Study of Fludarabine Drug Exposure in Pediatric Bone Marrow Transplantation
Hematologic MalignanciesNonmalignant Diseases6 moreFludarabine is a chemotherapy drug used extensively in bone marrow transplantation. The goal of this study is to determine what causes some children to have different drug concentrations of fludarabine in their bodies and if drug levels are related to whether or not a child experiences severe side-effects during their bone marrow transplant. The hypothesis is that clinical and genetic factors cause changes in fludarabine drug levels in pediatric bone marrow transplant patients and that high levels may cause severe side-effects.
State Of The Art Functional Imaging In Sickle Cell Disease
Sickle Cell AnemiaSickle cell anemia (SCA) is a serious blood disease with blood vessel changes leading to brain injury and stroke. Studies show about 11% of patients with SCA will develop obvious stroke before age 20 years, with children less than 10 years of age especially vulnerable. The main objective of the SCDMR4[State Of The Art Functional Imaging In Sickle Cell Disease] trial is to compare the gray matter cerebral blood flow, measured by MRI,[magnetic resonance imaging] ASL [Arterial Spin Labeling] perfusion before treatment begins and after the appropriate hydroxyurea dosage is reached (~ one year). Other important objectives of the SCDMR4 trial include describing the effect of hydroxyurea therapy and transfusion therapy on the functional MRI response, diffusion tensor imaging of white matter, brain function, and transcranial Doppler blood velocities.
Genes Influencing Iron Overload State
Sickle Cell DiseaseThalassemia1 moreIron overload, which can be defined operationally as too much iron in the body, develops as a consequence of too many blood transfusions given, or due to genetic defects hereditary hemochromatosis). Iron accumulates in several organs in the body, such as the heart, liver, endocrine glands (pancreas, thyroid, etc.), and spleen. Excessive iron can damage organs and may even cause death. Iron overload needs to be appropriately monitored and treated to avoid unnecessary morbidity and mortality. The present study, GENIOS, proposes to test prospectively the hypothesis that genetic modifiers influence the iron overload status of patients receiving transfusions. To test this hypothesis, the study will perform genetic studies to investigate possible genetic influences for iron accumulation in the body and will study iron accumulation not only in the liver, but also in the heart, pancreas, kidneys, and spleen. In addition: the study will investigate if these same genes have any role during treatment of iron overload, in other words, if certain genetic mutations will influence how iron exits the body. This study will also investigate how substances that are known to control the trafficking of iron in and out of the body and its damaging effects to the tissues (hepcidin and non transferrin-bound iron) are linked to the accumulation of iron in the heart and liver. Iron in the body will be measured by R2*MRI and no liver biopsies will be required. Genetic studies will be done by specialized tests using peripheral blood DNA. Iron accumulates differently in different people and in different organs of the body. Some people accumulate iron faster than others, even when receiving the same number of blood transfusions
Long-Term Effects of Hydroxyurea in Children With Sickle Cell Anemia (The BABY HUG Follow-up Study)...
AnemiaSickle CellSickle cell anemia (SCA) is an inherited blood disorder that can cause organ damage. The BABY HUG study is evaluating the use of the medication hydroxyurea at preventing organ damage in children with SCA. The purpose of this follow-up study is to evaluate the long-term effects of hydroxyurea in children who have participated in the BABY HUG study.
Sickle Cell Disease and Endothelial Progenitor Cells (EPCs)
Sickle Cell AnemiaSickle 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.
Role of Placenta Growth Factor in Sickle Acute Chest Syndrome
AnemiaSickle CellThe purpose of this research study is to find out whether Placenta Growth Factor (PlGF) and related tests can predict the development of acute chest syndrome (ACS) in patients with sickle cell disease (SCD) during a period where patients are well and during admission to the hospital for an acute sickle event to see if these measures can predict the development of ACS. Understanding events precipitating ACS may lead to preventative and interventional therapies which will improve patient outcomes and quality of life.
Long Term Effects of Hydroxyurea Therapy in Children With Sickle Cell Disease
Sickle Cell DiseaseThe primary objectives of this prospective, observational study are (1) to describe the long-term cellular, molecular, and clinical effects of hydroxyurea therapy in sickle cell disease, and (2) to perform hydroxyurea pharmacokinetics studies. This study will follow sickle cell patients being treated with hydroxyurea for a long period of time to evaluate the long-term cellular and molecular effects of the drug on the patients' body. This study will consist of two patient groups. One group will be made up of patients who have received hydroxyurea therapy before entering the study. The second group will be made up of patients who have not received hydroxyurea before study entry.
Pain Management Protocol for Pediatric Sickle Cell Disease
Sickle Cell DiseaseSickle cell disease (SCD) is a devastating chronic health condition that primarily affects African-Americans. Painful episodes are the most frequent form of morbidity in SCD and the most frequent reason for hospitalization. Cognitive-behavioral interventions for pain management have shown efficacy for improving coping abilities, reducing the amount of medication needed to manage pain, and improving daily functioning during painful episodes. However, difficulties with disseminating and implementing cognitive-behavioral treatments have resulted in almost no use of these techniques in pediatric settings. In South Carolina these difficulties are compounded by social and geographical factors that pose particular challenges. A major issue with implementing quality pain management protocols is the difficulty with providing adequate practice and monitoring of the use of the techniques, particularly given the rural population in South Carolina and transportation difficulties for economically disadvantaged families. Due to a history of under-treating pain in SCD it is also critical that psychological and medical treatments are presented in an integrated manner so that these approaches are viewed as complimentary, not mutually exclusive, approaches to pain management. Finally, we believe the same implementation issues for improving the use of behavioral coping skills are also important for improving adherence to medication protocols for appropriate home-based pain management. The purpose of this proposal is to develop, implement, and evaluate a pain management protocol that uses portable electronic devices and other technologies to increase the practice of psychosocial pain management techniques, improve adherence to the overall biopsychosocial pain management protocol, and improve the clinician's ability to track progress with fewer office visits. In addition to addressing important dissemination issues, by embedding methods to assess for adherence into the technology it will be possible to continuously evaluate and modify protocol efficacy, resulting in a product that is effective, empirically sound, and flexible. Participants will be randomly assigned to the intervention or waitlist control condition. Those on the waitlist condition will receive the same study procedures after a 2 month wait periods. We anticipate that the intervention will result in better pain management and less impairment in the participants.
Neuropsychological Studies of Children With Sickle Cell
Blood DiseaseAnemia2 moreTo identify those factors that contributed to cognitive deficiencies in children with sickle cell disease (SCD) who had not demonstrated any overt or clinically apparent neurological abnormalities.
Hemoglobin Desaturation in Sickle Cell Disease
Sickle Cell DiseaseAs part of routine care for SCD, some people are found to have low oxygen levels (≤ 88%) while sleeping, at rest, or with exercise. Testing is done with a small portable device positioned on the finger that measures oxygen levels during sleep, at rest, or following exercise. The investigators start oxygen treatment for people with low levels of oxygen. As a part of this study, the investigators will find out if any changes in cell "stickiness" occur with low oxygen levels (at rest, at night, or with exertion) and if cells become "less sticky" with oxygen treatment. Study subjects will be seen before testing and 2 months after testing. In some cases (people with low oxygen levels during testing), study subjects will have been prescribed oxygen, and the investigators will test the effects of that treatment on the stickiness of red cells.