New biomarkers can help target treatment for chronic skin disease

Sarcoidosis is a rare systemic disease that afflicts an estimated 200,000 people in the U.S., more often people who are Black and more women than men, particularly when it causes chronic skin disease. Now, clinicians may be better able to diagnose, monitor, and treat the condition, thanks to new research from scientists at the Perelman School of Medicine, published in the Journal of Clinical Investigation.

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Using skin, lung, and blood samples from sarcoidosis patients and other patients with granulomas (lumps), the team has found that cells called type 1 innate lymphoid cells (ILC1s) are found at much higher levels in the granulomas of patients with sarcoidosis. Additionally, in targeting a pathway, called CXCR4, these cells can inhibit granulomas from forming. These findings suggest that clinicians may be able to diagnose sarcoidosis by measuring patients’ ILC1 levels, and potentially even treat the condition by using already available medications that inhibit the CXCR4 pathway.

“Along with the challenge of diagnosing sarcoidosis, up to this point, first-line therapy for sarcoidosis patients is broad immunosuppression with steroids, which is like using a blunt instrument to make a fix,” says Thomas Leung, an assistant professor of dermatology at Penn. “By identifying a cause of the disease, we may have found a better way to diagnose the disease as well as a potential treatment that avoids major side effects.”

Sarcoidosis is characterized by the formation of granulomas, or clumps of immune cells, in organs, including the skin. The granulomas in the skin can form large lumps and often occur on the face. These lesions can compromise breathing and can severely affect patients’ interpersonal interactions and quality of life. Importantly, granulomas can also form internally, in and around vital organs like the heart, lungs, and eyes, causing chronic inflammation and permanent organ scarring, sometimes leading to death.

“ILC1 is an important part of the body’s inflammatory response,” says Leung. “Like everything, however, when it comes to the human body, the right balance is always critical, and a 12-fold difference between patients with sarcoidosis and patients without the disease is substantial and made us suspicious of these cells.”

Read more at Penn Medicine News.