Correlated Studies of Interstitial Pulmonary Disease

Abstract

Aseries of 90 cases presenting over a four-year period with a differential diagnosis of interstitial inflammatory disease was characterized by clinical, physiologic, serologic and radiologic features. Twenty-five had open lung biopsy and extensive multidisciplinary study of the lung specimen, including studies of collagen biochemistry and microbiology (Table 1). In addition, 12 patients with progressive diffuse interstitial lung disease had concurrent studies of cells obtained by bronchopulmonary lavage. The histologic sections were described with semiquantitative ratings of the degrees of mononuclear cell interstitial cell infiltration, intimal hyperplasia and muscular hypertrophy of small blood vessels, and extent of fibrosis. A total of 17 functional and four pathologic variables have been studied to date with mean and variance values determined for each variable. Kendall or Pearson correlation coefficients, as appropriate to the variable pairs, were calculated. The best single predictor of pulmonary pathology was the resting PaOz. The degree of fibrosis appeared more closely related to functional changes than either interstitial mononuclear cell infiltration or vessel wall enlargement; the fibrosis grade showed coefficients of correlation of 0.50 with resting PaO,, 0.45 with vital capacity, 0.39 with the rest and exercise A-aO, difference, 0.38 with the exercise PaO,, 0.37 with the maximal expiratory flow rate, and 0.36 with the total lung capacity (P < 0.04 in all cases). 'From the Departments of Medicine, Pathology and Epidemi