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Introduction. Ischemic stroke (IS) is a heterogeneous dis-order caused by several genetic and environmental risk factors. It was suggested that coagulation disorders cause 1-4% of cases with IS, especially in patients with early onset of IS. Case report. We describe a case of a young adult male who developed an unprovoked IS. Biochemical, immunological, and thrombophilia screening, as well as DNA sequencing, were performed in order to reveal molecular pathology underlying the stroke of the patient. Thrombophilia testing showed that patient was a homozygous carrier for PAI-1 4G/5G and MTHFR C677T mutations. Additional genetic analysis revealed the presence of the recently reported F2 c.1824C>T gene variant, located in the last exon of the pro-thrombin gene and has previously been shown to cause hy-perprothrombinemia, hypofibrinolysis, and altered fibrin clot phenotype. Conclusion. Our results suggest that the newly reported F2 c.1824C>T gene variant might have a synergistic effect with PAI 4G/4G and MTHFR 677TT genotype in the formation of altered fibrin clot phenotype characterized by thin, densely packed fibrin fibers, which makes clot less susceptible to fibrinolysis and greatly in-creases the risk for early ischemic stroke onset.

Introduction: Prothrombin Belgrade mutation is the result of the c.1787G>A substitution in the prothrombin gene. It is located in the antithrombin and sodium binding site and leads to impaired inactivation of thrombin by antithrombin, resulting in antithrombin resistance and thrombotic disorders. However, it negatively affects sodium binding and may have hypocoagulant effects. Considering that prothrombin Belgrade mutation mechanism is still not fully elucidated and that sodium binding is important for thrombin affinity towards fibrinogen, our aim was to determine whether this mutation affects fibrin clot formation and lysis. Methods: Using HEK293T cell line, recombinant wild type and mutated prothrombin were generated by transient transfection. Samples that correspond to plasma of a non‐carrier, heterozygous and homozygous carriers were reconstituted using prothrombin deficient plasma and recombinant proteins. Reconstituted samples were used in OHP assay (Overall Hemostasis Potential) to determine kinetic profiles of coagulation and fibrinolysis. Clot turbidity assay was performed to observe kinetics of clot formation and lysis more closely. Fibrin clots formed in reconstituted plasma samples were analyzed by confocal microscopy to determine density of fibrin network. Fibrin clots were additionally observed using electron microscopy to determine thickness of individual fibrin fibers. Results: No significant difference found in OHP, OCP, OFP, and fibrin network density between wild type, heterozygous, and homozygous carrier reconstituted plasma samples. There were significant differences between samples for slope and slope time parameters in kinetic profiles and fibrin fiber thickness. Conclusions: Results indicate that prothrombin Belgrade mutation has no significant impact on fibrinolysis, however it may affect kinetics of clot formation and its architecture. [ABSTRACT FROM AUTHOR]

The link between thrombotic disorders and cancer has been known for over 150 years, although the precise mechanism of this relationship has not yet been resolved. Current data show that thrombin has a significant role in cancer metabolism, invasiveness, adhesion and survival. However, data regarding the expression of the thrombin precursor prothrombin in various cancer cell lines are scarce. Therefore, it was our objective to determine whether common cancer-derived cell lines (Caco-2, MCF-7, SK-BR-3, U-87 and U-251) express prothrombin. The prothrombin RNA expression level was assessed by qPCR, and the presence of prothrombin was analyzed by Western blot analysis. Our results show that Caco-2 cells originating from colorectal adenocarcinoma express prothrombin, whereas other analyzed cell lines do not. Our results provide a background for further research into the role of (pro)thrombin in cancer etiopathology. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI 173008]

