The clinical course of essential thrombocythemia (ET) is complicated with thrombosis which significantly impacts patients' mortality. Studies have identified JAK2V617F mutation as an independent risk factor for thrombosis. Circulating extracellular vesicles (EVs) were evaluated in several studies regarding myeloproliferative neoplasms and thrombosis as potential biomarkers. The present study investigates the relationship between JAK2V617F mutation and EVs levels in 119 ET patients. Our analyses revealed that JAK2V617F-positive patients are at a significantly increased risk of thrombosis within five years before the ET diagnosis (hazard ratio [95% CI]: 11.9 [1.7-83.7], P = 0.013), and that JAK2V617F mutation is an independent risk factor for thrombosis at ET diagnosis or during the follow-up (hazard ratio [95% CI]: 3.56 [1.47-8.62], P = 0.005). ET patients have higher levels of platelet-EVs, erythrocyte-EVs and procoagulant activity of EVs than the healthy population. Absolute and relative counts of platelet-EVs are increased in the presence of JAK2V617F mutation (P = 0.018, P = 0.024, respectively). In conclusion, our results support the role of JAK2V617F mutation in the pathogenesis of thrombosis in essential thrombocythemia through enhancing platelet activation.

• Klíčová slova
• Essential thrombocythemia, JAK2V617F mutation, extracellular vesicles, risk factor, thrombosis,
• MeSH
• esenciální trombocytemie * genetika   komplikace   patologie   MeSH
• Janus kinasa 2 * genetika   MeSH
• lidé MeSH
• mutace MeSH
• myeloproliferativní poruchy * komplikace   genetika   patologie   MeSH
• trombocyty MeSH
• trombóza * genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Janus kinasa 2 * MeSH

Here, we present the first case of fibrinogen variant FGG c.8G>A. We investigated the behaviour of this mutated fibrinogen in blood coagulation using fibrin polymerization, fibrinolysis, fibrinopeptides release measurement, mass spectrometry (MS), and scanning electron microscopy (SEM). The case was identified by routine coagulation testing of a 34-year-old man diagnosed with thrombosis. Initial genetic analysis revealed a heterozygous mutation in exon 1 of the FGG gene encoding gamma chain signal peptide. Fibrin polymerization by thrombin and reptilase showed the normal formation of the fibrin clot. However, maximal absorbance within polymerization was lower and fibrinolysis had a longer degradation phase than healthy control. SEM revealed a significant difference in clot structure of the patient, and interestingly, MS detected several posttranslational oxidations of fibrinogen. The data suggest that the mutation FGG c.8G>A with the combination of the effect of posttranslational modifications causes a novel case of hypofibrinogenemia associated with thrombosis.

• MeSH
• afibrinogenemie * komplikace   genetika   MeSH
• dospělí MeSH
• fibrin metabolismus   MeSH
• fibrinogen genetika   metabolismus   MeSH
• fibrinogeny abnormální * genetika   metabolismus   MeSH
• hemostatika * MeSH
• lidé MeSH
• oxidační stres MeSH
• posttranslační úpravy proteinů MeSH
• trombóza * komplikace   genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• fibrin MeSH
• fibrinogen MeSH
• fibrinogeny abnormální * MeSH
• hemostatika * MeSH

Fibrinogen, an abundant plasma glycoprotein, is involved in the final stage of blood coagulation. Decreased fibrinogen levels, which may be caused by mutations, are manifested mainly in bleeding and thrombotic disorders. Clinically relevant mutations of fibrinogen are listed in the Human Fibrinogen Database. For the αC-connector (amino acids Aα240-410, nascent chain numbering), we have extended this database, with detailed descriptions of the clinical manifestations among members of reported families. This includes the specification of bleeding and thrombotic events and results of coagulation assays. Where available, the impact of a mutation on clotting and fibrinolysis is reported. The collected data show that the Human Fibrinogen Database reports considerably fewer missense and synonymous mutations than the general COSMIC and dbSNP databases. Homozygous nonsense or frameshift mutations in the αC-connector are responsible for most clinically relevant symptoms, while heterozygous mutations are often asymptomatic. Symptomatic subjects suffer from bleeding and, less frequently, from thrombotic events. Miscarriages within the first trimester and prolonged wound healing were reported in a few subjects. All mutations inducing thrombotic phenotypes are located at the identical positions within the consensus sequence of the tandem repeats.

