Platelet DysfunctionNCT01957345
Evaluation of a New Approach of the Diagnosis of Constitutional Functional Disorders of Platelets
A study testing Blood punction in people with Platelet Dysfunction, run by University Hospital, Toulouse at 1 site in France.
Trial summary
The primary purpose of the study is to evaluate a standardized method of screening for platelet signalling defects in patients with constitutional disorders of platelet function of unknown origin. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Platelet Dysfunction
- What is being tested?
- Blood punction
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 322 participants
- Where
- 1 siteFrance
- Study dates
- Feb 2013to 29 Jun 2017
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- patient consulting for hemorrhagic symptomatology with a bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand) / or constitutional platelet disorder (e.g. Glanzmann thrombasthenia) / or with a defect of platelet function of unknown origin, potentially defective in signalling pathway.
- Informed consent form
- patient with social security insurance or equivalent
Who cannot join
- treatment interfering with platelets function within 7 days prior to enrollment
- thrombocytopenia <100G/L
- pregnant or lactating females
- subjects under juridical protection guardianship or tutelage measure
- subjects involved in another clinical trial
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Multicentre Evaluation of a New Laboratory Approach for the Diagnosis of Constitutional Functional Disorders of Platelets
The primary purpose of the study is to evaluate a standardized method of screening for platelet signalling defects in patients with constitutional disorders of platelet function of unknown origin. We hypothesize that such defects are under-diagnosed in patients, due to heavy workup and requirement of relatively large blood sample by conventional biochemical methods. We propose to analyse kinase signalling downstream platelet membrane receptors using multiplex flow cytometry quantification and fluorescent platelet barcoding.
Read the detailed description
Little is known of the molecular basis of disorders of signalling pathways potentially responsible of constitutional defects of platelet functions (adhesion, aggregation or secretion) (1-5). Indeed, in routine practice, this investigation is limited by the complexity of the analyse using biochemical methods (western blotting), and the requirement of large amount of platelets.
We have designed a new approach for the quantification of platelet cytoplasmic phosphoproteins by flow cytometry. Fresh platelets in platelet rich plasma are analysed at baseline or after stimulation by major agonists (ADP, TRAP, thromboxane analogue, or collagen-related peptide), with and without relevant inhibitors of each pathway. Multiplex barcoding is used to identify each condition, allowing a high throughput analysis (6, 7). Platelet signalling profiling of Akt, Slp76, P38 MAPK and LIMK can be obtained from a blood sample of less than 10 ml, and within 6h The main objective of the study is to standardize the method between clinical laboratories with a standard expertise in flow cytometry. The study will be performed in 4 academic hospitals members of the French reference network of rare platelet diseases. Three groups of patients referred for mild or severe bleeding disorders will be included: 1) a control group of patients (30 per centre) with a bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand); 2) a group of 10 patients per centre with definite constitutional platelet disorder (e.g. Glanzmann thrombasthenia) and 3) a group of 10 patients per centre with a defect of platelet function of unknown origin, potentially defective in signalling pathway.
The control group will serve to standardize the method between centres and to establish the reference values. A quality control will be set up by using frozen platelet preparations. The patients with definite platelet disorder will be useful for detecting potential signalling defects still not described in these pathologies. Platelet signalling defects which could be evidenced in these groups will be further identified by conventional biochemical and molecular methods after confirmation on a new sample.
If this new approach can be proposed to clinical laboratories working on rare platelet diseases, we expect an advance in our knowledge in the field. In addition the method has a potential in pharmaceutical innovation, for identifying (8) or monitoring new antiplatelet agents (9, 10), or identifying platelet defects induced by new "target therapies" designed for other diseases such as cancer or immune pathologies (10).
- Conditions
- Platelet Dysfunction
- Being tested
- Blood punction
- Keywords
- constitutional functional disorders of platelets, platelet signalling defects
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood punctionOther
T1 and T2: one blood punction with signalisation test (T1 for each arm, T2 at +6 months only if an anomaly at signalisation test is detected)
signalisation test is made by flow cytometry
Stage 1: for arm "bleeding disorder" : flow cytometry analysis to establish reference values observed in subjects without thrombopathy for each marker after agonist stimulation and corresponding search of an effect if a center-center effect is observed on the reference values its origin will be sought and corrected.
