View clinical trials related to Asthma.
Filter by:This study will examine how allergen immunotherapy (allergy shots) works to reduce or prevent reactions to allergens such as pollen, dust or cat dander. Certain T cells (types of white blood cells) called Th2 cells produce substances that generate allergies. Other T cells called Th1 cells produce substances that have opposite effects. This study will determine if allergy shots change the immune response to allergens by reducing the number of Th2 cells or by changing them into Th1 cells. A better understanding of how this treatment works may help scientists develop more effective allergy therapies. People between 18 and 50 years of age who have had allergic asthma for at least 1 year may participate in this study. Candidates' medical, allergy and medication histories will be reviewed, and they will have a physical examination, including routine blood tests, urinalysis, electrocardiogram (EKG), and lung function test. Blood will also be drawn to test T cell response to allergens, and 12 skin tests (similar to a tuberculosis skin test) will be done to test for sensitivity to various allergens. Participants will be admitted to the Clinical Center for 1 to 2 days for rush therapy (see below). They will have a brief history and physical examination. A heparin lock (thin plastic tube similar to an intravenous line) will be placed in an arm vein. They will then undergo the following procedures: - Rush/Cluster Immunotherapy - An allergen is given in increasing doses over 2 to 5 weeks. During rush therapy, the dose is increased rapidly over 1 to 2 days until a moderate level dose is reached. To reduce the chance of an allergic reaction, patients take prednisone, cetirizine (Zyrtec® (Registered Trademark)), ranitidine (Zantac® (Registered Trademark)) and montelukast (Singular® (Registered Trademark)) starting 24 hours before treatment begins until rush therapy ends. After discharge on the third day, patients return to the clinic once a week for the next 2 to 5 weeks for cluster therapy, in which the dose is increased more gradually to a maintenance level. - Maintenance Immunotherapy - Participants receive 12 weekly injections at the maintenance dose. Blood is drawn during one visit between weeks 2 and 7 of maintenance therapy. - Follow-up Visits - Patients return to the clinic 2 and 3 weeks after the last maintenance dose for blood draws and evaluations. In addition, a "late-phase" allergen skin test is done at the 3-week follow-up to compare reaction results with those from the test done at the screening visit. - End-of-Study Visit - 12 to 16 weeks after the last allergy shot, patients return for a final blood draw and brief evaluation.
Asthma is a chronic inflammatory disorder of the airways characterized by reversible airflow obstruction. Fourteen million persons (6.4%) in the United States report having asthma, and from 1980 to 1994 the prevalence of self-reported asthma in the United States increased by 75%. A major factor in the pathogenesis of asthma is the development of an allergic inflammatory response to inhaled antigens. Interleukin-4 (IL-4) plays a key role in this response by promoting IgE production, upregulating IgE receptors, upregulating adhesion receptors such as VCAM-1, promoting Th2 cell development and increasing mucus secretion. Soluble recombinantly produced IL-4R (sIL-4R) has been shown to bind and inactivate IL-4, both in vitro and in animal models. As part of a multicenter trial, 20 subjects at the NIH site will receive 0.9 mg., 1.8 mg. sIL-4R or placebo once weekly for 12 weeks in a double blind placebo controlled study. Study drug will be delivered via the AERx aerosol drug delivery device. The primary objective of the study will be to evaluate efficacy as measured by FEV1. Secondary objectives will include changes in FVC, FEF 27-75, peak flow, bronchodilator usage, asthma symptoms, quality of life scores, immunologic and inflammatory markers, pharmacokinetics, safety and immunogenicity. The study population will consist of moderate to severe asthmatics on (Beta)-agonist monotherapy with an FEV1 of 50-80% of predicted. After 12 weeks of study drug, subjects will be followed for an additional 8 weeks.
