Comparison of two methods for measurement of serum angiotensin-converting enzyme in sarcoidosis

Abstract

A commercially available radiochemical (RC) assay (Ventrex®) and a spectrophotometric (SP) assay for serum angiotensin-converting enzyme (SACE) were compared in 80 adults (40 blood donors, 20 patients with and 20 patients without sarcoidosis), covering a wide range of enzyme activities. A good agreement and a linear correlation (P<0.001) between the assays were observed. SACE were 25 ± 5 kU/l (SP assay) and 98 ± 18 kU/l (RC assay) in blood donors, corresponding to a conversion factor of 3.9. The RC assay may have some theoretical advantages, but both methods seem to be equally suitable for use in the management of sarcoidosis. The choice may partly depend on the requisite technical equipment.

Key-words:

• angiotensin-converting enzyme
• assay
• radiøchemical
• sarcoidosis
• spectrophotometric