Cytologic, and Biochemical Aspects

Idiopathic pulmonary fibrosis is a fatal disorder that starts as an alveolitis and progresses to interstitial fibrosis. Correlative morphologic, physiologic, and biochemical studies in 29 patients have shown that the inflammatory process is best followed by serial bronchoalveolar lavage and 67Ga citrate scanning, and the fibrotic process is best followed by quantitation of the exercise-induced drop in arterial oxygen tension per unit of oxygen consumed. Although biopsies in idiopathic pulmonary fibrosis seem to show increased amounts of fibrotic tissue, biochemical studies suggest that the disease is probably one of collagen rearrangement rather than collagen increase. Perhaps because of this, peripheral lymphocytes of these patients recognize collagen as "non-self and, when exposed to it in vitro, produce lymphokines and cell lysis. The fibroti