In Production: Quick and Cheap Bedside Test for Cortisol Uses Smartphone

An innovative method of measuring the stress hormone cortisol is being developed by researchers in Utah. Requiring just a simple kit and a smartphone to read results, this new approach should allow quick, affordable, and accurate testing of cortisol levels, enabling rapid diagnosis of adrenal diseases, the investigators say.

“A lab charges about $25 to $50 for a quantitative salivary cortisol test and has a turnaround time of days to a week,” said lead researcher Joel Ehrenkranz, MD, director of diabetes and endocrinology at Intermountain Medical Center, Murray, Utah. “This test, taken in a medical office or at home, will cost less than $5 and take less than 10 minutes,” he noted.

Dr. Ehrenkranz reported the details of the new test kit, developed at his institution, at ICE/ENDO 2014 week. He said he and his fellow researchers are now collating clinical data for a Food and Drug Administration (FDA) submission and hope to gain approval of the test as a class 2 medical device in the United States in 2015.

Chair of the session, Jeremy Tomlinson, MD, of University of Birmingham, United Kingdom, said the new approach employs “great technology and is an interesting innovation, but there are a few concerns. For example, how well will it perform against the state-of-the-art technique for measuring salivary cortisol, which is mass spectrometry — is it as sensitive?”

Also there is a possibility the immunoassay in the new test will cross react with another steroid hormone, prednisolone, that people might be taking for a whole range of inflammatory conditions, so “you would want to make sure it’s measuring what you want it to,” he noted.

And finally, there is the question of exactly how this would be used.

Cortisol levels are needed when conditions are suspected where too much or too little cortisol is produced, but the diagnosis for most of these doesn’t really need to be immediate, Dr. Tomlinson explained to Medscape Medical News. However, he conceded there might be a role for the assay in patients presenting to the emergency room or in developing nations.

No More Presumptive Treatment of Adrenal Insufficiency

At the meeting, Dr. Ehrenkranz said that adrenal diseases are commonly overlooked because current methods of measuring salivary cortisol require instrumentation and technical personnel and so are costly and unable to deliver timely results.

He noted also that a stint in the developing world convinced him that a simpler test was needed, so he and his colleagues set about developing an assay that would be inexpensive and easy to perform — they came up with disposable cortisol immunoassay strips containing a glass fiber element with colloidal gold-labeled murine anticortisol antibodies and a saliva collection pad.

The person being tested inserts a strawlike saliva collector under the tongue, which wicks the saliva to the immunoassay test strip housed in a cassette, which is then inserted into a reader in the device.

“The device…includes a case, a light pipe, and a lens and costs about a dollar to make. There is no battery power, and it’s unbreakable, passive, and reusable,” Dr Ehrenkranz said.

Because of the physical properties of the gold nanoparticles, a smartphone flash can illuminate and camera-image the color generated by the colloidal gold-labeled anticortisol antibodies, he explained.

The color subsequently generated is “read” by an app on the smartphone to give a cortisol reading, based on an algorithm derived from observed vs reference salivary cortisol values. The R value of this curve was 0.996 for salivary cortisol in the range of 0.012-3.0 µg/dL, Dr Ehrenkranz noted.

The new technology can therefore measure cortisol in a range sufficient to diagnose adrenal insufficiency and hypercortisolism and monitor physiologic variations in cortisol concentration, he said.

And the software is “operating-system agnostic,” he added, meaning the device can be used on all platforms, including iOS, Android, Windows, and BlackBerry, and it has a universal form factor that works with all smartphones.

“Measuring salivary cortisol at the point of care in 5 minutes using an inexpensive immunochromatographic assay, reader, and smartphone may obviate the need to presumptively treat patients for adrenal insufficiency and makes cortisol assays available to regions of the world that currently lack access to this diagnostic test,” he concluded.

Test of Use in Emergency Room, in Developing Countries

Dr. Tomlinson explained that diagnosis of Cushing’s syndrome — caused either by tumors of the pituitary gland producing too much ACTH or tumors of the adrenal gland producing too much cortisol — or alternatively, diagnosis of conditions where it’s thought too little cortisol is being secreted, such as Addison’s disease — an autoimmune process whereby the adrenal gland is destroyed — are not conditions “you necessarily have to diagnose in a few minutes by the bedside,” and therefore it is better to use the “gold standard” of diagnosis, mass spectrometry, in these cases.

But the new test “might be of use in determining whether people have enough of their own natural corticosteroid, in terms of deciding whether you need to give supplemental cortisol to people in an emergency situation,” he explained.

This could include patients presenting with suspected or underlying pituitary or adrenal disease or in people who have been on large doses of steroids who have then stopped taking them, so there will be a resulting suppression of their natural steroid production, he noted.

“That’s not an uncommon situation that we see in the emergency room. At the moment, if there’s suspicion, we might take a test but it takes a day or 2 to come back from the laboratory, and in the meantime we will give patients [presumptive] steroids. But you could do this test by the bedside,” he acknowledged.

