Biomarkers in Exhaled Breath From Asthmatic Patients

This study will look for a relationship between asthma and factors released from the lungs in exhaled breath. If a relationship can be established, the identified factors may be used as biomarkers to predict episodes of increased asthma symptoms so that medications can be given to prevent the onset of an asthma attack. Healthy volunteers and people who have had asthma for at least 1 year may be eligible for this study. Candidates must be between 18 and 75 years of age. Participants undergo blood tests and breathing tests. For the latter, participants breathe into a machine before and after inhaling an asthma medication called albuterol. The machine measures the volume of air the subject can breathe out. Participants also provide a sample of exhaled breath by breathing normally for up to 30 minutes while wearing a mask devised for the procedure. Pulse rate, oxygen saturation and wheezing are monitored during the breath collection.