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1.
Zhonghua Yi Xue Za Zhi ; 101(43): 3588-3593, 2021 Nov 23.
Artigo em Chinês | MEDLINE | ID: mdl-34808753

RESUMO

Objective: To identify the influencing factors of thrombosis besides antiphospholipid antibodies in patients with antiphospholipid syndrome (APS). Methods: The 169 patients diagnosed with APS were enrolled according to the current APS classification criteria from January 2003 to August 2017 in Peking University People's Hospital. There were 23 males and 146 females with a mean age of (41±15) years. Antiphospholipid antibodies, including anticardiolipin (aCL), anti-ß2glycoprotein-1 (ß2GP1) antibodies and antibodies to the phosphatidylserine-prothrombin complex (aPS/PT), were determined by enzyme-linked immunosorbent assay (ELISA) methods. Lupus anticoagulant (LA) was identified using the STA Compact coagulation testing system. The differences of clinical and laboratory characteristics between patients with and without thrombosis were analyzed (100 cases and 69 cases, respectively). The influencing factors for thrombosis in patients with APS were determined using binary logistic regression. Results: Compared with patients without thrombosis, patients with thrombosis were older and had a longer disease duration ((45±17) years vs (35±9) years and M(Q1, Q3) 12.0(3.8, 84.0) months vs 48.0(12.0, 108.0) months, both P<0.05). The percentage of male, primary APS, smoking, low blood platelet count, hypertension, and diabetes in patients with thrombosis were significantly higher than those in patients without thrombosis (all P<0.05). Similarly, the rates of antinuclear antibodies positive, aCL positive, aPS/PT-IgM positive, and aPS/PT-IgG positive in patients with thrombosis were significantly higher than those in patients without thrombosis (all P<0.05). The levels of D-dimer in patients with thrombosis were significantly higher than that in patients without thrombosis (P<0.05). There was significant difference in global anti-phospholipid syndrome score (GAPSS) between patients with and without thrombosis (P<0.05). The GAPSS score was also significantly higher in patients with arterial thrombosis than that in patients with venous thrombosis (P<0.05). Smoking and D-dimer levels were independent influencing factors for thrombosis in patients with APS (smoking: OR=11.222, 95%CI:1.119-112.544, P=0.040, D-dimer levels: OR=1.002, 95%CI: 1.000-1.003, P=0.037). Conclusions: Thrombotic APS patients are older and have a longer suffering duration, a higher ratio of male, primary APS, smoking, hypertension, lower blood platelet count, diabetes, higher GAPSS scale, and higher D-dimer levels. Smoking and D-Dimer levels may be independent risk factors for thrombosis in patients with APS.


Assuntos
Síndrome Antifosfolipídica , Trombose , Adulto , Anticorpos Antifosfolipídeos , Feminino , Humanos , Inibidor de Coagulação do Lúpus , Masculino , Pessoa de Meia-Idade , Protrombina
2.
Rinsho Ketsueki ; 62(9): 1412-1414, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34615802

RESUMO

Dysprothrombinemia is the rarest inherited bleeding disorder that is characterized by a decrease in the prothrombin activity, but normal antigen levels. In this study, we report the case of a compound heterozygote of two mutations in prothrombin; Met337Thr and Arg388His, which has previously been identified as "Prothrombin Himi." A systemic blood coagulation evaluation revealed a prolonged prothrombin time (39%) and activated partial thromboplastin (64.4 sec), with an isolated severe decrease in the prothrombin activity (8.6%). Preoperative replacement of prothrombin with prothrombin complex concentrate, PPSB-HT "Nichiyaku," successfully prevented abnormal postoperative bleeding after laparoscopic hysterectomy for cervical cancer. This is the second reported case of Prothrombin Himi.


Assuntos
Protrombina , Fatores de Coagulação Sanguínea , Humanos
3.
Nutrients ; 13(10)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34684491