Stage 2: for the two others arms: Several markers will be analyzed, corresponding to routes or levels of different signaling. For each of these markers, the test will evaluate quantitatively the phosphorylation activity of the protein tested.
| Study group | Role | What they receive |
|---|---|---|
| bleeding disorder | Other | Blood punction at patients with bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand) Receives: Other: Blood punction |
| constitutional platelet disorder | Other | Blood punction at patients with constitutional platelet disorder (e.g. Glanzmann thrombasthenia) Receives: Other: Blood punction |
| defect of platelet function | Other | Blood punction at patients with defect of platelet function of unknown origin, potentially defective in signalling pathway. Receives: Other: Blood punction |
What is being measured
The primary outcome is the main question the study is designed to answer.
standardise the method between clinical laboratories
This is a pilot study of a new approach of screening platelet signalling pathways disorders by flow cytometry with methodological primary outcomes (12) as follows: 1)to standardise the method between clinical laboratories, 2)to establish reference values of the method and 3)to design a quality control assessment
The primary endpoint will focus on the overall variability of reference values observed in subjects without thrombopathy for each marker after agonist stimulation and corresponding search of an effect if a center-center effect is observed on the reference values its origin will be sought (deviation from the protocol, reagent lot .....) and corrected. The "center effect" will also be analyzed by the quarterly quality control, which will compare the results obtained from the same wafer tests analyzed simultaneously in three sites.
Measured: 3 years
Secondary outcomes (1)
To describe the signalling pathways in platelet disorders
To describe the signalling pathways in platelet disorders with definite diagnosis To screen putative defects in bleeding patients with disorders of platelet function of unknown origin To identify more deeply the defects found in these groups.
Several markers will be analyzed, corresponding to routes or levels of different signaling. For each of these markers, the test will evaluate quantitatively the phosphorylation activity of the protein tested. We can thus determine for each subject and each marker, the response to the test defined by:
- The percentage increase in the signal (relative to the rest) after stimulation with a receptor agonist,
- The percentage increase in the signal (relative to the rest) in the presence of the agonist to the associated receptor antagonist.
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2013 (estimated)
- Study startFeb 2013
- Primary completion29 Jun 2017
- Study completion29 Jun 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Platelet DysfunctionStudies of the same condition, open and under way.
- More trials run by University Hospital, ToulouseThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 322 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Toulouse
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Pierre SIE, MD PhD, Principal investigator, University Hospital, Toulouse
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01957345
- Sponsor's protocol ID
- 12 068 08
- Other IDs
- PHRCI 2012
- Status last verified
- Apr 2019
- First submitted
- 18 Jun 2013
- Last updated
- 10 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
Publications
Garcia C, Dejean S, Savy N, Bordet JC, Series J, Cadot S, Ribes A, Voisin S, Rugeri L, Payrastre B, Sie P. Multicolor flow cytometry in clinical samples for platelet signaling assessment. Res Pract Thromb Haemost. 2023 May 16;7(4):100180. doi: 10.1016/j.rpth.2023.100180. eCollection 2023 May.
PubMed 37538502
Study at a glance
From the registry record, last updated by the sponsor on 10 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Multicentre Evaluation of a New Laboratory Approach for the Diagnosis of Constitutional Functional Disorders of Platelets
- ClinicalTrials.gov ID
- NCT01957345
- Acronym / sponsor ID
- 12 068 08
- Conditions
- Platelet Dysfunction
- Keywords
- constitutional functional disorders of platelets, platelet signalling defects
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 322 participants (actual)
- Lead sponsor
- University Hospital, ToulouseUniversity, hospital or other
- Study start
- Feb 2013
- Primary completion
- 29 Jun 2017 (actual)
- Study completion
- 29 Jun 2017 (actual)
- First posted
- 8 Oct 2013 (estimated)
- 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 primary purpose of the study is to evaluate a standardized method of screening for platelet signalling defects in patients with constitutional disorders of platelet function of unknown origin. We hypothesize that such defects are under-diagnosed in patients, due to heavy workup and requirement of relatively large blood sample by conventional biochemical methods. We propose to analyse kinase signalling downstream platelet membrane receptors using multiplex flow cytometry quantification and fluorescent platelet barcoding.
Detailed description
Little is known of the molecular basis of disorders of signalling pathways potentially responsible of constitutional defects of platelet functions (adhesion, aggregation or secretion) (1-5). Indeed, in routine practice, this investigation is limited by the complexity of the analyse using biochemical methods (western blotting), and the requirement of large amount of platelets.
