Exhaled Breath Condensate as a Measurement of Airway Inflammation in Children With Asthma

Detailed Summary

This study will evaluate the usefulness of a new procedure for evaluating asthma in children. The method measures the pH (a measure of acidity and alkalinity) of exhaled breath condensate (water vapor created by the lungs). The condensate contains products of the lungs that may be associated with lung inflammation. Investigators will determine if the pH of the exhaled breath condensate correlates well with known asthma indicators, such as number of hospitalizations, school absenteeism, use of rescue medication, and others. Test results will be compared with findings from healthy normal volunteers. No experimental treatments or medicines are used in this study. Patients who require treatment for their asthma will receive standard care with medicines approved by the Food and Drug Administration and used widely in the United States. Children with asthma and healthy normal volunteers between 6 and 17 years of age may be eligible for this study. You must complete the study before your 18th birthday. Candidates are screened with a medical history and physical examination. Children with asthma undergo the following tests and procedures over six clinic visits, including an initial visit and follow-up visits at 4-8 weeks, 3, 6, 9, and 12 months: * Blood draw in children over 6 years of age. Medications are available to decrease the pain associated with blood drawing.(initial visit) * Allergen skin testing: Drops of up to 16 allergens are placed on the arm. The skin under each drop is scratched and the area is observed for an allergic reaction. (4- 8-week follow-up visit) * Expired nitric oxide testing: The child breathes into a balloon to collect a portion of the gases exhaled form the lungs. This test measures the amount of nitric oxide, which correlates with bronchial inflammation. (all visits) * Exhaled breath condensate: The child breathes into a plastic tube surrounded by a cold metal sleeve for 10 to 15 minutes. The water vapor created by the lungs (the same vapor that forms when breathing outside on a cold day) is collected and the pH measured. (all visits) * Pulmonary (lung) function test: The child blows very hard into a tube attached to a machine to measure the airflow from the child's lungs. This test measures airflow from the lungs. (all visits) The children are given small plastic device called a peak flow meter - a device used to measure lung function - to use at home. Children whose lung function is less than 80% of the predicted value for their age may be given medicine to see if their lung function improves. * Review of the patient's symptoms, sick days, medicines or actions taken to get over the illness; review of peak flow reports; and review of action plan. (3-, 6-, 9-, and 12-month visits) Healthy controls will have the expired nitric oxide test, exhaled breath condensate test, and pulmonary function test at each visit at the initial and over two additional visits scheduled 6 months apart.

Study Details

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