Background: Plasminogen activator inhibitor 1 (PAI-1) is an inhibitor of fibrinolysis. The PAI-1 4G/5G polymorphism is associated with elevated plasma levels of PAI-1. Overexpression of PAI-1 and impaired fibrinolysis in homozygous carriers of the 4G/4G PAI polymorphism may lead to abnormal placental formation and increased risk of fetal loss (FL). The aim of our study was to determine the frequency of this polymorphism in patients with FL in a Serbian population. Methods: The study was carried out in a group of 203 women (91 controls and 112 women with FL). The presence of PAI-1 4G/5G polymorphism was detected by PCR-RFLP analysis. Results: Slightly increased frequency of the PAI-1 4G/4G genotype was observed in the study group compared to the controls (32.1% vs. 30.8%). The frequency of PAI-1 was highest in women experiencing FL in the second trimester of pregnancy (50%), but this difference was not statistically significant. Conclusions: Our findings suggest that PAI-1 4G/4G might be a risk factor for FL occurring in the second trimester of pregnancy. Further studies are required in order to determine the role of PAI-1 4G/5G polymorphism in the etiology of FL.

Thrombophilia is a multifactorial disorder, involving both genetic and acquired risk factors that affect the balance between procoagulant and anticoagulant factors and lead to increased thrombotic tendency. The severe forms of thrombophilia are caused by a deficiency of natural anticoagulants: antithrombin, protein C and protein S. The advances in DNA technology played an important role in the identification of the exact nature of these deficiencies and opened up new possibilities in genetic research and molecular diagnostics of thrombophilia. The major breakthrough came with the discovery of activated protein C resistance and the Factor V Leiden gene mutation. Shortly afterwards, a variant in the 3' untranslated region of the Factor II gene (FII G20210A) associated with an increased concentration of Factor II in plasma was described. These two gene variants represent the most common thrombophilic genetic risk factors. Recently, a novel prothrombin mutation (c.1787G>T) was identified in a Japanese family with juvenile thrombosis. This mutation leads to impaired inhibition of mutant thrombin by antithrombin, proposing a new mechanism of thrombophilia named resistance to antithrombin. In the last decade, several prothrombotic genetic risk factors have been described, including gene variants associated with defects of natural coagulation inhibitors, increased levels of coagulation factors or their impaired inhibition and defects of the fibrinolytic system. However, most of them are not of diagnostic value, due to their minor or unknown impact on the thrombotic risk. Large-scale DNA analysis systems are now becoming available, opening a new era in the genetic studies of the molecular basis of thrombophilia.

Introduction: Plasminogen activator inhibitor 1 (PAI-1) has a major role in inhibition of firinolysis and normal haemostasis. The presence of the PAI-1 4G/4G genotype leads to increased expression of PAI-1. High blood level of PAI-1 is associated with many diseases such as thrombosis, cerebral insult, myocardial infarction, pregnancy loss, preeclampsia, insulin resistance, type 2 diabetes, breast cancer and asthma. In this study, the prevalence of PAI-1 4G/5G gene variant was determined in healthy subjects from Serbian population. Methods: The study was carried out in a group of 210 healthy subjects (105 women and 105 men). The presence of PAI-1 4G/5G gene variant was detected by PCR-RFLP analysis. Results: The prevalence of PAI-1 4G/4G genotype was 34.76% and it was increased compared to PAI-1 5G/5G genotype (19.05%). The most frequent was PAI-1 4G/5G genotype (46.19%). Allelic frequency for 4G allele was higher (0.58) compared to 5G allele (0.42). Conclusions: The prevalence of PAI-1 4G/5G gene variant in Serbian population is similar to the neighboring populations. Results of this study represent the first data for Serbian population. This study could be useful for further research where the role of PAI-1 4G/5G gene variant will be assessed in the pathogenesis of many diseases.

