Hemophilia AIMMUNHEMACNCT04805021
Acquired Hemophilia A and Autoimmunity. Study of Lymphocyte Populations and Myeloid-Derived Suppressor Cells
An observational study of Hemophilia A, run by Nantes University Hospital at 2 sites in France.
Trial summary
Acquired hemophilia A is a rare condition of hemostasis secondary to the development of antibodies against factor VIII. This is a potentially serious pathology that can be life-threatening due to the major risk of bleeding caused by the sometimes drastic decrease in the level of circulating factor VIII. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hemophilia A
- How many people
- 36 participants
- Where
- 2 sitesFrance
- Study dates
- 30 Nov 2021to 2 Jun 2025
- 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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with acquired hemophilia A will be recruited prospectively when diagnosed with acquired hemophilia A and will be followed in the study until recovery. Patients with constitutional hemophilia A will be recruited prospectively. They should be over 50 years old and have severe or moderate hemophilia A, and not be taking any treatment that could interfere with the immune system or inflammatory markers. Population of control subjects without coagulation abnormalities, over 60 years of age and not taking any treatment likely to interfere with the immune system or inflammatory markers. Patient population with inflammatory pathology will include subjects with an inflammatory pathology likely, according to the literature, to be associated with acquired hemophilia A and, in particular patients with rheumatoid arthritis, if possible at diagnosis and not taking any treatment likely to interfere with the disease. immune system or inflammatory markers.
Who may be able to join
- Patient population with acquired hemophilia A:
- Adult patients with a diagnosis of acquired hemophilia A and with a social security system. Obtaining oral non-opposition from the patient to participate in the study following the submission of an information note relating to the project.
- Obtaining signed and written informed consent for biocollection consent.
- Population of Patients with constitutional hemophilia A:
- Adult patients over 50 years of age with severe or moderate constitutional hemophilia A, with no history of autoimmune disease, and with a social security system.
- Obtaining oral non-opposition from the patient to participate in the study following the submission of an information note relating to the project.
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- Obtaining signed and written informed consent for biocollection consent.
- Population of control subjects:
- Adult patients, over the age of 60, without a coagulation abnormality, with no history of autoimmune disease, and with a social security system.
- Obtaining oral non-opposition from the patient to participate in the study following the submission of an information note relating to the project.
- Obtaining signed and written informed consent for biocollection consent.
- Patient population with inflammatory pathology:
- Adult patients over the age of 50 with an inflammatory pathology likely to be associated with acquired hemophilia A, and with a social security system.
- Obtaining oral non-opposition from the patient to participate in the study following the submission of an information note relating to the project.
- Obtaining signed and written informed consent for biocollection consent.
Who cannot join
- For the 4 groups:
- Minor patient, under guardianship or curatorship.
- Pregnant and lactating women.
- Blood transfusion less than 7 days old.
- Treatment with corticosteroids in the 7 days preceding inclusion or any other immunomodulatory or immunosuppressive treatment in the 4 weeks preceding inclusion.
Trial locations and contacts
2 sites in 1 country.
About this study
Acquired hemophilia A is a rare condition of hemostasis secondary to the development of antibodies against factor VIII. This is a potentially serious pathology that can be life-threatening due to the major risk of bleeding caused by the sometimes drastic decrease in the level of circulating factor VIII.
This pathology occurs overwhelmingly in elderly subjects or, more rarely, in young women, during the postpartum period. It appears idiopathic in 50% of cases and associated, for the other cases, with underlying pathologies such as autoimmune pathologies (rheumatoid arthritis and bullous pemphigoid in particular) and neoplasias, or with a particular circumstance represented by the post -partum.
Read more
The association between this autoimmune pathology and its association with pathologies of the same type or with circumstances involving the immune system, suggests that common mechanisms could favor its emergence.
This study therefore proposes to study lymphocyte populations and subpopulations as well as Myeloid-Derived Suppressor Cells and the cytokine profile, which are abnormal in a large part of autoimmune pathologies.
- Conditions
- Hemophilia A
- Being tested
- no intervention
- Medical subject headings
- Hemophilia A
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
no interventionOther
no intervention
| Study group | Role | What they receive |
|---|---|---|
| Patients in the Acquired Hemophilia A group. | Not described Receives: Other: no intervention | |
| patients in the constitutional hemophilia A group. | Not described Receives: Other: no intervention | |
| patients in the control subjects group. | Not described Receives: Other: no intervention | |
| patients in the group of patients with inflammatory pathology. | Not described Receives: Other: no intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate the evolution of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines in patients with hemophilia A acquired at diagnosis and during follow-up
Comparisons between diagnosis and during follow-up
Measured: 2 years
Secondary outcomes (3)
To test the link between the severity of the disease at diagnosis and the cellular and cytokine parameters.
Factor VIII level and inhibitor titration at diagnosis
Measured: 2 years
Comparisons of baseline lymphocyte and cytokine data between patients with a favorable versus unfavorable final diagnosis.
Cell populations and cytokine profile and half-life of the inhibitor under treatment, time before normalization of the Factor VIII / Willebrand factor ratio, total duration of treatment with corticosteroids, recurrence and mortality tested to define a favorable course of the disease or unfavorable.
