#Antech diagnostics with cushings free#

Values may be elevated to twice normal in pregnancy. Renal disease (decreased clearance) may cause falsely low values. Random urine specimens may yield falsely elevated values when patients have a high urinary output. Liquid chromatography-tandem mass spectrometry methodology eliminates analytical interferences including carbamazepine (Tegretol) and synthetic corticosteroids. Random urine cortisol results are less reliable than results obtained from properly collected and complete 24-hour urine specimens, which are not affected by diurnal variations in cortisol levels.Īcute stress (including hospitalization and surgery), alcoholism, depression, and many drugs (eg, exogenous cortisone, anticonvulsants) can obliterate normal diurnal variation, affect response to suppression/stimulation tests, and increase baseline levels. Excessive licorice consumption and use of carbenoxolone, a synthetic derivative of glycyrrhizinic acid used to treat gastroesophageal reflux disease, also may suppress the ratio to less than 1. Patients with 11-beta HSD deficiency may have cortisone to cortisol ratios less than 1, whereas a ratio of 2 or 3:1 is seen in normal patients. However, random urine specimens are not useful for evaluation of hypocorticalism. Suppressed cortisol and cortisone values may also be observed in primary adrenal insufficiency and hypopituitarism. In these circumstances a synthetic glucocorticoid screen might be ordered (SGSU / Synthetic Glucocorticoid Screen, Random, Urine). Patients with Cushing syndrome due to intake of synthetic glucocorticoids should have both suppressed cortisol and cortisone. In these cases, continuing follow-up and repeat testing are necessary to confirm the diagnosis. Values in the normal range may occur in patients with mild Cushing syndrome or with periodic hormonogenesis. Further studies, including suppression or stimulation tests, measurement of serum corticotrophin concentrations, and imaging are usually necessary to confirm the diagnosis and determine the etiology. Most patients with Cushing syndrome have increased urinary excretion of cortisol and/or cortisone. Use the conversion factors below to convert each analyte from mcg/g creatinine to nmol/mol creatinine:Ĭortisol: mcg/g creatinine x 312=nmol/mol creatinineĬortisone: mcg/g creatinine x 314=nmol/mol creatinine Licorice (active component glycyrrhetinic acid) inhibits 11-beta HSD and excess consumption can result in similar changes. Deficiency of 11-beta HSD results in a state of mineralocorticoid excess because cortisol (but not cortisone) acts as a mineralocorticoid receptor agonist. LC-MS/MS methodology eliminates analytical interferences including carbamazepine (Tegretol) and synthetic corticosteroids, which can affect immunoassay-based cortisol results.Ĭortisone, a downstream metabolite of cortisol, provides an additional variable to assist in the diagnosis of various adrenal disorders, including abnormalities of 11-beta-hydroxy steroid dehydrogenase (11-beta HSD), the enzyme that converts cortisol to cortisone. A measurement of 24-hour UFC excretion by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the preferred screening test for Cushing syndrome. UFC is a sensitive test for the various types of adrenocortical dysfunction, particularly hypercortisolism (Cushing syndrome).

#Antech diagnostics with cushings free#

UFC represents excretion of the circulating, biologically active, free cortisol that is responsible for the signs and symptoms of hypercortisolism. Urinary free cortisol (UFC) correlates well with the concentration of plasma free cortisol.

As plasma cortisol values increase, free cortisol (ie, unconjugated cortisol or hydrocortisone) increases and is filtered through the glomerulus. Only a small percentage of circulating cortisol is biologically active (free), with the majority of cortisol inactive (protein bound).

Its production is under hypothalamic-pituitary feedback control. It plays a critical role in glucose metabolism, maintenance of vascular tone, immune response regulation, and in the body's response to stress.

It is the main glucocorticoid in humans and acts as a gene transcription factor influencing a multitude of cellular responses in virtually all tissues. Cortisol is a steroid hormone synthesized from cholesterol by a multienzyme cascade in the adrenal glands.