning electron microscopy (SEM) of representative samples. Results: Three thrombin generation parameters (ETP, t_lag and peak height) and OHP were significantly increased in pre-eclampsia compared with controls, whereas overall fibrinolytic potential (OFP—determined as a parameter of the OHP assay) had significantly lower values. Clot lysis time was significantly prolonged in patients with pre-eclampsia. In the pre-eclamptic group after delivery, we observed a significant elevation in the peak height and a reduction in the time to peak and OFP compared with values before delivery. Pre-eclamptic patients with renal complications had significantly higher values for ETP, peak height and D-dimer. Turbidity measurements and SEM revealed dense fibrin structure in patients with pre-eclampsia. Conclusion: Patients with pre-eclampsia have enhanced coagulation and impaired fibrinolysis before, and even after, delivery. In particular, the presence of multi-organ dysfunction, such as renal dysfunction, may be associated with increased thrombin generation in pre-eclampsia. © 2020 John Wiley & Sons Ltd

Objective: Elevated factor VIII has been shown to be an independent risk factor for deep venous thrombosis and pulmonary embolism. It has been suggested that increased factor VIII levels by itself is insufficient to cause thrombosis; however, increased factor VIII with other risk factors could increase the risk of thrombosis. The aim of the study was to evaluate the factor VIII level with regard to the type of thrombosis and patient’s risk factors such as age or comorbidity. Materials and Methods: In total, 441 patients who were referred for thrombophilia testing from the period of January 2010 to December 2020 were included in the study. The patients who developed the first thrombosis before the age of 50 were eligible for the study. The patients’ data that were used in statistical analyses were collected from our thrombophilia register. Results: The number of the subjects with increased factor VIII over 1.5 IU/mL is equal regardless of the thrombosis type. Factor VIII activity already begins to increase over 40 years old and reaches the mean values of 1.45 IU/mL close to the cut-off (1.5 IU/mL), showing a statistically significant difference compared to those under 40, P = .001. Comorbidities other than thyroid disease or malignancy had no influence on the increase of factor VIII. In the mentioned conditions, the average factor VIII of 1.82 (0.79) and 1.65 (0.43) was obtained, respectively. Conclusion: Factor VIII activity is significantly affected by age. Thrombosis type and comorbid diseases oththan thyroid disease and malignancy had no effect on factor VIII. © 2023, AVES. All rights reserved.

Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the AT gene (SERPINC1). Considering that the genotype phenotype relationship in AT deficiency patients remains unclear, especially in pediatric patients, the aim of our study was to evaluate genotype phenotype correlation in a Serbian pediatric population. A retrospective cohort study included 19 children younger than 18 years, from 15 Serbian families, with newly diagnosed AT deficiency. In 21% of the recruited families, mutations affecting exon 4, 5, and 6 of the SERPINC1 gene that causes type I AT deficiency were detected. In the remaining families, the mutation in exon 2 causing type II HBS (AT Budapest 3) was found. Thrombosis events were observed in 1 (33%) of those with type I, 11 (85%) of those with AT Budapest 3 in the homozygous respectively, and 1(33%) in the heterozygous form. Recurrent thrombosis was observed only in AT Budapest 3 in the homozygous form, in 27% during initial treatment of the first thrombotic event. Abdominal venous thrombosis and arterial ischemic stroke, observed in almost half of the children from the group with AT Budapest 3 in the homozygous form, were unprovoked in all cases. Conclusion: Type II HBS (AT Budapest 3) in the homozygous form is a strong risk factor for arterial and venous thrombosis in pediatric patients.What is Known:• Inherited AT deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1gene.• The genotype phenotype correlation in AT deficiency patients remains unclear, especially in pediatric patients.What is New:• The genetic results for our paediatric population predominantly showed the presence of a single specific mutation in exon 2, that causes type II HBS deficiency (AT Budapest 3).• In this group thrombosis mostly occurred as unprovoked, in almost half of them as abdominal thrombosis or stroke with high incidence of recurrent thrombosis, in 27% during initial treatment. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Coagulation dysfunction is a serious issue in patients with Coronavirus disease-19 (COVID-19). With regard to recently published studies, a high number of patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 developed life-threatening thrombotic complications despite anticoagulation. We report a case of young woman with the type-II heparin-binding site (HBS) antithrombin (AT) deficiency (Budapest 3-homozygous), who developed acute deep vein thrombosis on two occasions due to COVID-19 infection in the course of stable anticoagulation with vitamin K antagonist. The first thrombotic event was observed during mild COVID-19 infection, while the second thrombotic event she developed 2 months after she was negative for severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). Our case highlights the complexity of the treatment in this particular type of thrombophilia and the need for precaution even in mild forms of viral infection. In the treatment of acute thrombosis, AT-deficient patients may benefit from the use of AT concentrate along with low-molecular weight heparin (LMWH), while in cases of type II-HBS, AT supplementation is mandatory. © 2021 Georg Thieme Verlag. All rights reserved.