RESUMO

Vitamin K dependent proteins (VKDP), such as hepatic coagulation factors and vascular matrix Gla protein (MGP), play key roles in maintaining physiological functions. Vitamin K deficiency results in inactive VKDP and is strongly linked to vascular calcification (VC), one of the major risk factors for cardiovascular morbidity and mortality. In this study we investigated how two vitamin K surrogate markers, dephosphorylated-undercarboxylated MGP (dp-ucMGP) and protein induced by vitamin K absence II (PIVKA-II), reflect vitamin K status in patients on hemodialysis or with calcific uremic arteriolopathy (CUA) and patients with atrial fibrillation or aortic valve stenosis. Through inter- and intra-cohort comparisons, we assessed the influence of vitamin K antagonist (VKA) use, vitamin K supplementation and disease etiology on vitamin K status, as well as the correlation between both markers. Overall, VKA therapy was associated with 8.5-fold higher PIVKA-II (0.25 to 2.03 AU/mL) and 3-fold higher dp-ucMGP (843 to 2642 pM) levels. In the absence of VKA use, non-renal patients with established VC have dp-ucMGP levels similar to controls (460 vs. 380 pM), while in HD and CUA patients, levels were strongly elevated (977 pM). Vitamin K supplementation significantly reduced dp-ucMGP levels within 12 months (440 to 221 pM). Overall, PIVKA-II and dp-ucMGP showed only weak correlation (r2 ≤ 0.26) and distinct distribution pattern in renal and non-renal patients. In conclusion, VKA use exacerbated vitamin K deficiency across all etiologies, while vitamin K supplementation resulted in a vascular VKDP status better than that of the general population. Weak correlation of vitamin K biomarkers calls for thoughtful selection lead by the research question. Vitamin K status in non-renal deficient patients was not anomalous and may question the role of vitamin K deficiency in the pathogenesis of VC in these patients.


Assuntos
Biomarcadores/sangue , Proteínas de Ligação ao Cálcio/sangue , Proteínas da Matriz Extracelular/sangue , Precursores de Proteínas/sangue , Calcificação Vascular/sangue , Deficiência de Vitamina K/sangue , Vitamina K/sangue , 4-Hidroxicumarinas/uso terapêutico , Estenose da Valva Aórtica/sangue , Estenose da Valva Aórtica/complicações , Fibrilação Atrial/sangue , Fibrilação Atrial/complicações , Doenças Cardiovasculares/etiologia , Estudos de Coortes , Suplementos Nutricionais , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Indenos/uso terapêutico , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Protrombina , Diálise Renal/efeitos adversos , Uremia/sangue , Uremia/complicações , Calcificação Vascular/complicações , Vitamina K/antagonistas & inibidores , Vitamina K/uso terapêutico , Deficiência de Vitamina K/complicações
4.
Bioessays ; 43(12): e2100158, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34677872

RESUMO

Severe COVID-19 is often accompanied by coagulopathies such as thrombocytopenia and abnormal clotting. Rarely, such complications follow SARS-CoV-2 vaccination. The cause of these coagulopathies is unknown. It is hypothesized that coagulopathies accompanying SARS-CoV-2 infections and vaccinations result from bacterial co-infections that synergize with virus-induced autoimmunity due to antigenic mimicry of blood proteins by both bacterial and viral antigens. Coagulopathies occur mainly in severe COVID-19 characterized by bacterial co-infections with Streptococci, Staphylococci, Klebsiella, Escherichia coli, and Acinetobacter baumannii. These bacteria express unusually large numbers of antigens mimicking human blood antigens, as do both SARS-CoV-2 and adenoviruses. Bacteria mimic cardiolipin, prothrombin, albumin, and platelet factor 4 (PF4). SARS-CoV-2 mimics complement factors, Rh antigens, platelet phosphodiesterases, Factors IX and X, von Willebrand Factor (VWF), and VWF protease ADAMTS13. Adenoviruses mimic prothrombin and platelet factor 4. Bacterial prophylaxis, avoidance of vaccinating bacterially infected individuals, and antigen deletion for vaccines may reduce coagulopathy risk. Also see the video abstract here: https://youtu.be/zWDOsghrPg8.


Assuntos
COVID-19 , Coinfecção , Autoanticorpos , Autoimunidade , Bactérias , Vacinas contra COVID-19 , Cardiolipinas , Proteínas de Transporte , Humanos , Fator Plaquetário 4 , Protrombina , SARS-CoV-2
5.
Artigo em Inglês | MEDLINE | ID: mdl-34501736

