Relationship between angiotensin-converting enzyme and lysozyme in sarcoidosis.

The relationship between serum angiotensin-converting enzyme (SACE) and serum lysozyme (SLZ) was examined in 48 patients with sarcoidosis. The level of at least one enzyme was elevated in all 41 cases with active sarcoidosis; both enzymes were elevated in 24. SACE and SLZ were positively correlated. The elevation of SLZ or SLZ+SACE was most frequent in patients with pulmonary parenchymal involvement or extrathoracic manifestations. Both enzymes are suitable for disease monitoring, but in most cases the more specific SACE must be preferred as a measure of disease activity, although SLZ seems to be a little more sensitive. Blood for SACE analysis must arrive at the laboratory not later than 3 days after blood collection in order to avoid enzyme inactivation.