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Thrombus Formation Under Different Flow-conditions

This study is enrolling participants by invitation only.
Netherlands Heart Foundation
Information provided by (Responsible Party):
Maastricht University Medical Center Identifier:
First received: April 12, 2010
Last updated: September 12, 2016
Last verified: September 2016

Rationale: Cardiovascular diseases are important causes of morbidity and mortality in the industrialized world. Clinical studies indicate an important role for the proteins of the contact activation system (coagulation factor XII (FXII), FXI, prekallikrein and high molecular weight kininogen (HMWK)) on the risk of cardiovascular disease. There is substantial evidence from mouse studies that FXII and FXI participate in the formation and stability of thrombi and in vitro studies showed that collagen is able to activate FXII and hereby stimulate thrombin formation and potentiate the formation of platelet-fibrin thrombi. The investigators want to determine the role of the proteins of the contact activation system in platelet mediated thrombus formation in human blood.

Objective: The investigators will study the effects of the proteins of the contact activation system on platelet mediated thrombus formation, embolization and degradation on collagen in a perfusion flow model.

Study design: Blood will be collected from human volunteers via a venipuncture in the forearm. Each volunteer will donate maximally four times 30 ml of blood over a period of two days. This blood is used in perfusion flow experiments: blood flows over a coverslip covered with collagen in a flow chamber. The investigators will vary several conditions such as the concentration of the proteins and the shear rate. For perfusion flow experiments, the investigators need fresh whole blood because platelets are viable for four hours. After this time, new blood is needed.

Study population: For this study the investigators need blood from human volunteers with a coagulation defect in one of the proteins of the contact activation system, e.g. FXII, FXI, prekallikrein or HMWK and controls without any coagulation defects.

Main study parameters/endpoints: The investigators main study endpoint is the ex vivo formation of platelet-mediated thrombi on collagen in a perfusion flow model. The investigators hypothesize that thrombi formed from blood of patients deficient in FXII or FXI are less stable than those formed from blood from controls.


Study Type: Observational
Study Design: Time Perspective: Cross-Sectional
Official Title: The Influence of the Proteins of the Contact Activation System on Thrombus Formation Under Different Flow-conditions in Blood

Resource links provided by NLM:

Further study details as provided by Maastricht University Medical Center:

Primary Outcome Measures:
  • Thrombus formation, stability and break down [ Time Frame: Up to 36 months ]
    Using perfusion-flow experiments the formation, stability and break down of clots formed from the blood of the study participants will be determined.

Biospecimen Retention:   Samples Without DNA
  • Whole blood
  • Platelet poor plasma

Estimated Enrollment: 46
Study Start Date: May 2011
Estimated Study Completion Date: April 2017
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Factor XII deficiency
Patients deficient in coagulation factor XII
Factor XI Deficiency
Patients deficient in coagulation factor XI
Prekallikrein deficiency
Patients deficient in prekallikrein
HMWK deficiency
Patients deficient in high molecular weight kininogen (HMWK)
Control group
Healthy controls


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population


Patients with a congenital factor XII-deficiency Patients with a congenital factor XI-deficiency Patients with a congenital prekallikrein-deficiency Patients with a congenital high molecular weight kininogen-deficiency


Healthy individuals without any coagulation defects


Inclusion Criteria:

  • Patient group:
  • Age: ≥ 18 years
  • Deficiency in factor XII, factor XI, prekallikrein or high molecular weight kininogen
  • Control group:
  • Age: ≥ 18 years

Exclusion Criteria:

  • (Other) Coagulation defects
  • Symptoms of active disease
  • The use of antiplatelet drugs
  • The use of aspirin/ascal
  Contacts and Locations
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Please refer to this study by its identifier: NCT01114074

Maastricht University
Maastricht, Limburg, Netherlands, 6229 ER
Sponsors and Collaborators
Maastricht University Medical Center
Netherlands Heart Foundation
Principal Investigator: Hugo Ten Cate, MD, PhD Maastricht University Medical Centre
  More Information

Responsible Party: Maastricht University Medical Center Identifier: NCT01114074     History of Changes
Other Study ID Numbers: 10-3-015
#2008B120 ( Other Grant/Funding Number: Netherlands Heart Fundation )
Study First Received: April 12, 2010
Last Updated: September 12, 2016

Keywords provided by Maastricht University Medical Center:
Blood coagulation
Perfusion flow experiments
Factor XII
Factor XI
High molecular weight kininogen

Additional relevant MeSH terms:
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Vasodilator Agents
Cysteine Proteinase Inhibitors
Protease Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action processed this record on May 25, 2017