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Epidemiology and Immunology of Hemophilia A Inhibitors

This study has been completed.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI) Identifier:
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: August 2004

To determine the risk factors associated with inhibitor formation in hemophilia A and to study the mechanism of tolerance in the murine hemophilia A model.

Blood Disease
Hemophilia A

Study Type: Observational
Study Design: Observational Model: Natural History

Resource links provided by NLM:

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: June 1998
Estimated Study Completion Date: August 2003
Detailed Description:


The major hypothesis of this study is that suppression of immunoregulatory cytokines will prevent factor VIII inhibitor formation in the hemophilia A murine model: if successful, a treatment protocol could be developed for individuals identified to be at highest risk for inhibitor formation. Through this approach to the epidemiology and immunology of inhibitor formation, the health care of individuals with hemophilia may be improved.

The study is in response to a Request for Applications released in 1998 on the Immunogenetics of Inhibitor Formation in Hemophilia. .


A case-control study is conducted comparing prevalent hemophilia patients with inhibitors identified in the HMS Study with three age-matched controls without inhibitors to determine clinical and laboratory characteristics associated with inhibitor development. A histocompatibility study is conducted identifying patterns of HLA Class II antigens by molecular typing in hemophilic subjects identified in HMS, with and without inhibitors, which may be linked to inhibitor formation. An animal tolerance study is conducted in the hemophilia A murine model, evaluating blockade of T cell costimulatory pathways by CTLA4-Ig and anti-CD40L mAb, to prevent inhibitor formation.


Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No

No eligibility criteria

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00005518

Sponsors and Collaborators
Investigator: M.V. Ragni University of Pittsburgh
  More Information

No publications provided Identifier: NCT00005518     History of Changes
Other Study ID Numbers: 5038
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Hematologic Diseases
Hemophilia A
Blood Coagulation Disorders
Blood Coagulation Disorders, Inherited
Coagulation Protein Disorders
Genetic Diseases, Inborn
Hemorrhagic Disorders processed this record on November 20, 2014