Measured: 2 years
Comparison of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines between different groups.
Cell populations and cytokine profile of the different groups at diagnosis and at the end of follow-up.
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2021
- Study start30 Nov 2021
- Primary completion25 Mar 2024
- Study completion2 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hemophilia AStudies of the same condition, open and under way.
- More trials run by Nantes University HospitalThe 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Nantes University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marc Fouassier, Principal investigator, Nantes University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04805021
- Sponsor's protocol ID
- RC20_0253
- Acronym
- IMMUNHEMAC
- Status last verified
- Sep 2026
- First submitted
- 16 Mar 2021
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Acquired Hemophilia A and Autoimmunity. Study of Lymphocyte Populations and Myeloid-Derived Suppressor Cells
- ClinicalTrials.gov ID
- NCT04805021
- Acronym / sponsor ID
- IMMUNHEMAC / RC20_0253
- Conditions
- Hemophilia A
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Nantes University HospitalUniversity, hospital or other
- Study start
- 30 Nov 2021 (actual)
- Primary completion
- 25 Mar 2024 (actual)
- Study completion
- 2 Jun 2025 (actual)
- First posted
- 18 Mar 2021 (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.
Acquired hemophilia A is a rare condition of hemostasis secondary to the development of antibodies against factor VIII. This is a potentially serious pathology that can be life-threatening due to the major risk of bleeding caused by the sometimes drastic decrease in the level of circulating factor VIII.
This pathology occurs overwhelmingly in elderly subjects or, more rarely, in young women, during the postpartum period. It appears idiopathic in 50% of cases and associated, for the other cases, with underlying pathologies such as autoimmune pathologies (rheumatoid arthritis and bullous pemphigoid in particular) and neoplasias, or with a particular circumstance represented by the post -partum.
The association between this autoimmune pathology and its association with pathologies of the same type or with circumstances involving the immune system, suggests that common mechanisms could favor its emergence.
This study therefore proposes to study lymphocyte populations and subpopulations as well as Myeloid-Derived Suppressor Cells and the cytokine profile, which are abnormal in a large part of autoimmune pathologies.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Patients in the Acquired Hemophilia A group. | – | Other: no intervention |
| patients in the constitutional hemophilia A group. | – | Other: no intervention |
| patients in the control subjects group. | – | Other: no intervention |
| patients in the group of patients with inflammatory pathology. | – | Other: no intervention |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with acquired hemophilia A will be recruited prospectively when diagnosed with acquired hemophilia A and will be followed in the study until recovery. Patients with constitutional hemophilia A will be recruited prospectively. They should be over 50 years old and have severe or moderate hemophilia A, and not be taking any treatment that could interfere with the immune system or inflammatory markers. Population of control subjects without coagulation abnormalities, over 60 years of age and not taking any treatment likely to interfere with the immune system or inflammatory markers. Patient population with inflammatory pathology will include subjects with an inflammatory pathology likely, according to the literature, to be associated with acquired hemophilia A and, in particular patients with rheumatoid arthritis, if possible at diagnosis and not taking any treatment likely to interfere with the disease. immune system or inflammatory markers.
Key inclusion criteria (15 listed)
- Patient population with acquired hemophilia A:
- Adult patients with a diagnosis of acquired hemophilia A and with a social security system. Obtaining oral non-opposition from the patient to participate in the study following the submission of an information note relating to the project.
- Obtaining signed and written informed consent for biocollection consent.
- Population of Patients with constitutional hemophilia A:
- Adult patients over 50 years of age with severe or moderate constitutional hemophilia A, with no history of autoimmune disease, and with a social security system.
Key exclusion criteria (5 listed)
- Minor patient, under guardianship or curatorship.
- Pregnant and lactating women.
- Blood transfusion less than 7 days old.
- Treatment with corticosteroids in the 7 days preceding inclusion or any other immunomodulatory or immunosuppressive treatment in the 4 weeks preceding inclusion.
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 |
|---|---|---|
| no interventionno intervention | Other | Patients in the Acquired Hemophilia A group., patients in the constitutional hemophilia A group., patients in the control subjects group., patients in the group of patients with inflammatory pathology. |
Primary outcome
Evaluate the evolution of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines in patients with hemophilia A acquired at diagnosis and during follow-up
Time frame: 2 years
Comparisons between diagnosis and during follow-up
3 secondary outcomes
To test the link between the severity of the disease at diagnosis and the cellular and cytokine parameters.
Time frame: 2 years
Comparisons of baseline lymphocyte and cytokine data between patients with a favorable versus unfavorable final diagnosis.
Time frame: 2 years
Comparison of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines between different groups.
Time frame: 2 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 24 Sep 2026.
- Individual participant dataSharing planned: Undecided
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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.
Marc Fouassier principal investigator
Nantes University Hospital
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hemophilia A, run by Nantes University Hospital at 2 sites 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 15 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 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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?
Evaluate the evolution of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines in patients with hemophilia A acquired at diagnosis and during follow-up (time frame: 2 years). 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 24 Sep 2026.