[The motility of lung lymphocytes in hypersensitivity pneumonitis and sarcoidosis]

Abstract

Hypersensitivity pneumonitis (HP) and pulmonary sarcoidosis (Sa) are characterized by an accumulation of large numbers of lymphocytes within the interstitium and the epithelial surface of the lung. Although the lymphocytes in bronchoalveolar lavage fluid (BALF) are representative of interstitial cells in these diseases, the mechanism involved in an accumulation of lymphocytes on the epithelial surface are yet unknown. To explore the possibility that the lymphocytes on the epithelial surface are migrated cells from the interstitium, we studied the motility of the BALF lymphocytes in five patients with HP and nine patients with Sa and compared them to that of peripheral blood lymphocytes. The lymphocyte migration assay was performed using blind well chemotaxis chambers and cells migrated into the cellulose nitrate membranes were assessed. The total migrated cell numbers of BALF lymphocytes in HP and Sa were 753.3 +/- 86.5 and 334.2 +/- 41.0, respectively. The migration distance of BALF lymphocytes in HP and Sa assessed with leading front method were 50.2 +/- 3.8 microns and 57.9 +/- 4.6 microns, respectively. The motility of BALF lymphocytes in HP and Sa was significantly greater than that of peripheral blood lymphocytes and the motility of BALF lymphocytes were comparable to that of PHA-activated lymphocytes. The motility of BALF lymphocytes were correlated with the proportion of lymphocytes in BALF cells and the proportion of Ia+T lymphocytes. These results suggest that BALF lymphocytes in these diseases are activated and enhanced motility may facilitate the accumulation of lymphocytes to the epithelial surface.