Skewing of the B cell receptor repertoire in myalgic encephalomyelitis/chronic fatigue syndrome.
Sato, Wakiro, Ono, Hirohiko, Matsutani, Takaji et al. · Brain, behavior, and immunity · 2021 · DOI
Quick Summary
This study looked at immune cells called B cells in people with ME/CFS and compared them to healthy people. The researchers found that ME/CFS patients have an unusual pattern of B cells—certain types are overrepresented while others are underrepresented. These abnormal B cell patterns were especially strong in patients whose ME/CFS started after an infection, suggesting the immune system may be stuck responding to something from that earlier infection.
Why It Matters
This study provides objective, molecular evidence of immune dysfunction in ME/CFS that could support development of diagnostic biomarkers and shed light on disease mechanisms. Understanding the skewed B cell response may help explain why ME/CFS often follows infections and could inform future therapeutic approaches targeting aberrant B cell responses.
Observed Findings
ME/CFS patients have significantly skewed B cell receptor gene usage compared to healthy controls, with biased usage of several IGHV genes.
B cell clones using IGHV3-30 and IGHV3-30-3 genes were more frequent in ME/CFS patients whose illness onset was preceded by an obvious infection.
B cell clones with IGHV3-30 and IGHV3-30-3 genes correlated with elevated interferon response gene expression in plasmablasts.
ROC curve analysis indicated the skewed B cell repertoire pattern could differentiate ME/CFS patients from healthy controls.
Inferred Conclusions
ME/CFS is characterized by an aberrant B cell response directed against infectious agents or antigens encountered before disease onset.
The B cell receptor skewing in ME/CFS suggests a sustained or dysregulated immune response to a prior infection rather than normal immune recovery.
The enrichment of infection-associated B cell clones in patients with infection-triggered onset implicates persistent antigen-driven B cell activation in ME/CFS pathophysiology.
Remaining Questions
What is the specific infectious agent or antigen that the skewed B cell population is targeting?
Does the skewed B cell repertoire persist indefinitely, or does it change over time with disease progression or recovery?
What This Study Does Not Prove
This study does not prove that the abnormal B cells cause ME/CFS symptoms—it only shows an association. It does not identify what specific infectious agent or antigen the B cells are responding to, nor does it demonstrate whether these B cell abnormalities persist, resolve, or change over the course of illness. The cross-sectional design cannot determine if the skewed repertoire is a cause, consequence, or marker of disease.