Bottom line: Serum ACE is not sensitive or specific enough to be helpful in diagnosing sarcoidosis. There is some evidence that it may be helpful in monitoring disease activity in patients who have been diagnosed with acute sarcoidosis.
Summary: Sarcoidosis in adults. In: DynaMed.
Under Blood Tests in Diagnosis section, DynaMed summarizes findings from various case series evaluating angiotensin-converting enzyme (ACE) levels in patients with sarcoidosis and other diseases. FINDINGS: Serum ACE is elevated in 30-90% of patients with sarcoidosis, but is also elevated in many other more common diseases. So it is not sensitive or specific enough for diagnosis. It is sometimes used to monitor disease activity, but there is not much evidence that this is useful.
Sarcoidosis, laboratory findings. In: Harrison’s Online. [AccessMedicine].
Reports that serum ACE levels have been reported in around 20% of patients with chronic sarcoidosis. Thus, measuring serum ACE in these patients may not be useful in monitoring disease activity.
Q J Med. 1985 Jun;55(218):253-70.
Ainslie GM, et al. Serum angiotensin converting enzyme in sarcoidosis: sensitivity and specificity in diagnosis: correlations with disease activity, duration, extra-thoracic involvement, radiographic type and therapy.
A small series that included 128 patients with sarcoidosis, found statistically significant correlations in ACE levels and stage of sarcoidosis based on chest x-ray. But Fig. 6 (p. 262) shows that the serum ACE levels overlap among patients in the various staging groups.
For information on how sarcoidosis is staged, see How is sarcoidosis staged?
Repost of 1/12/2012