Evidence browser

Energy MetabolismImmune System

Metabolomic and immune alterations in long COVID patients with chronic fatigue syndrome.

Saito, Suguru, Shahbaz, Shima, Luo, Xian et al.·Frontiers in immunology·2024

This study looked at blood samples from people with long COVID who have ME/CFS-like symptoms and compared them to people who recovered from COVID, people with acute COVID, and people who never had COVID. Researchers found that long COVID patients had unusual chemical patterns in their blood, higher levels of inflammation-promoting substances, and lower energy molecules (ATP). They also discovered that two specific chemicals (sarcosine and serine) were reduced in long COVID patients and connected to depression, anxiety, and brain fog.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study.

van Eeden, Charmaine, Mohazab, Naima, Redmond, Desiree et al.·Lancet regional health. Americas·2023

This study looked at fatigue in people with ANCA-vasculitis (a type of blood vessel inflammation) and found that over half met the diagnostic criteria for ME/CFS. The researchers discovered that the type of vasculitis matters: people with MPO-ANCA had fatigue patterns more similar to fibromyalgia, while those with PR3-ANCA had fatigue linked to inflammation markers. This suggests different types of vasculitis may cause fatigue through different biological mechanisms.

Immune System

The economic burden of myalgic encephalomyelitis/chronic fatigue syndrome in Australia.

Zhao, Ting, Cox, Ingrid A, Ahmad, Hasnat et al.·Australian health review : a publication of the Australian Hospital Association·2023

This study looked at how much money ME/CFS costs patients, their families, and Australia as a whole. Researchers surveyed 175 Australian patients and found that ME/CFS costs about $63,400 per person each year on average. Most of these costs come from lost work and productivity, plus care provided by family members, rather than from doctor visits and medicines. People with severe ME/CFS have much higher costs than those with milder forms.

E2 ModerateBehavioralPEM not requiredCross-Sectional

The persistent viral infections in the development and severity of myalgic encephalomyelitis/chronic fatigue syndrome.

Rasa-Dzelzkaleja, Santa, Krumina, Angelika, Capenko, Svetlana et al.·Journal of translational medicine·2023

This study examined whether three common viruses—HHV-6, HHV-7, and parvovirus B19—play a role in ME/CFS by comparing 200 ME/CFS patients with 150 healthy people. The researchers found that ME/CFS patients were much more likely to have these viruses in an active state (replicating) rather than dormant, and those with active infections had higher levels of inflammatory markers. The severity of ME/CFS symptoms appeared linked to the presence and activity level of these viral infections.

Immune System

Beyond Anxiety and Depression: Loneliness and Psychiatric Disorders in Adults with Atopic Dermatitis.

Zhang, Junfen, Loman, Laura, Oldhoff, Jantje M et al.·Acta dermato-venereologica·2023

This study found that adults with moderate-to-severe atopic dermatitis (a chronic skin condition causing itching and inflammation) were more likely to experience loneliness and several psychiatric conditions, including panic disorder, anxiety, depression, and chronic fatigue syndrome. The associations were strongest in people with more severe skin disease, while those with mild atopic dermatitis did not show these increased risks. The researchers suggest that doctors treating skin conditions should also consider screening for and addressing mental health concerns.

E2 ModerateCohortPEM unclearLongitudinal

Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue.

Palacios, Natalia, Molsberry, Samantha, Fitzgerald, Kathryn C et al.·Scientific reports·2023

This study examined whether ME/CFS is simply an extreme version of regular fatigue, or if it's a fundamentally different condition. Researchers surveyed over 41,000 nurses and found that ME/CFS and severe fatigue have different risk factors—meaning different things cause them. This suggests that ME/CFS is a distinct condition with its own underlying biology, not just 'really bad tiredness.'

Diagnostics

Association analysis between symptomology and herpesvirus IgG antibody concentrations in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis.

Domingues, Tiago Dias, Malato, João, Grabowska, Anna D et al.·Heliyon·2023

This study looked at whether past infections with common herpesviruses (like the virus that causes cold sores or chickenpox) are connected to specific symptoms in ME/CFS patients. Researchers tested blood samples from 222 ME/CFS patients and 46 MS patients to measure antibodies against six different herpesviruses, then compared these results to reported symptoms. They found some connections—particularly between a virus called HSV1 and brain fog in ME/CFS patients—but overall, herpesvirus antibodies explained symptoms better in MS patients than in ME/CFS patients.

