Chronic fatigue syndrome was once dismissed as an imagined condition, but after years of research, doctors and clinicians have realized that myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a genuine condition that can affect people dramatically. Symptoms can vary widely from one person to another, and can include brain fog, fatigue, joint pain, and extreme exhaustion after mental or physical exertion. One problem for clinicians is that it is very difficult to diagnose in part because the symptoms can be nonspecific and may resemble other disorders, and there have been if any few biomarkers of the disease.
New research may help change that, however. A new study published in Cell Reports Medicine has shown that ME/CFS can lead to a wide range of quantifiable changes and abnormalities. This work revealed that in patients with ME/CFS, there are shifts in biomarkers of cellular energy metabolism; in the populations and maturation status of immune cells in circulation; and in proteins that are linked to blood vessel dysfunction.
In this research, the scientists obtained whole blood samples from 61 individuals who had been diagnosed with ME/CFS, as well as age- and sex-matched volunteers who were unaffected.
In ME/CFS patients, there were higher levels of molecules called adenosine monophosphate (AMP) and adenosine diphosphate (ADP) in white blood cells. The unusually high levels of these molecules suggest that these cells are experiencing a kind of energy stress, since the common cellular fuel adenosine triphosphate (ATP) is made using AMP and ADP. These molecules don’t seem to be getting converted to the form that cells need to function.
The work also showed that in ME/CFS patients, the populations of immune cells were improperly distributed, and shifted towards subsets of dendritic cells, T-lymphocyte subsets, and natural killer cells that were immature.
There was also evidence of disruptions to blood vessels. The levels of proteins that have been linked to the activation of blood cell linings and vessel wall remodeling were unusually high, while certain circulating immune proteins were abnormally low.
The investigators used a modeling system to find a combination of seven variables that are closely linked to ME/CFS. While ME/CFS patients have been known to have problems with immunity and indications of cellular dysfunction, this research has shown how these problems can intersect.
"We know ME/CFS is a heterogeneous disease with abnormalities in several different biological systems, but these dysfunctions have rarely been studied simultaneously within the same patients,” noted first study author Dr. Benjamin Heng, a Research Fellow in the Macquarie Medical School. "Potential interactions between these dysregulated systems may contribute to how the disease presents clinically.”
Sources: Macquarie University, Cell Reports Medicine
