ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

181–200 of 270 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Low levels of serum acylcarnitine in chronic fatigue syndrome and chronic hepatitis type C, but not seen in other diseases.

Kuratsune, H, Yamaguti, K, Lindh, G et al.·International journal of molecular medicine·1998

Researchers measured a substance called acylcarnitine in the blood of people with ME/CFS and compared it to healthy people and those with other diseases. They found that people with ME/CFS had significantly lower levels of this substance, and this same pattern appeared in both Japanese and Swedish patients. Importantly, this low level was only seen in ME/CFS and one other condition (chronic hepatitis C), not in other common diseases like diabetes or high blood pressure.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM unclearObservational

Magnesium deficit in a sample of the Belgian population presenting with chronic fatigue.

Moorkens, G, Manuel y Keenoy, B, Vertommen, J et al.·Magnesium research·1997

This study tested whether people with chronic fatigue have low magnesium levels. Researchers gave 97 patients a special magnesium test and found that 44 had magnesium deficiency. After magnesium supplements, their bodies retained less magnesium, suggesting the treatment may have helped. However, the researchers did not find a clear link between low magnesium and chronic fatigue syndrome itself.

Biomarkers

E2 ModerateCohortPEM not requiredCross-Sectional

Preliminary determination of a molecular basis of chronic fatigue syndrome.

McGregor, N R, Dunstan, R H, Zerbes, M et al.·Biochemical and molecular medicine·1996

Researchers tested the urine of 20 ME/CFS patients and 45 healthy controls to look for chemical differences. They found that ME/CFS patients had different levels of several substances in their urine, particularly one called CFSUM1 and beta-alanine, which were higher in patients with more severe symptoms. These findings suggest ME/CFS may have measurable biological markers that could help identify the condition.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM not requiredCase-Control

Clinical laboratory test findings in patients with chronic fatigue syndrome.

Bates, D W, Buchwald, D, Lee, J et al.·Archives of internal medicine·1995

Researchers compared blood test results from 579 ME/CFS patients with results from 147 healthy people. They found that ME/CFS patients were much more likely to have certain abnormal results, particularly immune-related changes like unusual white blood cells and immune complexes. However, no single test was abnormal enough in all patients to serve as a reliable diagnostic tool on its own.

BiomarkersImmune System

E2 ModerateCohortPEM not requiredCross-Sectional

Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome.

Wassif, W S, Sherman, D, Salisbury, J R et al.·Annals of clinical biochemistry·1994

Researchers tested muscle function and examined muscle samples from people with ME/CFS and people with chronic alcohol problems to see if their muscle problems were similar or different. They found that while some people initially thought to have ME/CFS actually had other conditions (like a rare enzyme deficiency or inflammation), the muscle changes in alcohol misuse were quite distinct and recognizable through muscle biopsies.

Biomarkers

E2 ModerateCohortPEM not requiredCase-Control

Investigation of retroviral involvement in chronic fatigue syndrome.

Folks, T M, Heneine, W, Khan, A et al.·Ciba Foundation symposium·1993

Researchers tested whether certain viruses called retroviruses might be a biological marker that could help diagnose ME/CFS. They looked for five different retroviruses in people with ME/CFS and compared them to healthy controls. None of these viruses were found in either group, meaning they cannot be used to identify who has ME/CFS.

Biomarkers

E2 ModerateCohortPEM not requiredObservational

[Chronic fatigue syndrome--cases in the Kanebo Memorial Hospital].

Ogawa, R, Toyama, S, Matsumoto, H·Nihon rinsho. Japanese journal of clinical medicine·1992

This study looked at 134 ME/CFS patients seen at one hospital in Japan and found that many had immune system abnormalities, including weakened natural killer cells and reactions to common substances like dust and pollen. Researchers also discovered some patients had low levels of certain fatty acids in their blood. When treated with a traditional Chinese herbal medicine called Ren-Shen-Yang-Rong-Tang, about 73% of patients were able to return to work or school.

BiomarkersImmune System

E2 ModerateCohortPEM unclearObservational

Nondiscocytic erythrocytes in myalgic encephalomyelitis.

Simpson, L O·The New Zealand medical journal·1989

Researchers looked at red blood cells from 102 people with ME/CFS using a powerful microscope and compared them to healthy people and those with multiple sclerosis. They found that people with ME/CFS had fewer normal-shaped red blood cells and more cup-shaped red blood cells than the other groups. This suggests ME/CFS may have a physical cause that could potentially be detected through a blood test.

Biomarkers

E3 PreliminaryMechanismPEM requiredMechanistic

Deficient TRPM3-linked mitochondrial Ca2+ influx in natural killer cells associated with myalgic encephalomyelitis/chronic fatigue syndrome.

