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The Proteins of the Contact Activation System (CONTACT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02785718
Recruitment Status : Unknown
Verified May 2016 by Hospices Civils de Lyon.
Recruitment status was:  Recruiting
First Posted : May 30, 2016
Last Update Posted : June 1, 2016
Information provided by (Responsible Party):
Hospices Civils de Lyon

Tracking Information
First Submitted Date  ICMJE May 25, 2016
First Posted Date  ICMJE May 30, 2016
Last Update Posted Date June 1, 2016
Study Start Date  ICMJE June 2015
Estimated Primary Completion Date September 2016   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: May 27, 2016)
fibrinolytic degradation rate of the formed clots by ROTEM analysis [ Time Frame: 1 day (cross sectional) ]
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: May 27, 2016)
  • the ex-vivo formation of platelet-mediated thrombi on collagen in a perfusion flow mode [ Time Frame: 1 day (cross sectional) ]
  • biochemical composition of the thrombi formed in the Chandler loop [ Time Frame: 1 day (cross sectional) ]
  • endogenous thrombin potential (ETP) of the platelet rich plasma of these patients [ Time Frame: 1 day (cross sectional) ]
Original Secondary Outcome Measures  ICMJE Same as current
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE The Proteins of the Contact Activation System
Official Title  ICMJE The Influence of the Proteins of the Contact Activation System on Thrombus Formation in Human Blood
Brief Summary

Cardiovascular diseases are important causes of morbidity and mortality in the industrialized world. Abnormalities in the coagulation system, causing a hypercoagulable state, are a known risk factor for arterial and venous thrombosis. The contact activation system is part of the coagulation system and consists of four proteins: coagulation factor XII (FXII), FXI, prekallikrein and high molecular weight kininogen (HMWK). Clinical studies indicate an important role for the contact activation system on the risk of arterial thrombosis. Furthermore, there is substantial evidence from mouse studies that FXII and FXI participate in the formation and stability of thrombi. In vitro studies show that collagen, present in the vascular wall, is able to activate FXII and hereby stimulate thrombin formation and potentiate the formation of platelet-fibrin thrombi and FXIIa is able to change the structure of fibrin clots by binding to fibrin(ogen) and by generation of additional thrombin. However, the contact system also participates in the process of fibrinolysis, which degrades thrombi.

The investigators would like to investigate the contribution of the contact activation system to the formation of thrombi. The formation of a thrombus within the vascular bed is the main cause for occlusion of an artery or vein, which can lead to an infarct such as a heart attack. Due to the other functions of the contact system it is important to fully understand how the contact system contributes to thrombus formation, before it can be used as a target in the treatment of arterial thrombosis. The aim of this study is to determine the contribution of the proteins of the contact system, mainly FXII and FXI, in the platelet mediated formation and degradation of thrombi. This will be studied in flow models (perfusion-flow model and Chandler loop), in a static model (ROTEM®) and using thrombin generation assay.

Detailed Description Not Provided
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Intervention Model: Single Group Assignment
Masking: None (Open Label)
Condition  ICMJE
  • Factor XI Deficiency
  • Factor XII Deficiency
Intervention  ICMJE Other: Global Haemostasis assays
Study Arms  ICMJE Experimental: Patients with FXI or FXII deficiency
12 patients with FXI deficiency and 6 patients with FXII deficiency
Intervention: Other: Global Haemostasis assays
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Unknown status
Estimated Enrollment  ICMJE
 (submitted: May 27, 2016)
Original Estimated Enrollment  ICMJE Same as current
Estimated Study Completion Date  ICMJE September 2016
Estimated Primary Completion Date September 2016   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Deficiency in coagulation factor XII and factor XI (factor level<5%)
  • Subjects of both gender
  • Age ≥18 and ≤ 65
  • Written informed consent from the subject
  • Subject with a social security plan or beneficiary of such a plan.

Exclusion Criteria:

  • Age below 18
  • Age above 65
  • Other known abnormalities of the coagulation system
  • Thrombocytopenia
  • Known platelet disorders
  • Personal history of severe liver diseases
  • Symptoms of active disease (e.g. cancer)
  • The use of antiplatelet drugs
  • The use of drugs that interfere with coagulation
  • Ongoing diagnosed pregnancy upper 3 months
  • Adult patients protected by law
  • Concomitant participation to a biomedical research
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 65 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE France
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT02785718
Other Study ID Numbers  ICMJE 2012.785
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Hospices Civils de Lyon
Study Sponsor  ICMJE Hospices Civils de Lyon
Collaborators  ICMJE Not Provided
Investigators  ICMJE Not Provided
PRS Account Hospices Civils de Lyon
Verification Date May 2016

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP