Evidence browser

RNase L levels in peripheral blood mononuclear cells: 37-kilodalton/83-kilodalton isoform ratio is a potential test for chronic fatigue syndrome.

Tiev, Kiet Phong, Demettre, Edith, Ercolano, Philippe et al.·Clinical and diagnostic laboratory immunology·2003

This study looked at a protein called RNase L in the immune cells of ME/CFS patients and healthy people. Researchers found that ME/CFS patients had a different pattern of RNase L forms compared to healthy volunteers, and this pattern could potentially be used as a simple blood test to help diagnose ME/CFS. The test showed promise in distinguishing ME/CFS patients from healthy people in this small group.

Associations between bronchial hyperresponsiveness and immune cell parameters in patients with chronic fatigue syndrome.

Nijs, Jo, De Becker, Pascale, De Meirleir, Kenny et al.·Chest·2003

Some ME/CFS patients experience unusual airway sensitivity (called bronchial hyperresponsiveness), but the reason why is unclear. This study tested whether this airway sensitivity is caused by specific immune system problems. Researchers found that patients with airway sensitivity had different immune cell patterns than healthy people, but these differences were not the same type seen in asthma, suggesting a different mechanism is at work.

E2 ModerateCohortPEM not requiredObservational

Non-vascular claudication: a clinical conundrum.

Fasih, T, Pickin, M, Cuschieri, R J·International journal of clinical practice·2003

Doctors sometimes see patients complaining of leg pain that resembles poor circulation (claudication), but the pain isn't actually caused by blood vessel problems. This study looked at over 1,000 patients with suspected circulation problems and found that 33 had other causes for their symptoms, including spine problems, nerve damage, or other conditions. One patient was diagnosed with chronic fatigue syndrome (ME/CFS). The study highlights that doctors need to correctly identify the real cause of symptoms before recommending treatments.

Diagnostics

E2 ModerateBehavioralPEM not requiredCross-Sectional

Comparative study of anxiety, depression, somatization, functional disability, and illness attribution in adolescents with chronic fatigue or migraine.

Smith, Mark S, Martin-Herz, Susanne P, Womack, William M et al.·Pediatrics·2003

This study compared teenage girls and boys with chronic fatigue, migraine headaches, and healthy peers to understand their emotional health and how much school they missed. Teenagers with chronic fatigue that met official diagnostic criteria had higher rates of anxiety, depression, and physical complaints than the other groups, and missed far more school days. Interestingly, parents of teenagers with unexplained chronic fatigue were less likely to think psychological stress was contributing to their child's illness compared to parents of teenagers with migraines.

Predictive immunophenotypes: disease-related profile in chronic fatigue syndrome.

Stewart, Carleton C, Cookfair, Diane L, Hovey, Kathleen M et al.·Cytometry. Part B, Clinical cytometry·2003

This study compared immune system cells called natural killer (NK) cells and cytotoxic T cells between people with ME/CFS and healthy controls. Researchers found that people with ME/CFS had different patterns of these immune cells compared to healthy people, but interestingly, healthy people living in the same town as ME/CFS cases had immune cell patterns that looked more similar to ME/CFS patients. This suggests that living in an area where ME/CFS is common might affect how people's immune systems work.

E2 ModerateCohortPEM unclearCase-Control

Complement activation in a model of chronic fatigue syndrome.

Sorensen, Bristol, Streib, Joanne E, Strand, Matthew et al.·The Journal of allergy and clinical immunology·2003

Researchers asked people with ME/CFS and healthy controls to exercise on a stationary bike, then tracked their symptoms and blood markers over the following week. They found that people with ME/CFS had a specific increase in a immune system marker called C4a six hours after exercise, and their fatigue and reduced activity worsened significantly, while healthy controls did not show these changes.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM not requiredObservational

Enterovirus related metabolic myopathy: a postviral fatigue syndrome.

Lane, R J M, Soteriou, B A, Zhang, H et al.·Journal of neurology, neurosurgery, and psychiatry·2003

Researchers tested muscle samples from ME/CFS patients to see if they contained enterovirus (a type of virus). They found that about 21% of ME/CFS patients had enterovirus in their muscles, while none of the healthy control subjects did. Patients with enterovirus in their muscles were more likely to show abnormal lactate (a byproduct of muscle work) buildup during exercise, suggesting their muscles weren't using energy efficiently.

Energy MetabolismPost-Exertional Malaise

Prolonged acetylcholine-induced vasodilatation in the peripheral microcirculation of patients with chronic fatigue syndrome.

Khan, Faisel, Spence, Vance, Kennedy, Gwen et al.·Clinical physiology and functional imaging·2003

This study looked at how blood vessels in the skin of ME/CFS patients respond to acetylcholine, a chemical messenger in the body. Researchers found that while the initial response was similar in patients and healthy controls, the blood vessels of ME/CFS patients took much longer to return to normal after the chemical was applied. This suggests that the way nerve signals control blood vessel function may be different in ME/CFS.

Autonomic Nervous System

Aerobic capacity of Gulf War veterans with chronic fatigue syndrome.

Nagelkirk, Paul R, Cook, Dane B, Peckerman, Arnold et al.·Military medicine·2003

This study tested whether Gulf War veterans with ME/CFS had reduced exercise capacity compared to healthy Gulf War veterans. Researchers measured how well the heart and lungs worked during maximum exercise on a stationary bike. Surprisingly, the two groups performed similarly—those with ME/CFS were able to exercise just as hard and achieve similar fitness levels as the healthy veterans.

Chronic fatigue syndrome versus neuroendocrineimmune dysfunction syndrome:differential attributions.