RESUMO

Venous thromboembolism (VTE) constitutes a serious and potentially fatal disease, often complicated by pulmonary embolism and is associated with inherited or acquired factors risk. A series of risk factors are known to predispose to venous thrombosis, and these include mutations in the genes that encode anticoagulant proteins as antithrombin, protein C and protein S, and variants in genes that encode instead pro-coagulant factors as factor V (FV Leiden) and factor II (FII G20210A). However, the molecular causes responsible for thrombotic events in some individuals with evident inherited thrombosis remain unknown. An improved knowledge of risk factors, as well as a clear understanding of their role in the pathophysiology of VTE, are crucial to achieve a better identification of patients at higher risk. Moreover, the identification of genes with rare variants but a large effect size may pave the way for studies addressing new antithrombotic agents in order to improve the management of VTE patients. Over the past 20 years, qualitative or quantitative genetic risk factors such as inhibitor proteins of the hemostasis and of the fibrinolytic system, including fibrinogen, thrombomodulin, plasminogen activator inhibitor-1, and elevated concentrations of factors II, FV, VIII, IX, XI, have been associated with thrombotic events, often with conflicting results. The aim of this review is to evaluate available data in literature on these genetic variations to give a contribution to our understanding of the complex molecular mechanisms involved in physiologic and pathophysiologic clot formation and their role in clinical practice.


Assuntos
Embolia Pulmonar , Tromboembolia Venosa , Trombose Venosa , Humanos , Protrombina , Fatores de Risco , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/genética
6.
Int J Artif Organs ; 44(11): 838-845, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34541968

RESUMO

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.


Assuntos
Coração Auxiliar , Trombofilia , Trombose , Adulto , Feminino , Coração Auxiliar/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Protrombina , Trombofilia/diagnóstico , Trombofilia/genética , Trombose/genética
7.
Front Immunol ; 12: 741589, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34567006

RESUMO

Autoantibodies targeting prothrombin (aPT) can be found in antiphospholipid syndrome (APS) patients. However, their detection has proven difficult to standardize. Here, we developed a new ELISA assay to improve the identification of aPT and compared its performance with currently available anti-phosphatidylserine/prothrombin antibodies (aPS/PT) and autoantibodies targeting prothrombin bound to the plastic plate (aPT-A) assays using a cohort of 27 APS patients at high risk of thrombosis. We generated a novel prothrombin variant, ProTS525A-Biot, carrying an artificial tag at the C-terminus suitable for site-specific biotinylation and added the mutation S525A to improve stability. ProTS525A-Biot was immobilized to neutravidin-coated plates at the desired density and with a defined orientation, i.e., pointing the N-terminal fragment-1 toward the solvent. Antibodies against ProTS525A-Biot (aPT-Bio) were found in 24 out of 27 triple-positive APS patients (88%). When compared to aPS/PT and aPT-A, aPT-Bio showed an excellent linear correlation with aPS/PT (R2 = 0.85) but not with aPT-A (R2 = 0.40). Since aPS/PT but not aPT-A are an emerging biomarker of thrombosis in APS, this method may find utility for detecting pathogenic aPT in APS but also other prothrombotic conditions such as COVID-19.


Assuntos
Síndrome Antifosfolipídica/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/sangue , Protrombina/imunologia , Síndrome Antifosfolipídica/imunologia , Biotinilação , Humanos , Imunoglobulina G/imunologia , Mutação , Fosfatidilserinas/imunologia , Protrombina/genética , Risco , Trombose
8.
World J Gastroenterol ; 27(28): 4687-4696, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34366629

RESUMO

BACKGROUND: Diagnostic accuracy of various tumor markers and their combinations for hepatocellular carcinoma (HCC) was not fully investigated. AIM: To evaluate the diagnostic accuracy of alpha-fetoprotein (AFP), the Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) and their combination for HCC diagnosis. METHODS: Patients with newly detected liver mass or elevated serum AFP levels were considered eligible. Serum AFP level, AFP-L3 fraction, and PIVKA-II level were measured at the first visit. RESULTS: In total, 622 patients were included; 355 patients (57.1%) had chronic liver disease, and 208 (33.4%) had liver cirrhosis. HCC was diagnosed in 160 patients (25.7%). The area under the receiver operating characteristics curves (AUROCs) of the serum AFP, AFP-L3 fraction, AFP-L3, and PIVKA-II levels for the diagnosis of HCC were 0.775, 0.792, 0.814, and 0.834, respectively. A novel diagnostic model was developed by classifying patients in a 1:1 ratio into training and validation sets. Using the binary regression analysis of the training cohort, the AFP, AFP-L3 fraction, and PIVKA-II (ALPs) score was calculated as follows: ALPs score = 3.8 × [serum AFP level (ng/mL) × AFP-L3 fraction (%) × 0.01] + 0.2 × PIVKA-II level (mAU/mL). The AUROC of the ALPs score for diagnosis of HCC was 0.878, significantly higher than that of serum AFP level (P < 0.001), AFP-L3 fraction (P < 0.001), PIVKA-II level (P = 0.036), and AFP-L3 level (P = 0.006). The optimal ALPs score cut-off was 5.3 (sensitivity, 85.0%, specificity 80.1%). The validation cohort showed similar results. CONCLUSION: The ALPs score calculated using serum AFP level, AFP-L3 fraction, and PIVKA-II level showed improved accuracy in HCC diagnosis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Biomarcadores , Biomarcadores Tumorais , Carcinoma Hepatocelular/diagnóstico , Humanos , Neoplasias Hepáticas/diagnóstico , Lectinas de Plantas , Precursores de Proteínas , Protrombina , alfa-Fetoproteínas
9.
Nutrients ; 13(8)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34444740

