Angiotensin-converting enzyme in newly detected sarcoidosis. With special reference to enzyme levels in patients with erythema nodosum.

Serum angiotensin-converting enzyme (SACE) was measured in 56 patients with sarcoidosis within three months after diagnosis. Serial analyses were performed in 42 patients, who were followed for two months to one year. SACE was elevated in 49 (70%) of the patients at some time during the period of observation. Erythema nodosum (EN) was present in 14 patients. Only one out of seven had elevated SACE during EN, but four months later SACE was elevated in all 14. In this group there was a negative correlation between SACE and S-lysozyme. Among 42 patients without EN the frequency of SACE elevation was rather constant, about 60%. In half of the patients SACE was normal at first examination, and subsequent elevation was observed in 19%. SACE and S-lysozyme were positively correlated. Enzyme activity was independent of mode of presentation, but a non-significant trend toward higher SACE in patients with pulmonary involvement was observed, and changes in SACE were roughly correlated to roentgenological changes. Among healthy controls, significantly higher SACE levels were found in children up to 17 years of age (reference interval 21.2-42.2 U/ml) than in adults aged 18-65 years (12.0-36.8 U/ml). The observations on patients with sarcoidosis demonstrate that a unique pattern of SACE occurs in those with EN, different from that of patients without EN. The findings support the view that EN is a hallmark of acute-onset sarcoidosis. The value of serial SACE analyses is emphasized.