The cellular components in bronchoalveolar lavage fluids (BALF) and biopsied lung tissues of patients with various types of interstitial pneumonia were analyzed to clarify cellular kinetics in the lung. The T-cell subsets of lymphocytes in BALF and biopsied lung tissues were examined in 7 cases of hypersensitivity pneumonitis (HP), 2 cases of sarcoidosis (Sar), one case of idiopathic interstitial pneumonia (IIP) and 2 cases of rheumatoid arthritis with interstitial pneumonia (RA+IP). The T-cell subsets in BALF were analyzed by flow cytometry and the T-cell subsets in lung tissue were detected in frsh frozen and thin-sliced specimens using an avidine-biotine complex (ABC) kit. The mean CD4/CD8 ratio in BALF was 0.36 in HP, 3.1 in Sar, 1.07 in IIP and 2.59 in RA+IP, while the mean CD4/CD8 ratio in lung tissues was 0.52 in HP, 2.59 in Sar, 1.11 in IIP and 2.25 in RA+IP, respectively. The ratios of CD4/CD8 in BALF and lung tissues from patients with these various interstitial pneumonia showed a positive correlation. Significant correlation was seen between CD4/CD8 rations of the alveolar portion findings indicate that BAF findings reflect the changes in the lung tissues, although BALF might reflect only a part of the changes in the whole lung.
bronchoalveolar lavage (BAL)
transbronchial lung biopsy (TBLB)