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ME/CFS Atlas — A public knowledge atlas for ME/CFS

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ME/CFS Atlas is an evidence reference platform, not a medical provider. Content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.

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ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

Evidence browser

Search and filter 6,206 studies by evidence level, diagnostic criteria, PEM status, and research domain. Each entry links to the original source.

Studies sorted by evidence level, then year. Browse by topic instead →

Evidence level (E0–E3) reflects study type and replication, not methodological quality. A weak systematic review still sits at E0. How evidence levels work →

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1205 studies

E0 — Consensus655E1 — Replicated321E2 — Moderate2,807E3 — Preliminary2,423

ME/CFS4,041Long COVID224Post-infectious190Overlapping1,064

Required for diagnosis417Not specified / unclear2,252Not required3,537

Post-Exertional Malaise1,082Cognitive Dysfunction1,750Pain1,629Unrefreshing Sleep805Orthostatic Intolerance484

Cytokines821Gene Expression573Metabolomics478Neuroimaging472Autoantibodies460

Infection-Triggered1,182Long COVID Overlap604Pediatric496Severe232

Strong Phenotyping445Sex-Stratified330Severe ME Included119

Systematic Review272Meta-Analysis61RCT301

Peer-reviewed6,149Preprint3Unclear54

1181–1200 of 1,205 studies

E3 PreliminaryCommentaryPEM not requiredEditorial

Dual infections of the immune system in patients with chronic active Epstein-Barr virus infection mimicking chronic fatigue syndrome.

Purtilo, D T·Canada diseases weekly report = Rapport hebdomadaire des maladies au Canada·1991

This article discusses the importance of distinguishing patients with ME/CFS (the commonly recognized illness) from those who have dual infections or weakened immune systems that only look like ME/CFS. The authors argue that some patients appearing to have ME/CFS may actually have other treatable conditions involving multiple infections, and recommend long-term studies tracking people who develop ME/CFS-like symptoms after documented viral infections.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Molecular approaches to epidemiologic evaluation of viruses as risk factors for patients who have chronic fatigue syndrome.

Miller, G·Reviews of infectious diseases·1991

This paper proposes that studying how viral infections like flu, hepatitis, and mono can trigger long-term fatigue might help us understand ME/CFS. The researchers suggest examining not just whether someone had a virus, but how much virus was present, which type of virus it was, where it spread in the body, and whether the virus was active or dormant. They also recommend looking carefully at how individual patients' immune systems respond to specific parts of viruses.

E3 PreliminaryCohortPEM not requiredObservational

Postinfectious chronic fatigue syndrome: case history of thirty-five patients in Germany.

Hilgers, A, Krueger, G R, Lembke, U et al.·In vivo (Athens, Greece)·1991

This study followed 35 ME/CFS patients in Germany for up to eight years and found that most experienced severe fatigue, joint and muscle pain, sore throats, and various other symptoms. Researchers found evidence of herpesvirus reactivation in about 73% of patients and Epstein-Barr virus in about 34%, suggesting ongoing viral activity may play a role in the condition. While treatments were tried including immune therapy and antiviral drugs, none consistently worked well, though immune globulin therapy showed the most promise.

E3 PreliminaryMechanismPEM unclear

Immunodysregulation and chronic fatigue syndrome.

Kundu, S K, Ahronheim, G A, Menezes, J·Canada diseases weekly report = Rapport hebdomadaire des maladies au Canada·1991

This study examined whether ME/CFS involves problems with the immune system that aren't working properly. The researchers looked at immune system dysfunction in patients with chronic fatigue syndrome to understand if an imbalance in immune responses might explain the illness. This early research helped establish that immune abnormalities could be involved in ME/CFS.

E3 PreliminaryMechanismPEM not requiredMechanistic

Altered cytokine release in peripheral blood mononuclear cell cultures from patients with the chronic fatigue syndrome.

Chao, C C, Janoff, E N, Hu, S X et al.·Cytokine·1991

This study found that immune cells from people with ME/CFS respond differently to stimulation than cells from healthy people. Specifically, when researchers activated these immune cells in the lab, they released higher levels of inflammatory molecules (IL-1 beta, IL-6, and TNF-alpha), suggesting that ME/CFS patients' immune cells may be in a heightened state of readiness. The study also found unusual patterns in a molecule called TGF-beta, which normally helps regulate immune responses.

