doctors in an effort to find a diagnosis for her symptoms, is finally diagnosed with CFS. American author Ann Bannon had CFS. Laura Hillenbrand, author of the popular book Seabiscuit, has struggled with CFS since age 19. Research Current research into ME/CFS may lead to a better understanding of the disease's causes, biomarkers to aid in diagnosis, and treatments to relieve symptoms. The emergence of long COVID has sparked increased interest in ME/CFS, as the two conditions may share pathology, and a treatment for one may treat the other. Causes Recent research suggests dysfunction in many biological processes. These changes may share a common cause, but the true relationship between them is currently unknown. Metabolic areas of interest include disruptions in amino acid metabolism, the TCA cycle, ATP synthesis, and potentially increased lipid metabolism. Other research has investigated immune dysregulation and its potential connections to mitochondrial dysfunction. Autoimmunity has been proposed as a cause, but evidence is scant. People with ME/CFS may have abnormal gut microbiota, which has been proposed to affect mitochondria or nervous system function. Several small studies have investigated the genetics of ME/CFS, but none of their findings have been replicated. A larger study, DecodeME, is currently underway in the United Kingdom. Treatments The drug rintatolimod is currently in an experimental trial in the US to treat both ME/CFS and Long COVID. Rituximab, a drug that depletes B cells, was studied and found to be ineffective. Biomarkers Many biomarkers for ME/CFS have been proposed, but none have been validated or made available outside of research. Challenges The existence of multiple diagnostic criteria, and variations in how scientists apply them, complicate comparisons between studies. Some definitions, like the Oxford and Fukuda criteria, may fail to distinguish between chronic fatigue in general and ME/CFS, which requires PEM in modern definitions. Definitions also vary in which co-occurring conditions preclude a diagnosis of ME/CFS. ME/CFS affects multiple bodily systems, varies widely in severity, and fluctuates over time, creating heterogeneity within patient groups and making it very difficult to identify a singular cause. Dividing patients into subtypes may help manage this heterogeneity. See also Long COVID Unrest (2017 film) References External links Immune system disorders Neurological disorders Syndromes of unknown causes