Elevation of the bronchoalveolar concentration of angiotensin I converting enzyme in sarcoidosis.

The concentration of angiotensin converting enzyme (ACE) and that of albumin (AIb) were assayed in the serum (SACE, SAlb) and in bronchoalveolar lavage fluid (LACE, LAlb). Three groups of patients were studied: 14 healthy volunteers (Group I), 45 patients with active sarcoidosis (Group II), and 7 patients with sarcoidosis in remission (Group III). The SACE in Group II (4,466 +/- 2,202 U/100 ml, mean +/- SD) was higher (p less than 0.001) than in Group I (2,470 +/- 547 U/100 ml) or in Group III (2,640 +/- 610 U/100 ml); LACE was higher in Group II (65.2 +/- 48.4 U/100 ml, p less than 0.001) than in Group I (21.1 +/- 14.7 U/100 ml), or in Group III (25.7 +/- 14.6 U/100 ml). The SAlb was found to be, respectively, 3,908 +/- 385 mg/100 ml, 3,982 +/- 965 mg/100 ml, and 3.613 +/- 222 mg/100 ml in Groups I, II, and III. The LAlb in Group II (8.2 +/- 6.2 mg/100 ml) was higher (p less than 0.01) than in Group I (2.5 +/- 1.4 mg/100 ml) or in Group III )4.1 +/- 1.0 mg/100 ml). The LACE in Group II increased with the number of alveolar lymphocytes, in nonsmokers (4 = + 0.56, df = 34, p less than 0.001) and in smokers (4 = + 0.88, df = 7, p less than 0.01). In the smokers in this group, LACE was higher with respect to the number of lymphocytes than in the nonsmokers. We conclude from this study (1) that the permeability of the alveolocapillary membrane to albumin and to ACE is increased in active pulmonary sarcoidosis, (2) that LACE increases during sarcoidosis and returns to normal when the disease is cured, and (3) that the concentration of ACE in alveolar fluid increases with tobacco use.