Active clinical trials for "Anemia, Sickle Cell"

The goal of this research study is to establish chimerism and avoid graft-versus-host disease in patients with hemoglobinopathies.

Acute chest syndrome is a severe respiratory complication of sickle cell disease. The standard prevention of this dangerous complication is spirometry in wich patient is required to take deep breaths trough a little device several times a day. This treatment is compromised when pain in important or when the patient is asleep and cannot participate. The investigators hypothesised that non invasive ventilation in wich patient have no effort to take might be a better prevention than spirometry and may improve pain and quality of sleep. Children with vaso-occlusive crisis necessitating morphinic treatment will be randomly assigned with either spirometry or ventilation and the investigators will monitor for occurrence of acute chest syndrome, pain and quality of sleep.

The primary objectives of this study were to assess the immunogenicity and the tolerance of the heptavalent pneumococcal conjugate vaccine (Prevenar) in young infants (2 months of age) with sickle cell disease when administred at 2,3, and 4 months of age.

Numerous pathologies (sickle cell disease, thalassemia, spherocytosis, etc.) lead to changes in the rheological properties of the blood, in particular via alterations in the deformability of red blood cells. These alterations lead to circulatory complications of which an emblematic example is the sickle cell crisis which manifests itself by microcirculatory occlusions. Several authors suggest that the deformability of erythrocytes is a key parameter for the diagnosis and monitoring of patients. Numerous studies, especially in vitro, show that the mechanical properties of the red blood cell significantly influence its dynamics in flow (blood viscosity, distribution in capillary networks). Moreover, concerning the specific problem of vaso-occlusion, the proportion of the most rigid red blood cells is a determining factor of the probability of occlusion more than the average value of this rigidity which can hide great disparities. There is no clinically usable test to assess the alteration of the fine rheology of the red blood cell in a patient. Functional tests such as ektacytometry require heavy equipment and teams of specialized biologists; this technique is therefore only available in 3 biological reference centers in France. "Mechanical phenotyping" seems to be a potentially simpler and more accessible technique, and has already shown promising prospects in other nosological settings than red blood cell pathologies. Today, there is no specific marker of sickle cell vaso-occlusive crisis, nor marker of severity, that would be useful for pathophysiological understanding but also for clinical management.

The primary goal of the Phase III SCATE trial is to compare 30 months of alternative therapy (hydroxyurea) to standard care (observation) in children with sickle cell anemia and conditional (170 - 199cm/sec) Transcranial Doppler (TCD) velocities. For the alternative regimen (hydroxyurea) to be declared superior to the standard treatment regimen (observation), the hydroxyurea-treated group must have a three-fold reduction in the incidence of conversion to abnormal TCD velocities (≥ 200 cm/sec), compared to the standard treatment arm.

In patients with SCD, the use of low dose anticoagulation as an outpatient may lead to a significant decrease in morbidity and as a result, decrease healthcare utilization and costs. This study attempts to critically avoid admissions by reducing daily pain scores and pain crisis as an outpatient by use of a novel oral anticoagulant.

Objective: To study the safety and efficacy of deferasirox as treatment of oxidative stress in adult subjects with sickle cell disease. Endpoints: The investigators will determine whether treatment with iron chelators results in decreased sickling of RBCs, oxidative stress, neutrophil activation, inflammation, endothelial activation and hypercoagulability and ultimately reduced disease severity. If the hypothesis is confirmed in this pilot dose-finding study, a larger randomized controlled clinical trial will be initiated. Study design: This will be an open-label pilot study, including 12 patients per dose group with a maximum of 3 dose groups. As the antioxidant capacity of deferasirox might be dose-dependent, the investigators will start with the highest dose of deferasirox (360 mg) deemed adequate for chronic use without causing iron depletion in adult SCD patients. Study population: Adult patients with sickle cell anemia (HbSS) or HbS-β0-thalassemia (HbSβ0-thal) visiting the outpatient-clinic of the Academic Medical Center, Amsterdam will be asked for inclusion in the study.