And in developing countries, use of this test “is feasible, where cost comes into the equation and you might not have access to mass spectrometry; this could be an alternative and would help you to exclude or make these diagnoses,” he concluded.

This study was privately funded. Dr. Ehrenkranz and colleagues report no relevant financial relationships.

Joint Meeting of the International Society of Endocrinology and the Endocrine Society: ICE/ENDO 2014; June 24, 2014. Abstract OR48-2

From http://www.medscape.com/viewarticle/827580

Etomidate drip quickly curbs severe hypercortisolism


AT ICE/ENDO 2014


VITALS  Key clinical point: The anesthetic induction agent etomidate is a potent suppressor of cortisol synthesis in the adrenal cortex at subhypnotic doses, making it a safe and effective agent for management of severe hypercortisolism in Cushing’s syndrome.

Major finding: Continuous infusion of etomidate using a standardized protocol resulted in a reduction in serum cortisol from a mean of 138 mcg/dL to a goal range of 10-20 mcg/dL in an average of 64 hours.

Data source: This was a retrospective case series involving six patients with severe hypercortisolism caused by adrenocorticotropic hormone–dependent Cushing’s syndrome.

Disclosures: The study was carried out with institutional funds. The presenter reported having no financial conflicts.

Continuous intravenous infusion of etomidate safely and swiftly gains control of severe hypercortisolism in patients with adrenocorticotropic hormone–dependent Cushing’s syndrome when conventional presurgical oral treatment is problematic.

“From our cumulative experience, we have now developed a standardized titrated etomidate infusion protocol, which should provide clinicians with a simple, safe, and effective means to lower serum cortisol in patients with severe clinical, metabolic, and neuropsychiatric consequences of prodigious hypercortisolism as a bridge to definitive medical or surgical therapy,” explained Dr. Katarzyna G. Zarnecki at the joint meeting of the International Congress of Endocrinology and the Endocrine Society.

Etomidate (Amidate) is a sedative hypnotic agent with an excellent cardiovascular safety profile. It is widely used in emergency settings, such as reduction of dislocated joints and cardioversion. It suppresses adrenal steroidogenesis by potently inhibiting 11-beta hydroxylase. Fortunately for endocrinologic purposes, etomidate suppresses cortisol synthesis even at subhypnotic doses. In using it off label for management of severe hypercortisolism, it’s essential to keep the drug at subhypnotic doses, meaning not more than 0.3 mg/kg per hour, emphasized Dr. Zarnecki of the University of Wisconsin, Milwaukee.

Dr. Zarnecki and her coworkers utilize as their standard etomidate infusion protocol an initial 5-mg bolus followed by an infusion at 0.02 mg/kg per hour, with dose titration in increments of 0.01-0.02 mg/kg per hour every 4-6 hours based on changes in serum cortisol level. The goal is to bring the cortisol down to a target range of 10-20 mcg/dL.

She presented an illustrative six-patient series in which she and her colleagues turned to continuous infusion of etomidate because conventional oral therapy would have taken too long to rein in the severe hypercortisolism or because medication side effects were intolerable.

Mean baseline pretreatment serum cortisol was 138 mcg/dL, with an adrenocorticotropic hormone level of 419 pg/mL. Five of the six patients reached the goal of 10-20 mcg/dL in an average time of 64 hours. The mean rate of serum cortisol reduction was 1.93 mcg/dL per hour. The average etomidate infusion rate at the time the target level was reached was 0.07 mg/kg per hour, with a maximum rate of 0.1 mg/kg per hour. Monitoring via the Richmond Agitation Sedation Scale confirmed that none of the patients experienced sedative effects.

In the sole patient who didn’t reach goal, etomidate therapy was suspended because the patient entered palliative care because of extensive tumor progression.

Dr. Zarnecki reported having no financial conflicts of interest.

From Clinical Endocrinology News

Use late-night salivary cortisol to catch recurrent Cushing’s


AT ICE/ENDO 2014


CHICAGO – Late-night salivary cortisol exceeded normal limits in 10 women with recurrent Cushing’s disease a mean of 3.5 years after transsphenoidal surgery, but their urinary free cortisol remained in normal limits, according to a retrospective review from the Medical College of Wisconsin, Milwaukee.

That adds strength to the notion that late-night salivary cortisol (LNSC) catches recurrent Cushing’s that’s missed by urinary free cortisol, even though UFC remains a standard screening approach in some places.

The study is tiny and retrospective, but at the joint meeting of the International Congress of Endocrinology and the Endocrine Society, lead investigator Dr. Ty Carroll explained why the findings still matter, and also why two LNSC measurements are better than one.

Video: http://www.clinicalendocrinologynews.com/home/article/video-use-late-night-salivary-cortisol-to-catch-recurrent-cushings/d7fad98e9289f9402034e73455b7560c.html

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