Magawa, Chandi Tabeth, Eaton-Fitch, Natalie, Muraki, Katsuhiko et al.·BMC immunology·2026

Researchers compared immune cells called natural killer cells from people with ME/CFS and healthy controls, focusing on how calcium moves in and out of these cells. They observed that calcium entry into cells was reduced in ME/CFS, but calcium accumulation in the energy-producing part of the cell (mitochondria) was higher. This is a preliminary finding from a small study that may help explain some immune dysfunction in ME/CFS, but much more research is needed before drawing conclusions about what this means for patients.

BiomarkersImmune System

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Pipeline-optimized machine learning for chronic fatigue syndrome diagnosis: A lightweight, interpretable model using blood biochemical and metabolomic data.

Li, Junrong, Cao, Hanyu, Zhu, Zirun et al.·Computational biology and chemistry·2026

Researchers developed a computer program that uses blood tests to help diagnose ME/CFS more accurately and quickly. The program was trained on data from over 1,100 people with ME/CFS and nearly 67,000 control participants, and it correctly identified ME/CFS in about 94% of cases. This tool could help doctors catch the condition earlier and tailor treatment to individual patients.

Biomarkers

E3 PreliminaryMechanismPEM unclearMechanistic

Indistinguishable mitochondrial phenotypes after exposure of healthy myoblasts to myalgic encephalomyelitis/chronic fatigue syndrome or control serum.

Ryback, Audrey A, Hillier, Charles B, Loureiro, Camila M et al.·PloS one·2026

Researchers wanted to test whether something in the blood of people with ME/CFS could damage the energy-producing parts of cells (mitochondria) when added to healthy cells in the lab. They tested blood from 67 people with ME/CFS and 53 healthy people on cultured muscle cells and measured how well the cells could use oxygen. Unlike a previous smaller study, they found no difference between the ME/CFS blood and healthy blood samples.

BiomarkersEnergy Metabolism

E3 PreliminaryDiagnosticPEM unclearMethods-Paper

Application of DNA Methylome Analysis to Patients with ME/CFS.

Peppercorn, Katie, Edgar, Christina D, Al Momani, Suzan et al.·Methods in molecular biology (Clifton, N.J.)·2025

This study describes a technique called RRBS that examines how chemical tags on our DNA (called methylation) are different in ME/CFS patients compared to healthy people. These tags act like switches that turn genes on or off, and abnormal patterns might help explain why ME/CFS causes such severe symptoms. The researchers show how this method can be used to identify patterns that could eventually lead to better diagnostic tests or ways to track how the illness changes over time.

Biomarkers

E3 PreliminaryCohortPEM not requiredCross-Sectional

Histone phosphorylation analysis of two main TCM syndromes of chronic fatigue syndrome.

Xu, Tingting, Gao, Shuo, Cheng, Xinxin et al.·Journal of translational medicine·2025

Researchers studied blood cells from 20 ME/CFS patients (divided into two Traditional Chinese Medicine symptom patterns) and 10 healthy controls. They found differences in how proteins were modified in the blood cells of ME/CFS patients compared to healthy people. These differences involved processes that affect how cells communicate with each other and organize their internal structures.

BiomarkersImmune System

E3 PreliminaryMechanismPEM requiredMechanistic

Precision Medicine Study of Post-Exertional Malaise Epigenetic Changes in Myalgic Encephalomyelitis/Chronic Fatigue Patients During Exercise.

Sharma, Sayan, Hodges, Lynette D, Peppercorn, Katie et al.·International journal of molecular sciences·2025

This study looked at how exercise affects the chemical switches on our genes (epigenetics) in ME/CFS patients, particularly during post-exertional malaise (PEM)—the exhaustion that worsens after physical activity. Researchers took blood samples from five ME/CFS patients before, immediately after, and 24-48 hours after an exercise test, and found distinct patterns of genetic changes that were specific to ME/CFS patients and not seen in healthy controls. These changes affected genes related to immune function, inflammation, and blood vessel health, suggesting the body's response to exercise in ME/CFS is fundamentally different at the molecular level.

BiomarkersImmune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM unclearCross-Sectional

Metabolomics-Based Machine Learning Diagnostics of Post-Acute Sequelae of SARS-CoV-2 Infection.

Cai, Ethan, Kouznetsova, Valentina L, Tsigelny, Igor F·Metabolites·2025

Researchers developed a computer program that can identify Long COVID (PASC) by analyzing chemical markers in the blood called metabolites. The program successfully distinguished Long COVID from several similar conditions like Lyme disease and POTS, but had difficulty telling Long COVID apart from fibromyalgia, suggesting these two conditions may share similar chemical patterns in the body.

Biomarkers

E3 PreliminaryMechanismPEM unclearCross-Sectional

Upregulation of olfactory receptors and neuronal-associated genes highlights complex immune and neuronal dysregulation in Long COVID patients.

Shahbaz, Shima, Rezaeifar, Maryam, Syed, Hussein et al.·Brain, behavior, and immunity·2025

Researchers studied blood samples from Long COVID patients with ME/CFS-like symptoms and compared them to healthy controls. They found that certain genes related to immune function and brain health were turned on in the patients, while others were turned off. The study also discovered unusual activation of smell-related genes and changes in immune cell types, suggesting the body remains in a state of ongoing inflammation and stress.

