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Study of Megakaryocytes From Patients With Abnormal Platelet Vesicles
NCT00086476 · View on ClinicalTrials.gov ↗
Study Summary
Congenital bleeding disorders characterized by abnormal platelet granules include Gray Platelet syndrome (GPS; defective alpha-granules), Hermansky-Pudlak syndrome (HPS; defective delta-granules), and combined alpha delta-storage pool deficiency (alpha delta-SPD). Other diseases associated with variable defects in platelet gamma-granules include Chediak-Higashi, Griscelli, Wiskott-Aldrich, and Thrombocytopenia Absent Radius syndromes. These disorders are models for the study of organelle formation in megakaryocytes and platelets. Characteristics of megakaryocytopoiesis in these disorders have not been investigated because megakaryocytes could not be cultured from patients in sufficient quantities for experimental purposes. Recent advances have made it possible to culture megakaryocytes using serum-free media supplemented with recombinant human thrombopoietin (TPO). Such cultured human megakaryocytes, amplified from bone marrow-derived CD34+ stem cells, synthesize and store organellar proteins and produce functional platelets. In this protocol, we plan to obtain bone marrow aspirates from 40 children and adults (ages 2 to 80 years) with GPS, HPS, and related disorders. Patients admitted to the NIH Clinical Center on specific disease-related protocols will be enrolled in this protocol during their routine 3-5 day visits. We will culture megakaryocytes from CD34+ stem cells isolated from bone marrow aspirates. Studies of cultured megakaryocytes will include evaluation of granule membrane and soluble proteins using fluorescent antibodies and immunoelectron microscopy and comparison of RNA and protein expression patterns between normal and patient cells. Precautions will be taken to prevent the primary risk of the bone marrow aspiration, i.e., prolonged bleeding at the aspiration site. Standard diagnostic studies on the bone marrow sample may reveal information that may directly benefit patients. However, the broader benefit of this study is the acquisition of a better u
Conditions Studied
Study Locations (1)
Maryland
- National Institutes of Health Clinical Center, 9000 Rockville Pike — Bethesda
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 3 participants |
| Start Date | 2004-06-29 |
| Est. Completion | 2011-06-13 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT00086476
The ClinicalTrials.gov registry entry for NCT00086476 describes a study currently listed as completed. It is categorized as an unspecified phase, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 3 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is National Human Genome Research Institute (NHGRI), which has 242 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 1 condition, with Blood Coagulation Disorders appearing as the primary indexed condition, and to 0 interventions. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT00086476 reports 1 study location spanning 1 distinct geographic area — top geographies include Maryland. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT00086476 about?
NCT00086476 is a clinical study titled "Study of Megakaryocytes From Patients With Abnormal Platelet Vesicles". Congenital bleeding disorders characterized by abnormal platelet granules include Gray Platelet syndrome (GPS; defective alpha-granules), Hermansky-Pudlak syndrome (HPS; defective delta-granules), and combined alpha delta-storage pool deficiency (alpha delta-SPD). Other diseases associated with vari...
What is the current status of trial NCT00086476?
This trial is currently completed. The enrollment target is 3 participants. The study started on 2004-06-29. Estimated completion is 2011-06-13.
What conditions does trial NCT00086476 study?
This clinical trial studies the following conditions: Blood Coagulation Disorders. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
Who is sponsoring clinical trial NCT00086476?
This trial is sponsored by National Human Genome Research Institute (NHGRI), which has 242 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT00086476 being conducted?
This trial has 1 study location across Maryland. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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