Sickle Cell AnemiaDREPANOPECNCT00783627
Sickle Cell Disease and Endothelial Progenitor Cells (EPCs)
An observational study of Sickle Cell Anemia, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
Trial summary
Sickle Cell Disease (SCD) is the most prevalent genetic disease of haemoglobin.The underlying abnormality in the red blood cell (RBC) of SCD is the presence of abnormal sickle cell hemoglobin (HbS), which, when deoxygenated, becomes relatively insoluble, forms aggregates with other hemoglobin molecules within the RBC… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Sickle Cell Anemia
- What is being tested?
- Angiography
- Type of treatment
- Surgery or procedure
- How many people
- 66 participants
- Where
- 1 siteFrance
- Study dates
- Nov 2006to Nov 2009
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Sickle cell patient : followed by the participating center. Healthy volunteers : matched on sex, age and BMI with the patients.
Who may be able to join
- Age between 18 and 45 yo
- SS genotype if patient
- Absence of relative with sickle cell anemia if healthy volunteer.
- Affiliated to the national health insurance benefit
- Signature of Informed consent form
- oral contraceptive regiment with micro or mini estro-progestative (women)
Who cannot join
- present or past (or interrupted for less than 3 months) therapy with hydroxyurea
- Present or recent blood transfusion and/or exchange (in the past 3 months)
- SC genotype (patients)- BMI > 30 kg/m2
- Positive serodiagnosis for HIV, HVB, HVC
- Know allergy to fluorescein (patients)
- Hemoglobin < 7.5 g/dL
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- Pregnancy confirmed by Beta-HCG test in plasma
- Menopause
- Extreme difficulty for adequate venous puncture
- Smoking for the last month.
- ALAT or ASAT > 2 x N
- Hypercholesterolemia (cholesterol total > 2.,2g/L or 6.55 mmol/L),
- Treatment by statin
- Diabetes (fasting blood glucose level equal or superior to 6,1 mmol/L)
- Hypertension (systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg).
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Angiogenic Potential in Sickle Cell Disease. CARACTERIZATION of Endothelial Progenitor Cells
Sickle Cell Disease (SCD) is the most prevalent genetic disease of haemoglobin.The underlying abnormality in the red blood cell (RBC) of SCD is the presence of abnormal sickle cell hemoglobin (HbS), which, when deoxygenated, becomes relatively insoluble, forms aggregates with other hemoglobin molecules within the RBC and causes rigid deformation of the cell. Acute pain vaso-occlusive crisis, strokes and acute chest syndrome are the main acute complications, sometimes life-threatening, often leading to organic and functional squeal. Although the common SS form of SCD is a unique gene disorder, the range of the clinical severity is remarkably wide and striking, suggesting that clinical polymorphism is due to modifier genes and environmental factors.Most of the research efforts have been focused on the biology of haemoglobin and of the red cells. Meanwhile, the complex pathophysiology of SCD is undoubtedly influenced by the many physiologic functions of the vascular wall. In line with this hypothesis are several reports of increased circulating levels of endothelium-derived surface molecules in SCD patients suggesting marked endothelial stress in SCD. Similarly, other processes that involve the endothelium, such as leukocyte adhesion and activation, may play a role in vascular occlusion. This accumulation of data raises the unanswered question of the mechanisms of endothelium maintenance and regeneration in SCD. Through these mechanisms, it is likely that function or dysfunction of the vascular endothelium contributes to the overall vascular pathobiology of this disease, which includes recurrent vaso-occlusions, stroke, leg ulcers, chronic organ ischemic damages, and neovascularizing retinopathy that affect nearly one-half (48%) of the surviving patients by the fifth decade.Thus, our groups have combined their respective clinical and biological expertises to test the hypothesis that SCD is a condition of specific endothelial stress and dysfunction upon chronic and Paracystic abnormal interactions with circulating cells and abnormal oxygen delivery to tissues. Specifically, we hypothesize that chronic endothelial stress with detachment of activated endothelial cells require increases mobilisation of the Endothelial Progenitor Cells (EPCs) that maintain endothelial homeostasis to avoid major thromboembolic events and vasospasm. Inappropriate mobilisation or maturation of the EPCs in SCD may participate to the severity of the disease.
