View clinical trials related to Asthma.
Filter by:Asthma is a chronic inflammatory disease. We propose to study inflammatory changes in the lungs of subjects with atopic asthma of different severity in vivo using positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG). It has been shown that the uptake of FDG as detected by PET scanning correlates with inflammation in animal models as well as in human disease processes such as sarcoidosis, tuberculosis and abscess formation. In addition, it has been shown that the inflammation associated with allergen challenge in patients with atopic asthma can be visualized using PET scanning with FDG. We hypothesize that the degree of FDG-uptake as a measure of inflammation correlates with the severity of asthma as determined by pulmonary function tests and clinical signs and symptoms. In addition, information about the spatial distribution of the inflammatory changes will be obtained. To compare the characteristics of the inflammation in asthma with non-asthmatic inflammation of the lung, the images obtained in asthmatic subjects will be compared with images from subjects who have inflammatory changes of the lung caused by Wegener's granulomatosis. Subjects with atopic asthma and non-atopic control subjects will be selected from the community and, if eligible for the study, undergo skin testing against common allergens and pulmonary function testing. Subjects with Wegener's granulomatosis will be selected from a large group of subjects followed with this disease at NIAID. PET scanning with FDG will be used to measure inflammation in the PET scanning facility at the Clinical Center of the NIH and the results of the scanning will be correlated with the severity of the disease. We expect that for the first time this methodology will permit an objective measure of the basic pathogenic process, the allergic inflammation, in patients with atopic asthma. Using this methodology it will be possible to study the efficacy of currently available therapies for allergic inflammation. In addition, this methodology will provide an extremely useful tool for the development of new therapeutic approaches to the treatment of asthma.
Bronchoalveolar lavage (BAL) is a diagnostic and therapeutic procedure conducted by placing a small fiberoptic scope into the lung of a patient, and injecting sterile water (saline) into the lung and removing the fluid. The sterile solution removed contains secretions, cells, and protein from the lower respiratory tract. This sample can be analyzed to provide more information about possible disease processes going on in the lungs. This protocol will be used to perform BAL, bronchial brushing, and bronchial wall biopsy in normal volunteers and patients with pulmonary disease. The samples collected during the study will be used to examine biochemical processes in the lung that may contribute to lung disease
This study will examine the movement of T cells (a type of white blood cell) from the blood to the lungs in patients with asthma after exposure to an allergen, such as cat dander or pollen. Asthma is in large part due to inflammation of the bronchi (the breathing tubes of the lungs), causing heat, swelling and redness. T cells play a major role in the inflammatory reaction. A better understanding of T cell migration to the lungs after allergen exposure may lead to improved therapies for asthma. Patients between 18 and 50 years of age with mild allergic asthma may be eligible for this study. In addition, patients and healthy normal volunteers between 18 and 65 years of age may participate in a sub-study (blood draw) of this protocol. Participants will undergo the following procedures: Visit 1 (screening visit) - Blood tests for blood counts and HIV - Urine pregnancy test for women of childbearing potential. Visit 2 - Physical examination and electrocardiogram (EKG) - Prick skin testing - A drop of allergen extract is put on the skin and the underlying skin is scratched with a needle. A positive test resembles an insect bite and may itch. - Intradermal skin tests - Increasing concentrations of a drop of diluted allergen are injected into the skin and the allergic response is monitored until a 5-mm swelling (1/4 inch) swelling develops. - Methacholine challenge - The subject has repeated pulmonary function (breathing) tests after breathing methacholine, a drug that temporarily (for 5 to 10 minutes) worsens asthma symptoms. - Physician evaluation and repeat pulmonary function test Visit 3 - Allergen bronchoprovocation - This test will be done in patients whose physical evaluation and breathing test permit them to continue with the study. A heparin lock (needle device that stays in a vein to allow multiple blood draws without repeated sticks) is placed. The subject breathes 5 breaths of allergen through a nebulizer (device that creates a mist), followed by a breathing test. This procedure will be repeated with increasingly higher allergen doses until lung function significantly declines or for a maximum of 6 doses. Subjects are monitored for 8 hours after the last dose. Blood samples of 50 ml each (3.5 tablespoons) are collected at 1, 3, 5 and 8 hours, and a physician evaluation is done at the end of the 8 hours. Additional 50-mm blood samples are collected the following two mornings. Visit 4 - Physician evaluation, blood test for anemia and pulmonary function test - Serial blood draws - 50 ml of blood will be drawn, followed by salt-water nebulization and another 50-ml blood draw after 1 hour. Additional 50-ml blood samples will be drawn 7 hours later and then on the next two mornings. Participants in the sub-study portion of this protocol will undergo the screening blood test, prick skin testing, breathing test after methacholine inhalation and a 100 ml-blood draw. These tests will be done in three sessions.
The purpose of this study is to evaluate current and novel therapies and management strategies for children with asthma. The emphasis is on clinical trials that help identify optimal therapy for children with different asthma phenotypes, genotypes, and ethnic backgrounds and children at different developmental stages.
To conduct a collaborative program of research on asthma and pregnancy consisting of two studies: the Asthma in Pregnancy Study (APS) was an observational study to evaluate relationships between asthma severity and treatment programs and perinatal outcome, and the Asthma Therapy in Pregnancy Trial (ATPT) was a randomized clinical trial of inhaled beclomethasone versus theophylline in the treatment of moderate asthma during pregnancy. Both studies were conducted in the Maternal-Fetal Medicine Unit (MFMU) Network, an ongoing group of participating obstetric centers supported by the National Institute of Child Health and Human Development. Studies were co-funded by the NHLBI.
The purpose of this study is to evaluate the long term effects of anti-inflammatory therapy compared to bronchodilator therapy on the course of asthma, particularly on lung function and bronchial hyperresponsiveness, and on physical and psychosocial growth and development.