Active clinical trials for "Anemia, Sickle Cell"

To conduct a randomized controlled internal pilot feasibility trial for the prevention of recurrent ischemic priapism referred to as the Priapism in Nigeria (PIN) trial. The study team will enroll a minimum of 30 participants and a maximum of 200 participants. Study investigators hypothesize that hydroxyurea therapy combined with tadalafil is superior to a combination of hydroxyurea and placebo in the prevention of recurrent ischemic priapism.

The purpose of the present observational study is to remotely reevaluate the cohort of 67 sickle cell patients with transcranial Doppler-detected cerebral vasculopathy included in the national "Sickle Cell Transplant" protocol and whose 1- and 3-year results were published in JAMA (Journal of the American Medical Association) in 2019 and in BHJ in 2020.

The purpose of this research study is to better understand how blood flow and metabolism change can influence brain development in the early decades of life. SCA participants and healthy controls are age and sex-matched for comparison. Within the SCA cohort, children with infarcts may have thinner cortices than those without, reflecting a greater loss. The investigators will examine brain blood flow and metabolism using magnetic resonance imaging (MRI). The brain's blood vessels expand and constrict to regulate blood flow based on the brain's needs. The amount of expanding and contracting the blood vessels may vary by age. The brain's blood flow changes in small ways during everyday activities, such exercise, deep concentration, or normal brain growth. Significant illness or psychological stress may increase the brain's metabolic demand or cause other bigger changes in blood flow. If blood vessels are not able to expand to give more blood flow when metabolic demand is high, the brain may not get all of the oxygen it needs. In extreme circumstances, if the brain is unable to get enough oxygen for a long time, a stroke may occur. Sometimes small strokes occur without other noticeable changes and are only detectable on an MRI. These are sometimes called "silent strokes." In less extreme circumstances, not having a full oxygen supply may cause the brain to grow and develop more slowly than when it has a full supply. One way to test the ability of blood vessels to expand is by measuring blood flow while breathing in carbon dioxide. Carbon dioxide causes blood vessels in the brain to dilate without increasing brain metabolism. During this study participants may be asked to undergo a blood draw, MRI, cognitive assessments, and brief questionnaires. The study team will use a special mask to control the amount of carbon dioxide the participants breathe in.

Rationale: Non-myeloablative allogeneic stem cell transplantation (SCT) has become a feasible curative treatment option for sickle cell disease (SCD) patients with an available matched sibling donor. Chemotherapy free conditioning with alemtuzumab and 3 Gy total body irradiation (TBI) is increasingly being used as preferred conditioning scheme for these patients. This regimen typically results in mixed donor chimerism and has only few toxic effects. However, the risk of graft failure (rejection) is still significant, with an occurrence of 13% in the latest series. Levels of T cell chimerism are crucial for the success of this kind of transplantation. A donor T cell level of at least 50% at 1-year post-transplantation seems to be sufficient to allow the discontinuation of immunosuppressive medication without risk of graft rejection. Low levels of alemtuzumab prior to or shortly after SCT are thought to facilitate rejection of the donor graft. Recently, a positive correlation between alemtuzumab levels on day+14 was found with levels of T cell chimerism +2 and +4 months post-transplantation in adult SCD patients receiving matched sibling donor SCT. However, in this study alemtuzumab levels prior to the infusion of hematopoietic stem cells and beyond day +28 post-transplantation were not measured. Furthermore, the alemtuzumab levels were measured in 2 patient groups undergoing two different conditioning regimens. Here, the investigators aim to thoroughly investigate the correlation of alemtuzumab levels and T cell chimerism. This will be the first study involving SCD patients receiving matched sibling donor SCT with alemtuzumab/TBI conditioning that includes alemtuzumab level measurements before the infusion of hematopoietic stem cells and beyond 1-month post-transplantation. Findings from this study will improve the insights into the etiology of graft failure in these patients and might ultimately lead to a more personalized approach in dosing alemtuzumab in order to achieve a more robust and stable engraftment of donor hematopoietic stem cells. Objectives: To investigate whether serum alemtuzumab concentrations are predictive of the robustness of engraftment in SCD patients undergoing a matched sibling donor transplantation with alemtuzumab/TBI conditioning resulting in mixed chimerism. Study design: Prospective observational laboratory study. Serum alemtuzumab concentration will be measured at various time points before and after stem cell infusion (days -3, 0, +7, +14, +28, +60). Study population: Adult SCD patients that are planned for a matched sibling donor transplantation with alemtuzumab/TBI conditioning at the Amsterdam UMC. Main study parameters/endpoints: The correlation between serum alemtuzumab concentration and levels of donor chimerism. Secondary endpoints: correlation between serum alemtuzumab levels and patients with and without successful engraftment. Correlation of serum alemtuzumab levels and the dosing of alemtuzumab in mg/kg, number of patient lymphocyte count and total number of infused enucleated donor-derived cells.