E3 PreliminaryCohortPEM unclearCase-Control

Fibromyalgia and parvovirus infection.

Leventhal, L J, Naides, S J, Freundlich, B·Arthritis and rheumatism·1991

This study describes three patients who developed fibromyalgia (a condition causing widespread pain and fatigue) shortly after having parvovirus B19 infections. Blood tests confirmed the virus was present, and sleep studies showed abnormal sleep patterns in two patients. The researchers suggest that doctors should look more carefully for viral infections in fibromyalgia patients whose symptoms started with flu-like illness.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Detection of Epstein-Barr virus with molecular hybridization techniques.

Pagano, J S·Reviews of infectious diseases·1991

This paper reviews different laboratory techniques for detecting Epstein-Barr virus (EBV), a common virus that some researchers suspect might play a role in ME/CFS. The authors explain that newer methods like genetic testing and blood analysis are much faster and more accurate than older traditional tests, and could help scientists understand whether EBV actually causes chronic fatigue syndrome.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Nervous system-immune system communication.

Arnason, B G·Reviews of infectious diseases·1991

Some people's bodies may be genetically or biologically wired to respond to infections in a way that leads to ME/CFS. This review examines how the immune system and nervous system communicate with each other through chemical messengers like interleukin-1 and hormones. The author suggests that measuring these chemicals in patients with ME/CFS compared to healthy people could help us understand why some people develop this disease after an infection.

E3 PreliminaryReviewPEM unclearReview-Narrative

Human herpesvirus 6 (HHV6) and chronic fatigue syndrome (CFS).

Ablashi, D V, Zompetta, C, Lease, C et al.·Canada diseases weekly report = Rapport hebdomadaire des maladies au Canada·1991

This review article examines whether human herpesvirus 6 (HHV6), a common virus that infects most people in childhood, might be connected to ME/CFS. The authors gathered available evidence about HHV6 and its potential role in causing or contributing to chronic fatigue syndrome symptoms.

E3 PreliminaryMechanismPEM unclearObservational

Anti-neuronal antibody levels in chronic fatigue syndrome patients with neurologic abnormalities.

Buchwald, D, Wener, M H, Komaroff, A L·Arthritis and rheumatism·1991

This study looked at whether people with ME/CFS who have neurological symptoms (like problems with thinking or nerve function) have unusual antibodies in their blood that attack nerve cells. Researchers tested blood samples from ME/CFS patients and compared antibody levels between those with and without neurological problems. The goal was to understand whether immune system misdirection might be causing some of the neurological symptoms patients experience.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Human herpesvirus-6 (HHV-6) (short review).

Ablashi, D V, Salahuddin, S Z, Josephs, S F et al.·In vivo (Athens, Greece)·1991

This review examines Human Herpesvirus-6 (HHV-6), a common virus that most people carry. The virus can reactivate in people with certain illnesses, including ME/CFS. The study found that people with ME/CFS sometimes have higher levels of antibodies to HHV-6, suggesting the virus may be active in their bodies.

E3 PreliminaryMechanismPEM not requiredMechanistic

Electrophoretic analysis of human herpesvirus 6 polypeptides immunoprecipitated from infected cells with human sera.

Balachandran, N, Tirawatnapong, S, Pfeiffer, B et al.·The Journal of infectious diseases·1991

This study examined how the immune system responds to human herpesvirus 6 (HHV-6), a virus that researchers have investigated in ME/CFS patients. Scientists took blood samples from healthy people and patients with various conditions including ME/CFS, and looked at which HHV-6 proteins the immune system recognized. They found that people with detectable antibodies (immune proteins) against HHV-6 recognized multiple viral proteins, with stronger responses corresponding to higher antibody levels.

E3 PreliminaryReviewPEM not requiredReview-Narrative

The chronic fatigue syndrome.

Shafran, S D·The American journal of medicine·1991

ME/CFS is a serious condition causing extreme fatigue lasting at least 6 months that doctors cannot fully explain. While most patients report getting sick before their fatigue started, researchers have not found proof that any specific infection causes ME/CFS. The condition mainly affects people aged 20-50, with more women than men affected.

E3 PreliminaryCohortPEM not requiredCase-Control

Infectious mononucleosis, Epstein-Barr virus, and chronic fatigue syndrome: a prospective case series.