NeuroinflammationBiomarkersImmune System

E3 PreliminaryDiagnosticPEM unclearMethods-Paper

Multifaceted evolution focused on maximal exploitation of domain knowledge for the consensus inference of Gene Regulatory Networks.

Segura-Ortiz, Adrián, Giménez-Orenga, Karen, García-Nieto, José et al.·Computers in biology and medicine·2025

Researchers created a new computer tool called BIO-INSIGHT that helps scientists better understand which genes control other genes by analyzing genetic data from patients. They tested this tool on data from people with fibromyalgia, ME/CFS, and both conditions together, and found it could identify different gene patterns specific to each illness. This could help doctors find better ways to diagnose and treat these conditions in the future.

Biomarkers

E3 PreliminaryMechanismPEM requiredMechanistic

Extracellular vesicle proteomics uncovers energy metabolism, complement system, and endoplasmic reticulum stress response dysregulation postexercise in males with myalgic encephalomyelitis/chronic fatigue syndrome.

Glass, Katherine A, Giloteaux, Ludovic, Zhang, Sheng et al.·Clinical and translational medicine·2025

Researchers studied tiny particles called extracellular vesicles in the blood of ME/CFS patients before and after exercise. They found that in people with ME/CFS, these particles show signs of energy problems, immune overactivity, and cellular stress after exertion—changes that were linked to post-exertional malaise (the worsening of symptoms after activity). These findings suggest new targets for treatment that could help improve recovery and energy in ME/CFS.

BiomarkersPost-Exertional Malaise

E3 PreliminaryReviewPEM requiredReview-Narrative

Tetrahydrobiopterin in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Friend or Foe?

Rahman, A F M Towheedur, Benko, Anna, Bulbule, Sarojini et al.·Biomolecules·2025

This review article examines a molecule called tetrahydrobiopterin (BH4) and its possible role in ME/CFS, particularly in patients who experience orthostatic intolerance (dizziness or fainting when standing up). The researchers found that BH4 metabolism—the way the body processes this molecule—is not working properly in ME/CFS patients with these symptoms. By understanding how BH4 goes wrong, scientists hope to explain why ME/CFS patients have problems with blood flow to the brain.

BiomarkersPost-Exertional Malaise

E3 PreliminaryDiagnosticPEM requiredMethods-Paper

Measuring Biomarkers of Oxidative Stress in ME/CFS Patients.

Walker, Max·Methods in molecular biology (Clifton, N.J.)·2025

This study looked at whether certain molecules in the blood and immune cells could show signs of oxidative stress (cellular damage from harmful molecules called free radicals) in ME/CFS patients. The researchers tested two different markers before and after exercise: one test successfully measured protein damage, while another test designed to measure DNA damage was not sensitive enough to detect changes in this patient group.

BiomarkersPost-Exertional Malaise

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Evidence browser

Low levels of serum acylcarnitine in chronic fatigue syndrome and chronic hepatitis type C, but not seen in other diseases.

Magnesium deficit in a sample of the Belgian population presenting with chronic fatigue.

Preliminary determination of a molecular basis of chronic fatigue syndrome.

Clinical laboratory test findings in patients with chronic fatigue syndrome.

Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome.

Investigation of retroviral involvement in chronic fatigue syndrome.

[Chronic fatigue syndrome--cases in the Kanebo Memorial Hospital].

Nondiscocytic erythrocytes in myalgic encephalomyelitis.

Deficient TRPM3-linked mitochondrial Ca2+ influx in natural killer cells associated with myalgic encephalomyelitis/chronic fatigue syndrome.

Pipeline-optimized machine learning for chronic fatigue syndrome diagnosis: A lightweight, interpretable model using blood biochemical and metabolomic data.

Indistinguishable mitochondrial phenotypes after exposure of healthy myoblasts to myalgic encephalomyelitis/chronic fatigue syndrome or control serum.

Application of DNA Methylome Analysis to Patients with ME/CFS.

Histone phosphorylation analysis of two main TCM syndromes of chronic fatigue syndrome.

Precision Medicine Study of Post-Exertional Malaise Epigenetic Changes in Myalgic Encephalomyelitis/Chronic Fatigue Patients During Exercise.

Metabolomics-Based Machine Learning Diagnostics of Post-Acute Sequelae of SARS-CoV-2 Infection.

Upregulation of olfactory receptors and neuronal-associated genes highlights complex immune and neuronal dysregulation in Long COVID patients.

Multifaceted evolution focused on maximal exploitation of domain knowledge for the consensus inference of Gene Regulatory Networks.

Extracellular vesicle proteomics uncovers energy metabolism, complement system, and endoplasmic reticulum stress response dysregulation postexercise in males with myalgic encephalomyelitis/chronic fatigue syndrome.

Tetrahydrobiopterin in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Friend or Foe?

Measuring Biomarkers of Oxidative Stress in ME/CFS Patients.

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