Background: The mutant CCR5Δ32 allele confers resistance to HIV infection. Several hypotheses regarding its origin and persistence in the human population have been proposed. It is assumed that the Δ32 mutation was introduced in Northern or Eastern Europe and that it spread to the south. Although the frequency of CCR5Δ32 was determined in numerous European nations and regions, further data are needed to complete the puzzle of CCR5Δ32 distribution within the continent. Methods: To this end, CCR5Δ32 frequency was determined in a Serbian population (sample size 352). DNA was extracted from peripheral whole blood and polymerase chain reaction specific for CCR5 gene was performed. A reaction product of 263 bp was obtained from the wild­type CCR5 sequence and a product of 231 bp was obtained from the truncated CCR5Δ32 sequence. Results: Overall allele frequency of CCR5Δ32 is 4.55%; 0.57% of individuals in the examined population are homozygous and 8.52% are heterozygous for CCR5Δ32. Conclusions: The determined frequency of the CCR5Δ32 allele in a Serbian population is unexpectedly low, considering ethnically related populations.

Copyright of Genetika (0534-0012) is the property of Serbian Genetics Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study sought to identify different subpopulations of extracellular vesicles (EVs) in plasma from female patients with established rheumatoid arthritis (RA) in relation to the activation of coagulation and fibrin formation in these patients. Forty women were included in the study, 20 patients and 20 age-matched healthy controls. The mean disease duration in patients was 13.0 (5.0–25.0) years, with medium to high disease activity despite ongoing treatment with low-dose prednisolone and methotrexate. There were no differences between the investigated groups regarding the presence of traditional cardiovascular risk factors. The concentration of phosphatidylserine-positive (PS+) EVs; platelet (CD42a+), leucocyte (CD45+), monocyte (CD14+), and endothelial (CD144+)-derived EVs; and EVs-expressing tissue factor (CD142+), P-selectin (CD62P+), and E-selectin (CD62E+) were determined by flow cytometry analysis. Overall hemostasis potential (OHP) was assessed to follow the hemostatic disturbances, including the parameters for overall coagulation potential (OCP) and overall fibrinolytic potential (OFP). Fibrin clot turbidity was measured together with clot lysis time, and scanning electron microscopy was performed. Increased concentrations of PS+, CD42a+, CD142+, CD45+, CD14+, and CD62P+ EVs were found in plasma from patients with RA compared to healthy controls, and the concentrations of PS+, CD42a+, CD14+, and CD62P+ EVs were positively correlated with the inflammatory parameters in RA patients. Positive correlations were also found between the levels of PS+ and CD42a+ EVs and OCP as well as between the levels of PS+, CD42a+, and CD62P+EVs and OHP. The levels of PS+, CD42a+, CD14+, CD62P+, and CD62E+ EVs were negatively correlated with OFP. Elevated levels of circulating EVs of different cell origins were found in patients with established RA, in relation to the inflammatory burden and coagulation activation in the disease. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Breast cancer is the leading cause of cancer-related death among women. An increased burden of thrombotic events among breast cancer patients, leading to higher mortality and morbidity rates, is well established. There are a number of genetic risk factors associated with thrombosis, but their contribution to thrombotic tendencies in patients with cancer is not completely elucidated. We aimed to investigate possible role of FV Leiden, FII G20210A, MTHFR C677T and PAI-1 4G/5G gene variants in etiopathology of breast cancer and accompanying thrombosis in cohort of Serbian patients. Our study included 316 subject divided in three groups: breast cancer patients with (97) or without (99) accompanying thrombosis and healthy control group (120). According to our results, the prevalence for all four prothrombotic gene variants were similar in cancer patients with and without thrombosis and no statistically significant difference was observed between these groups. We detected lower frequency of MTHFR 677TT genotype in breast cancer patients when compared to control group (P=0.014; OR=0.145 (95%CI 0.031-0.679)), indicated that MTHFR C677T homozygosity could play a protective role in breast cancer susceptibility. Our study noted the lack of association between common prothrombotic gene variants and increased prothrombotic risk in Serbian breast cancer patients. Also, our results point out possible role of MTHFR 677TT genotype in etiology of breast cancer, but further studies on larger cohort of patients are needed. [ABSTRACT FROM AUTHOR]