Immune System

Do diagnostic criteria for ME matter to patient experience with services and interventions? Key results from an online RDS survey targeting fatigue patients in Norway.

Kielland, Anne, Liu, Jing, Jason, Leonard A·Journal of health psychology·2023

This study surveyed 660 people with ME/CFS in Norway to understand how different diagnostic criteria and symptoms affect their experiences with treatments and healthcare services. Most patients reported that available interventions had little benefit or made them feel worse. The researchers found that post-exertional malaise (a hallmark symptom where activity makes fatigue and other symptoms worse) was strongly linked to how patients tolerated different treatments, suggesting this symptom should be a key consideration when recommending interventions.

Circulating microRNA expression signatures accurately discriminate myalgic encephalomyelitis from fibromyalgia and comorbid conditions.

Nepotchatykh, Evguenia, Caraus, Iurie, Elremaly, Wesam et al.·Scientific reports·2023

Researchers studied tiny molecules called microRNAs in the blood to see if they could tell the difference between ME/CFS, fibromyalgia, and people who have both conditions. They found that each condition has a unique pattern of these microRNAs, like a biological fingerprint. Using these patterns, they created a computer model that could accurately identify which condition a person has, which could help with proper diagnosis.

Biomarkers

Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome.

Friedberg, Fred, Adamowicz, Jenna L, Bruckenthal, Patricia et al.·Scientific reports·2023

This study looked at how men and women with ME/CFS respond differently to a simple exercise test (a six-minute walk). Researchers tracked fatigue levels and heart function for 15 days in 37 ME/CFS patients and 14 healthy people. Women with ME/CFS felt more tired after the first walk test, while men reported fewer work limitations in the days after exercise. Surprisingly, the study did not find the expected differences between men and women in how long it took to recover.

Skin Temperature Circadian Rhythms and Dysautonomia in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Role of Endothelin-1 in the Vascular Tone Dysregulation.

Cambras, Trinitat, Zerón-Rugerio, Maria Fernanda, Díez-Noguera, Antoni et al.·International journal of molecular sciences·2023

This study looked at how the bodies of people with ME/CFS respond to position changes and whether problems with their blood vessel function might be involved. Researchers compared 67 women with ME/CFS to 48 healthy women, measuring their blood pressure, heart rate, body temperature patterns, and blood markers related to blood vessel health. They found that people with ME/CFS had higher blood pressure and heart rate, disrupted daily temperature rhythms, and elevated levels of substances in the blood that suggest blood vessel problems.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredCross-Sectional

Orthostatic Intolerance and Chronotropic Incompetence in Patients With Myalgic Encephalomyelitis or Chronic Fatigue Syndrome.

Miwa, Kunihisa·Circulation reports·2023

This study looked at how the hearts of ME/CFS patients respond when standing up. Researchers found that some patients have difficulty increasing their heart rate enough during standing, even when they don't experience the rapid heartbeat (POTS) that others with ME/CFS develop. For these patients, the ability to stand longer seemed to depend on having that rapid heartbeat response, suggesting their bodies may not be activating the right nervous system pathways to maintain blood pressure.

Autonomic Nervous System

Chronic Fatigue, Depression and Anxiety Symptoms in Long COVID Are Strongly Predicted by Neuroimmune and Neuro-Oxidative Pathways Which Are Caused by the Inflammation during Acute Infection.

Al-Hakeim, Hussein Kadhem, Al-Rubaye, Haneen Tahseen, Almulla, Abbas F et al.·Journal of clinical medicine·2023

This study examined whether severe COVID-19 infection—particularly high fever and low oxygen levels—can trigger lasting fatigue, depression, and anxiety through inflammation and oxidative stress in the body. Researchers compared 86 long COVID patients with 39 healthy controls and found that about one-third of long COVID patients had very high signs of immune activation and cellular damage. The study suggests that the severity of initial COVID infection may predict who develops long-term symptoms through measurable changes in inflammatory markers.

