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Spontaneous Induced Unexplained HaemorrhagicAGRADNCT04095715

Anomalies of Dense Platelet Granules

An observational study of Spontaneous Induced Unexplained Haemorrhagic, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The study aims to know the overall prevalence of granular deficits and their breakdown by type (anomaly of number, content or secretion) in a population of patients with hemorrhagic symptomatology after exclusion of other known causes. Read more about this study

Who is it for?
Ages 2 years and older
What is being tested?
Haemostasis consultation and Standard management of patients suspected of thrombopathy
How many people
166 participants
Where
1 siteFrance
Study dates
9 Dec 2019to 21 Feb 2023
Phase
Observational
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 2 years and older
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Study population: Patients addressed to the specialized haemostasis consultations of the various services associated with the project for the exploration of haemorrhagic symptomatology referring to a primary haemostasis anomaly.

Who may be able to join

  • Adult or child patient ≥ 2 years
  • Having a hemorrhagic score ISTH > 3 for men, > 5 for women and > 2 for children.
  • With no abnormal coagulation (defined by normal TP and TCK or activity ≥ 50% of FII, FV, FVII, FX, FVIII, FIX, FXI)
  • no deficiency of Willebrand factor (defined by a cofactor activity with Ristoctin (VWF: RCo < 50%))
  • no a known major thrombocytopenia/thrombopathy linked to a deficiency of one of the major platelet receptors
  • Information of the patient and/or his legal representative present

Who cannot join

  • Inability or refusal of compliance with research requirements
  • Thrombocytopenia < 100 G/L
  • Treatments interfering with platelet functions within 10 days prior to inclusion
  • Malignant hemopathy

Trial locations and contacts

1 site in 1 country.

France1 site
  • Hôpital Necker Enfants Malades - AP-HP

    Paris, 75015

Other trials in France

About this study

Official title: Diagnosis of Platelet Dense Granules Anomalies in Unexplained Hemorrhagic Syndromes

The study aims to know the overall prevalence of granular deficits and their breakdown by type (anomaly of number, content or secretion) in a population of patients with hemorrhagic symptomatology after exclusion of other known causes.

This study consists also to evaluate the association between the presence of a deficit in dense granules and (1) the intensity of the hemorrhagic phenotype (hemorrhagic score) (2) the nature of hemorrhages (post-operative, spontaneous, atypical...)

-Evaluate the association between the type of deficit in dense granules and (1) the intensity of the hemorrhagic phenotype (hemorrhagic score) (2) the nature of hemorrhages (post-operative, spontaneous, atypical...)

Read the detailed description

Patients will be recruited during the exploration visit (v0) or the confirmation/typing visit (v1) according to their follow-up.

  • Exploration visit (v0): inclusion of patients without prior platelet exploration, and study of their dense platelet granules.
  • Confirmation/typing visit (v1): verification of the persistence of anomalies detected in patients with an abnormality identified during v0 (no later than 6 months after v0) and in patients for whom a dense granules anomaly has already been identified during their standard management prior to the start of the study. Completion of complementary examinations to complement the typing of the granular anomaly and molecular analysis for family cases
Being tested
Haemostasis consultation, Standard management of patients suspected of thrombopathy
Keywords
Dense platelet granules, Thrombopathy, Hemorrhagic symptomatology

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Haemostasis consultationOther

    Haemostasis consultation

  • Standard management of patients suspected of thrombopathyBiological

    Standard management of patients suspected of thrombopathy

Study groups in NCT04095715
Study groupRoleWhat they receive
Children and adults with unexplained hemorrhagic syndromePatients with spontaneous or induced hemorrhagic manifestations who are present for a consultation to investigate a thrombopathy or during follow-up consultations as part of their usual care.
Receives: Other: Haemostasis consultation; Biological: Standard management of patients suspected of thrombopathy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Platelet response to different agonists

    Us of some low-dose agonists such as ADP, epinephrine or collagen, which are particularly susceptible to granular defects, on platelet-rich plasma (PRP) prepared from the patient's blood sample to be explored

    Measured: Baseline (M0)

  2. Platelet response to different agonists

    Use of some low-dose agonists such as ADP, epinephrine or collagen, which are particularly susceptible to granular defects, on platelet-rich plasma (PRP) prepared from the patient's blood sample to be explored

    Measured: At 6 months

  3. Granular Delta content

    Dosage of platelet serotonin by measuring platelet serotonin by HPLC.