RESUMO

The aim of this study was to evaluate the effects of vitamin K1 on various vitamin K-dependent proteins in critically ill patients with prolonged Owren PT. We included critically ill non-bleeding adult patients without liver failure or anticoagulation treatment, with Owren PT > 1.2, who were prescribed intravenous vitamin K1. Blood was drawn at baseline and at 20-28 h after vitamin K1 administration. At both time points, we measured various vitamin K-dependent proteins and coagulation assays. ClinicalTrials.gov; Identifier: NTC3782025. In total, 52 patients were included. Intravenous vitamin K1 reduced Owren PT, Quick PT, protein induced by vitamin K absence/antagonist-II and desphospho-uncarboxylated matrix Gla protein (dp-ucMGP), but not to normal levels. Concomitantly, there were increases in thrombin generation and the activity of coagulation factors II, VII, IX and X that was only counteracted with a small increase in Protein C activity. In conclusion, the results suggest that vitamin K1 strengthens coagulation as measured by PT decrease and increases in the activity of vitamin K-dependent clotting factors and thrombin generation. The decreased dp-ucMGP, and its potential positive short- and long-term non-coagulative effects, merits further research.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Estado Terminal , Tempo de Protrombina , Vitamina K 1/administração & dosagem , Idoso , Biomarcadores/sangue , Fatores de Coagulação Sanguínea/metabolismo , Proteínas de Ligação ao Cálcio/sangue , Proteínas da Matriz Extracelular/sangue , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Proteína C/metabolismo , Precursores de Proteínas/sangue , Protrombina , Trombina/metabolismo
10.
J Pak Med Assoc ; 71(7): 1780-1784, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34410246

RESUMO

OBJECTIVE: To determine the association of Factor V Leiden / prothrombin gene mutation in Pakistani women with adverse pregnancy outcomes. Method: The prospective study was conducted at the Aga Khan University Hospital, Karachi, from January 1 to December 31, 2016, and comprised females > 40 years having history of two or more foetal losses with no apparent aetiology. Restriction fragment length polymorphism- Polymerase chain reaction was performed using MnlI and HindIII restriction enzymes for factor V Leiden G1691A and prothrombin gene mutation G20210A. Females with two or more consecutive normal pregnancies were enrolled as the control group. Data was analysed using SPSS 19. RESULTS: Of the 172 participants with a mean age of 29.3±5.9 years (range: 19-38 years). 86(50%) each were healthy controls and those with recurrent pregnancy loss. There were 238 livebirths among the controls compared to 13 in the other group. Factor V Leiden G1691A was identified in 2(2.3%) women, and prothrombin gene mutation G20210A in 1(1.2%) woman in the patient group, while no mutation was identified in the control group. CONCLUSIONS: The prevalence of Factor V Leiden / prothrombin gene mutation in women with recurrent pregnancy loss was found to be very low.


Assuntos
Resultado da Gravidez , Protrombina , Adulto , Fator V/genética , Feminino , Humanos , Mutação , Gravidez , Resultado da Gravidez/epidemiologia , Resultado da Gravidez/genética , Estudos Prospectivos , Protrombina/genética , Adulto Jovem
11.
Sci Rep ; 11(1): 16841, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34446727