• Klíčová slova
• Human Fibrinogen Database, afibrinogenemia, dysfibrinogenemia, fibrinogen, hypodysfibrinogenemia, hypofibrinogenemia, mutations, αC-connector,
• MeSH
• fibrinogen genetika   MeSH
• hemokoagulace genetika   MeSH
• krvácení genetika   MeSH
• lidé MeSH
• mutace genetika   MeSH
• trombóza genetika   MeSH
• vyšetření krevní srážlivosti metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• fibrinogen MeSH

BACKGROUND/AIM: This work aimed to prospectively evaluate the clinical significance of circulating microparticles (MPs) in relation to thrombotic risk factors and thrombotic complications in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). PATIENTS AND METHODS: In a cohort of 206 patients with MPN, MPs' procoagulant activity was measured by the Zymuphen functional assay in 429 samples, while platelet- and erythrocyte-MPs were enumerated by flow cytometry in 558 samples. RESULTS: MPN patients had higher MP levels than the control group. The levels of MPs were higher in male patients, smokers, and those who were older than 60 years, and in the presence of JAK2V617F mutation, history of thrombosis, platelets >400×109/l, hematocrit >45%, or leukocytes >10×109/l. Cytoreductive treatment reduced MP levels, with anagrelide being associated with lower MP levels than hydroxyurea. CONCLUSION: The relationship with thrombotic risk factors indicates a possible role of MPs in the complex thrombotic mechanism, though cytoreductive treatment seems to affect this role through reducing MP levels.

• Klíčová slova
• Myeloproliferative neoplasm, anagrelide, hydroxyurea, microparticle, procoagulant activity, thrombosis,
• MeSH
• lidé MeSH
• mikropartikule * MeSH
• myeloproliferativní poruchy * farmakoterapie   genetika   MeSH
• nádory * MeSH
• trombocyty MeSH
• trombóza * etiologie   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Thrombosis is the most common complication in BCR-ABL1 negative myeloproliferative neoplasms (MPN) that significantly impacts patients' mortality. Generally, there is an agreement on risk factors that possibly contribute to the increased risk of thrombosis, including age, history of thrombosis, JAK2V617F mutation, and cardiovascular risk factors. This study retrospectively investigates MPN-related and patient-related variables in relation to the thrombosis occurrence in MPN. Our analyses show that JAK2V617F-mutated patients are at a significantly increased risk of thrombosis within five years before the MPN diagnosis point with a hazard ratio (HR) of 15.49 (p=0.006). In multivariate analyses, independent risk factors for thrombotic complications during the follow-up are history of thrombosis (HR=2.23, p=0.019), age over 60 years at diagnosis (HR=1.56, p=0.037), the presence of JAK2V617F mutation (HR=3.01, p=0.002), and tobacco smoking (HR=1.75, p=0.01). Our results support the multifactorial mechanism of thrombosis in MPN patients, which demands individual and complex management.

• MeSH
• Janus kinasa 2 genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace MeSH
• nádory * MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• trombóza * genetika   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Janus kinasa 2 MeSH

INTRODUCTION: Inherited thrombophilias represent a concerning risk factor due to a proclivity to an aberrant clot formation. However, in patients with left ventricular assist device (LVAD), their impact on bleeding and thrombotic complications remains still poorly understood. The aim of the present study was to evaluate the effect of thrombophilic mutation directed anticoagulation therapy on adverse clinical outcomes in LVAD patients. MATERIALS AND METHODS: About 138 consecutive patients indicated for LVAD implant (HeartMate II, Abbott, Plymouth, USA) were prospectively screened for three major thrombophilic mutations: factor II (prothrombin), factor V Leiden, and homozygous methylenetetrahydrofolate reductase (MTHFR). Subsequently, discordant individualized anticoagulation targets of INR 2.5-3.0 in thrombophilia positive and INR 1.8-2.2 in negative patients were established; notably without anti-platelet agents given the center standard of care. RESULTS: Mean age was 50 ± 12.7 years, 83% male. Mean duration of support was 464.5 days (SD 482.9; SEM 41.1) and median of 310 days (IQR 162; 546). Full thrombophilia positive cohort analysis has not revealed any significant impact on event free survival. In contrast, detailed analysis of specific thrombophilias subsets has revealed Factor II prothrombin mutation as a significant predisposition for the pump thrombosis risk (SHR 10.48; p = 0.001) despite more aggressive prespecified anticoagulation target. Moreover, the incidence of bleeding events in prothrombin group was also significantly increased (SHR 6.0; p = 0.03). CONCLUSIONS: Our observations suggest that specific thrombophilias in LVAD patients may pose different intensity predisposition for thrombotic complications. Factor II (prothrombin) positive mutation was identified as significant risk factor associated with the pump thrombosis.

