BACKGROUND:

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology characterized pathologically by a chronic inflammatory process (alveolitis) that precedes and likely controls the alterations in connective tissue matrix that eventually destroys the normal lung architecture. The mechanisms involved in this process are not known. A complex cell-cell interactive sequence, involving principally neutrophils, lymphocytes, macrophages, fibroblast, and epithelial cells is believed to be responsible.

The SCOR in Occupational and Immunological Lung Diseases was first awarded in December, 1981. The subproject on idiopathic pulmonary fibrosis was first awarded in December, 1986.

DESIGN NARRATIVE:

The cross-sectional comparison examined bronchoalveolar lavage, high resolution, thin-section computer tomography (HRCT), neutrophil or monocyte labeled scintigraphy). The serial, longitudinal evaluation monitored the progression of disease. The study of PSS patients, without disease or with subclinical disease, was particularly useful because it allowed examination of the early events in the pathogenesis of IPF. The long-term goal of the project was to determine what alterations in cellular composition, function and trafficking occurred in the lung parenchyma of patients with IPF and to relate these alterations to the disease stage, prognosis, and therapeutic responsiveness.

The major objectives of the study were: (1) to continue the prospective, longitudinal study of carefully defined cases of IPF; (2) to initiate a study of patients with PSS, a disease that provided a useful paradigm for studying the early events of the disease; (3) to determine the role of the lymphocyte in IPF, by defining the subset of T lymphocytes responsible for modulating macrophage function; (4) to establish the role of non-invasive techniques (bronchoalveolar lavage (BAL), HRCT scanning and scintigraphy -- neutrophil and monocyte labelled cells) in assessing the activity of inflammation in carefully evaluated patients; (5) to determine the relationship of these results to the -- carefully defined and serially obtained -- clinical, radiographical, and physiological findings and to the histopathologic abnormalities (in patients that underwent lung biopsy, predominantly IPF cases).

(6) to perform studies utilizing blood, BAL fluid and lung tissue in an effort to understand the pathogenic mechanisms that underlied the inflammatory/immune cellular injury and fibrosis that characterize this disease.