Bleeding DisorderSWISS-BUCNCT05713734
Bleeding of Unknown Cause: a Swiss Case-control Study
An observational study of Bleeding Disorder, run by University Hospital, Geneva at 7 sites in Switzerland.
Trial summary
The goal of this prospective cohort is to identified specific biological patterns in patients with a bleeding of unknown cause and to study the specific mechanisms of the bleeding disorder for each subset of patients. Read more about this study
- Who is it for?
- Ages 16 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Bleeding Disorder
- What is being tested?
- Thrombin generation, Fibrinolysis and Fibrin clot structure
- How many people
- 400 participants
- Where
- 7 sitesSwitzerland
- Study dates
- 1 Apr 2023to 1 Apr 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 65 years
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: Women and men aged 16-65 years who have been diagnosed as patients with bleeding of unknown cause Women and men aged 16-65 years without bleeding tendency
Who may be able to join
- Man with ISTH BAT>3. If the calculated score includes a surgical bleeding, then two other items of the score should be >0
- Woman with ISTH BAT >5 points. If the calculated score includes a surgical or a postpartum bleeding, then two other items of the score should be >0
Who cannot join
- Ongoing pregnancy
- Intake of antithrombotic treatment or non-steroidal anti-inflammatory drugs for least 10 days at time of blood collection
- Intake of antifibrinolytic or blood product administration (factor concentrate, frozen fresh plasma, prothrombin complex concentrate) for least 14 days before blood collection
- Active cancer (defined as cancer diagnosis within the last five years or treatment within the two last years before study inclusion)
- Active autoimmune disease
- Active chronic inflammatory disease
Show all 12Show fewer
- Severe liver disease (cirrhosis > Child A)
- Renal insufficiency stage 3
- Active or recent infection (within the last 30 days)
- Recent hospitalization (<3 months)
- Recent surgery (<3 months)
- Recent trauma requiring medical intervention (<3 months)
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
Switzerland7 sites, 7 recruiting
- Recruiting
Ospedale Regionale di Bellinzona
Bellinzona
Eugenia Biguzzi, +4191811886, eugenia.biguzzi@eoc.ch
- Recruiting
Inselspital - Universitätsspital Bern
Bern
Ioannis Chanias, +41316640852, ioannis.chanias@insel.ch
- Recruiting
University Hospital
Geneva
Alessandro Casini
- Recruiting
Centre Hospitalier Universitaire Vaudois
Lausanne
Lorenzo Alberio, +413143432, lorenzo.alberio@chuv.ch
- Recruiting
Gruppo Ospedaliero Moncucco
Lugano
Ida Martinelli, +41919608666, Ida.Martinelli@moncucco.ch
- Recruiting
Kantonsspital St.Gallen
Sankt Gallen
Lukas Graf, 0041714941111, lukas.graf@zlmsg.ch
- Recruiting
USZ - Universitätsspital Zürich
Zurich
Jan-Dirk Studt, +41442553488, jan-dirk.studt@usz.ch
About this study
Official title: Bleeding of Unknown Cause, Insight Into a Multifactorial Bleeding Disorder: a Swiss Case-control Study
The goal of this prospective cohort is to identified specific biological patterns in patients with a bleeding of unknown cause and to study the specific mechanisms of the bleeding disorder for each subset of patients.
Read the detailed description
Patients with bleeding of unknown cause are included. At baseline, blood will be drawn to evaluate the hemostatic profile. Findings are compared to a control group of healthy individuals. Patients and controls are followed for 3 years.
- Conditions
- Bleeding Disorder
- Being tested
- Thrombin generation, Fibrinolysis, Fibrin clot structure, Coated platelets
- Keywords
- Bleeding, Hemostatics, Fibrin, Fibrinolysis, Thrombin
- Medical subject headings
- Hemostatic Disorders, Hemorrhage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Thrombin generationDiagnostic test
Measurement of thrombin generation by ST Genesia
FibrinolysisDiagnostic test
Measurement of fibrinolysis by Lysis Timer
Fibrin clot structureDiagnostic test
Measurement of fibrin polymerisation and permeability
Coated plateletsDiagnostic test
Measurement of coated platelets by flow cytometry
| Study group | Role | What they receive |
|---|---|---|
| Patients | Patients with bleeding of unknown cause Receives: Diagnostic Test: Thrombin generation; Diagnostic Test: Fibrinolysis; Diagnostic Test: Fibrin clot structure; Diagnostic Test: Coated platelets | |
| Controls | Healthy voluntaries without bleeding tendency Receives: Diagnostic Test: Thrombin generation; Diagnostic Test: Fibrinolysis; Diagnostic Test: Fibrin clot structure; Diagnostic Test: Coated platelets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fibrin clot polymerisation
maximal absorption (optical density)
Measured: At inclusion
Fibrin clot permeability
darcy coefficient (ks, cm2)
Measured: At inclusion
Fibrinolysis
Clot lysis time (min)
Measured: At inclusion
Thrombin generation
Endogenous thrombin potential (ETP, nM x min)
Measured: At inclusion
Coated platelets
Absolute number of coated platelets
Measured: At inclusion
Secondary outcomes (9)
Fibrinogen gamma' levels
Ratio fibrinogen gamma'/total fibrinogen (%)
Measured: At inclusion
Scan electron microscopy
Fibrin fiber diameter (nm)
Measured: At inclusion
Clot retraction
Ratio clot weight/serum extruded (%)
Measured: At inclusion
Plasmin generation
Plasmin (nM)
Measured: At inclusion
Fibrin clot formation (thrombodynamics)
Initial rate of clot growth (μM/min)
Measured: At inclusion
Major bleeding episodes
Incidence of major bleeding
Measured: Three years