We have designed a new approach for the quantification of platelet cytoplasmic phosphoproteins by flow cytometry. Fresh platelets in platelet rich plasma are analysed at baseline or after stimulation by major agonists (ADP, TRAP, thromboxane analogue, or collagen-related peptide), with and without relevant inhibitors of each pathway. Multiplex barcoding is used to identify each condition, allowing a high throughput analysis (6, 7). Platelet signalling profiling of Akt, Slp76, P38 MAPK and LIMK can be obtained from a blood sample of less than 10 ml, and within 6h The main objective of the study is to standardize the method between clinical laboratories with a standard expertise in flow cytometry. The study will be performed in 4 academic hospitals members of the French reference network of rare platelet diseases. Three groups of patients referred for mild or severe bleeding disorders will be included: 1) a control group of patients (30 per centre) with a bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand); 2) a group of 10 patients per centre with definite constitutional platelet disorder (e.g. Glanzmann thrombasthenia) and 3) a group of 10 patients per centre with a defect of platelet function of unknown origin, potentially defective in signalling pathway.
The control group will serve to standardize the method between centres and to establish the reference values. A quality control will be set up by using frozen platelet preparations. The patients with definite platelet disorder will be useful for detecting potential signalling defects still not described in these pathologies. Platelet signalling defects which could be evidenced in these groups will be further identified by conventional biochemical and molecular methods after confirmation on a new sample.
If this new approach can be proposed to clinical laboratories working on rare platelet diseases, we expect an advance in our knowledge in the field. In addition the method has a potential in pharmaceutical innovation, for identifying (8) or monitoring new antiplatelet agents (9, 10), or identifying platelet defects induced by new "target therapies" designed for other diseases such as cancer or immune pathologies (10).
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| bleeding disorder | Other | Other: Blood punctionBlood punction at patients with bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand) |
| constitutional platelet disorder | Other | Other: Blood punctionBlood punction at patients with constitutional platelet disorder (e.g. Glanzmann thrombasthenia) |
| defect of platelet function | Other | Other: Blood punctionBlood punction at patients with defect of platelet function of unknown origin, potentially defective in signalling pathway. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- patient consulting for hemorrhagic symptomatology with a bleeding disorder definitely other than of platelet origin (e.g. "low" von Willebrand) / or constitutional platelet disorder (e.g. Glanzmann thrombasthenia) / or with a defect of platelet function of unknown origin, potentially defective in signalling pathway.
- Informed consent form
- patient with social security insurance or equivalent
Key exclusion criteria (5 listed)
- treatment interfering with platelets function within 7 days prior to enrollment
- thrombocytopenia <100G/L
- pregnant or lactating females
- subjects under juridical protection guardianship or tutelage measure
- subjects involved in another clinical trial
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 |
|---|---|---|
| Blood punctionT1 and T2: one blood punction with signalisation test (T1 for each arm, T2 at +6 months only if an anomaly at signalisation test is detected) signalisation test is made by flow cytometry Stage 1: for arm "bleeding disorder" : flow cytometry analysis to establish reference values observed in subjects without thrombopathy for each marker after agonist stimulation and corresponding search of an effect if a center-center effect is observed on the reference values its origin will be sought and corrected. Stage 2: for the two others arms: Several markers will be analyzed, corresponding to routes or levels of different signaling. For each of these markers, the test will evaluate quantitatively the phosphorylation activity of the protein tested. | Other | bleeding disorder, constitutional platelet disorder, defect of platelet function |
Primary outcome
standardise the method between clinical laboratories
Time frame: 3 years
This is a pilot study of a new approach of screening platelet signalling pathways disorders by flow cytometry with methodological primary outcomes (12) as follows: 1)to standardise the method between clinical laboratories, 2)to establish reference values of the method and 3)to design a quality control assessment The primary endpoint will focus on the overall variability of reference values observed in subjects without thrombopathy for each marker after agonist stimulation and corresponding search of an effect if a center-center effect is observed on the reference values its origin will be sought (deviation from the protocol, reagent lot .....) and corrected. The "center effect" will also be analyzed by the quarterly quality control, which will compare the results obtained from the same wafer tests analyzed simultaneously in three sites.
1 secondary outcome
To describe the signalling pathways in platelet disorders
Time frame: 3 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Dec 2025.
- Results publication: PubMed 37538502Garcia C, Dejean S, Savy N, Bordet JC, Series J, Cadot S, Ribes A, Voisin S, Rugeri L, Payrastre B, Sie P. Multicolor flow cytometry in clinical samples for platelet signaling assessment. Res Pract Thromb Haemost. 2023 May 16;7(4):100180. doi: 10.1016/j.rpth.2023.100180. eCollection 2023 May.
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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. This study is not recruiting at the moment.
Pierre SIE, MD PhD principal investigator
University Hospital, Toulouse
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Blood punction in people with Platelet Dysfunction, run by University Hospital, Toulouse at 1 site in France.
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 3 inclusion and 5 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: finished, as of the sponsor's last update on 10 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
standardise the method between clinical laboratories (time frame: 3 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01957345, which also lists 1 linked publication.
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 10 Dec 2025.