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Evaluating Routine Blood Tests According to Clinical Symptoms and Diagnostic Criteria in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Baklund, Ingrid H, Dammen, Toril, Moum, Torbjørn Åge et al.·Journal of clinical medicine·2021

Researchers compared blood test results from 149 ME/CFS patients with 264 healthy people to look for differences. They found that ME/CFS patients had higher levels of inflammation markers and certain blood cells, along with lower potassium and muscle enzyme levels. These differences suggest that ME/CFS may involve both inflammation and possible muscle or metabolic problems.

Sex-Based Differences in Plasma Autoantibodies to Central Nervous System Proteins in Gulf War Veterans versus Healthy and Symptomatic Controls.

Abou-Donia, Mohamed B, Krengel, Maxine H, Lapadula, Elizabeth S et al.·Brain sciences·2021

Researchers found that Gulf War veterans with Gulf War illness have abnormal immune proteins in their blood that attack brain cells, and these patterns differ between men and women. The study also found that these same immune markers can help distinguish Gulf War illness from other similar conditions like ME/CFS and IBS. This discovery is important because it offers a possible objective blood test that doctors could use to identify and diagnose these difficult-to-recognize illnesses.

E2 ModerateCohortPEM unclearObservational

Sex-specific plasma lipid profiles of ME/CFS patients and their association with pain, fatigue, and cognitive symptoms.

Nkiliza, Aurore, Parks, Megan, Cseresznye, Adam et al.·Journal of translational medicine·2021

This study analyzed fatty substances in the blood of ME/CFS patients and healthy controls to see if they differ in ways that might explain symptoms. Researchers found that men and women with ME/CFS had different patterns of these blood fats compared to healthy people. Importantly, certain blood fats were connected to the severity of fatigue, headaches, and thinking difficulties, suggesting that problems with how the body processes fats may play a role in ME/CFS symptoms.

BiomarkersEnergy MetabolismImmune System

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

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.

E2 ModerateCohortPEM not requiredLongitudinal

Lasting Immunological Imprint of Primary Epstein-Barr Virus Infection With Associations to Chronic Low-Grade Inflammation and Fatigue.

Fevang, Børre, Wyller, Vegard Bruun Bratholm, Mollnes, Tom Eirik et al.·Frontiers in immunology·2021

This study tracked 200 teenagers with mononucleosis (caused by Epstein-Barr virus) for 6 months to understand why some developed chronic fatigue. Researchers found that teenagers who developed chronic fatigue showed persistent signs of immune system activation and inflammation, particularly elevated levels of RANTES (a signaling protein) and other inflammatory markers, both at the start of illness and 6 months later.

E2 ModerateCohortPEM unclearLongitudinal

Salivary DNA Loads for Human Herpesviruses 6 and 7 Are Correlated With Disease Phenotype in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Lee, Ji-Sook, Lacerda, Eliana M, Nacul, Luis et al.·Frontiers in medicine·2021

This study tested saliva samples from people with ME/CFS and healthy people to measure levels of common viruses that stay dormant in the body. Researchers found that two viruses (HHV-6B and HHV-7) were present at higher levels in people with ME/CFS, especially in those whose viral levels went up and down over time. Importantly, when these viral levels were higher, patients reported worse symptoms like pain, brain fog, and heart/blood pressure problems.

E2 ModerateCohortPEM not requiredCross-Sectional

Lowered serum cesium levels in schizophrenia: association with immune-inflammatory biomarkers and cognitive impairments.

Almulla, Abbas F, Moustafa, Shatha R, Al-Dujaili, Arafat H et al.·Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999)·2021

This study looked at a mineral called cesium in the blood of people with schizophrenia and compared it to healthy people. They found that people with schizophrenia had lower cesium levels, and this was connected to cognitive problems (like memory and thinking difficulties), fatigue symptoms, and signs of immune system activity. The researchers suggest that low cesium might contribute to some of the symptoms seen in schizophrenia.

Complement Component C1q as a Potential Diagnostic Tool for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Subtyping.