RESUMO

The pathogenesis of kidney stone formation includes multi-step processes involving complex interactions between mineral components and protein matrix. Calcium-binding proteins in kidney stones have great influences on the stone formation. The spatial distributions of these proteins in kidney stones are essential for evaluating the in vivo effects of proteins on the stone formation, although the actual distribution of these proteins is still unclear. We reveal micro-scale distributions of three different proteins, namely osteopontin (OPN), renal prothrombin fragment 1 (RPTF-1), and calgranulin A (Cal-A), in human kidney stones retaining original mineral phases and textures: calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD). OPN and RPTF-1 were distributed inside of both COM and COD crystals, whereas Cal-A was distributed outside of crystals. OPN and RPTF-1 showed homogeneous distributions in COM crystals with mosaic texture, and periodically distributions parallel to specific crystal faces in COD crystals. The unique distributions of these proteins enable us to interpret the different in vivo effects of each protein on CaOx crystal growth based on their physico-chemical properties and the complex physical environment changes of each protein. This method will further allow us to elucidate in vivo effects of different proteins on kidney stone formation.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Cálculos Renais/diagnóstico por imagem , Rim/patologia , Osteopontina/metabolismo , Fragmentos de Peptídeos/metabolismo , Precursores de Proteínas/metabolismo , Protrombina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Oxalato de Cálcio/química , Oxalato de Cálcio/metabolismo , Cristalização/métodos , Feminino , Humanos , Rim/metabolismo , Masculino , Microscopia Eletrônica de Varredura/métodos , Pessoa de Meia-Idade
12.
Biosci Rep ; 41(8)2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34328172

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection, the cause of coronavirus disease 2019 (COVID-19), is characterized by unprecedented clinical pathologies. One of the most important pathologies, is hypercoagulation and microclots in the lungs of patients. Here we study the effect of isolated SARS-CoV-2 spike protein S1 subunit as potential inflammagen sui generis. Using scanning electron and fluorescence microscopy as well as mass spectrometry, we investigate the potential of this inflammagen to interact with platelets and fibrin(ogen) directly to cause blood hypercoagulation. Using platelet-poor plasma (PPP), we show that spike protein may interfere with blood flow. Mass spectrometry also showed that when spike protein S1 is added to healthy PPP, it results in structural changes to ß and γ fibrin(ogen), complement 3, and prothrombin. These proteins were substantially resistant to trypsinization, in the presence of spike protein S1. Here we suggest that, in part, the presence of spike protein in circulation may contribute to the hypercoagulation in COVID-19 positive patients and may cause substantial impairment of fibrinolysis. Such lytic impairment may result in the persistent large microclots we have noted here and previously in plasma samples of COVID-19 patients. This observation may have important clinical relevance in the treatment of hypercoagulability in COVID-19 patients.


Assuntos
COVID-19/patologia , Fibrina/metabolismo , Fibrinólise/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Trombose/patologia , Adulto , Idoso , Amiloide/metabolismo , Plaquetas/metabolismo , Complemento C3/metabolismo , Feminino , Fibrinogênio/metabolismo , Humanos , Pulmão/patologia , Masculino , Técnicas Analíticas Microfluídicas , Pessoa de Meia-Idade , Protrombina/metabolismo , SARS-CoV-2/metabolismo , Trombose/virologia , Tripsina/metabolismo
13.
J Biol Chem ; 297(2): 100955, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34265300

RESUMO

In the penultimate step of the coagulation cascade, the multidomain vitamin-K-dependent zymogen prothrombin is converted to thrombin by the prothrombinase complex composed of factor Xa, cofactor Va, and phospholipids. Activation of prothrombin requires cleavage at two residues, R271 and R320, along two possible pathways generating either the intermediate prethrombin-2 (following initial cleavage at R271) or meizothrombin (following initial cleavage at R320). The former pathway is preferred in the absence of and the latter in the presence of cofactor Va. Several mechanisms have been proposed to explain this preference, but the role of the sequence and position of the sites of cleavage has not been thoroughly investigated. In this study, we engineered constructs where the sequences 261DEDSDRAIEGRTATSEYQT279 and 310RELLESYIDGRIVEGSDAE328 were swapped between the R271 and R320 sites. We found that in the absence of cofactor Va, the wild-type sequence at the R271 site is cleaved preferentially regardless of its position at the R271 or R320 site, whereas in the presence of cofactor Va, the R320 site is cleaved preferentially regardless of its sequence. Additional single-molecule FRET measurements revealed that the environment of R271 changes significantly upon cleavage at R320 due to the conformational transition from the closed form of prothrombin to the open form of meizothrombin. Detailed kinetics of cleavage at the R271 site were monitored by a newly developed assay based on loss of FRET. These findings show how sequence and position of the cleavage sites at R271 and R320 dictate the preferred pathway of prothrombin activation.


