Bleeding of Unknown Cause: a Swiss Case-control Study (SWISS-BUC)

April 28, 2026 updated by: Casini Alessandro, University Hospital, Geneva

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
400

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Switzerland
      • Bellinzona, Switzerland
        • Recruiting
        • Ospedale Regionale di Bellinzona
        • Contact:
      • Bern, Switzerland
        • Recruiting
        • INSELSPITAL - Universitätsspital Bern
        • Contact:
      • Geneva, Switzerland
        • Recruiting
        • University Hospital
        • Contact:
          • Alessandro Casini
      • Lausanne, Switzerland
        • Recruiting
        • Centre Hospitalier Universitaire Vaudois
        • Contact:
      • Lugano, Switzerland
      • Sankt Gallen, Switzerland
        • Recruiting
        • Kantonsspital St.Gallen
        • Contact:
      • Zurich, Switzerland
        • Recruiting
        • USZ - Universitätsspital Zürich
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

16 years to 65 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

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

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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
  • 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)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Patients
Patients with bleeding of unknown cause
Diagnostic test: Thrombin generation
Measurement of thrombin generation by ST Genesia
Diagnostic test: Fibrinolysis
Measurement of fibrinolysis by Lysis Timer
Diagnostic test: Fibrin clot structure
Measurement of fibrin polymerisation and permeability
Diagnostic test: Coated platelets
Measurement of coated platelets by flow cytometry
Controls
Healthy voluntaries without bleeding tendency
Diagnostic test: Thrombin generation
Measurement of thrombin generation by ST Genesia
Diagnostic test: Fibrinolysis
Measurement of fibrinolysis by Lysis Timer
Diagnostic test: Fibrin clot structure
Measurement of fibrin polymerisation and permeability
Diagnostic test: Coated platelets
Measurement of coated platelets by flow cytometry

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Fibrin clot polymerisation
Time Frame: At inclusion
maximal absorption (optical density)
At inclusion
Fibrin clot permeability
Time Frame: At inclusion
darcy coefficient (ks, cm2)
At inclusion
Fibrinolysis
Time Frame: At inclusion
Clot lysis time (min)
At inclusion
Thrombin generation
Time Frame: At inclusion
Endogenous thrombin potential (ETP, nM x min)
At inclusion
Coated platelets
Time Frame: At inclusion
Absolute number of coated platelets
At inclusion

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Fibrinogen gamma' levels
Time Frame: At inclusion
Ratio fibrinogen gamma'/total fibrinogen (%)
At inclusion
Scan electron microscopy
Time Frame: At inclusion
Fibrin fiber diameter (nm)
At inclusion
Clot retraction
Time Frame: At inclusion
Ratio clot weight/serum extruded (%)
At inclusion
Plasmin generation
Time Frame: At inclusion
Plasmin (nM)
At inclusion
Fibrin clot formation (thrombodynamics)
Time Frame: At inclusion
Initial rate of clot growth (μM/min)
At inclusion
Major bleeding episodes
Time Frame: Three years
Incidence of major bleeding
Three years
Non-major bleeding episodes
Time Frame: Three years
Incidence of clinically relevant non-major bleeding
Three years
Health related quality of life
Time Frame: three years
SF36 questionnaire, 0 - 100 (high score, better outcome)
three years
International Society Thrombosis Hemostasis Bleeding assessment tool
Time Frame: three years
ISTH BAT score, 0 - 56 (high score, worse outcome)
three years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Geneva

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Alessandro Casini, University Hospitals of Geneva

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 27, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 27, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 6, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CCER 2022-02121

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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