• Klíčová slova
• Thrombophilias, hemocompatibility, individualized anticoagulation, pump thrombosis, ventricular assist device,
• MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• podpůrné srdeční systémy * škodlivé účinky   MeSH
• prospektivní studie MeSH
• protrombin MeSH
• trombofilie * diagnóza   genetika   MeSH
• trombóza * genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protrombin MeSH

Although it is well known that myeloproliferative neoplasms occur in younger patients, few large cohorts of such patients have been reported. Thus, our knowledge about circumstances of diagnosis, outcome and treatment is limited, especially for children and young adults. We therefore performed a systematic review of cases, published since 2005, concerning patients aged below 20 years at the time of diagnosis of essential thrombocythemia or polycythemia vera. We identified 396 cases of essential thrombocythemia and 75 of polycythemia vera. The median age at diagnosis was 9.3 and 12 years, respectively, and females constituted 57.6% and 45% of the groups, respectively. Half of the patients were asymptomatic at diagnosis. The proportion of so-called triple negativity was high: 57% in essential thrombocythemia and 73% in polycythemia vera. The incidence of thrombosis during the follow-up was 9.3% in patients with polycythemia vera and less, 3.8%, in those with essential thrombocythemia. Venous events were predominant (84.2%), with hemorrhagic episodes being rarer (<5%). The risk of evolution also seemed low (2% to myelofibrosis and no reports of acute leukemia), but the median follow-up was only 50 months. Survival curves were not available. Half of the patients received an antithrombotic drug and 40.5% received a cytoreductive drug. All data should be analyzed with care because of the proportion of missing data (10.7% to 74.7%). This review highlights interesting points concerning this population of young patients with myeloproliferative neoplasms, including that such patients were identified as negative for all common driver mutations, but also shows the need for larger contemporary cohorts with longer follow-up to assess the true prognosis of these patients.

• MeSH
• asymptomatické nemoci MeSH
• časná diagnóza MeSH
• cytotoxiny terapeutické užití   MeSH
• dítě MeSH
• esenciální trombocytemie diagnóza   farmakoterapie   genetika   patologie   MeSH
• exprese genu MeSH
• fibrinolytika terapeutické užití   MeSH
• Janus kinasa 1 genetika   MeSH
• Janus kinasa 2 genetika   MeSH
• krvácení diagnóza   farmakoterapie   genetika   patologie   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mutace MeSH
• polycythaemia vera diagnóza   farmakoterapie   genetika   patologie   MeSH
• prognóza MeSH
• splenomegalie diagnóza   farmakoterapie   genetika   patologie   MeSH
• trombóza diagnóza   farmakoterapie   genetika   patologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Publikační typ
• časopisecké články MeSH
• systematický přehled MeSH
• Názvy látek
• cytotoxiny MeSH
• fibrinolytika MeSH
• JAK1 protein, human MeSH Prohlížeč
• JAK2 protein, human MeSH Prohlížeč
• Janus kinasa 1 MeSH
• Janus kinasa 2 MeSH

Induction of thrombosis in tumor vasculature represents an appealing strategy for combating cancer. Herein, we combined unique intrinsic coagulation properties of staphylocoagulase with new acquired functional potentials introduced by genetic engineering, to generate a novel bi-functional fusion protein consisting of truncated coagulase (tCoa) bearing an RGD motif on its C-terminus for cancer therapy. We demonstrated that free coagulase failed to elicit any significant thrombotic activity. Conversely, RGD delivery of coagulase retained coagulase activity and afforded favorable interaction of fusion proteins with prothrombin and αvβ3 endothelial cell receptors, as verified by in silico, in vitro, and in vivo experiments. Although free coagulase elicited robust coagulase activity in vitro, only targeted coagulase (tCoa-RGD) was capable of producing extensive thrombosis, and subsequent infarction and massive necrosis of CT26 mouse colon, 4T1 mouse mammary and SKOV3 human ovarian tumors in mice. Additionally, systemic injections of lower doses of tCoa-RGD produced striking tumor growth inhibition of CT26, 4T1 and SKOV3 solid tumors in animals. Altogether, the nontoxic nature, unique shortcut mechanism, minimal effective dose, wide therapeutic window, efficient induction of thrombosis, local effects and susceptibility of human blood to coagulase suggest tCoa-RGD fusion proteins as a novel and promising anticancer therapy for human trials.

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• infarkt patologie   MeSH
• koagulasa genetika   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mutace MeSH
• myši inbrední C57BL MeSH
• myši nahé MeSH
• nádorové buněčné linie MeSH
• nádory genetika   metabolismus   terapie   MeSH
• oligopeptidy genetika   MeSH
• patologická angiogeneze genetika   metabolismus   patologie   MeSH
• rekombinantní fúzní proteiny genetika   metabolismus   MeSH
• trombóza genetika   metabolismus   MeSH
• tumor burden genetika   MeSH
• xenogenní modely - testy protinádorové aktivity metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• arginyl-glycyl-aspartic acid MeSH Prohlížeč
• bakteriální proteiny MeSH
• koagulasa MeSH
• oligopeptidy MeSH
• rekombinantní fúzní proteiny MeSH

