Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia are indistinguishable by their cerebrospinal fluid proteomes.
Schutzer, Steven E, Liu, Tao, Tsai, Chia-Feng et al. · Annals of medicine · 2023 · DOI
Quick Summary
Researchers examined the fluid surrounding the brain and spinal cord in people with ME/CFS—some of whom also had fibromyalgia and some who did not. Using advanced technology to measure thousands of proteins in this fluid, they found no significant differences between the two groups. This suggests that ME/CFS and fibromyalgia may not be completely separate diseases, but rather may overlap or be related conditions.
Why It Matters
Understanding whether ME/CFS and fibromyalgia are distinct diseases or related conditions has important implications for diagnosis, treatment, and research priorities. If they share underlying biological mechanisms, patients and clinicians may benefit from integrated treatment approaches, and researchers can focus resources on common pathways rather than studying them separately.
Observed Findings
No proteins in cerebrospinal fluid showed statistically significant differences between ME/CFS patients with and without fibromyalgia
2,083 total proteins were successfully quantified across the study samples
1,789 proteins were reliably measured in all CSF samples examined
The study compared two groups of 15 ME/CFS patients each, stratified by fibromyalgia comorbidity
Inferred Conclusions
ME/CFS and fibromyalgia, as currently clinically defined, may not be distinct central nervous system entities
They may represent overlapping conditions or extensions of a common underlying process
Quantitative CSF proteomics is a viable approach for discovering biomarkers in these conditions
Remaining Questions
Would larger sample sizes reveal subtle protein differences between ME/CFS with and without fibromyalgia?
Are there differences in other biological markers (metabolites, cytokines, or proteins in other body fluids) that distinguish these conditions?
Do shared CSF protein profiles reflect shared disease mechanisms, or do separate mechanisms produce similar protein signatures?
What This Study Does Not Prove
This study does not prove that ME/CFS and fibromyalgia are the same disease—only that their CSF protein profiles are currently indistinguishable using this method. It does not establish whether other biological differences exist in other body fluids or tissues, nor does it clarify whether shared protein patterns mean shared causes or separate diseases with overlapping symptoms.