Jason, Leonard A, Holbert, Cordelia, Torres-Harding, Susan et al.·Journal of health & social policy·2003

This study looked at how doctors and nurses react differently to the name of this illness. Researchers presented the same patient case to healthcare providers but used different diagnostic labels—some were told it was "chronic fatigue syndrome," while others were told it was "chronic neuroendocrineimmune dysfunction syndrome." The results showed that the more medical-sounding name led providers to view the illness as more serious and disabling, even though it was the same patient story.

Chronic fatigue syndrome in children: a cross sectional survey.

Patel, M X, Smith, D G, Chalder, T et al.·Archives of disease in childhood·2003

This study looked at 36 children with ME/CFS who were seen at a specialist clinic in England. Most children improved significantly or returned to normal health, and those who received treatment attended school more often. However, about one-third of children left school without any qualifications, showing that ME/CFS can seriously disrupt education even when health improves.

Interventions

E2 ModerateCohortPEM unclearCase-Control

Subclassifying chronic fatigue syndrome through exercise testing.

Vanness, J Mark, Snell, Christopher R, Strayer, David R et al.·Medicine and science in sports and exercise·2003

Researchers tested 189 people with ME/CFS using an exercise test that measures how much oxygen the body can use. They sorted patients into four groups based on fitness level—from no impairment to severe. The study found that people with ME/CFS vary widely in their physical capacity, and that fitness level affects how the body responds to exercise in measurable ways.

Post-Exertional Malaise

Normal production of inflammatory cytokines in chronic fatigue and fibromyalgia syndromes determined by intracellular cytokine staining in short-term cultured blood mononuclear cells.

Amel Kashipaz, M R, Swinden, D, Todd, I et al.·Clinical and experimental immunology·2003

Researchers tested whether immune system cells from ME/CFS and fibromyalgia patients produce abnormal levels of inflammatory chemicals called cytokines. Using advanced microscopy techniques to examine individual immune cells, they found that cytokine production was normal in patients compared to healthy controls. This suggests that abnormal cytokine production may not be the main cause of these conditions.

E2 ModerateCohortPEM not requiredObservational

Variability in diagnostic criteria for chronic fatigue syndrome may result in substantial differences in patterns of symptoms and disability.

Jason, Leonard A, Helgerson, Jena, Torres-Harding, Susan R et al.·Evaluation & the health professions·2003

This study compared two different sets of diagnostic criteria used to identify ME/CFS: one created by Fukuda and colleagues, and another specifically for myalgic encephalomyelitis (ME). The researchers found that these two definitions identified somewhat different groups of patients, with important differences in neurological symptoms, psychiatric issues, fatigue, and joint/muscle pain. This matters because it means studies using different definitions may not be easily compared.

Diagnostics

Chronic fatigue and organophosphate pesticides in sheep farming: a retrospective study amongst people reporting to a UK pharmacovigilance scheme.

Tahmaz, N, Soutar, A, Cherrie, J W·The Annals of occupational hygiene·2003

This study looked at sheep farmers in the UK who reported health problems they believed were caused by pesticides used in sheep dipping. Researchers wanted to know if repeated exposure to these pesticides was linked to chronic fatigue. They found that fatigue was very common among farmers who thought pesticides affected their health, and there was some association between higher pesticide exposure and higher fatigue scores, though the evidence was limited.

E2 ModerateCohortPEM unclearObservational

Chronic fatigue syndrome in patients with macrophagic myofasciitis.

Authier, François-Jérôme, Sauvat, Stéphane, Champey, Julien et al.·Arthritis and rheumatism·2003

This study looked at patients with macrophagic myofasciitis (MMF), a rare inflammatory muscle condition, and found that some of them also developed symptoms very similar to chronic fatigue syndrome (ME/CFS). The researchers observed that these patients experienced persistent fatigue, muscle pain, and other symptoms characteristic of ME/CFS alongside their muscle inflammation.

Medication use by persons with chronic fatigue syndrome: results of a randomized telephone survey in Wichita, Kansas.

Jones, James F, Nisenbaum, Rosane, Reeves, William C·Health and quality of life outcomes·2003

This study looked at what medications and supplements people with ME/CFS use compared to people without the illness. Researchers called people in Wichita, Kansas and identified those with ME/CFS, then invited them to a clinic visit where they reported all their medications and supplements. People with ME/CFS used about twice as many different drugs as healthy people, with pain relievers and vitamins being most common.

Multiple co-infections (Mycoplasma, Chlamydia, human herpes virus-6) in blood of chronic fatigue syndrome patients: association with signs and symptoms.

Nicolson, G L, Gan, R, Haier, J·APMIS : acta pathologica, microbiologica, et immunologica Scandinavica·2003

This study tested the blood of 200 ME/CFS patients and 100 healthy controls for three types of infections: Mycoplasma bacteria, Chlamydia bacteria, and human herpesvirus-6 (HHV-6). The researchers found that ME/CFS patients had significantly higher rates of these infections compared to healthy people, and patients with multiple infections at the same time tended to have more severe symptoms.

Comparison of subjective and objective measures of insomnia in monozygotic twins discordant for chronic fatigue syndrome.

Watson, Nathaniel F, Kapur, Vishesh, Arguelles, Lester M et al.·Sleep·2003

People with ME/CFS report feeling like they sleep poorly and don't rest well, but when researchers measured their actual sleep using medical equipment, the sleep looked similar to their healthy identical twins. The main difference was that people with ME/CFS had more REM sleep (a specific sleep stage) and felt much less refreshed after sleeping, even though the equipment showed they were sleeping normally. This suggests that ME/CFS may involve a mismatch between how sleep actually is and how it feels.

Sleep