Castro-Marrero, Jesús, Zacares, Mario, Almenar-Pérez, Eloy et al.·Journal of clinical medicine·2021

Researchers analyzed blood samples from 250 women with ME/CFS to see if specific blood markers could help identify different types of the disease. They found that about 43% of participants had high levels of a protein called C1q, which was particularly associated with those experiencing more pain symptoms. This discovery suggests that blood tests might one day help doctors identify which ME/CFS patients belong to which subgroup, potentially leading to better tailored treatments.

E2 ModerateCohortPEM not requiredCross-Sectional

Clinical Heterogeneity in ME/CFS. A Way to Understand Long-COVID19 Fatigue.

Murga, Iñigo, Aranburu, Larraitz, Gargiulo, Pascual A et al.·Frontiers in psychiatry·2021

This study examined 84 ME/CFS patients and 22 healthy controls using questionnaires to measure fatigue, pain, sleep quality, heart rate problems, thinking difficulties, mood, and other symptoms. Researchers used statistical clustering to group patients into five distinct subtypes based on their symptom patterns. The findings suggest that ME/CFS is not one-size-fits-all—some patients have high anxiety and depression without fibromyalgia, while others have fibromyalgia combined with heart rate regulation problems, hormone imbalances, or immune issues.

Immune SystemPost-Exertional Malaise

Tryptophan Metabolites, Cytokines, and Fatty Acid Binding Protein 2 in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Simonato, Manuela, Dall'Acqua, Stefano, Zilli, Caterina et al.·Biomedicines·2021

This study compared blood samples from 40 people with ME/CFS to 40 healthy people to look for biological differences. Researchers found that ME/CFS patients had different levels of certain molecules related to immune function, gut health, and how the body uses the amino acid tryptophan. These differences were independent of each other, suggesting multiple biological pathways may be disrupted in ME/CFS.

Identification of actin network proteins, talin-1 and filamin-A, in circulating extracellular vesicles as blood biomarkers for human myalgic encephalomyelitis/chronic fatigue syndrome.

Eguchi, Akiko, Fukuda, Sanae, Kuratsune, Hirohiko et al.·Brain, behavior, and immunity·2020

This study found that people with ME/CFS have higher levels of tiny particles called extracellular vesicles in their blood, which contain specific proteins (talin-1 and filamin-A) that appear to be unique markers of the disease. By measuring these particles and proteins in a simple blood test, researchers were able to correctly identify ME/CFS patients about 90-94% of the time, suggesting this could become a useful diagnostic tool.

E2 ModerateCohortPEM requiredCase-Control

Human Leukocyte Antigen alleles associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Lande, Asgeir, Fluge, Øystein, Strand, Elin B et al.·Scientific reports·2020

Researchers studied immune system markers called HLA alleles in 426 Norwegian ME/CFS patients and compared them to healthy controls. They found that two specific immune markers (HLA-C*07:04 and HLA-DQB1*03:03) were more common in ME/CFS patients than in healthy people, suggesting the immune system may play a role in developing ME/CFS. About 1 in 5 ME/CFS patients carried one or both of these markers, compared to 1 in 8 healthy people.

Assessing diagnostic value of microRNAs from peripheral blood mononuclear cells and extracellular vesicles in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Almenar-Pérez, Eloy, Sarría, Leonor, Nathanson, Lubov et al.·Scientific reports·2020

This study looked for biological markers (tiny genetic molecules called microRNAs) in blood samples from severely ill ME/CFS patients that could help doctors diagnose the disease. Researchers found that certain microRNAs and physical characteristics of particles in the blood appeared different in ME/CFS patients compared to healthy controls. If validated in larger studies, these findings could eventually lead to a simple blood test for diagnosis.

E2 ModerateCohortPEM unclearCase-Control

Cytomegalovirus, Epstein-Barr virus, and human herpesvirus-6 infections in patients with myalgic еncephalomyelitis/chronic fatigue syndrome.

