Completed

NCT Number: NCT04805021

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

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.

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Key information

Conditions

Hemophilia A Blood Coagulation Disorders Blood Coagulation Disorders, Inherited Coagulation Protein Disorders Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemorrhagic Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

CHU de Nantes, Nantes, France

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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.

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.

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.

Treatment and study plan

No intervention

Other

no intervention

Primary outcomes

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

Secondary outcomes

To test the link between the severity of the disease at diagnosis and the cellular and cytokine parameters.

Time frame: 2 years

Factor VIII level and inhibitor titration at diagnosis
Comparisons of baseline lymphocyte and cytokine data between patients with a favorable versus unfavorable final diagnosis.

Time frame: 2 years

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.
Comparison of lymphocyte populations and subpopulations, MDSCs and inflammatory cytokines between different groups.

Time frame: 2 years

Cell populations and cytokine profile of the different groups at diagnosis and at the end of follow-up.

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Sponsors and collaborators

Lead sponsor

Nantes University Hospital

Other

Registry information

Acronym: IMMUNHEMAC

Important dates

Study start: 2021
Primary completion: 2024
Study completion: 2025
First posted: Mar 18, 2021
Registry last updated: Sep 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed