Diagnosing Cystic Fibrosis with Sweat Sticker
Scientists have developed a “sweat sticker” device for anticipated use in diagnosing cystic fibrosis (CF). The sticker collects the wearer’s sweat and measures the level of chloride, a component of salt, in the sweat in real time. High levels of chloride in sweat indicate CF.
The gold standard for diagnosing CF is measuring the amount of chloride in sweat. Excessive chloride levels in sweat are a common symptom of CF. People with CF can have sweat that is two times saltier than people without CF.
Current devices used to measure chloride in sweat are often strapped around the arm. However, these devices can be awkward or uncomfortable, especially for delicate infant skin. Some of the current sweat chloride tests take as long as 30 minutes. Additionally, the current methods frequently do not collect sufficient sweat from infants and the sweat that is collected must be transferred to another device for reading.
In contrast, the silicone material from the sweat sticker allows for flexibility and gently shapes to an infant’s arm. The sticker also collects 33% more sweat than the current standard for sweat collection. In a study of 51 participants, the sticker collected sufficient sweat from all participants to receive reliable results.
Furthermore, the sweat sticker can measure chloride levels itself and does not require the transfer of sweat to another device for further analysis. A smartphone camera can read the colored results made by the sticker, so the test can be administered at home. A more intense purple color indicates a higher concentration of chloride.
Larger studies and additional testing of these new sweat stickers are necessary before they can be made widely available.
CF is an inherited disorder and is among the most common recessive genetic disorders in the United States. About 35,000 people in the United States have the disorder. It is estimated that over 10 million Americans carry a mutated gene that causes CF but many are likely unaware of it.
People with CF produce thick, sticky mucus in their respiratory and digestive systems which leads to complications throughout the body. When the mucus builds up in the lungs, it’s easy for bacteria to grow, which then causes frequent infections. Mucus can build up in the pancreas, an organ that produces enzymes that help digest food. Mucus buildup in the pancreas can prevent it from properly functioning and cause malnutrition.
While CF cannot be cured, the disorder can be managed. Diagnosis of CF at younger ages allows for early treatment and minimizing complications caused by the condition.
Today, there are a number of tests to detect CF early-on. Newborns are routinely screened for CF with a blood test and/or genetic testing using blood collected from the heel. Adults who suspect they have CF or who want to know if they are genetic carriers of the disorder can have genetic testing. If these initial tests suggest the person has CF, a sweat chloride test can confirm the results. There is increasing research on the role of wearables in the detection and management of CF. Additional studies will inform which technology can be best paired with which patients.
Experts tailor treatment plans to meet the individual needs of each person with CF. Techniques range from conducting frequent breathing exercises to wearing a vibrating vest that loosens the mucus in the chest. Medications can be prescribed to clear mucus, relax the muscles for breathing, or to fight infection.
As scientists develop new treatments and therapies, people with CF are living longer than ever and with better quality of life.
Ray TR, Ivanovic M, Curtis PM, et al.. Soft, skin-interfaced sweat stickers for cystic fibrosis diagnosis and management. Sci Transl Med. 2021 Mar 31;13(587):eabd8109. Accessed December 7, 2021. doi: 10.1126/scitranslmed.abd8109. PMID: 33790027; PMCID: PMC8351625.
Doctrow, B. (2021, April 20). “Sweat sticker” for diagnosing cystic fibrosis. National Institutes of Health (NIH). Accessed December 7, 2021, from https://www.nih.gov/news-events/nih-research-matters/sweat-sticker-diagnosing-cystic-fibrosis
Centers for Disease Control and Prevention. (2020, May 18). Cystic Fibrosis. Accessed December 7, 2021. https://www.cdc.gov/genomics/disease/cystic_fibrosis.htm
National Heart, Lung, and Blood Institute. Cystic Fibrosis. Accessed December 7, 2021. https://www.nhlbi.nih.gov/health-topics/cystic-fibrosis
Cystic Fibrosis Foundation. Airway Clearance. Accessed December 7, 2021. https://www.cff.org/managing-cf/airway-clearance
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