Studies on the pathogenesis of sarcoidosis Part I. Studies on bronchoalveolar lavage fluid

The present study was designed to investigate the local immunity and pathological state of sarcoidosis. Cell populations and angiotensin converting enzyme (ACE) activity were examined in the fluid obtained by bronchoalveolar lavage (BAL) of 28 patients with sarcoidosis and 31 healthy volunteers. The proportion and number of lymphocytes in BAL fluid were significantly higher in patients with sarcoidosis than in healthy volunteers. Furthermore, the number of T lymphocytes and B lymphocytes were increased. The cell number in BAL fluid was also higher in non-smokers with sarcoidosis than in healthy non-smokers. The ACE activity in bronchoalveolar lavage fluid (BALF-ACE activity) was highly elevated in patients with sarcoidosis as compared with healthy volunteers and correlated with the number of macrophages in BAL fluid of non-smokers with sarcoidosis (r=0.474, p