Researchers aim to develop non-invasive methods to diagnose chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a complex, long-term disorder characterized by severe fatigue that does not improve with rest and may be worsened by physical activity. This fatigue is so severe that it limits a person’s ability to perform everyday tasks, such as cooking, showering, or even getting dressed. Additional symptoms include muscle pain, joint pain, memory problems, headaches, sleep disturbances, and sensitivity to light and sound.

There is currently no known cause or cure for CSU, which affects about 3.3 million people in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC).

There is also no specific diagnostic test.

“It’s a mysterious disease. There is no biological indicator that can be used to diagnose chronic fatigue syndrome, so doctors have to make a diagnosis by excluding other symptoms and conditions,” says Xuanhong Cheng, a Lehigh University researcher and professor of bioengineering and materials science.

Cheng is part of an international research team that recently received funding from the US National Institutes of Health (NIH) to study molecular and cellular changes in muscle tissue that could potentially lead to better diagnostic tools and therapeutics for treating CSU and related conditions such as “long COVID.”

“The symptoms of CSU are very similar to those of long COVID,” Cheng notes. “But one of the most consistent symptoms of both diseases is muscle pain. Our partner, Tiziana Pietrangelo at Gabriele d’Annunzio University in Italy, has been studying CSU for over a decade and has found that people with the disease also have elevated levels of oxidative stress in muscle tissue, which contributes to rapid muscle fatigue.”

Multidisciplinary approach to research

The team is using an interdisciplinary approach to study whether there are biological indicators in muscle tissue that could be used to diagnose or treat patients with CSU.

• Pietrangelo investigates the physiology of skeletal muscle tissue and muscle stem cells, as well as the role played by oxidative stress.
• Stefano Cagnin, a professor at the University of Padova in Italy, studies gene expression in muscle fibers and muscle stem cells, comparing results from healthy people with those from patients with CSU to identify molecular changes associated with the disease.
• Cheng analyzes the electrical characteristics of skeletal muscle stem cells using broadband electrical sensing technology she co-developed to identify signs of healthy or diseased cells.

"We'll try to find out whether these electrical signatures are specific enough to be used to diagnose the disease," Cheng says.

Electrical measurements could be a valuable diagnostic tool because they are simpler and cheaper than molecular analysis. But first, the researchers must determine how these electrical changes relate to molecular abnormalities that other team members identify.

Innovative approach

“When it comes to SKU, researchers have focused on different tissues, organs, and mechanisms, but we are one of the first teams to look specifically at changes in skeletal muscle stem cells,” Cheng notes. “And we are using a multidisciplinary approach to study these changes at the molecular, subcellular, and cellular levels.”

By combining their data, the team hopes to develop a more complete understanding of how CSU affects muscle and whether these changes can be used as diagnostic markers or therapeutic targets.

The team’s long-term goal is to create non-invasive diagnostic tools. “For example, using an electrode at a certain frequency could allow us to detect abnormal readings that indicate pathology in the muscles,” Cheng explains.

Prospects for therapy

Additionally, the team plans to explore therapeutic strategies that could, for example, reduce oxidative stress and improve symptoms in patients.

“Because CSF was so poorly understood, people with the disease were often told they were lazy or that their symptoms were imaginary,” Cheng says. “I think long COVID has unfortunately made people realize that these symptoms are very real and can occur after a viral infection. We’re glad that attitudes are changing and hope to help these people regain their health.”

The study was published on Lehigh University's website.