Currently, many Americans suffer from asthma. The exact mechanism by which airway inflammation leads to asthma symptoms has yet to be clearly explained. In previous studies, persons with asthma appear to have different types of inflammation in their lungs. The reasons for this difference remain a mystery. Allergy is known to play a role in bronchospasm. Other mechanisms have not been discovered.
It is known that asthma and heartburn are correlated. Studies have confirmed a direct relationship between cough and heartburn (Gastroesophageal reflux). Other researchers have determined that asthma is often worsened by GER. Determination of the exact relationship between these two entities remains unclear.
Heartburn may contribute to airway inflammation in asthmatics, resulting in different patterns of inflammation between those people with and without GER. In fact, adult-onset asthma may result primarily from longstanding heartburn. This has yet to be proven.
This study will evaluate how heartburn may lead to different types of inflammation in one's airways. Additionally, the goal of this study is to determine whether aggressive treatment of heartburn results in improvement in both symptoms of heartburn and asthma but also in documented improvement in airway inflammation as determined by biopsy. The results of this study will be important in directing future research into the relationship between heartburn and asthma and may provide a clue whether certain subtypes of asthma may be caused primarily by GER.
A total of 30 subjects will be studied, randomized to twice daily lansoprazole or placebo. Study procedures are as follows:
A. Esophageal studies and validated questionnaires:
Patients will be evaluated with validated SF-36 Quality of Life Questionnaire, Mini-asthma Quality of Life Questionnaire, and GER Questionnaire. Patients will undergo esophageal manometry and pH detection with a 24- hour pH probe to confirm the presence of pathologic GER.
B. Bronchoscopy:
After an overnight fast, subjects will report to the bronchoscopy suite as directed. Bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsy will be performed following the University of Utah's standardized protocol. Bronchoscopy and endobronchial biopsies present minimal risk to asthmatic airways when performed by appropriate, trained personnel. Conscious sedation with intravenous remifentanyl and propofol will be administered by a trained nurse experienced in conscious sedation. The nose and pharynx will be anesthetized with 1% lidocaine administered by nebulization and by lidocaine jelly administered topically to the nasal mucosa. Additional lidocaine will be administered via the bronchoscope to the vocal cords, trachea, main carina and mainstem bronchi. The total dose of lidocaine will not exceed 400 mg. All subjects will have continuous cardiac and oxygen saturation monitoring and will receive supplemental oxygen during the procedure sufficient to maintain SpO2 \> 90%.
The subject will be placed in a recumbent position and the bronchoscope will be introduced via the nose. After passing the vocal cords, the bronchoscope will be introduced via the right mainstem bronchus into the right middle lobe where it will be wedged into a segmental bronchus. (Should, for any reason, the right middle lobe be inaccessible, the same procedure will be used to wedge the bronchoscope into a lingular segment in the left lung.) A 60 cc aliquot of room temperature normal saline will be instilled through the bronchoscope and recovered using the same syringe. This procedure will be repeated three more times (total lavage volume of 240 cc) and the recovered volumes will be pooled and measured. Forceps biopsies of respiratory mucosa will then be taken from the trachea, main carina, bronchus intermedius and right middle lobe areas. Two to six biopsies will be taken from each site. Specific tissue from each site will be frozen and stored for future use.
Individuals will be randomized to lansoprazole 30 mg twice daily or placebo (all patients will undergo lifestyle modification for reflux) for 6 weeks. It has been determined in previous studies that higher levels of acid suppression are needed to result in clinical improvement in asthma.
Patients will be monitored by telephone at regular intervals. Rescue inhaler use, hospitalizations, exercise tolerance, and study compliance will be assessed and recorded to document clinical progress. Patients will be asked to maintain their standard inhaler therapy (especially that of inhaled steroids). Any changes to the therapy will be immediately reported to the investigators. If subjects experience an acute flare, appropriate medications will be given until the patient is stable to return to their initial inhaler regimen. If patients remain on stable medication throughout the trial, repeat bronchoscopy will be performed at 6 weeks.
After 6 weeks, patients will once again undergo bronchoscopy with BAL/biopsies. Cytokine protein arrays will be repeated. Comparisons will then be made intra-group before and after therapy. Additional comparisons of inflammation and bronchial hyper-responsiveness will be made between groups. Randomization will allow the investigators to control for any changes in cytokine patterns due to seasonal affect (if both groups reduce the concentration of Interleukin-5 in a similar pattern, this is more likely seasonal than due to acid suppression).
Primary outcome will include change in cellular infiltration in the bronch specimens of lymphocytes. Secondary outcome will include RNA expression changes of tumor necrosis factor (TNF) alpha from BAL samples.