Sickle cell disease (SCD) is an autosomal recessive red blood cell blood disorder. One especially vital organ affected in SCD is the brain. Individuals with SCD have an increased risk of both overt cerebral infarctions and silent infarctions. The latter are brain lesions without apparent neurological sequelae. Since cortical neurons in the brain lack the ability to regenerate, tissue damage accumulates throughout the already shortened lifespan of individuals with SCD, resulting in far-reaching consequences such as significant cognitive impairment. Currently, only hematological stem cell transplantation can halt the multiorgan tissue damage. However, the criteria to determine the timing of curative therapy do not center the brain, despite that subtle anomalies of this critical organ can have long-lasting consequences. Since it is not yet known whether brain tissue damage precedes, parallels, or lags behind non-brain tissue damage, it is critical to map these effects in youth with SCD. While importantly comparing images with a healthy reference population. Understanding how the brain is affected is critical for clinical decision making, such as timing of potentially curative interventions but also, to prevent long term irreversible brain damage in youth with SCD. In this study, a cohort of 84 SCD patients between the ages of 6 and 18 at baseline, will undergo MR imaging, neurological examination, neuropsychological assessment and blood sampling three times in total, with intervals of two years; results will be innovatively compared with children included in the Generation R population study (±8000 MRIs children and (young)adults) 6-20 years of age). Our hypothesis, based on the inability of the brain to generate new cortical neurons following cell death, is that brain function is impaired earlier than other organ systems and that there is an age-dependent limit in the brain's ability to remodel itself based on neuroplasticity.

The Sickle Cell Children's Exercise Study (SuCCESs) will explore the feasibility and effects of a moderate intensity strengthening, balance, speed, and agility intervention program in children with sickle cell disease.

Hypothesis Efficient unloading of oxygen to regions of high metabolic demand requires a healthy microvasculature to sense local oxygen tension and regulate flow, accordingly. In sickle cell disease patients, the investigators have demonstrated oxygen supply-demand mismatch, or SDM, in proportion to anemia severity. SDM occurs in both the peripheral circulation and the brain, and four characteristics: 1) Hyperemia beyond expected for the level of anemia, 2) Corresponding loss of vascular dilatory reserve, 3) Impaired oxygen unloading to the tissues, and 4) Tissue hypoxia. In sickle cell disease, red blood cell (RBC) and white blood cell (WBC) adhere to vascular endothelium triggering transient or irreversible microvascular damage as well as releasing vasoactive substances that contribute to microvascular dysregulation. The investigators postulate that ongoing microvascular damage/dysregulation in the setting of increased total blood flow contributes to SDM. The investigators believe SEG101, by lowering RBC and WBC adhesion to the microvasculature, will improve SDM and tissue oxygenation. Objectives Primary - The investigators will test whether SEG101 improves SDM in patients with sickle cell anemia by measuring the change in tissue oxygenation measured by near infrared spectroscopy (NIRS). Secondary/Exploratory - The investigators will identify end-organ disease and whether improvement of SDM by SEG101 occurs in patients with sickle cell anemia.

Despite the important work of previous sickle cell disease (SCD) cohort studies, there remain many understudied areas that require investigation. An important knowledge deficit is the slow but progressive process of chronic end-organ dysfunction. The majority of organ dysfunction becomes apparent in the young adult years, but comprehensive assessment of adults and understanding of predictors of adulthood organ dysfunction are insufficient. Similarly, the role of disease-modifying therapies, such as hydroxyurea, in preventing organ dysfunction later in life is not clear. Extended follow-up of patients through the transition into adulthood is imperative to understand the long-term implications of pediatric sickle cell care. This observational study will collect data in a systematic fashion at participants' regular clinic visits (in-person or remote) to answer the objectives described below. In addition to primary study objectives, SCCRIP participants will be eligible to participate in a sub-study, which will investigate genetically determined responses to Hydroxyurea (HU) via a pharmacokinetic study (PK). This one time study will involve blood collection at timed intervals proceeding a dose of HU. Defining the basis for this inter-individual variability will allow the identification of poor HU responders prior to initiation of therapy and the seeking of alternative treatments which seek to optimize disease treatment by accounting for individual variability in genes, environment, and lifestyle.

The purpose of this study is to find out how teenagers with chronic pain and sickle cell disease respond to a new training program called Back2Life and get their feedback about how to modify the program to best fit their needs. The Back2Life training program focuses on teaching pain coping skills (also known as cognitive-behavioral therapy). The program teaches skills and strategies that may help teens improve chronic pain management and get back into their everyday activities.

multicentric interventional biomedical research phase II, prospective, non-randomized evaluating a haploidentical marrow transplants after reduced-intensity conditioning and prevention of GvHD based on cyclophosphamide administration post transplantation in patients with severe sickle cell disease.