Non-major bleeding episodes
Incidence of clinically relevant non-major bleeding
Measured: Three years
Health related quality of life
SF36 questionnaire, 0 - 100 (high score, better outcome)
Measured: three years
International Society Thrombosis Hemostasis Bleeding assessment tool
ISTH BAT score, 0 - 56 (high score, worse outcome)
Measured: three years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2023
- Study start1 Apr 2023
- Primary completion1 Jun 2026 (estimated)
- Study completion1 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bleeding DisorderStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Geneva
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Casini Alessandro, University Hospital, Geneva
- Investigators
- Alessandro Casini, Principal investigator, University Hospitals of Geneva
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05713734
- Sponsor's protocol ID
- CCER 2022-02121
- Acronym
- SWISS-BUC
- Status last verified
- Apr 2026
- First submitted
- 27 Jan 2023
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Bleeding of Unknown Cause, Insight Into a Multifactorial Bleeding Disorder: a Swiss Case-control Study
- ClinicalTrials.gov ID
- NCT05713734
- Acronym / sponsor ID
- SWISS-BUC / CCER 2022-02121
- Conditions
- Bleeding Disorder
- Keywords
- Bleeding, Hemostatics, Fibrin, Fibrinolysis, Thrombin
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- University Hospital, GenevaUniversity, hospital or other
- Study start
- 1 Apr 2023 (actual)
- Primary completion
- 1 Jun 2026 (estimated)
- Study completion
- 1 Apr 2027 (estimated)
- First posted
- 6 Feb 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this prospective cohort is to identified specific biological patterns in patients with a bleeding of unknown cause and to study the specific mechanisms of the bleeding disorder for each subset of patients.
Detailed description
Patients with bleeding of unknown cause are included. At baseline, blood will be drawn to evaluate the hemostatic profile. Findings are compared to a control group of healthy individuals. Patients and controls are followed for 3 years.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Patients | – | Diagnostic Test: Thrombin generation, Diagnostic Test: Fibrinolysis, Diagnostic Test: Fibrin clot structure, Diagnostic Test: Coated plateletsPatients with bleeding of unknown cause |
| Controls | – | Diagnostic Test: Thrombin generation, Diagnostic Test: Fibrinolysis, Diagnostic Test: Fibrin clot structure, Diagnostic Test: Coated plateletsHealthy voluntaries without bleeding tendency |
Who may qualify
- Ages
- 16 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Women and men aged 16-65 years who have been diagnosed as patients with bleeding of unknown cause Women and men aged 16-65 years without bleeding tendency
Key inclusion criteria (2 listed)
- Man with ISTH BAT>3. If the calculated score includes a surgical bleeding, then two other items of the score should be >0
- Woman with ISTH BAT >5 points. If the calculated score includes a surgical or a postpartum bleeding, then two other items of the score should be >0
Key exclusion criteria (12 listed)
- Ongoing pregnancy
- Intake of antithrombotic treatment or non-steroidal anti-inflammatory drugs for least 10 days at time of blood collection
- Intake of antifibrinolytic or blood product administration (factor concentrate, frozen fresh plasma, prothrombin complex concentrate) for least 14 days before blood collection
- Active cancer (defined as cancer diagnosis within the last five years or treatment within the two last years before study inclusion)
- Active autoimmune disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Thrombin generationMeasurement of thrombin generation by ST Genesia | Diagnostic test | Controls, Patients |
| FibrinolysisMeasurement of fibrinolysis by Lysis Timer | Diagnostic test | Controls, Patients |
| Fibrin clot structureMeasurement of fibrin polymerisation and permeability | Diagnostic test | Controls, Patients |
| Coated plateletsMeasurement of coated platelets by flow cytometry | Diagnostic test | Controls, Patients |
Primary outcome
Fibrin clot polymerisation
Time frame: At inclusion
maximal absorption (optical density)
Fibrin clot permeability
Time frame: At inclusion
darcy coefficient (ks, cm2)
Fibrinolysis
Time frame: At inclusion
Clot lysis time (min)
Thrombin generation
Time frame: At inclusion
Endogenous thrombin potential (ETP, nM x min)
Coated platelets
Time frame: At inclusion
Absolute number of coated platelets
9 secondary outcomes
Fibrinogen gamma' levels
Time frame: At inclusion
Scan electron microscopy
Time frame: At inclusion
Clot retraction
Time frame: At inclusion
Plasmin generation
Time frame: At inclusion
Fibrin clot formation (thrombodynamics)
Time frame: At inclusion
Major bleeding episodes
Time frame: Three years
Non-major bleeding episodes
Time frame: Three years
Health related quality of life
Time frame: three years
International Society Thrombosis Hemostasis Bleeding assessment tool
Time frame: three years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Alessandro Casini principal investigator
University Hospitals of Geneva
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Bleeding Disorder, run by University Hospital, Geneva at 7 sites in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Alessandro Casini (0041223729757, alessandro.casini@hcuge.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fibrin clot polymerisation (time frame: At inclusion). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2026.