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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: May 12, 2016
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

Resource links provided by NLM:

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

Study Start Date: June 1998
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.

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


Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria
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Please refer to this study by its identifier: NCT00005518

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: M.V. Ragni University of Pittsburgh
  More Information Identifier: NCT00005518     History of Changes
Other Study ID Numbers: 5038
R01HL061937 ( U.S. NIH Grant/Contract )
Study First Received: May 25, 2000
Last Updated: May 12, 2016

Additional relevant MeSH terms:
Hemophilia A
Hematologic Diseases
Blood Coagulation Disorders, Inherited
Blood Coagulation Disorders
Coagulation Protein Disorders
Hemorrhagic Disorders
Genetic Diseases, Inborn processed this record on August 18, 2017