Chronic fatigue syndrome: a working case definition.
Holmes, G P, Kaplan, J E, Gantz, N M et al. · Annals of internal medicine · 1988 · DOI
Quick Summary
This landmark 1988 paper proposed a new name and formal definition for what was previously called 'chronic Epstein-Barr virus syndrome.' The authors recognized that the condition was poorly understood and inconsistently diagnosed, so they renamed it 'chronic fatigue syndrome' (ME/CFS) and created a working definition to help doctors identify and study it more consistently. This definition focused on severe, ongoing fatigue along with other symptoms like sore throat, headaches, and muscle pain.
Why It Matters
This paper established the first standardized diagnostic framework for ME/CFS, enabling consistent case identification across research studies and clinical practice. Without this definition, the condition remained fragmented and poorly recognized, hindering research progress and patient diagnosis. This work laid the foundation for decades of subsequent ME/CFS research and remains foundational to how the disease is understood today.
Observed Findings
- Chronic Epstein-Barr virus syndrome was poorly defined and diagnosed inconsistently
- Epstein-Barr virus serologic testing showed doubtful diagnostic value despite the syndrome's name
- Patients presented with chronic or recurrent debilitating fatigue combined with sore throat, lymph node tenderness, headache, myalgia, and arthralgias
- The proposed causal relationship between EBV infection and the syndrome could not be supported
Inferred Conclusions
- The syndrome should be renamed 'chronic fatigue syndrome' to reflect its primary feature and unknown etiology
- A standardized case definition is necessary to improve comparability across clinical research and epidemiologic studies
- The condition should be classified as a syndrome of unknown cause, disconnected from EBV causation claims
- A rational diagnostic framework would help evaluate patients with chronic fatigue of undetermined cause
Remaining Questions
- What is the underlying biological cause(s) of ME/CFS?
- How do the clinical and molecular features of ME/CFS differ from other post-infectious conditions?
What This Study Does Not Prove
This study does not prove what causes ME/CFS or establish Epstein-Barr virus as a causal agent—in fact, the authors explicitly rejected the assumed EBV connection. The definition proposed is a clinical case definition for research purposes and does not constitute a validated diagnostic test or etiological explanation. It does not provide epidemiologic data on prevalence, incidence, or natural history of the condition.