Sweat sensor could warn of impending COVID-19 cytokine storm

April 16 (UPI) -- Scientists have unveiled a new sweat sensor that can anticipate a looming cytokine storm and provide warning to doctors and patients.

Cytokine storms feature a surge of pro-inflammatory immune proteins. They can be triggered by a variety of infections, including COVID-19 and the flu. Studies have linked cytokine storms with more severe COVID-19 infections.

Developers are scheduled to present the new wristwatch-like device Friday at the spring meeting of the American Chemical Society. The presentation will be streamed online at 5:15 p.m. EDT.

"Especially now in the context of COVID-19, if you could monitor pro-inflammatory cytokines and see them trending upwards, you could treat patients early, even before they develop symptoms," lead researcher Shalini Prasad, professor of systems biology science at the University of Texas at Dallas, said in a news release.

Once the onslaught of cytokine proteins has arrived, a runaway cycle of inflammation can damage organs and even result in death. But with sufficient warning, an impending cytokine storm can be headed off by steroids and other therapies.

By helping doctors catch and treat cytokine storms before they turn severe, the new sweat sensor could help lower COVID mortality rates and shorten hospital stays, relieving pressure on medical resources.

Cytokines are excreted at lower levels in sweat than in blood, but efforts to induce larger amounts of sweat for sampling -- by having volunteers exercise or by applying a small electrical current to patient's skin -- altered cytokine levels.

"When it comes to cytokines, we found that you have to measure them in passive sweat," Prasad said. "But the big challenge is that we don't sweat much, especially in air-conditioned environments."

Instead of trying to induce higher quantities of sweat, researchers developed an extremely sensitive sensor. Prasad and her research partners adapted technology originally used to detect markers for inflammatory bowel disease.

The IBD sweat sensor, which features a disposable sensor attached to an electronic reader, is produced by EnLiSense LLC, a company co-founded by Prasad. The sensor features a pair of electrodes and is coated with antibodies that bind to two proteins associated with IBD flare-ups.

To make the new cytokine-sensitive sweat sensor, dubbed SWEATSENSER Dx, researchers substituted antibodies that bind to a variety of pro-inflammatory proteins: interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), TNF-related apoptosis-inducing ligand, IL-10, interferon-γ-induced protein-10 and C-reactive protein.

In tests on healthy individuals, the sweat sensor measured low cytokine levels -- concentrations that matched the levels picked up in blood serum samples. When they tested the sweat sensor on patients infected with the flu, the technology successfully identified rising levels of cytokine proteins in two of the patients.

The sensor was able to accurately track cytokine levels for up to 168 hours before the strip coated with antibodies needed to be replaced.

A number of wearable devices and biomedical technologies -- originally designed to capture a variety of health data, including heartbeat and respiratory rates -- have been offered as tools for addressing the COVID-19 pandemic, but the latest device is one of the first products designed specifically to track COVID-19-related biometrics.

EnLiSense is currently working with scientists to test their product in a clinical trial involving patients with respiratory infections.

"Access to COVID-19 patients has been a challenge because healthcare workers are overwhelmed and don't have time to test investigational devices," Prasad said. "But we're going to continue to test it for all respiratory infections because the disease trigger itself doesn't matter -- it's what's happening with the cytokines that we're interested in monitoring."