Evidence browser

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.

Immune System

Energy MetabolismPost-Exertional Malaise

A map of metabolic phenotypes in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Hoel, Fredrik, Hoel, August, Pettersen, Ina Kn et al.·JCI insight·2021

This study examined the chemicals in the blood of 83 ME/CFS patients compared to 35 healthy people to understand how their bodies use energy differently. Researchers found that ME/CFS patients had common metabolic changes suggesting their bodies are working harder to produce energy and are using fats and proteins differently as fuel. Interestingly, patients also fell into different subgroups with distinct metabolic patterns, suggesting ME/CFS may involve different energy problems in different people.

Homebound versus Bedridden Status among Those with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Conroy, Karl, Bhatia, Shaun, Islam, Mohammed et al.·Healthcare (Basel, Switzerland)·2021

This study looked at over 2,100 people with ME/CFS to understand different levels of severity, focusing on those who are homebound (unable to leave home) and bedridden (unable to leave bed). The researchers found that people who are bedridden experience post-exertional malaise (PEM)—a worsening of symptoms after physical or mental activity—differently or more severely than those who are only homebound. This research helps doctors and patients better understand how severe ME/CFS can become.

Patients with Persistent Polyclonal B-Cell Lymphocytosis Share the Symptomatic Criteria of Systemic Exertion Intolerance Disease.

Morizot, Romain, de Korwin, Jean-Dominique, Feugier, Pierre et al.·Journal of clinical medicine·2021

Researchers studied a rare blood condition called persistent polyclonal B-cell lymphocytosis (PPBL) and found that most patients with PPBL experience symptoms very similar to ME/CFS, including severe fatigue that doesn't improve with rest, worsening after physical activity, sleep problems, and difficulty thinking clearly. Out of 39 patients surveyed, 72% met the official criteria for ME/CFS, and nearly all reported chronic fatigue lasting more than 6 months. This finding suggests these two conditions may share common underlying features, though more research is needed to understand why.

E2 ModerateCohortPEM not requiredCross-Sectional

Monitoring treatment harm in myalgic encephalomyelitis/chronic fatigue syndrome: A freedom-of-information study of National Health Service specialist centres in England.

McPhee, Graham, Baldwin, Adrian, Kindlon, Tom et al.·Journal of health psychology·2021

This study looked at how 38 ME/CFS specialist clinics in England monitor and report harms from treatments like graded exercise therapy and cognitive behavioural therapy. Researchers found that clinics were inconsistent in how they handle treatment-related harm, rarely warned patients about potential risks in their written materials, and reported zero cases of harm despite knowing many patients dropped out of treatment. The study suggests clinics need better systems to detect, record, and stop treatments when patients are being harmed.

A retrospective cross-sectional study on tinnitus prevalence and disease associations in the Dutch population-based cohort Lifelines.

Schubert, Nick M A, Rosmalen, Judith G M, van Dijk, Pim et al.·Hearing research·2021

This study looked at how common tinnitus (ringing in the ears) is in a large group of Dutch adults and found that about one-third experience it at some point. The researchers discovered that tinnitus is linked to various conditions including hearing problems, heart issues, depression, and notably, chronic fatigue syndrome (ME/CFS). Understanding these connections may help doctors better treat tinnitus and related conditions.

Autoantibodies to Vasoregulative G-Protein-Coupled Receptors Correlate with Symptom Severity, Autonomic Dysfunction and Disability in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Freitag, Helma, Szklarski, Marvin, Lorenz, Sebastian et al.·Journal of clinical medicine·2021

This study examined whether certain antibodies in ME/CFS patients' blood relate to how severe their symptoms are. The researchers tested 116 ME/CFS patients for antibodies that target receptors controlling blood vessel function and other vital processes. They found that patients whose ME/CFS started after an infection had stronger connections between these antibodies and key symptoms like fatigue and muscle pain, suggesting these antibodies might play a role in how the disease develops.

Medical Care Situation of People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Germany.

Froehlich, Laura, Hattesohl, Daniel B R, Jason, Leonard A et al.·Medicina (Kaunas, Lithuania)·2021

This study surveyed nearly 500 people with ME/CFS in Germany to understand how well they can access medical care and how satisfied they are with the care they receive. The researchers found that many patients struggle to get medical help because of cost and distance, and many are unhappy with their doctors' care. The study also created and tested a German language symptom questionnaire that could help doctors diagnose ME/CFS.

E2 ModerateCohortPEM not requiredCross-Sectional

Chronotropic Incompetence in Non-Hospitalized Patients with Post-COVID-19 Syndrome.

Jimeno-Almazán, Amaya, Pallarés, Jesús G, Buendía-Romero, Ángel et al.·Journal of clinical medicine·2021

Some people who recover from COVID-19 experience persistent fatigue and difficulty exercising for months afterward. This study tested 32 people with long-lasting COVID symptoms and found that about 12% had a specific heart problem called chronotropic incompetence—their heart rate doesn't increase normally during exercise. This heart rhythm problem may explain why some patients struggle with exercise intolerance after COVID-19.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredObservational

Fatigue as the limiting factor for vaginal birth in patients with multiple sclerosis.

