A review of angiotensin converting enzyme in health and disease.

ACE, a carboxypeptidase that hydrolyses angiotensin-1 to angiotensin-2, is widely found in human tissues including vascular endothelium. It is also produced by epithelioid cells of sarcoid granulomata which elevate serum ACE, a useful test of active sarcoidosis, despite its less than optimal sensitivity and specificity. It is not known why ACE production is increased in only certain granulomatous disorders. The explanation may assist our understanding of the pathogenesis of sarcoidosis.