Classification of Disease Process
Subjects are also classified according to the suspected underlying biologic process(es) based on available clinical, genetic, radiologic, and pathologic data. Reporting site investigators identified subjects as having interstitial fibrosis (n=112), airway disease (n=198), pulmonary hemorrhage (n=82), altered intrinsic lung development (n=104), pulmonary alveolar proteinosis (n=30), immune deficiency or dysregulation (n=134), or eosinophilic disorders (n=20). Among the 112 subjects with a fibrotic disease process, 34 (30.4%) had connective tissue or immune-mediated disorders and 25 (22.3%) had surfactant dysfunction. If an individual experienced multiple co-existing disease processes, then each contributing biologic mechanism was recorded. For example, 74% of subjects characterized as having a fibrotic disease process were designated to have an additional type of disease process present (e.g., immune dysregulation; airway disease).