Study of immune cell populations in patients with acquired hemophilia A

Acquired Hemophilia A and Autoimmunity. Study of Lymphocyte Populations and Myeloid-Derived Suppressor Cells

This study looks at the immune cells in adults with acquired hemophilia A to see how they differ from those in people with regular hemophilia and healthy individuals over 60.

Quick facts

• Study type: Observational
• Enrollment: 40 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Nantes University Hospital (Academic / other)
• Locations: 2 sites (Nantes and 1 other locations)
• Trial ID: NCT04805021 on ClinicalTrials.gov

What this trial studies

This observational study focuses on acquired hemophilia A, a rare bleeding disorder caused by antibodies against factor VIII. It aims to investigate lymphocyte populations and myeloid-derived suppressor cells in patients with this condition, as well as in control subjects. The study includes adult patients diagnosed with acquired hemophilia A, those with constitutional hemophilia A, and healthy controls over the age of 60. By understanding the immune mechanisms involved, the study hopes to shed light on the pathology and potential treatment avenues.

Who should consider this trial

Good fit: Ideal candidates include adults diagnosed with acquired hemophilia A or constitutional hemophilia A, as well as healthy adults over 60 without coagulation abnormalities.

Not a fit: Patients with congenital hemophilia A who have a history of autoimmune disease may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of acquired hemophilia A and lead to improved management strategies for patients.

How similar studies have performed: While there is limited data on similar studies, the investigation of immune cell populations in bleeding disorders is a growing area of interest, suggesting potential for novel insights.

Eligibility criteria

Inclusion Criteria:

1. 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.
2. 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.

   Obtaining signed and written informed consent for biocollection consent.
3. 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.
4. 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.

Exclusion Criteria:

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.

Where this trial is running

Nantes and 1 other locations

• CHU de Nantes — Nantes, France (Recruiting)
• CH de Saint Nazaire — Saint-Nazaire, France (Recruiting)

Study contacts

• Principal investigator: Marc Fouassier — Nantes University Hospital
• Study coordinator: Marc Fouassier

Conditions Hemophilia A