Read the detailed description
In the bone marrow, a reservoir of EPCs does exist, which can be mobilized into circulation when needed, for example during ischemia, a situation which may occur in sickle cells disease. These cells are able to reach distant targets and to participate to the neovascularisation processes necessary for tissue and vascular healing. Conversely, abnormalities of the maturation, mobilization or homing processes would contribute to the thrombotic and ischemic risks associated to ischemia. Furthermore, vascular stress such that encountered in SCD leads to the detachment of endothelial cells from the vessels. The number of detached mature circulating endothelial cells (CEC) seems to be related to vascular hurting. The balance between EPCs and CECs would thus be informative of the vascular condition in patients during the progression of the disease. A relatively high level of EPCs would indicate a prominence of a healing neoangiogenesis or vasculogenesis process, while increasing levels of CECs would be indicative severe progression of the disease. Our studies and those published by others indicate that the number of EPCs in peripheral blood is tightly regulated. Indeed, mediators of inflammation could participate to EPC mobilization and to their recruitment to the diseased areas by local activation of the vascular endothelium. In this context, sickle cells disease provokes transient occlusion episodes, leading to a situation of chronic ischemia in different organs, sometimes with acute episodes. This suggests defect of the maintenance of the vascular integrity in these target organs.Within this project, we will compare the number of EPCs and CECs in 25 SCD patients and 25 normal individuals in search of a correlation with the severity of the disease. SCD patients with potential confounding factors that may alter endothelial physiology (drugs, blood transfusions, hydroxyurea therapy) are excluded. In addition, we will analyse and compare in culture and in vivo the phenotypic and functional characteristics of EPCs obtained from patients and controls. We have a working bilateral hypothesis, since we do not know whether SCD subjects have appropriate angiogenic balance (high EPCs/CEC ratio with functional EPCs) to face the situation of endothelial activation and tissue hypoxia induced by SCD. Therefore, we will quantitatively and qualitatively study several distinct biological steps:1. Evaluate the number of colonies generated by the EPCs in culture and their kinetics of appearance in patients (major end point)2. Enumerate EPCs and CECs by flow cytometry using a specific set of markers (CD133, CD146, KDR).3. Measure of the plasma concentrations of PlGF, VEGF, EPO, ET-1, modulators of angiogenesis.4. Test of correlations between these respective characteristics of EPCs with clinical vascular abnormalities of the disease (retinopathy assessed by angiography, nephropathy, leg ulcers) and severity of vaso-occlusive crisis assessed by number and length of hospitalizations during the previous year and during the study.
- Conditions
- Sickle Cell Anemia
- Being tested
- Angiography
- Keywords
- Endothelium, progenitors, stem cells, sickle cell
- Medical subject headings
- Anemia, Sickle Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AngiographyProcedure or surgery
Angiography done at the J1 visit
| Study group | Role | What they receive |
|---|---|---|
| 1 | Patient with sickle cell disease Receives: Procedure: Angiography | |
| 2 | Healthy volunteers |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measure the relative levels of endothelial progenitors (EPCs) derived from cultured mononuclear cells in patients and carefully matched healthy subjects at day 0 and after 6 months later (number of endothelial cells colony forming units).
Measured: at day 0 and 6 months
Secondary outcomes (2)
Comparison of the number of circulating EPCs and CECs by FACS. The blood mononuclear cell fraction are depleted from all the haematopoietic cells using a depletion magnetic bead column. The lineage minus population is then subjected to a triple labelling
Measured: at day 1 and at 6 months
Correlations tests will be performed between these markers and markers of clinical severity (retinopathy, leg ulcers, number of vaso-occlusive events in the past year, microalbuminuria, leukocyte count, HbF level).
