Graduation Year


Document Type




Degree Granting Department

Public Health

Major Professor

Stuart Brooks, M.D.


Asthma, Inflammatory, Allergic, Bronchoalveolar lavage, Noninvasive


Several tests are available for evaluation of respiratory disorders but most of them are invasive and associated with some risk or patient discomfort. Examples include bronchoscopy (bronchoalveolar lavage, BAL) [1], venopuncture [2] and sputum induction [3]. Noninvasive sampling of nongaseous substances contained in expired air, collected as exhaled breath condensate (EBC) has been used to detect inflammatory markers and by-products including nitric oxide and arachidonic acid metabolites and proteins [4]. Nerve growth factor (NGF) is a protein that has been implicated in neurogenic airway inflammation and this pilot study aimed to develop a non-invasive approach for evaluation of allergic airway inflammatory disease by measuring and comparing levels of NGF in the induced sputum and EBC of ten (10) asthmatics and ten (10) non-asthmatics.Though twenty (20) subjects were sampled, an unexpected event due to a defective NGF kit inadvertently resulted in an unsuccessful analysis of fifteen (15) sets of specimen (6 non-asthmatics and 9 asthmatics), limiting the study.This study is significant because occupational lung diseases are the number one work-related illness in the United States and occupational asthma is the most common form [9]. Toluene diisocyanate (TDI) is the commonest cause of occupational asthma and workers exposed to TDI vapor may develop inflammatory conditions including asthma, rhinitis and nasal irritation [7].Results: NGF was detected and measured only in sputum, with a mean NGF level of 210 (210-210, range 0) in asthmatics and 164 (7-280, range 273) in non-asthmatics. Nonetheless, we failed to reject the null hypothesis (number 3).Conclusion: This limited study did not have adequate power (power 11%) due to the small sample size and thus lacks internal validity. Further studies are needed using a larger sample size.