Highlights • Proteins C and S explain part of OHP and ETP posttreatment values in haemophilia A. • Thrombophilia does not protect against a severe bleeding phenotype. • The prevalence of thrombophilia in haemophilia A patients is similar to controls. • OHP and ETP were not affected by coagulation factors and TAFI. [ABSTRACT FROM AUTHOR]

Copyright of Genetika (0534-0012) is the property of Serbian Genetics Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recurrent pregnancy loss (RPL) is a health problem affecting up to 5% of women of reproductive age. Several thrombophilic risk factors might contribute to RPL.To investigate relationship between a novel C20068T gene variant in the 3' end of prothrombin gene and RPL, we tested 153 women with RPL and 111 controls for the presence of this gene variant. In patients, we have detected four heterozygous (2.61%) and no homozygous carriers. In controls, no carriers were detected. Our results indicate higher prevalence of C20068T gene variant in women with RPL but this difference was not statistically significant. However, in patients who suffered 5 or more RPL, frequency of C20068T gene variant was significantly increased compared to controls (12.5% vs. 0%, P=0.02). This is the first study which points out a possible role of C20068T gene variant in etiology of RPL, but larger studies should be carried out to confirm our findings. [ABSTRACT FROM AUTHOR]

Background: Prothrombin (FII) A19911G and C20221T gene variants are associated with increased prothrombin levels and potentially represent thrombotic risk factors. Objective: To determine the frequency of A19911G and C20221T FII gene variants in patients with thrombotic disorders and in women who have experienced pregnancy loss (PL). Methods: We determined the frequency of these variants in 133 patients with deep venous thrombosis (DVT), 80 patients with isolated pulmonary embolism (PE), 101 patients with idiopathic PL, and 180 control individuals. Results: The FII A19911G variant was more prevalent in patients with DVT and with PL compared with controls; however, these differences were not statistically significant. The 19911GG genotype was associated with increased risk of PE (odds ratio, 1.91; 95% confidence interval, 1.04-3.51). We did not detect carriers of the FII C20221T gene variant in this study. Conclusions: This is the first study, to our knowledge, that demonstrates the FII 19911GG genotype may represent a risk factor for isolated PE. Also, our results show that the FII C20221T is a rare variant in this population and therefore, routine thrombophilia screening should not include screening for this genotype. [ABSTRACT FROM AUTHOR]

Background Estimates of the risk ratio of tamoxifen-associated venous thromboembolism (VTE) in breast cancer patients range from 2.4 to 7.1. The occurrence of thrombosis in patients with breast cancer complicates the clinical condition and causes a change of treatment. Our study was conducted in order to investigate the influence of patient-related risk factors for thrombosis development in breast cancer patients whose treatment included adjuvant tamoxifen. Methods The prospective, single center, case control study included 150 breast cancer women, 50 whom developed venous thrombosis during adjuvant tamoxifen and 100 whom did not have thrombosis, as a control group. Patient-related risk factors such as: age, body mass index, previous VTE, varicose veins, concomitant diseases, the presence of prothrombotic mutations (FV Leiden, FII G20210A) and FVIII activity were evaluated in both groups. Results In respect of prothrombotic mutations, the FV Leiden mutation was present in a higher number of women from the VTE group (10/50 vs 7/100; P = 0.020). Additionally, FVIII activity was significantly higher in the VTE group; median (IQR), of 1.79 (0.69) vs 1.45 (0.55); P < 0.001 and more women in this group (24/50 vs 34/100) had increased FVIII activity; P = 0.020. In those women with FVIII > 1.5 IU/ml, who were carriers of prothrombotic mutations, an OR of 3.76 (CI 95% 1.276–11.096; P = 0.016) was obtained for VTE. Conclusion The results of our study showed that the factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen. [ABSTRACT FROM AUTHOR]