An Epidemiological Study of Subjects With Immune Thrombocytopenic Purpura to Evaluate the Relationship Between Platelet Counts, Endogenous Thrombopoietin Levels, Endogenous Anti-Thrombopoietin Antibodies, and Selected Autoimmune Markers

Sponsor

National Heart, Lung, and Blood Institute (NHLBI) (NIH)

Overall Status

Completed

CT.gov ID

NCT00005570

Collaborator

(none)

200

Enrollment

Location

Duration (Months)

66.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

This study involves the collection of blood samples from patients with immune thrombocytopenic purpura (ITP) to evaluate the relationship between platelet counts, blood levels of a hormone called thrombopoietin that controls platelet production by the bone marrow, and blood levels of antibodies against thrombopoietin that could interfere with the action of this hormone. Blood samples will also be stored if separately agreed to by the patient for analysis of genes that might affect platelet production. At a single outpatient clinic visit, patients will have a medical history taken, and blood samples drawn for testing. Results from this study may help further understand the control of platelet production in patients with ITP, and suggest new therapeutic approaches.

Condition or Disease	Intervention/Treatment	Phase
Purpura, Thrombocytopenic, Idiopathic Immune Thrombocytopenic Purpura

Detailed Description

Study Design

Study Type:

Observational

Official Title:

An Epidemiological Study of Subjects With Immune Thrombocytopenic Purpura to Evaluate the Relationship Between Platelet Counts, Endogenous Thrombopoietin Levels, Endogenous Anti-Thrombopoietin Antibodies, and Selected Autoimmune Markers

Study Start Date :

Apr 1, 2000

Study Completion Date :

Jul 1, 2000

Outcome Measures

Primary Outcome Measures

Eligibility Criteria

Criteria

Ages Eligible for Study:

N/A and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Diagnosis of ITP, based on the history, physical examination, complete blood count, and examination of the peripheral smear, which should exclude other causes of thrombocytopenia. These criteria for ITP are based on the American Society of Hematology practice guideline for ITP.

Subjects 5 years of age or older.

Before the study specific procedure, the subject or legally acceptable representative must give written informed consent(s) for participation in the study.

No subjects with documented history of Human Immunodeficiency Virus (HIV) or Hepatitis.

No subjects with known underlying causes of thrombocytopenia such as lupus erythematosus, autoimmune thyroid disorders, drug-induced thrombocytopenia, bone marrow disorders, and liver disease.

No psychiatric or addictive disorders that compromise the subject's ability to give truly informed consent for participation in the study.