Utility of angiotensin-converting enzyme and serum calcium levels in cutaneous sarcoidosis.

BACKGROUND
Sarcoidosis is a granulomatous disease of unknown etiology but is theorized to result from immune overactivity in the setting of an environmental or genetic trigger. It most commonly affects the lungs and lymph nodes but can affect other organ systems, with cutaneous involvement in 30% of patients. The granulomas associated with sarcoidosis lead to increased activity of angiotensin-converting enzyme (ACE) and 1α-hydroxylase resulting in an uncontrolled synthesis of 1,25-dihydroxyvitamin D3 by macrophages, along with elevated serum ACE and calcium levels. Serum ACE and calcium levels are frequently ordered when a patient is diagnosed with cutaneous sarcoidosis. However, their clinical utility in this setting remains unknown.


METHODS
In this retrospective chart review, we assessed serum ACE and calcium levels in 19 patients with cutaneous sarcoidosis diagnosed by histopathology without preceding evidence of systemic involvement. Serum ACE and calcium levels were also investigated as markers in the progression from mono-organ cutaneous sarcoidosis to systemic sarcoidosis.


RESULTS
No patients with biopsy-proven cutaneous sarcoidosis had abnormal levels of serum calcium at presentation in a cohort of 17 patients at a single institution. An abnormally elevated ACE level was only seen in one of 13 patients presenting with cutaneous sarcoidosis.


CONCLUSIONS
Our data suggest that serum ACE and calcium levels are not reliable markers of either cutaneous sarcoidosis or the progression to systemic sarcoidosis.