Background/Aim. Haemoglobin (Hb) determination is a routine part of the blood donor selection process. Previously reported studies have revealed that iron deficiency is common in frequent donors. This prospective investigation was aimed at examining iron status among blood donors with low circulating Hb and evaluating correlation between Hb values determined by capillary methods and those obtained by reference method from venous blood count (BC), as well as ferritin level. Methods. Between February 2017 and December 2018, 200 consecutively recruited regular blood donors with low Hb, aged 19 to 64 years (median 39), were included. Hb level was determined using the copper sulphate method, the HemoCue capillary method, and also from venous blood within the complete blood count (CBC) test. Plasma ferritin was determined turbidimetrically. Results. In 42.7% of men and 57.3% of women, ferritin concentration was low (p = 0.008). The relative numbers of males and females, with levels < 12 μg/L (p = 0.023) or > 50 μg/L (p = 0.022), differed. Comparison of the values obtained with the capillary methods with reference Hb levels obtained from the CBC test showed that the copper sulphate procedure gave false fails in 10.5% of cases (p < 0.001). Hb values from HemoCue were significantly correlated with Hb values from the CBC test, but no correlation was observed between ferritin levels and Hb levels determined by both capillary method. Conclusion. Low ferritin was observed in 51.5% of Serbian blood donors deferred due to low Hb. Based on our results, the determination of the algorithm in the iron deficiency detection is necessary, while the capillary method (HemoCue) represents a more convenient method for Hb testing prior to blood donation. © 2021 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Background: Pre-eclampsia (P-EC) is associated with systemic inflammation, endothelial dysfunction and hypercoagulability. The role of extracellular vesicles (EVs) in coagulation disturbances affecting the development and severity of P-EC remains elusive. We aimed to evaluate the concentration of EVs expressing phosphatidylserine (PS) and specific markers in relation to the thrombin and fibrin formation as well as fibrin clot properties, in pregnant women with P-EC in comparison to healthy pregnant women of similar gestational age. Methods: Blood samples of 30 pregnant women diagnosed with P-EC were collected on the morning following admission to hospital and after delivery (mean duration 5 days). The concentration of the PS-exposing EVs (PS+ EVs) from platelets (CD42a+, endothelial cells (CD62E+), and PS+ EVs expressing tissue factor (TF) and vascular cell adhesion molecule 1 (VCAM-1) were measured by flow cytometry. Further phenotyping of EVs also included expression of PlGF. Markers of maternal haemostasis were correlated with EVs concentration in plasma. Results: Preeclamptic pregnancy was associated with significantly higher plasma levels of PS+ CD42a+ EVs and PS+ VCAM-1+ EVs in comparison with normotensive pregnancy. P-EC patients after delivery had markedly elevated concentration of PS+ CD42a+ EVs, CD62E+ EVs, TF+ EVs, and VCAM-1+ EVs compared to those before delivery. Inverse correlation was observed between EVs concentrations (PS+, PS+ TF+, and PlGF+) and parameters of overall haemostatic potential (OHP) and fibrin formation, while PS+ VCAM-1+ EVs directly correlated with FVIII activity in plasma. Conclusion: Increased levels of PS+ EVs subpopulations in P-EC and their association with global haemostatic parameters, as well as with fibrin clot properties may suggest EVs involvement in intravascular fibrin deposition leading to subsequent microcirculation disorders. Copyright © 2021 Lalic-Cosic, Dopsaj, Kovac, Mandic-Markovic, Mikovic, Mobarrez and Antovic.