Measured: at day 1 and 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Nov 2008 (estimated)
- Study startNov 2006
- Primary completionJun 2009
- Study completionNov 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell AnemiaStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 66 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Investigators
- Pierre Louis THARAUX, MDPH, Principal investigator, Assistance Publique - Hôpitaux de Paris
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00783627
- Sponsor's protocol ID
- P 050310
- Acronym
- DREPANOPEC
- Status last verified
- Feb 2011
- First submitted
- 15 Oct 2008
- Last updated
- 23 Feb 2011
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Feb 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Angiogenic Potential in Sickle Cell Disease. CARACTERIZATION of Endothelial Progenitor Cells
- ClinicalTrials.gov ID
- NCT00783627
- Acronym / sponsor ID
- DREPANOPEC / P 050310
- Conditions
- Sickle Cell Anemia
- Keywords
- Endothelium, progenitors, stem cells, sickle cell
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 66 participants (actual)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Study start
- Nov 2006
- Primary completion
- Jun 2009 (actual)
- Study completion
- Nov 2009 (actual)
- First posted
- 3 Nov 2008 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Sickle Cell Disease (SCD) is the most prevalent genetic disease of haemoglobin.The underlying abnormality in the red blood cell (RBC) of SCD is the presence of abnormal sickle cell hemoglobin (HbS), which, when deoxygenated, becomes relatively insoluble, forms aggregates with other hemoglobin molecules within the RBC and causes rigid deformation of the cell. Acute pain vaso-occlusive crisis, strokes and acute chest syndrome are the main acute complications, sometimes life-threatening, often leading to organic and functional squeal. Although the common SS form of SCD is a unique gene disorder, the range of the clinical severity is remarkably wide and striking, suggesting that clinical polymorphism is due to modifier genes and environmental factors.Most of the research efforts have been focused on the biology of haemoglobin and of the red cells. Meanwhile, the complex pathophysiology of SCD is undoubtedly influenced by the many physiologic functions of the vascular wall. In line with this hypothesis are several reports of increased circulating levels of endothelium-derived surface molecules in SCD patients suggesting marked endothelial stress in SCD. Similarly, other processes that involve the endothelium, such as leukocyte adhesion and activation, may play a role in vascular occlusion. This accumulation of data raises the unanswered question of the mechanisms of endothelium maintenance and regeneration in SCD. Through these mechanisms, it is likely that function or dysfunction of the vascular endothelium contributes to the overall vascular pathobiology of this disease, which includes recurrent vaso-occlusions, stroke, leg ulcers, chronic organ ischemic damages, and neovascularizing retinopathy that affect nearly one-half (48%) of the surviving patients by the fifth decade.Thus, our groups have combined their respective clinical and biological expertises to test the hypothesis that SCD is a condition of specific endothelial stress and dysfunction upon chronic and Paracystic abnormal interactions with circulating cells and abnormal oxygen delivery to tissues. Specifically, we hypothesize that chronic endothelial stress with detachment of activated endothelial cells require increases mobilisation of the Endothelial Progenitor Cells (EPCs) that maintain endothelial homeostasis to avoid major thromboembolic events and vasospasm. Inappropriate mobilisation or maturation of the EPCs in SCD may participate to the severity of the disease.
