Epidemiology and Immunology of Hemophilia A Inhibitors

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00005518
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : May 13, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
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.

Condition or disease
Blood Disease Hemophilia A

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.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type : Observational
Study Start Date : June 1998
Actual Study Completion Date : August 2003

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hemophilia

Information from the National Library of Medicine

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Ages Eligible for Study:   up to 100 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00005518

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: M.V. Ragni University of Pittsburgh Identifier: NCT00005518     History of Changes
Other Study ID Numbers: 5038
R01HL061937 ( U.S. NIH Grant/Contract )
First Posted: May 26, 2000    Key Record Dates
Last Update Posted: May 13, 2016
Last Verified: August 2004

Additional relevant MeSH terms:
Hemophilia A
Hematologic Diseases
Blood Coagulation Disorders, Inherited
Blood Coagulation Disorders
Coagulation Protein Disorders
Hemorrhagic Disorders
Genetic Diseases, Inborn