[No abstract available]

Background: Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1 gene. The most common clinical presentation in AT deficient patients includes venous thrombosis and pulmonary embolism, while the association of AT deficiency and its effect on the development of pregnancy complications has been less studied. The aim of our research was to evaluate the effect of AT deficiency types, determined by genotyping, on pregnancy outcomes. Methods: A retrospective cohort study included 28 women with AT deficiency, and their 64 pregnancies were analyzed. Results: With regard to live birth rate, a significant difference was observed among women who were carriers of different SERPINC1 mutations, as the rate varied from 100% in cases of type I to the extremely low rate of 8% for women with type II HBS (AT Budapest 3) in the homozygous variant, P = 0.0005. All pregnancies from the type I group, even untreated ones, resulted in live births. In women with AT Budapest 3 in homozygous variant the overall live birth rate increased to 28.5% in the treated pregnancies. In this group the highest incidence of fetal death was observed of 62%; repeated fetal losses in 30%; fetal growth restriction in 22% and placental abruption in 7% of all pregnancies. Conclusion: Our study results indicate a difference between type I and type II AT deficiency. The risk of pregnancy related VTE was equally present in both groups, except for AT Budapest 3 in the heterozygous variant, while adverse pregnancy outcomes were strictly related to type II, especially AT Budapest 3 in the homozygous variant. © 2018 Elsevier Ltd

Background: Thrombosis is a major global disease burden with almost 60% of cases related to underlying heredity and most cases still idiopathic. Synonymous single nucleotide polymorphisms (sSNPs) are considered silent and phenotypically neutral. Our previous study revealed a novel synonymous FII c.1824C>T variant as a potential risk factor for pregnancy loss, but it has not yet been associated with thrombotic diseases. Methods: To determine the frequency of the FII c.1824C>T variant we have sequenced patients' DNA. Prothrombin RNA expression was measured by quantitative PCR. Functional analyses included routine hemostasis tests, western blotting and ELISA to determine prothrombin levels in plasma, and global hemostasis assays for thrombin and fibrin generation in carriers of the FII c.1824C>T variant. Scanning electron microscopy was used to examine the structure of fibrin clots. Results: Frequency of the FII c.1824C>T variant was significantly increased in patients with venous thromboembolism and cerebrovascular insult. Examination in vitro demonstrated increased expression of prothrombin mRNA in FII c.1824T transfected cells. Our ex vivo study of FII c.1824C>T carriers showed that the presence of this variant was associated with hyperprothrombinemia, hypofibrinolysis, and formation of densely packed fibrin clots resistant to fibrinolysis. Conclusion: Our data indicate that FII c.1824C>T, although a synonymous variant, leads to the development of a prothrombotic phenotype and could represent a new prothrombotic risk factor. As a silent variant, FII c.1824C>T would probably be overlooked during genetic screening, and our results show that it could not be detected in routine laboratory tests. © 2020 American Association for Clinical Chemistry. All rights reserved.

Direct oral anticoagulants (DOACs) are the first-line anticoagulants for the secondary prevention of venous thromboembolism (VTE). However, patients with severe inherited thrombophilias represent a group in whom the efficiency and safety of DOACs is poorly studied. In this communication, we focus on the utility of DOACs in the secondary prevention of VTE in patients with severe thrombophilia. Current evidence is based only on cohort or single-center studies, and poor data are available on compliance of the patients in the studies. Analysis of the studies suggested that full-dose DOACs and vitamin K antagonists have a similar efficacy and bleeding risk in the secondary prevention of VTE in patients with thrombophilia, with a low hazard ratio for recurrent VTE calculated from cohort studies for DOAC vs warfarin, ranging from 0.3 to 0.75. We wish to highlight that treatment failure is greater in those with severe forms of protein S deficiency (below 20%) and possibly in antithrombin deficiency type II heparin-binding site homozygous Budapest 3. In summary, the current approach to using DOACs in patients with severe thrombophilia is dependent on clinical judgment and experience. Limited evidence suggests that for those with severe thrombophilias, full-dose DOACs have similar utility as vitamin K antagonists. We recommend caution in using low-dose DOACs due to lack of evidence. Ideally, large randomized multicenter studies are required to develop a reliable treatment algorithm. © 2024 International Society on Thrombosis and Haemostasis