Re: Relationship between sarcoidosis and hypercalcemia


rajamohan82@xxxxxxxxx wrote:
This is a short question, but I am wondering why there is hypercalcemia
in patients with sarcoidosis? What is the underlying physiological
mechanism? Thanks.

Sarcoidosis is a general immune activation as seen by elevated
angiotension converting enzyme levels and Tcell subset alternations
with resultant granulomatous formation.
In the liver they can act as a space occupying lesion with markers of
cholestasis being present.

In the lungs with Bronchial-lavage samples yielding lymphocytosis and
subset alternations.

"In vitro experiments of cultured alveolar macrophages from patients
with sarcoidosis and of homogenized sarcoid lymph node tissue have
demonstrated that the sarcoid macrophage is able to synthesize
1,25-dihydroxyvitamin D via 25-hydroxyvitamin D3-1-alpha hydroxylating
activity. The excess circulating 1,25-dihydroxyvitamin D produced
extrarenally causes increased intestinal absorption of calcium,
enhanced bone resorption, and resultant hypercalciuria with or without
hypercalcemia."

http://www.emedicine.com/PED/topic2043.htm

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