A watch-sized device can scan for sweat and detect signs of an impending and deadly cytokine storm caused by Covid-19 and other infections.
The phenomenon occurs when chemicals in the blood, called cytokines, multiply rapidly and remain uncontrolled.
These small chemicals are designed to restrict and control the immune system and when they break down can lead to inflammation and organ damage.
At the beginning of the COVID-19 pandemic, doctors recognized that patients who developed a “cytokine storm” were often the sickest and most at risk of death.
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A watch-sized device can detect sweating and detect signs of an impending and deadly cytokine storm that is caused by Covid-19 and other infections.
A cytokine storm occurs when cytokines in the body pass through the bloodstream, causing the creation of other immune cells, leading to organ damage.
Researchers at the University of Texas at Dallas made sensory tapes with antibodies against seven pro-inflammatory proteins and tested six healthy people and five people with the flu, another virus that can trigger a cytokine storm.
Two of the patients had high levels of cytokines, while all participants had cytokines in sweat, which corresponded to the expected values based on previous research.
An early warning system would allow doctors to administer steroids quickly, reducing the risk of a cytokine storm getting out of control, “said the researchers.
“Especially now in the context of COVID-19, if you could monitor pro-inflammatory cytokines and see them on an upward trend, you could treat patients early, even before they develop symptoms,” said study author Shalini Prasad.
Early detection is important, because once a storm of cytokines is triggered, excessive inflammation can damage organs, causing serious illness and death.
Conversely, if doctors could administer steroid or other therapies as soon as cytokine levels begin to rise, hospitalizations and deaths could be reduced.
Although blood tests can measure cytokines, they are difficult to perform at home and are not able to continuously monitor protein levels.
Cytokines are excreted in sweat at lower levels than in the blood.
To collect enough sweat for testing, the scientists asked the patients to move or applied a small electric current to the patients’ skin.
However, these procedures can themselves alter cytokine levels, according to Prasad.
“When it comes to cytokines, I found that you have to measure them in passive perspiration,” said the lead investigator.
“But the big challenge is that we don’t sweat too much, especially in air-conditioned environments,” she says.
The team estimates that most people produce only about 5 microliters, or a tenth of a drop, of passive perspiration in a 0.5-inch square in 10 minutes.
Thus, the researchers wanted to develop an extremely sensitive method to measure cytokine levels in small amounts of passive perspiration.
They relied on their previous work on a portable sweat sensor to monitor markers of inflammatory bowel disease (IBD).
The wristwatch measures the levels of two proteins that increase during the onset of IBD and, when worn on the arm, passive perspiration diffuses into a sensory band.
Early detection is important because once a cytokine storm is triggered, excessive inflammation can damage organs, causing serious illness and death, says study author Shalini Prasad (center image)
Researchers at the University of Texas at Dallas developed sensory tapes with antibodies against seven pro-inflammatory proteins and tested six healthy people and five people with the flu, another virus that can trigger a cytokine storm.
The sensor, which contains two electrodes, is coated with antibodies that bind to the two proteins, a process that changes the electric current that goes to the reader.
The reader then wirelessly transfers the data to a smartphone app that converts electrical measurements into protein concentrations.
After a few minutes, the old sweat spreads and the newly excreted sweat enters the band for analysis.
For their new cytokine sensor, known as SWEATSENSER Dx, the researchers made sensory strips with antibodies against seven pro-inflammatory proteins.
SWEATSENSER Dx was sensitive enough to measure cytokines in patients taking anti-inflammatory drugs that excrete far fewer chemicals.
The device tracked cytokine levels up to 168 hours before the sensor band was needed for replacement.
EnLiSense, in partnership with researchers, is now planning clinical trials of the cytokine sensor in people with respiratory infections.
“Access to patients with COVID-19 has been a challenge because health care workers are overwhelmed and do not have time to test investigative devices,” says Prasad.
But we will continue to test it for all respiratory infections, because the triggering disease itself does not matter – this is what happens to the cytokines we are interested in monitoring.
The findings are presented at the ACS meeting in the spring of 2021.