NeuroinflammationImmune System

E2 ModerateCohortPEM unclear

Repetitive transcranial magnetic stimulation ameliorates symptoms in patients with myalgic encephalomyelitis (chronic fatigue syndrome).

Miwa, Kunihisa, Inoue, Yukichi·IBRO neuroscience reports·2023

This small study tested a brain stimulation treatment called repetitive transcranial magnetic stimulation (rTMS) in 30 ME/CFS patients. The treatment targeted specific areas of the brain involved in movement and decision-making. After treatment, most patients reported improvements in their ability to do daily activities, reduced dizziness when standing, better balance, and less pain.

Autonomic Nervous System

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Adults: United States, 2021-2022.

Vahratian, Anjel, Lin, Jin-Mann S, Bertolli, Jeanne et al.·NCHS data brief·2023

This study looked at how many adults in the United States had ME/CFS during 2021-2022 by surveying a large, representative group of people. Researchers found that ME/CFS affects people across all ages, races, and ethnic groups. The study also showed that ME/CFS costs the U.S. economy between $18-51 billion each year.

E2 ModerateCohortPEM unclearLongitudinal

Risk factors for suicidal ideation in a chronic illness.

Elliott, Meghan K, Jason, Leonard A·Death studies·2023

This study looked at why some people with ME/CFS experience suicidal thoughts. Researchers surveyed 559 people with ME/CFS and found that certain factors—including sleep problems, feeling stigmatized by others, loss of physical abilities, severe disability, and being unmarried—were associated with increased suicide risk. The findings suggest that better education about ME/CFS, reducing stigma, and developing effective treatments could help protect people with this illness.

Sleep

A unique circular RNA expression pattern in the peripheral blood of myalgic encephalomyelitis/chronic fatigue syndrome patients.

Cheng, Yuning, Xu, Si-Mei, Takenaka, Konii et al.·Gene·2023

Researchers looked at a special type of genetic material called circular RNA (circRNA) in the blood of ME/CFS patients and healthy people, measuring it before and after exercise. They found that ME/CFS patients have a different pattern of circular RNAs compared to healthy controls, and unlike healthy people, ME/CFS patients didn't show the normal increase in these molecules after exercise. The study identified 14 specific circular RNAs that were present in ME/CFS patients but completely absent in healthy controls, suggesting these could potentially be used as markers to help diagnose the disease.

What lies beneath: White matter microstructure in pediatric myalgic encephalomyelitis/chronic fatigue syndrome using diffusion MRI.

Josev, Elisha K, Chen, Jian, Seal, Marc et al.·Journal of neuroscience research·2023

Researchers used advanced brain imaging to look for structural changes in the brains of teenagers recently diagnosed with ME/CFS compared to healthy peers. While teens with ME/CFS showed worse fatigue, pain, sleep quality, and cognitive problems like slower thinking speed, the brain scans did not reveal significant differences in white matter (the brain tissue that carries signals between brain regions). This suggests that early-stage ME/CFS in teenagers may not involve obvious structural brain changes, unlike what has been found in adult ME/CFS patients.

Typing myalgic encephalomyelitis by infection at onset: A DecodeME study.

Bretherick, Andrew D, McGrath, Simon J, Devereux-Cooke, Andy et al.·NIHR open research·2023

This large study asked over 17,000 people with ME/CFS about their symptoms, when their illness started, and what health conditions they experience. The researchers found that ME/CFS is not one-size-fits-all: people whose ME/CFS began after an infection (like COVID-19 or glandular fever) reported different patterns of symptoms and other health problems compared to those whose illness started without a clear infection. The study also confirmed that women are more affected by ME/CFS than men, and discovered that women tend to have more additional health conditions alongside ME/CFS.

Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort.

Vaes, Anouk W, Van Herck, Maarten, Deng, Qichen et al.·Journal of translational medicine·2023

This study looked at whether people with ME/CFS can be grouped into different subtypes based on their specific combination of symptoms. Researchers asked 337 people with ME/CFS to report their symptoms and found 13 major groups, where people in each group shared similar patterns of symptom severity and frequency. While fatigue and post-exertional malaise (PEM) appeared in all groups, other symptoms varied—meaning people with ME/CFS experience the illness quite differently from one another.