Search results for "Factor XI"

Antithrombotics and new interventions for venous thromboembolism: Exploring possibilities beyond factor IIa and factor Xa inhibition.

2021

Abstract Direct oral anti–activated factor X and antithrombin agents have largely replaced vitamin K antagonists as the standard of care in treatment of venous thromboembolism. However, gaps in efficacy and safety persist, notably in end‐stage renal disease, implantable heart valves or assist devices, extracorporeal support of the circulation, and antiphospholipid syndrome. Inhibition of coagulation factor XI (FXI) emerges as a promising new therapeutic target. Antisense oligonucleotides offer potential advantages as a prophylactic or therapeutic modality, with one dose‐finding trial in orthopedic surgery already published. In addition, monoclonal antibodies blocking activation and/or activ…

Severe plasma prekallikrein deficiency : clinical characteristics, novel KLKB1 mutations, and estimated prevalence

2020

BACKGROUND Severe plasma prekallikrein (PK) deficiency is an autosomal-recessive defect characterized by isolated activated partial thromboplastin time prolongation. To date, no comprehensive methodologically firm analysis has investigated the diagnostic, clinical, and genetic characteristics of PK deficiency, and its prevalence remains unknown. PATIENTS/METHODS We described new families with PK deficiency, retrieved clinical and laboratory information of cases systematically searched in the (gray) literature, and collected blood of these cases for complementary analyses. The Genome Aggregation Database (gnomAD) and the population-based Gutenberg Health Study served to study the prevalence …

Hereditary angioedema: an update on causes, manifestations and treatment.

2019

Hereditary angioedema is a rare genetic disorder caused by deficiency of C1 esterase inhibitor (C1-INH) and characterized by recurrent episodes of severe swelling that affect the limbs, face, intestinal tract and airway. Since laryngeal oedema can be life-threatening as a result of asphyxiation, correct diagnosis and management of hereditary angioedema is vital. Hereditary angioedema attacks are mediated by bradykinin, the production of which is regulated by C1-INH. Hereditary angioedema therapy relies on treatment of acute attacks, and short- and long-term prophylaxis. Acute treatment options include C1-INH concentrate, icatibant and ecallantide. Self-administration of treatment is recomm…

An Evaluation of Fibrin(ogen) Determinants of Thromboelastography

2011

Abstract Abstract 2251 Thromboelastography (TEG) was used in ∼200 studies published in 2009, is mainly used for global blood coagulation assessment, and is thrombin and fibrinogen concentration-dependent. Reflecting the time course of fibrin polymerization, TEG measures lag time, rate, and maximum amplitude (MA) of clot stiffness, and is substantially enhanced by platelets. To identify more specific fibrin(ogen) determinants potentially relevant to interpretation we investigated MA under different TEG conditions. The procedure utilizes a polymethylmethacrylate (hydrophobic surface) cup and pin set, the cup oscillating through 4° 45' (6 cycles/minute). The pin (sensor) is suspended via a tor…

Mutations in the Factor XII Gene in Solitary Cases of Recurrent Angioedema with Normal C1 Inhibitor Induced or Worsened by Oral Contraceptives or Hor…

2012

Missense Mutations in the Proline-Rich Region of Coagulation Factor XII in Hereditary and Idiopathic Angioedema.

2006

Abstract Hereditary angioedema (HAE) is characterized by recurrent skin swelling, abdominal pain attacks, and potentially life-threatening upper airway obstruction. The two classic HAE types (I and II) are caused by mutations in the complement C1 inhibitor gene, resulting in a functional deficiency of C1 inhibitor. Recently, a novel type of hereditary angioedema has been described, these patients showing normal C1 inhibitor concentration and activity in plasma (HAE with normal C1 inhibitor, HAE type III). With few exceptions, all reported patients have been women, and exposition to estrogens appears to be an important precipitating factor. Screening of twenty unrelated female patients with …

Hereditary angioneurotic oedema and blood-coagulation: interaction between C1-esterase-inhibitor and the activation factors of the proteolytic enzyme…

1983

C-1-inactivator (C-1-INA) does not only exert its important inhibitory functions in the complement system but also in the first step in the activation of the coagulation, fibrinolytic and kallikrein system. We therefore determined in nine patients with hereditary angioneurotic oedema (HANE) with obvious quantitative or functional defects of C-1-INA, and one further patient with Quincke-type oedema of different origin, the coagulation factors of the initial phase such as Hageman factor, plasma thromboplastin antecedent (PTA) and high molecular weight kininogen (HMWK). These factors were further correlated with the concentration as well as functional activity of C-1-INA. Nine of ten patients …

Interaction between C1-INA, coagulation, fibrinolysis and kinin system in hereditary angioneurotic edema (HANE) and urticaria.

1984

The C1-inactivator plays an important role not only in the initial phases of the complement system, but also in those of the coagulation, fibrinolysis and kinin systems. The present study was concerned with the reciprocal influence of decreased C1-inactivator levels in patients with hereditary angioneurotic edema (HANE, HAE). In 13 HANE-I patients there were significantly increased levels of the coagulation factors XII, XI, V, of plasminogen and of alpha 2-antiplasmin, while the factors IX and VII were decreased. Conversely, it emerged that in patients with markedly raised prephase factor levels, angioneurotic edema occurred in the presence of normal or only slightly decreased C1-inactivato…

Predictive Value for Increased Factor XIa and Plasma Kallikrein Activity in Acute Venous Thromboembolism

2021

Abstract Venous thromboembolism (VTE) is associated with increased coagulation activity, which in part can be attributed to the contact pathway of coagulation. Evidence from pre-clinical and epidemiological studies suggests that deficiency in factors of contact activation (e.g. coagulation factors (F) XI and FXII) protects against VTE. However, limited information exists regarding the activation of the contact system in the setting of acute VTE. In the current study, patients with confirmed VTE events (n=321) from the VTEval study and controls (n=300) from the population-based PREVENT-it pilot study were included. Plasma samples were collected from patients after confirmed VTE events or con…

POST-OPERATIVE CHANGES IN FACTOR XIII and FIBRCNETITN

1987

Wound healing processes after surgery are not restricted to certain areas tut affect the vhole body; the ooagulaticn systan in particular is involved. We studied Factor XIII and fibrcnectin in the blood plasma of 16 patients before surgery, after surgery and cn the 1st, 3rd and 7th days after surgery; fibrcnectin was determined using IC-Partigen iimunodiffusicn and Factor XIII by Behringwerke rapid test. In 11 patients normal wound healing was observed (group A), while in 5 patients explications oocured (group B). Factor XIII: normal group (A): fall in concentration oenpared with the precpera-tive value up to the 7th day after surgery; group with explications (B): fall in concentration more…