Shikova, Evelina, Reshkova, Valentina, Kumanova, Аntoniya et al.·Journal of medical virology·2020

Researchers tested 58 ME/CFS patients and 50 healthy people for three common viruses (EBV, CMV, and HHV-6) that have been suspected of triggering ME/CFS. They found that ME/CFS patients had significantly higher rates of active EBV infection in their bloodstream compared to healthy people, though most people in both groups carried these viruses in a dormant state. This suggests that for some patients, active EBV infection may play a role in ME/CFS development.

Cytokine profiling of extracellular vesicles isolated from plasma in myalgic encephalomyelitis/chronic fatigue syndrome: a pilot study.

Giloteaux, Ludovic, O'Neal, Adam, Castro-Marrero, Jesús et al.·Journal of translational medicine·2020

This study looked at tiny particles called extracellular vesicles (EVs) in the blood of ME/CFS patients and compared them to healthy people. The researchers found that ME/CFS patients had more of these small particles, and the chemical messengers (cytokines) inside and around them showed unusual patterns of interaction that differed from healthy controls. This suggests that immune system signaling may be working differently in ME/CFS.

Peripheral endothelial dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome.

Scherbakov, Nadja, Szklarski, Marvin, Hartwig, Jelka et al.·ESC heart failure·2020

This study looked at blood vessel function in people with ME/CFS by measuring how well small arteries in the arm respond to increased blood flow. Researchers found that about half of ME/CFS patients had abnormal blood vessel responses, compared to only 20% of healthy people. People with this blood vessel problem reported more severe fatigue, more frequent need for rest breaks, and worse immune-related symptoms like sore throat and swollen lymph nodes.

E2 ModerateCohortPEM not requiredCross-Sectional

Metabolic analysis of amino acids and vitamin B6 pathways in lymphoma survivors with cancer related chronic fatigue.

Fosså, Alexander, Smeland, Knut Halvor, Fluge, Øystein et al.·PloS one·2020

This study looked at blood chemicals called amino acids and B vitamins in lymphoma survivors who experienced lasting fatigue after cancer treatment. Researchers found that people with this fatigue had lower tryptophan (an amino acid) and signs of ongoing low-level immune activation and inflammation. The study suggests that persistent tiredness after lymphoma treatment may be caused by the body's immune system staying activated longer than expected.

Plasma proteomic profiling suggests an association between antigen driven clonal B cell expansion and ME/CFS.

Milivojevic, Milica, Che, Xiaoyu, Bateman, Lucinda et al.·PloS one·2020

Researchers studied blood proteins in ME/CFS patients and healthy controls to look for disease markers. They found that certain immune-related proteins, particularly immunoglobulin proteins (which are part of the immune system), were abnormal in ME/CFS patients and could help identify who has the disease. The results suggest ME/CFS involves an overactive or dysregulated immune response.

E2 ModerateCohortPEM unclearCase-Control

Autoimmunity-Related Risk Variants in PTPN22 and CTLA4 Are Associated With ME/CFS With Infectious Onset.

Steiner, Sophie, Becker, Sonya C, Hartwig, Jelka et al.·Frontiers in immunology·2020

This study looked at specific genetic variations that are known to affect how the immune system works. Researchers compared DNA from ME/CFS patients and healthy controls, and found that certain genetic variations were more common in ME/CFS patients whose illness started with an infection. These genetic changes affect how immune cells are controlled, suggesting that autoimmunity may play a role specifically in ME/CFS cases that begin with an infection.

Autoantibodies to beta-adrenergic and muscarinic cholinergic receptors in Myalgic Encephalomyelitis (ME) patients - A validation study in plasma and cerebrospinal fluid from two Swedish cohorts.

Bynke, Annie, Julin, Per, Gottfries, Carl-Gerhard et al.·Brain, behavior, & immunity - health·2020

Researchers tested blood and spinal fluid samples from ME/CFS patients and healthy people to look for certain antibodies (immune proteins) that mistakenly attack nerve receptors in the body. They found higher levels of some of these antibodies in ME/CFS patients compared to healthy controls, particularly antibodies targeting muscarinic receptors (involved in nerve signaling). However, the amount of these antibodies did not match how severe patients' symptoms were.