Detailed description
In the bone marrow, a reservoir of EPCs does exist, which can be mobilized into circulation when needed, for example during ischemia, a situation which may occur in sickle cells disease. These cells are able to reach distant targets and to participate to the neovascularisation processes necessary for tissue and vascular healing. Conversely, abnormalities of the maturation, mobilization or homing processes would contribute to the thrombotic and ischemic risks associated to ischemia. Furthermore, vascular stress such that encountered in SCD leads to the detachment of endothelial cells from the vessels. The number of detached mature circulating endothelial cells (CEC) seems to be related to vascular hurting. The balance between EPCs and CECs would thus be informative of the vascular condition in patients during the progression of the disease. A relatively high level of EPCs would indicate a prominence of a healing neoangiogenesis or vasculogenesis process, while increasing levels of CECs would be indicative severe progression of the disease. Our studies and those published by others indicate that the number of EPCs in peripheral blood is tightly regulated. Indeed, mediators of inflammation could participate to EPC mobilization and to their recruitment to the diseased areas by local activation of the vascular endothelium. In this context, sickle cells disease provokes transient occlusion episodes, leading to a situation of chronic ischemia in different organs, sometimes with acute episodes. This suggests defect of the maintenance of the vascular integrity in these target organs.Within this project, we will compare the number of EPCs and CECs in 25 SCD patients and 25 normal individuals in search of a correlation with the severity of the disease. SCD patients with potential confounding factors that may alter endothelial physiology (drugs, blood transfusions, hydroxyurea therapy) are excluded. In addition, we will analyse and compare in culture and in vivo the phenotypic and functional characteristics of EPCs obtained from patients and controls. We have a working bilateral hypothesis, since we do not know whether SCD subjects have appropriate angiogenic balance (high EPCs/CEC ratio with functional EPCs) to face the situation of endothelial activation and tissue hypoxia induced by SCD. Therefore, we will quantitatively and qualitatively study several distinct biological steps:1. Evaluate the number of colonies generated by the EPCs in culture and their kinetics of appearance in patients (major end point)2. Enumerate EPCs and CECs by flow cytometry using a specific set of markers (CD133, CD146, KDR).3. Measure of the plasma concentrations of PlGF, VEGF, EPO, ET-1, modulators of angiogenesis.4. Test of correlations between these respective characteristics of EPCs with clinical vascular abnormalities of the disease (retinopathy assessed by angiography, nephropathy, leg ulcers) and severity of vaso-occlusive crisis assessed by number and length of hospitalizations during the previous year and during the study.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | – | Procedure: AngiographyPatient with sickle cell disease |
| 2 | – | –Healthy volunteers |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Sickle cell patient : followed by the participating center. Healthy volunteers : matched on sex, age and BMI with the patients.
Key inclusion criteria (6 listed)
- Age between 18 and 45 yo
- SS genotype if patient
- Absence of relative with sickle cell anemia if healthy volunteer.
- Affiliated to the national health insurance benefit
- Signature of Informed consent form
Key exclusion criteria (15 listed)
- present or past (or interrupted for less than 3 months) therapy with hydroxyurea
- Present or recent blood transfusion and/or exchange (in the past 3 months)
- SC genotype (patients)- BMI > 30 kg/m2
- Positive serodiagnosis for HIV, HVB, HVC
- Know allergy to fluorescein (patients)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AngiographyAngiography done at the J1 visit | Procedure or surgery | 1 |
Primary outcome
Measure the relative levels of endothelial progenitors (EPCs) derived from cultured mononuclear cells in patients and carefully matched healthy subjects at day 0 and after 6 months later (number of endothelial cells colony forming units).
Time frame: at day 0 and 6 months
2 secondary outcomes
Comparison of the number of circulating EPCs and CECs by FACS. The blood mononuclear cell fraction are depleted from all the haematopoietic cells using a depletion magnetic bead column. The lineage minus population is then subjected to a triple labelling
Time frame: at day 1 and at 6 months
Correlations tests will be performed between these markers and markers of clinical severity (retinopathy, leg ulcers, number of vaso-occlusive events in the past year, microalbuminuria, leukocyte count, HbF level).
Time frame: at day 1 and 6 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Feb 2011.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pierre Louis THARAUX, MDPH principal investigator
Assistance Publique - Hôpitaux de Paris
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Sickle Cell Anemia, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Feb 2011. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measure the relative levels of endothelial progenitors (EPCs) derived from cultured mononuclear cells in patients and carefully matched healthy subjects at day 0 and after 6 months later (number of endothelial cells colony forming units). (time frame: at day 0 and 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Feb 2011.