Serum angiotensin converting enzyme activity in Crohn's disease and ulcerative colitis.

The relationship between serum angiotensin-converting enzyme activity (SACE) and inflammatory bowel disease was investigated in 30 patients with active Crohn's disease (CD) (CDAI > 150), 12 patients were not taking active medication, while 11 were on prednisone and 7 on mesalazine (5-ASA). Of 12 patients with active ulcerative colitis (UC), 4 patients were without treatment, 4 were on prednisone and 4 on mesalazine. Twelve patients with acute pulmonary sarcoidosis and 25 healthy subjects were studied. SACE levels in CD were not significantly different compared to healthy subjects and did not appear to be affected by the anti-inflammatory therapy. The average levels of SACE in UC were significantly higher than those of healthy subjects and CD (p < 0.005). Among the UC patients there was a trend for lower levels in the group treated with prednisone. In patients with active sarcoidosis SACE levels were extremely elevated and were significantly higher than in all other groups examined (p < 0.0001). The granulomatous inflammation in Crohn's disease differs from that of sarcoidosis, in which there is a striking elevation of angiotensin converting enzyme in serum. In other words, SACE levels seem to differentiate patients with active CD from patients with UC.