11 deoxy cortisol
It is a simple blood test that measures 11-deoxycortisol levels in blood. It is also called cortodoxone test or compound S test. This test is used in the diagnosis of an adrenal gland inherited disorder called congenital adrenal hyperplasia (CAH).this test is also used in patients with Cushing’s syndrome to assess the adrenal gland response to metyrapone.
There are two adrenal glands in the body .they are located on top of each kidney. These glands secrete certain hormones such as cortisol, aldosterone and androgens. These hormones play many important functions and are essential for life. These glands are stimulated by ACTH (adrenocorticotropic hormone) secreted by pituitary gland in the brain. Thus ACTH regulates cortisol and androgen production from adrenal glands
11-deoxycortisol levels are increased in conditions where ACTH levels are high such as ACTH producing tumours in the brain .its levels also increase in rare form of CAH caused due to deficiency of11b-hydroxylase enzyme.
Congenital adrenal hyperplasia (CAH) is an inherited disorder in which there can be deficiency of certain enzyme called 11b-hydroxylase .this enzyme is required for conversion of 11-deoxycortisol to cortisol. Thus in this condition there is increase in 11-deoxycortisol levels and low cortisol levels.
Cushing’s syndrome is a condition in which there is an increase cortisol blood level due to excessive production of cortisol from adrenal glands. Metyrapone inhibits the enzyme 11b-hydroxylase.so 11-deoxycortisol levels are seen after giving metyrapone to find out the differential diagnosis of Cushing’s syndrome.11-deoxycortisol levels increases many fold after administration of metyrapone. Reduced response may occur in patients with adrenal gland failure, pituitary gland dysfunction or hypothalamic dysfunction.
The healthcare provider may prescribe this test in following situations:
The sample for 11-deoxycortisol test is taken from blood (serum) by inserting a small needle into vein of your arm .A small amount of blood (about 1ml) is then collected in test tube or vial. You may feel some pain due to needle prick. Early morning blood sample is preferred.
Normal adult range-0.7 to 2.7 nmol/L
Normal neonates-<20 nmol/L
Patients with untreated 11b-hydroxylase deficiency->100 nmol/L