Biringer, Kamil, Sivak, Stefan, Sivakova, Jana et al.·Neuro endocrinology letters·2021

This study looked at 15 women with multiple sclerosis (MS) who were pregnant and gave birth between 2015-2020. The researchers found that severe fatigue combined with nerve damage was the main reason why most of these women had caesarean sections instead of vaginal deliveries. The study suggests that better diagnosis and treatment of fatigue during pregnancy might allow more women with MS to have vaginal births safely.

E2 ModerateCohortPEM unclearLongitudinal

Impact of Life Stressors on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Symptoms: An Australian Longitudinal Study.

Balinas, Cassandra, Eaton-Fitch, Natalie, Maksoud, Rebekah et al.·International journal of environmental research and public health·2021

This Australian study followed 36 ME/CFS patients over five months to see how life stressors affected their symptoms. The researchers found that major life changes like work disruptions or money problems were linked to worsening symptoms like brain fog, stomach issues, pain, and sleep problems. Interestingly, patients who had better access to healthcare and support services experienced fewer severe symptoms.

Pain and SensitizationSleep

Characterizing long COVID in an international cohort: 7 months of symptoms and their impact.

Davis, Hannah E, Assaf, Gina S, McCorkell, Lisa et al.·EClinicalMedicine·2021

This study surveyed nearly 3,800 people from around the world who had long-lasting COVID-19 symptoms lasting more than 28 days. By seven months after illness onset, most participants had not fully recovered and experienced an average of 56 symptoms affecting multiple body systems. The three most persistent symptoms were fatigue, post-exertional malaise (feeling worse after activity), and cognitive problems, with nearly 86% experiencing relapses triggered by exercise, physical activity, mental stress, or other exertion.

E2 ModerateCohortPEM not requiredCross-Sectional

Are Circulating Fibroblast Growth Factor 21 and N-Terminal Prohormone of Brain Natriuretic Peptide Promising Novel Biomarkers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

Domingo, Joan Carles, Cordobilla, Begoña, Ferrer, Roser et al.·Antioxidants & redox signaling·2021

This study looked for new blood markers that could help identify ME/CFS by measuring two proteins called FGF21 and NT-proBNP in patients and healthy people. The researchers found that ME/CFS patients had significantly higher levels of both proteins and showed signs of increased inflammation and oxidative stress (cellular damage). These findings suggest these proteins might be useful tools for diagnosing ME/CFS or developing new treatments.

BiomarkersImmune System

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

E2 ModerateCohortPEM unclearCase-Control

Central sensitisation in chronic fatigue syndrome and fibromyalgia; a case control study.

Bourke, Julius H, Wodehouse, Theresa, Clark, Lucy V et al.·Journal of psychosomatic research·2021

This study tested whether ME/CFS and fibromyalgia involve a condition called 'central sensitisation,' where the nervous system becomes overly sensitive to pain signals. Researchers compared pain sensitivity in 19 ME/CFS patients, 19 fibromyalgia patients, and 20 healthy people using physical tests. They found that 84% of ME/CFS patients and 95% of fibromyalgia patients showed signs of central sensitisation, while none of the healthy controls did.

Pain and Sensitization

E2 ModerateCohortPEM unclearObservational

Male vs. Female Differences in Responding to Oxygen-Ozone Autohemotherapy (O2-O3-AHT) in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Chirumbolo, Salvatore, Valdenassi, Luigi, Franzini, Marianno et al.·Journal of clinical medicine·2021

This study looked at how well a treatment called oxygen-ozone autohemotherapy (O₂-O₃-AHT) worked for ME/CFS fatigue in men versus women. Two hundred patients received this treatment and filled out a fatigue questionnaire before and one month after. The results showed that women experienced more improvement in their fatigue than men did, especially among younger patients aged 14-29.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Major Impact on Lives of Both Patients and Family Members.

Brittain, Esme, Muirhead, Nina, Finlay, Andrew Y et al.·Medicina (Kaunas, Lithuania)·2021

This study looked at how ME/CFS affects the quality of life of patients and their family members using two surveys. The researchers found that ME/CFS seriously damages patients' quality of life, particularly in physical health, and also significantly impacts the wellbeing of partners and family members who care for them. The study shows that family members experience worry, sadness, and difficulty maintaining normal family activities because of their loved one's illness.

E2 ModerateCohortPEM requiredObservational

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.

BiomarkersImmune System

Predicting post-exertional malaise in Gulf War Illness based on acute exercise responses.

Boruch, Alexander E, Lindheimer, Jacob B, Klein-Adams, Jacquelyn C et al.·Life sciences·2021

This study looked at how Gulf War Veterans' bodies responded during exercise and whether those responses could predict post-exertional malaise (PEM)—the worsening of symptoms after physical activity. Veterans with Gulf War Illness had more severe symptom flare-ups after exercising compared to healthy veterans, but the researchers found that common exercise measurements like breathing patterns and muscle pain didn't reliably predict who would experience worse PEM.