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[Immunopathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)].

Yamamura, Takashi, Ono, Hirohiko, Sato, Wakiro · Brain and nerve = Shinkei kenkyu no shinpo · 2018 · DOI

Quick Summary

This study found that people with ME/CFS have unusual patterns of immune system chemicals (cytokines) in their blood and spinal fluid, and some patients have antibodies that attack their own bodies. When researchers treated some ME/CFS patients with a medication that removes certain immune cells called B cells, patients improved. This suggests that ME/CFS may be caused by the immune system mistakenly attacking the body.

Why It Matters

This work supports the emerging understanding that ME/CFS has a biological, immune-mediated basis rather than a purely psychological etiology—an important validation for patients. The demonstration that a targeted immunological treatment (rituximab) shows efficacy provides a proof-of-concept for disease-modifying therapies and opens new avenues for clinical trials.

Observed Findings

  • Elevated inflammatory and anti-inflammatory cytokines present in sera and cerebrospinal fluid of ME/CFS patients
  • Presence of autoantibodies detected in subgroups of ME/CFS patients
  • Clinical improvement observed in ME/CFS patients treated with anti-CD20 antibody (rituximab) in investigator-initiated trials
  • Differences in immune markers between patient subgroups suggest heterogeneous immune phenotypes

Inferred Conclusions

  • Immune abnormalities, particularly enhanced autoimmune responses, play a significant role in ME/CFS neuroinflammation
  • B cells and their products (autoantibodies) may represent therapeutic targets in ME/CFS
  • ME/CFS demonstrates features consistent with autoimmune and/or neuroimmunological disease pathogenesis

Remaining Questions

  • Which specific autoantibodies are pathogenic in ME/CFS and what are their target antigens?
  • Why do only subgroups of ME/CFS patients exhibit detectable autoimmune markers, and are there distinct disease subtypes?
  • What is the mechanism by which B cell depletion alleviates symptoms—antibody reduction, altered cytokine production, or changes in B cell signaling?
  • Are elevated cytokines in cerebrospinal fluid produced locally by CNS-resident immune cells or derived from peripheral circulation?

What This Study Does Not Prove

This study does not establish that autoimmunity is the primary cause of ME/CFS in all patients, as autoimmune markers are found only in subgroups. It does not prove that cytokine elevation is pathogenic rather than a consequence of disease, nor does it clarify whether B cell depletion works through reducing autoantibodies specifically or through other immune mechanisms.

Topics

Tags

Symptom:Fatigue
Biomarker:CytokinesAutoantibodies
Method Flag:Weak Case Definition

Metadata

DOI
10.11477/mf.1416200947
PMID
29348373
Review status
Machine draft
Evidence level
Early hypothesis, preprint, editorial, or weak support
Last updated
7 April 2026