Researchers at the University of Texas and EnLiSense, a Texas startup, have developed a skin sweat sensor that can measure cytokine levels continuously for up to 168 hours. The technology has been adapted so that it can detect cytokines involved in the deadly cytokine storms that occur in patients with COVID-19 and other illnesses, such as influenza. The researchers hope that it might serve as an early warning system for an impending storm, allowing early treatment.
Cytokine storms involve a massive release of pro-inflammatory cytokines, leading to intense inflammation that can cause significant damage to organs, sometimes leading to death. It can occur in severe cases of COVID-19, so methods to predict an impending storm would be very useful for clinicians. Early treatment with anti-inflammatories could help to save a patient’s life.
“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,” says Shalini Prasad, a researcher involved in the study.
One option is a blood test to check if cytokine levels are increasing, but this is inconvenient, and provides only one snapshot in time. Continuous measurement is preferable, and these researchers have shown that sweat sensing may be a viable alternative.
The researchers adapted a previous sweat sensor that they had developed to detect cytokines involved in inflammatory bowel disease. It consists of a sensor strip into which passive sweat diffuses. The strip contains two electrodes and is loaded with antibodies against the cytokines of interest. When the cytokines bind, they change the electric current running through the device, and this is measured and wirelessly transmitted to a smartphone.
The current sensor measures seven different cytokines that are relevant to cytokine storms. These are interleukin-6, -8 and -10, tumor necrosis factor-α, tumor necrosis factor-related apoptosis-inducing ligand, interferon-γ-induced protein-10 and C-reactive protein.
The researchers have tested the device in a small number of volunteers, but eventually want to test it with COVID-19 patients. “Access to COVID-19 patients has been a challenge because healthcare workers are overwhelmed and don’t have time to test investigational devices,” said Prasad. “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.”
See a video about the technology below:
The research was presented at the spring meeting of the American Chemical Society (ACS)