Fark, A R·The Journal of family practice·1991

This study looked at whether Epstein-Barr virus (EBV), the virus that causes infectious mononucleosis (mono), might be the cause of ME/CFS. Researchers found that some people with chronic fatigue had high levels of antibodies (immune markers) against EBV, and some of them had never fully recovered from a previous mono infection. The study suggests a possible link between EBV infection and the development of chronic fatigue, though it doesn't prove the virus directly causes ME/CFS.

E3 PreliminaryReviewPEM not requiredReview-Narrative

[The chronic fatigue syndrome. A multifactorial approach and the treatment possibilities].

Pinardi, G, Scarlato, G·Recenti progressi in medicina·1990

This review describes ME/CFS as a complex condition marked by severe, long-lasting fatigue accompanied by symptoms like sore throat, headaches, muscle pain, and mood changes. While researchers have suspected viruses like Epstein-Barr virus might cause it, the evidence hasn't been convincing due to study design problems. The authors suggest the condition may result from an abnormal immune response rather than a single virus.

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Naloxone-reversible monocyte dysfunction in patients with chronic fatigue syndrome.

Prieto, J, Subirá, M L, Castilla, A et al.·Scandinavian journal of immunology·1989

Researchers examined immune cells called monocytes in 35 ME/CFS patients and 25 healthy people. They found that most ME/CFS patients had monocytes that weren't working properly, but these cells improved dramatically when treated with naloxone, a drug that blocks opioid effects. This suggests that the body's natural opioid-like chemicals may be overactive in ME/CFS and could be damaging immune function.

E3 PreliminaryReviewPEM unclearReview-Narrative

The chronic fatigue syndrome: definition, current studies and lessons for fibromyalgia research.

Komaroff, A L, Goldenberg, D·The Journal of rheumatology. Supplement·1989

This review describes ME/CFS as a serious illness where extreme tiredness lasts for more than 6 months, often starting suddenly like the flu. People with ME/CFS frequently experience fever, sore throat, muscle pain, swollen lymph nodes, brain fog, and mood problems. Blood tests sometimes show changes in immune cells and antibodies, and researchers have found links between ME/CFS and several viruses, particularly Epstein-Barr virus, though no virus has been proven to directly cause the disease.

E3 PreliminaryReviewPEM not requiredReview-Narrative

What's new in human herpesvirus-6? Clinical immunopathology of the HHV-6 infection.

Krueger, G R, Sander, C·Pathology, research and practice·1989

This review examines human herpesvirus-6 (HHV-6), a common virus that most people carry in a dormant state. When the immune system is weakened, this virus can reactivate and potentially cause long-lasting fatigue and other health problems. The authors discuss how HHV-6 might contribute to chronic fatigue syndrome and other conditions, particularly in people with weak immune systems.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic fatigue syndrome: review of the literature.

Turgeon, S A·Canadian family physician Medecin de famille canadien·1989

This review article examines what was known about ME/CFS in 1989, a time when the condition was still poorly understood. The authors note that while some initially thought the Epstein-Barr virus (which causes mononucleosis) might cause ME/CFS, that theory no longer seems correct. They found evidence that both psychiatric factors and subtle immune system problems may play a role in the illness.

E3 PreliminaryMechanismPEM not requiredMechanistic

Immunotherapy and enhanced antibody-dependent cell-mediated cytotoxicity using virally-infected target cells.

Bosse, D, Ades, E W·Journal of clinical & laboratory immunology·1989

This study looked at whether adding a immune-boosting substance called IL-2 to a blood treatment (gammaglobulin) could help the body's immune cells better fight cells infected with Epstein-Barr virus. The researchers found in laboratory tests that IL-2 did enhance this immune response, and they suggested it might help ME/CFS patients who receive gammaglobulin treatment.

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PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Curated Collections

Thematic groupings by clinical question or research area.

Neuroinflammation Evidence

PET imaging and other studies providing evidence for brain inflammation in ME/CFS.

Metabolism & Mitochondria

Metabolomics and mitochondrial function studies revealing energy metabolism disruption.

Biomarkers

Studies identifying potential biological markers for ME/CFS diagnosis and stratification.

PEM-Specific Research

Studies specifically examining post-exertional malaise, the hallmark symptom of ME/CFS.