Sickle cell disease (SCD) is an autosomal recessive disorder resulting from a substitution in the β chain of hemoglobin (Hb) which causes hemoglobin S to polymerize when deoxygenated. SCD patients present immune abnormalities that have always been attributed to functional asplenia. It it is now being recognized that patients with SCD have a pro-inflammatory condition with altered immune system activation contributing to the pathology of SCD. Increased levels of neutrophils, monocytes or cytokines have been reported in SCD patients. SCD is associated with many acute and chronic complications requiring immediate support. Actual strongly recommended therapies include chronic blood transfusions (CT) and hydroxyurea (HU). In addition, episodic transfusions are recommended and commonly used to manage many acute SCD complications.There is strong evidence to support the use of HU in adults with 3 or more severe vaso-occlusive crises during any 12-month period, with SCD pain or chronic anemia, or with severe or recurrent episodes of acute chest syndrome. HU use is now also common in children with SCD. Some patients receive chronic monthly RBC transfusion with the objective to reduce the proportion of HbS to < 30 %. Long-term RBC transfusions prevent and treat complications of SCD decreasing the risk of stroke and the incidence of acute chest syndrome (ACS). Therapeutic complications, such as alloimmunization against RBC in 20-50% of patients or hematopoietic stem cell transplantation (HSCT) graft rejection, constitute an immune-based clinical issue in SCD. Poorly understood RBC alloimmunization is responsible for serious hemolytic transfusion reaction associated with severe mortality and morbidity underlying the need for a better understanding of the immunology of SCD to improve SCD transfusion support/outcome. Little evidence exists about HU effects on immune functions in SCD. HU treatment doesn't appear to have deleterious effects on immune function and appears to decrease the abnormally elevated number of total WBC and lymphocytes, while CT does not. Patients with SCD are at higher risk of infections and prophylactic vaccination is strongly recommended. Recent data suggest that vaccinal response to pneumococcal antigens in SCD patients is identical to healthy control while controversy concern the stability of the immune protection after vaccination of SCD patient. Antibody levels declined over the year and the need for more frequent vaccination in SCD patient should be investigated. Currently, there is no evidence whether HU may interfere with pneumococcal immune response. Purohit showed that immune response to inactivated influenza A (H1N1) virus vaccine was altered in patient with SCD receiving CT but little is known on immune response to vaccination in patients with SCD receiving HU. Recent data suggest that not only inflammatory status but also humoral immune response to antigens in SCD patients may differ according to treatment. Yazdanbakhsh reported an imbalance between regulatory T cell (Treg) and effector T cell (Teff) in alloimmunized SCD patients with as consequence an increase in antibody production. In a model proposed by the authors, the balance between Treg and Teff is dictated by the monocyte control of cytokines expression. Altered activity of monocyte heme oxidase-1 (HO-1) would be responsible of a decrease in IL-12 and an increase in IL-10 cytokines secretion impacting the Treg/Teff cells ratio and promoting antibody production by B cells. The objectives of the project are to assess whether different humoral immune responses to vaccines or to erythrocyte alloantigens are related to the type of treatment administered to patients with SCD. We also aim to study if these differences might be related to different expressions of HO-1 by monocytes.

The overall goal of the project is to reduce pain-related, 30-day readmission rates for sickle cell disease (SCD) patients. The investigators want to see if a mobile phone application (app) can help decrease the need for repeat admission to the hospital because of sickle cell pain.

The objective of this proposal is to test the feasibility of red blood cell (RBC) rejuvenation to chronic transfusion in sickle cell disease (SCD) and the potential benefit of RBC rejuvenation in this population to determine if a larger clinical trial powered to definitively characterize the benefits of rejuvenation is warranted. This is a small pilot study is to see if restoring important energy molecules (ATP and 2,3,DPG) in stored red blood cells before they are transfused, with a rejuvenating solution (Rejuvesol), offers any advantages to individuals over standard blood transfusion. Subjects will receive either rejuvenated (R) or standard (S) RBCs with each transfusion for 6 transfusions (over approximately a 6-month period) in a pre-defined order to maximize detection of any signal.