Clinical Use
The main application of ACE testing is monitoring of patients diagnosed with sarcoidosis, due to the increased production of ACE by sarcoidal granulomas. However, ACE should not be used as a diagnostic test for sarcoidosis at it lacks sensitivity and specificity; ACE levels are greatly influenced by ACE gene polymorphisms. Sarcoidosis is a diagnosis of exclusion which usually requires careful examination of history and histological evidence.
Background
In vivo, Angiotensin-Converting Enzyme (ACE) catalyses the conversion of Angiotensin I to Angiotensin II, and inactivates bradykinin during regulation of blood pressure via Renin-Angiotensin-System. Elevated serum ACE levels are reported in granulomatous-inflammatory diseases such as sarcoidosis and mixed connective tissue disease, nephropathies associated with diabetes and glomerulonephritis, cardiovascular diseases (such as left ventricular hypertrophy), brain and myocardial infarction. Elevated levels of serum ACE have been measured in patients suffering from various disorders. Low serum values have been reported in lung cancer, malignant lymphoma and multiple myeloma. They may indicate a poor prognosis or rapid progression of disease.
Reference Range
6 months to 17 years: 29 – 112 U/L
18 years and above: 20 – 70 U/L
Associated Diseases
Sarcoidosis
Specimen requirements
Serum (SST yellow top tube) specimen
Turnaround time
Specimens are analysed in a single batch every week; turn-around time is up to 7 days.