Asthma is a chronic inflammatory disorder of the airways characterized by reversible airflow obstruction. Fourteen million people (6.4%) in the United States report having asthma, and from 1980 to 1994 the prevalence of self-reported asthma in the United States increased 75%. Interleukin-4 (IL-4) plays a key role in this response by promoting IgE production, upregulating IgE receptors, upregulating adhesion receptors such as VCAM-1, promoting Th2 cell development and promoting mucus secretion. A soluble form of the receptor for IL-4 (IL-4R) that has antagonist activity has been developed for clinical use. Soluble IL-4R acts by competing with endogenous cell bound IL-4R for free IL-4, thus inhibiting IL-4 function. IL-4 is required for the development of allergen specific Th2 memory cells. Less well understood are the factors required for maintenance of Th2 responses. The maintenance of polarized Th2 responses to allergens have been postulated to require IL-4 itself, by acting as an anti-apoptotic/survival factor or by differentiating naive allergen specific T cells to the Th2 phenotype. Subjects on sIL-4 therapy represent a unique patient group that possess allergen specific Th2 cells, but in which the capacity for IL-4 to promote further Th2 cell survival or differentiation has been blocked. This is a single site adjunct study proposed to study subjects ages 14 years and older who are enrolled at the NIH Clinical Center on a multicenter trial of IL-4R in moderate to severe asthma (Phase II Efficacy Study of Aerosolized Recombinant Human IL-4 Receptor in Asthma). A maximum of 40 subjects will be enrolled. We hypothesize that effective blocking of such Th2 priming would result in a decreased frequency of both allergen specific Th2 cells as well as mitogen activated Th2 cells. Determination of the fate of Th2 cell responses during long term IL-4R therapy may have important implications both for future development of anti-cytokine therapies as well as for understanding the T cell biology of allergic diseases and asthma.
The proposed study is a phase II clinical trial of TNFR:Fc therapy in a segmental allergen bronchoprovocation model of atopic asthma. The goal of this study is to assess whether inhibition of tumor necrosis factor (TNF) bioactivity can attenuate airway inflammation in mild-to-moderate allergic asthmatics. This protocol will utilize a randomized, double-blind, placebo-controlled trial design. TNF bioactivity will be inhibited via systemic administration (e.g., subcutaneous injection) of a dimeric fusion protein consisting of the extracellular ligand binding domain of the 75-kilodalton TNF receptor linked to the Fc portion of human IgG1 (TNFR:Fc, Immunex). The data generated by this study will address the utility of anti-TNF therapy for patients with asthma.
Fiberoptic bronchoscopy is a procedure which involves passing a pencil-thin tube into the lung in order to collect fluid and cells from the airways. Fiberoptic bronchoscopy can collect cells from the walls of airways by gently brushing them (bronchial brushing). In addition, squirting small amounts of sterile water in to the airway and gently suctioning it back into the bronchoscope (bronchoalveolar lavage) collects cells. In this study, researchers plan to perform these tests on patients with asthma and normal volunteers. This research may help to improve the understanding of the processes involved in airway inflammation and asthma....
Asthma is the third leading cause of preventable admissions to the hospital in the United States. Deaths and diseases associated with asthma increase every year. Asthma is a disorder of airway inflammation. There are several factors thought to play a role in the process of inflammation. In this study researchers are particularly interested in studying a factors known as TNF (tumor necrosis factor) and the sites where this factor attaches called receptors. Another factor associated with receptor processing is called aminopeptidase-like protein. It may be involved in the relationship between TNF, it's receptors, and inflammation. In order to understand the relationship between these factors, researchers plan to simulate an allergic reaction in the lungs and airways of patients participating in the study. By doing this they can collect and study the factors causing airway inflammation. Samples collected from patients with asthma will be compared to samples from volunteers without asthma. Patients and volunteers participating in this study will not directly benefit from this research. However, the study may help researchers understand the causes and processes involved in asthma. In addition, the study may lead to the development of new treatments for asthma and airway inflammation.
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 is designed to evaluate the genetics involved in the development of lung disease by surveying genes involved in the process of breathing and examining the genes in lung cells of patients with lung disease. The study will focus on defining the distribution of abnormal genes responsible for processes directly involved in different diseases affecting the lungs of patients and healthy volunteers. Optional CT Sub-study The standard CT scan will be compared to the low dose radiation CT scan for the 150 subjects enrolled in the sub-study to assess the variation between the two techniques. Specifically, the quantitative computer aided detection of lung CT abnormalities from LAM can be compared to assess whether low radiation dose CT exams is an alternative to conventional CT to monitor disease status. This optional sub-study will be offered to up to 100 adult subjects with lung disease and up to 50 children age 9 and older with CF. Children will not be enrolled in the optional CT sub-study unless they have had a standard CT scan for medical purposes to use in comparison. One additional low dose radiation CT scan of the chest may be done as part of this sub-study when these subjects have their next annual CT scan.
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.