Assuntos
Protrombina , Coagulação Sanguínea , Cinética
14.
BMC Cancer ; 21(1): 775, 2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34218801

RESUMO

BACKGROUND: Few biomarkers can predict the efficiency of PD-1 blockade in patients with hepatocellular carcinoma (HCC). This study aimed to investigate the prognostic role of AFP and PIVKA-II in HCC patients receiving anti-PD-1 immunotherapy. METHODS: A total of 235 HCC patients treated with PD-1 blockade were enrolled. Serum AFP and PIVKA-II levels were collected before and after treatments. The patients were divided into groups based on the reduction in AFP and PIVKA-II: AFP reduction ≤50% vs AFP reduction > 50% and PIVKA-II reduction ≤50% vs PIVKA-II reduction > 50%. The primary endpoints included objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). Binary logistic regression analyses were used to explore the related factors of ORR. A Cox proportional hazards model was employed to identify the potential prognostic factors of PFS and OS. RESULTS: Among all the patients, 34.9% (82/235) achieved a complete or partial response. There was a positive correlation between AFP reduction > 50% or PIVKA-II reduction> 50% and the ORR of PD-1 blockade (P < 0.001 and = 0.003). PFS was significantly improved in patients with AFP reduction > 50% and PIVKA-II reduction > 50% (p < 0.001 and = 0.021). In addition, AFP reduction > 50% and PIVKA-II reduction> 50% were positively correlated with longer OS (p = 0.003 and 0.006). CONCLUSION: Early reductions in AFP and PIVKA-II can be predictors of the efficacy of PD-1 blockade in HCC patients.


Assuntos
Biomarcadores Tumorais/sangue , Biomarcadores/metabolismo , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/métodos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/tratamento farmacológico , Precursores de Proteínas/metabolismo , Protrombina/metabolismo , alfa-Fetoproteínas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
15.
Sci Rep ; 11(1): 15572, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34330995

RESUMO

Factor (F) VIII deficiency causes bleeding in haemophilia A patients because of the reduced formation of procoagulant enzyme thrombin, which is needed to make the blood clot. We measured the dynamics of coagulation in haemophilia A patients by measuring thrombin generation (TG). Additionally, we quantified the procoagulant process of prothrombin conversion and anticoagulant process of thrombin inhibitor complex formation. In haemophilia A, prothrombin conversion is severely reduced, causing TG to be low. Nevertheless, the thrombin inactivation capacity of these patients is comparable to that in healthy subjects, leading to a severe imbalance between procoagulant and anticoagulant processes and a subsequent increased bleeding risk. A novel therapy in haemophilia A is the targeting of anticoagulant pathway, e.g. thrombin inhibitor antithrombin (AT), to restore the haemostatic balance. We simulated the effect of AT reduction on TG in silico. Lowering AT levels restored TG dose-dependently and an AT reduction of 90-95% led to almost normal TG in most patients . However, the variation in response to AT reduction was large between patients, indicating that this approach should be tailored to each individual patients. Ideally, TG and thrombin dynamics simulation could in the future contribute to the management of patients undergoing AT targeting therapy.


Assuntos
Antitrombinas/farmacologia , Hemofilia A/tratamento farmacológico , Adulto , Coagulação Sanguínea/efeitos dos fármacos , Hemofilia A/metabolismo , Hemofilia B/tratamento farmacológico , Hemofilia B/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Protrombina/metabolismo , Trombina/metabolismo
17.
Medicine (Baltimore) ; 100(23): e26221, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34115006

RESUMO

BACKGROUND: Vitamin K has long been regarded as a procoagulant drug by physicians, and concerns have been raised with regard to its effects on hemostasis. Although many studies have shown that vitamin K supplementation is safe for thrombotic events, the effect of vitamin K supplementation on the activities of vitamin K dependent procoagulation factors in healthy individuals is not available. OBJECTIVES: This study aimed to investigate whether vitamin K2 supplementation at recommended doses affects the activity of vitamin K dependent procoagulation factors in healthy individuals without any anticoagulation treatment. DESIGN: Forty healthy volunteers between 25 and 40 years of age were recruited. Menaquinone-7 (MK-7) was administrated at 90 µg for 30 days. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and blood coagulation factors II, VII, IX, and X activities and Protein induced by vitamin K absence or antagonist-II (PIVKA-II) were measured on days 0 and 30 after MK-7 administration. RESULTS: PT, APTT, and TT showed no significant differences on day 30 when compared with baseline. The activities of coagulation factors II, VII, IX, and X on day 30 showed no significant differences with those at baseline. PIVKA-II levels were unchanged after 30 days of MK-7 supplementation. CONCLUSIONS: MK-7 supplementation at recommended dosage does not affect vitamin K-dependent coagulation factors' coagulation activity, and does not enhance the carboxylation of prothrombin in healthy individuals. This indicated that MK-7 administration does not alter hemostatic balance in healthy populations without anticoagulation treatment.