    Measured: Baseline (M0)

  4. Measurement of ATP

    The measurement is based on the principle of bioluminescence with a two-step transformation reaction of luciferin in the presence of luciferase, this reaction requiring the presence of ATP

    Measured: Baseline (M0)

  5. Measurement of ATP

    The measurement is based on the principle of bioluminescence with a two-step transformation reaction of luciferin in the presence of luciferase, this reaction requiring the presence of ATP

    Measured: At 6 months

  6. Measurement of granules opacity

    Delta granules contain calcium, which makes them naturally opaque to electrons and thus allows their direct visualization in electronic microscopy.

    Measured: Baseline (M0)

  7. Measurement of granules opacity

    Delta granules contain calcium, which makes them naturally opaque to electrons and thus allows their direct visualization in electronic microscopy.

    Measured: at 6 months

Secondary outcomes (5)
  1. Hemorrhagic risk assessment

    Evaluation using the ISTH score

    Measured: Baseline (M0)

  2. Typage of delta granules anomalies

    Fib-SEM technic by focussed ion beam scanning which allows a 3D reconstitution of the platelets and thus to visualize any empty granules

    Measured: At 6 months

  3. Genetic anomalies of delta granules

    Sequencing on a broad set of genes involved in platelet function. Bioinformatic analysis is carried out using BWA-MEM software (Alignment on the genome version HG19)

    Measured: At 6 months

  4. Prothrombin consumption

    Evaluated by% of residual Thrombin after plasma coagulation

    Measured: Baseline (M0)

  5. Prothrombin consumption

    Evaluated by% of residual Thrombin after plasma coagulation

    Measured: at 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted19 Sep 2019
  2. Study start9 Dec 2019
  3. Primary completion21 Feb 2023
  4. Study completion21 Feb 2023

Resources

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
Cohort
Time perspective
Prospective
Enrolment
166 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04095715
Sponsor's protocol ID
APHP190393
Acronym
AGRAD
Status last verified
Mar 2026
First submitted
18 Jun 2019
Last updated
23 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Gresele P, Harrison P, Bury L, Falcinelli E, Gachet C, Hayward CP, Kenny D, Mezzano D, Mumford AD, Nugent D, Nurden AT, Orsini S, Cattaneo M. Diagnosis of suspected inherited platelet function disorders: results of a worldwide survey. J Thromb Haemost. 2014 Sep;12(9):1562-9. doi: 10.1111/jth.12650. Epub 2014 Jul 25.

    PubMed 24976115
  • Quiroga T, Goycoolea M, Panes O, Aranda E, Martinez C, Belmont S, Munoz B, Zuniga P, Pereira J, Mezzano D. High prevalence of bleeders of unknown cause among patients with inherited mucocutaneous bleeding. A prospective study of 280 patients and 299 controls. Haematologica. 2007 Mar;92(3):357-65. doi: 10.3324/haematol.10816.

    PubMed 17339185
  • Fiore M, Garcia C, Sié P, et al. δ-storage pool disease: an underestimated cause of unexplained bleeding. Hématologie 2017-8; 243-254.

  • Gresele P; Subcommittee on Platelet Physiology of the International Society on Thrombosis and Hemostasis. Diagnosis of inherited platelet function disorders: guidance from the SSC of the ISTH. J Thromb Haemost. 2015 Feb;13(2):314-22. doi: 10.1111/jth.12792. Epub 2015 Jan 22. No abstract available.

    PubMed 25403439
  • Mumford AD, Frelinger AL 3rd, Gachet C, Gresele P, Noris P, Harrison P, Mezzano D. A review of platelet secretion assays for the diagnosis of inherited platelet secretion disorders. Thromb Haemost. 2015 Jul;114(1):14-25. doi: 10.1160/TH14-11-0999. Epub 2015 Apr 16.

    PubMed 25879272
  • Selle F, James C, Tuffigo M, Pillois X, Viallard JF, Alessi MC, Fiore M. Clinical and Laboratory Findings in Patients with delta-Storage Pool Disease: A Case Series. Semin Thromb Hemost. 2017 Feb;43(1):48-58. doi: 10.1055/s-0036-1584568. Epub 2016 Jun 15.

    PubMed 27304079

Questions about this trial

What is this clinical trial studying?

An observational study of Spontaneous Induced Unexplained Haemorrhagic, run by Assistance Publique - Hôpitaux de Paris 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 6 inclusion and 4 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 23 Mar 2026. 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?

Platelet response to different agonists (time frame: Baseline (M0)). The study lists 7 primary outcomes in all. 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 NCT04095715, which also lists 6 linked publications.

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 23 Mar 2026.

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