Elevated Serum Angiotensin-converting Enzyme Research Articles

The level of angiotensin-converting enzyme as indicator of 2-year prognosis in untreated pulmonary sarcoidosis without erythema nodosum.

In order to evaluate the prognostic significance of elevated serum angiotensin-converting enzyme (SACE) in pulmonary sarcoidosis, the 2-year prognosis was studied in 33 untreated patients without erythema nodosum. Elevated SACE was found in 19 patients among whom total regression or improvement was noted in 42%, against 86% in 14 patients with normal SACE in serial measurements. The groups with and without elevated enzyme levels were not different with respect to sex, age, pulmonary changes, or extrathoracic manifestations. Thus, the findings of elevated SACE in this category of sarcoidosis patients may have some prognostic significance, pointing toward a greater risk of a chronic course.

Angiotensin-converting enzyme in hypercalcaemic disorders.

Serum angiotensin-converting enzyme (SACE) was elevated (mean +/- S.D. 55.2 +/- 19.8 U/ml) in 11 patients with hypercalcaemia due to sarcoidosis, whereas it was within the normal limits ((20.0 +/- 5.2 U/ml) in 23 patients with other hypercalcaemic conditions. Among these, 16 had primary hyperparathyroidism and a SACE level of 18.6 +/- 4.7 U/ml, significantly lower than in healthy controls (24.4 +/- 6.2 U/ml). In 7 patients with hypercalcaemia due to malignancies or prolonged immobilization SACE was 21.8 +/- 5.9 U/ml. A weakly positive correlation was found between SACE and S-calcium in hypercalcaemic sarcoidosis patients but not in the other patients or in a control group of 144 consecutive sarcoidosis patients. sarcoidosis with hypercalcaemia seems to be associated with a very high prevalence of elevated SACE. Especially when sarcoidosis is suspected to be the cause of hypercalcaemia, SACE measurement may be useful as a rapid diagnostic guide.

The angiotensin converting enzyme in pulmonary sarcoidosis and the relative diagnostic value of serum lysozyme.

The serum lysozyme and angiotensin converting enzyme (ACE) levels in 39 untreated patients with sarcoidosis were compared to values obtained from 106 healthy subjects. Only minor variations due to age and sex could be demonstrated in the values of ACE and lysozyme in the healthy control groups. ACE and lysozyme activities were significantly elevated in sarcoidosis, and a correlation was established between the level of these enzymes in this disease (r=0.54,P<0.01). In addition, the serum ACE and lysozyme levels were studied in three groups of disorders which are occasionally confused with sarcoidosis, namely tuberculosis (10 patients), lymphoma (10 patients) and bronchogenic carcinoma (14 patients). In distinguishing sarcoidosis from these illnesses, ACE was demonstrated to be a more specific test than lysozyme as none of our other disease groups demonstrated elevated levels of ACE, but as many as 40% had elevated lysozyme levels. We suggest that in the presence of an appropriate clinical picture, an elevated serum ACE may be sufficient evidence to eliminate the need for biopsy in sarcoidosis.

Serum and Lymph-node Collagenase in Sarcoidosis: Comparison with Angiotensin-converting Enzyme

Serum collagenase was significantly elevated in stage II, but not stage I sarcoidosis, in contrast to elevation of serum angiotensin-converting enzyme in stages I and II. Neither serum collagenase nor angiotensin-converting enzyme was elevated in active tuberculosis. Elevated serum collagenase and angiotensin-converting enzyme levels were decreased with steroid therapy. Serum collagenase and angiotensin-converting enzyme were significantly correlated but did not vary identically. Collagenase was not elevated in lymph nodes in sarcoidosis, in contrast to marked elevation of angiotensin-converting enzyme. The results suggest that serum angiotensin-converting enzyme is a more sensitive index of sarcoidosis activity than serum collagenase, which may have an ancillary role in assessment of the disease.

Marked Elevation of Serum Angiotensin-converting Enzyme and Hepatic Fibrosis Containing Long-spacing Collagen Fibrils in Type 2 Acute Neuronopathic Gaucher’s Disease

Serum angiotensin-converting enzyme in a patient with type 2 acute neuronopathic Gaucher's disease (242 nmol/min/ml) was 10.8 times higher than values for eight patients with other hereditary neurologic abnormalities (22.5 +/- 2.0) and 9.4 times higher than those for 12 patients with other diseases (25.7 +/- 2.6) (P less than 0.001). Serum lysozyme was not elevated in the patient with type 2 Gaucher's disease. These results indicate that elevated serum angiotensin-converting enzyme in an infant with neurologic involvement and hepatosplenomegaly is suggestive of the possibility of type 2 Gaucher's disease. Typical Gaucher's cells and fibrosis were observed by light and electron microscopy of the liver. An aspect hitherto unreported in Gaucher's disease or in the liver was that approximately 20% of the collagen fibrils were of the long-spacing type, with periodicity of 1,000 to 1,100 A and diameters of 900 to 1,500 A.

Histoplasmosis vs Sarcoidosis

To the Editor.— Walker et al (237:1350-1352, 1977) described a patient with histoplasmosis in whom noncaseating granulomas were seen. They emphasized the fact that it is sometimes difficult to determine the origin of such granulomas or to distinguish between sarcoidosis and disseminated histoplasmosis. This is certainly true, although much assistance can now be obtained by an assay of serum angiotensin-converting enzyme (ACE). The association of elevated serum ACE levels with active sarcoidosis was fully reported in 1975 1-3 and has since been confirmed by a number of authors. Elevated levels as seen in sarcoidosis do not usually occur in patients with those mycobacterial or fungal lung diseases that enter into the differential diagnosis of sarcoidosis. For example, we found only one of 15 patients with disseminated coccidiodomycosis to have an elevation of serum ACE, 4 and this one case brings under consideration the possibility of coexistent sarcoidosis and pulmonary fungal

Elevated serum and spleen angiotensin converting enzyme and serum lysozyme in Gaucher's disease

In adult chronic non-neuronopathic (Type 1) Gaucher's disease significant ( p < 0.001) elevations of angiotensin converting enzyme in serum (93.3 ± 14.8 nmol/min/ml; number elevated, 8/11; normal control 32.2 ± 1.30, n = 58) and spleen (5.62 ± 0.35 nmol/min/mg protein, n = 2; control, 0.431 ± 0.101, n = 4) and serum lysozyme (15.6 ± 3.37 μg/ml; number elevated, 4/5) were observed. The K M for hippuryl- l-histidyl- l-leucine of Gaucher (1.31 mM) and normal (1.23 mM) serum angiotensin converting enzyme were similar. The increased angiotensin converting enzyme (ACE) in Gaucher's disease may be related to the genetic defect resulting in increased ACE synthesis in Gaucher cells, or perhaps generally, while high lysozyme may reflect an increased body mass of reticuloendothelial cells. These enzyme elevations may be of use in suggesting the possible presence of Gaucher's disease and perhaps in assessing the magnitude of pathologic involvement.