Subsets of lymphocytes in bronchoalveolar-lavage fluid from patients with idiopathic bronchiolitis obliterans organizing pneumonia

Abstract

Lymphocyte activation may be involved in interstitial inflammatory processes in the lungs. We analyzed lymphocytes in bronchoalveolar lavage fluid obtained from 5 patients with idiopathic bronchiolitis obliterans organizing pneumonia and from 7 control subjects. Lymphocytes were analyzed by two-flow cytometry. Differential cell counts showed that the percentage and the number of lymphocytes was higher in the patients (32.9 +/- 21.9%, 12.8 +/- 8.32 x 10(4) cells/ml) than in the controls (8.31 +/- 3.66%, 0.69 +/- 0.39 x 10(4) cells/ml, p < 0.05). In particular, the patients had many more CD8+ S6F1+ lymphocytes (which are considered to be activated cytotoxic T lymphocytes; 32.2 +/- 11.8%, 42.0 +/- 26.5 x 10(3) cells/ml) than did the controls (6.31 +/- 1.69%, 0.42 +/- 0.25 x 10(3) cells/ml, p < 0.01). These data indicate that activated cytotoxic T lymphocytes may be important in the pathogenesis of bronchiolitis obliterans organizing preumonia.