Controversies still exist regarding definition of the thrombotic risks in Ph- (BCR/ABL1-) myeloproliferative disorders with thrombocythemia (MPD-T). Platelet counts at diagnosis are currently not taken as a risk factor of thrombosis. In our cohort of 1179 patients with MPD-T, prospectively registered for anagrelide treatment, we found that the median platelet count prior to the thrombotic event was significantly higher than at time points without any ensuing thrombosis (453 vs. 400 × 10(9)/L, P < 0.001), albeit higher platelet counts at diagnosis tended to be connected with fewer thrombotic events (in contrast to WBC counts at diagnosis). The JAK2(V617F) mutation predicted both arterial and venous events, while age >65 yr, hypertension, diabetes mellitus, smoking, elevated triglyceride and homocysteine levels predicted arterial events only. For venous events, the specific thrombophilic risk factors (factor V 'Leiden' and others), antiphospholipid antibodies, and elevated factor VIII levels played a major role. During anagrelide treatment (± aspirin), we documented a decrease in both venous (6.7-fold) and arterial events (1.8-fold), while bleeding (mostly minor events) increased twofold compared to history. Our results suggest that keeping platelet counts at low levels may be a meaningful therapeutic measure to prevent thrombosis, although their counts at diagnosis lack any prognostic value.

• Klíčová slova
• JAK2, anagrelide, myeloproliferative disorders, platelets, thrombophilia, thrombosis,
• MeSH
• Aspirin aplikace a dávkování   MeSH
• bcr-abl fúzní proteiny MeSH
• chinazoliny aplikace a dávkování   MeSH
• filadelfský chromozom * MeSH
• Janus kinasa 2 genetika   MeSH
• lidé MeSH
• missense mutace MeSH
• počet trombocytů MeSH
• prospektivní studie MeSH
• registrace * MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• substituce aminokyselin MeSH
• trombocytóza * krev   komplikace   farmakoterapie   genetika   MeSH
• trombóza * krev   farmakoterapie   etiologie   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anagrelide MeSH Prohlížeč
• Aspirin MeSH
• bcr-abl fúzní proteiny MeSH
• BCR-ABL1 fusion protein, human MeSH Prohlížeč
• chinazoliny MeSH
• JAK2 protein, human MeSH Prohlížeč
• Janus kinasa 2 MeSH

A patient with dilated cardiomyopathy and no history of thromboembolic events received a surgically implanted axial-flow left ventricular assist device. After implantation, transesophageal echocardiography revealed a giant thrombus on the lateral and anterior aspects of the left ventricle. The inflow cannula inserted through the apex of the left ventricle was not obstructed, and the device generated satisfactory blood flow. Laboratory screening for thrombophilia showed protein S deficiency, heterozygous factor V Leiden mutation, and heterozygous MTHFR C667T mutation. During the entire duration of circulatory support, no significant suction events were detected, and the patient was listed for heart transplantation. Ventricular assist device implantation can unmask previously undiagnosed thrombophilia; therefore, it should be necessary to identify thrombophilic patients before cardiac support implantation.

• Klíčová slova
• Anticoagulants/therapeutic use, blood coagulation disorders/complications, factor V Leiden, factor V/genetics, left ventricular assist device, perioperative care, postoperative complications, thrombophilia/genetics, thrombus/etiology/prevention & control,
• MeSH
• barevná dopplerovská echokardiografie MeSH
• dilatační kardiomyopatie komplikace   patofyziologie   MeSH
• echokardiografie transezofageální MeSH
• faktor V genetika   MeSH
• fatální výsledek MeSH
• funkce levé komory srdeční * MeSH
• genetická predispozice k nemoci MeSH
• genetické testování metody   MeSH
• infekce spojené s protézou etiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• methylentetrahydrofolátreduktasa (NADPH2) genetika   MeSH
• mutace MeSH
• mutační analýza DNA MeSH
• nedostatek proteinu S komplikace   diagnóza   genetika   MeSH
• nemoci srdce krev   diagnostické zobrazování   etiologie   genetika   MeSH
• podpůrné srdeční systémy škodlivé účinky   MeSH
• prediktivní hodnota testů MeSH
• protézy - design MeSH
• pulzní dopplerovská echokardiografie MeSH
• srdeční selhání diagnostické zobrazování   etiologie   patofyziologie   terapie   MeSH
• tepový objem MeSH
• trombofilie krev   komplikace   diagnóza   genetika   MeSH
• trombóza krev   diagnostické zobrazování   etiologie   genetika   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• factor V Leiden MeSH Prohlížeč
• faktor V MeSH
• methylentetrahydrofolátreduktasa (NADPH2) MeSH
• MTHFR protein, human MeSH Prohlížeč