Assuntos
Fatores de Coagulação Sanguínea/efeitos dos fármacos , Suplementos Nutricionais/normas , Vitamina K 2/farmacologia , Adulto , Antifibrinolíticos/farmacologia , Antifibrinolíticos/uso terapêutico , Fatores de Coagulação Sanguínea/análise , Suplementos Nutricionais/estatística & dados numéricos , Fator IX/análise , Fator IX/efeitos dos fármacos , Fator VII/análise , Fator VII/efeitos dos fármacos , Fator X/análise , Fator X/efeitos dos fármacos , Feminino , Voluntários Saudáveis/estatística & dados numéricos , Humanos , Masculino , Tempo de Tromboplastina Parcial/métodos , Tempo de Tromboplastina Parcial/estatística & dados numéricos , Protrombina/análise , Protrombina/efeitos dos fármacos , Tempo de Protrombina/métodos , Tempo de Protrombina/estatística & dados numéricos , Tempo de Trombina/métodos , Tempo de Trombina/estatística & dados numéricos , Vitamina K 2/uso terapêutico
19.
Infez Med ; 29(2): 259-262, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34061792

RESUMO

COVID-19 patients may experience a hypercoagulable condition, leading to thrombotic events. We describe a patient with COVID-19, carrying a rare homozygous mutation of the prothrombin gene, who developed a severe systemic vein thrombosis. In COVID-19 patients with hypercoagulability disorders the most common inherited and acquired risk factors should be investigated.


Assuntos
COVID-19/complicações , Homozigoto , Protrombina/genética , Trombofilia/genética , Trombose Venosa/genética , Adulto , COVID-19/sangue , COVID-19/diagnóstico por imagem , Humanos , Artéria Pulmonar/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X
20.
Acta Anaesthesiol Scand ; 65(9): 1178-1186, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34152599

RESUMO

BACKGROUND: Bleeding is a common problem in children with congenital heart disease undergoing major cardiac surgery requiring cardiopulmonary bypass (CPB). Little is known about optimal management with blood products. OBJECTIVE: To investigate clinical outcome and hemostatic effects of fibrinogen concentrate (FC) in combination with prothrombin complex concentrate (PCC) versus standard treatment with fresh frozen plasma (FFP) in children undergoing cardiac surgery. METHODS: For this single-institution cohort study, data on 525 children were analyzed. Propensity score matching in 210 children was applied to reduce the impact of various baseline characteristics. RESULTS: Three children treated with FC/PCC developed surgical site bleeding requiring surgical revision. One child developed central venous line-related thrombosis. Blood loss through chest tube drainage was independent of FC/PCC. Coagulation abnormalities were not present in any of these children. Time to extubation and ICU stay did not differ. In the FC/PCC group, children received (median, Q1, Q3) 52 mg/kg (32, 83) FC and 28IU/kg (13, 44) PCC. Fibrinogen concentration was comparable at baseline. On admission to the ICU, fibrinogen was higher in children receiving FC/PCC, namely, 232 mg/dL (196, 280), than in children receiving FFP (186 mg/dL, 149, 224; P < .001). On discharge from the ICU, values did not differ ((FC/PCC 416 mg/dL (288, 501)), non-FC/PCC 418 mg/dL (272, 585; P = 1.000)). CONCLUSION: FC/PCC was well tolerated and permitted hemostasis to be maintained, even in the very young. We were not able to detect a signal for inferiority of this treatment. We conclude that FC/PCC can safely replace FFP.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Fibrinogênio , Cardiopatias Congênitas , Hemostáticos , Protrombina , Criança , Estudos de Coortes , Fibrinogênio/análise , Cardiopatias Congênitas/cirurgia , Hemostasia , Hemostáticos/uso terapêutico , Humanos , Pontuação de Propensão , Protrombina/análise
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