Evidence browser

No serological evidence for a role of HHV-6 infection in chronic fatigue syndrome.

Burbelo, Peter D, Bayat, Ahmad, Wagner, Jason et al.·American journal of translational research·2012

This study tested whether a virus called HHV-6 might be causing chronic fatigue syndrome (ME/CFS). Researchers compared antibodies (immune system markers) against HHV-6 in people with ME/CFS and healthy controls. They found that both groups had similar levels of HHV-6 antibodies, suggesting this virus is unlikely to be a major cause of ME/CFS.

E2 ModerateCohortPEM not requiredObservational

No evidence of cross-species transmission of mouse retroviruses to animal workers exposed to mice.

Brooks, James, Lycett-Lambert, Karly, Caminiti, Kyna et al.·Transfusion·2012

Researchers tested 43 people who work closely with mice to see if they had been infected with mouse viruses (XMRV and MLV) that some scientists had previously linked to ME/CFS. Using blood tests and genetic analysis, they found no evidence that these viruses had jumped from mice to humans, even among workers with high exposure.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Co-morbid pain conditions and feelings of invalidation and isolation among women with vulvodynia.

Nguyen, Ruby H N, Ecklund, Ali M, Maclehose, Richard F et al.·Psychology, health & medicine·2012

This study looked at women with vulvodynia (chronic pain in the vulva) who also had other chronic pain conditions like ME/CFS, fibromyalgia, or endometriosis. The researchers found that women with multiple pain conditions were more likely to feel that others didn't believe their pain was real and to feel socially isolated. Having ME/CFS alongside vulvodynia was particularly linked to these feelings.

Chronic fatigue syndrome and subsequent risk of cancer among elderly US adults.

Chang, Cindy M, Warren, Joan L, Engels, Eric A·Cancer·2012

Researchers investigated whether people with ME/CFS have a higher risk of developing cancer. Using medical records from over 1.2 million elderly Americans, they found that people with ME/CFS had a slightly increased risk of non-Hodgkin lymphoma (a blood cancer), particularly certain subtypes. The study does not prove that ME/CFS causes cancer, but suggests that shared immune system problems or infections might explain the connection.

E2 ModerateCohortPEM unclearCross-Sectional

Prevalence of xenotropic murine leukemia virus-related virus infection in different risk populations in Spain.

Arredondo, Miguel, Hackett, John, de Bethencourt, Fermín R et al.·AIDS research and human retroviruses·2012

Researchers tested blood samples from over 1,100 people in Spain, including those with ME/CFS and fibromyalgia, to look for a virus called XMRV that had been suggested as a possible cause of these conditions. They found no reliable evidence that XMRV was present in any of the groups they studied, including people with ME/CFS, cancer, other viral infections, or healthy blood donors.

E2 ModerateBehavioralPEM unclearLongitudinal

A preliminary prospective study of nutritional, psychological and combined therapies for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in a private care setting.

Arroll, Megan Anne, Howard, Alex·BMJ open·2012

This study looked at whether three different approaches—psychology-based treatment, nutrition-based treatment, or a combination of both—could help people with ME/CFS over a 3-month period. All three groups reported feeling better in terms of fatigue, daily functioning, and overall symptoms, with the psychology group also feeling more in control of their condition. However, the study had important limitations: people weren't randomly assigned to groups, there was no control group to compare against, and many participants dropped out, so the results need to be interpreted carefully.

Heterogeneous nuclear RNPs as targets of autoantibodies in systemic rheumatic diseases.

Op De Beéck, Katrijn, Maes, Liesbeth, Van den Bergh, Karolien et al.·Arthritis and rheumatism·2012

This study looked for specific autoantibodies (immune proteins that attack the body's own cells) in people with various rheumatic diseases, including those with chronic fatigue syndrome. Researchers tested blood samples from hundreds of patients and healthy controls, measuring antibodies against different protein targets called hnRNPs. They found that people with Sjögren's syndrome (an autoimmune disease affecting glands) had significantly more of these antibodies compared to healthy people.

Xenotropic murine leukemia virus-related virus does not pose a risk to blood recipient safety.

Dodd, Roger Y, Hackett, John, Linnen, Jeffrey M et al.·Transfusion·2012

Researchers tested thousands of blood donors and transfusion recipients to see if XMRV (a virus once suspected to be linked to ME/CFS) was present in the blood supply and could be transmitted through blood transfusions. They found no evidence of the virus in any of the donors or recipients tested, suggesting that XMRV does not pose a safety risk to people receiving blood transfusions.

Increased autoimmune activity against 5-HT: a key component of depression that is associated with inflammation and activation of cell-mediated immunity, and with severity and staging of depression.

Maes, Michael, Ringel, Karl, Kubera, Marta et al.·Journal of affective disorders·2012

This study found that people with depression have more antibodies attacking serotonin (a brain chemical) compared to healthy people, especially those with severe depression. These antibodies were linked to higher inflammation, immune activation, fatigue, and cognitive problems. The more depressive episodes someone had experienced, the more likely they were to have these antibodies, suggesting that repeated depression may change the immune system over time.

E2 ModerateBehavioralPEM not requiredCross-Sectional

[How do patients interpret terms for medically unexplained symptoms?].

Kingma, Eva M, Moddejonge, Raquel S, Rosmalen, Judith G M·Nederlands tijdschrift voor geneeskunde·2012

This study asked 184 patients in Dutch waiting rooms how they felt about different medical terms used to describe unexplained tiredness. The researchers found that patients reacted most negatively to the term 'psychosomatic tiredness' (suggesting the tiredness is psychological), while they were more accepting of terms like 'chronic fatigue syndrome' and 'functional fatigue.' This suggests that patients prefer medical terms that don't imply their condition is 'all in their head.'

Confidence judgment in depression and dysphoria: the depressive realism vs. negativity hypotheses.

Szu-Ting Fu, Tiffany, Koutstaal, Wilma, Poon, Lucia et al.·Journal of behavior therapy and experimental psychiatry·2012

This study looked at how accurately people judge their own knowledge and abilities. Researchers compared three groups: healthy people, those with clinical depression, and people with chronic fatigue syndrome who felt sad or low. They found that people with depression were overly critical of themselves, while people with chronic fatigue syndrome were more realistic about their abilities—similar to healthy controls.

Cognitive Impairment

E2 ModerateCohortPEM unclearCross-Sectional

No evidence for xenotropic murine leukemia-related virus infection in Sweden using internally controlled multiepitope suspension array serology.

Blomberg, Jonas, Blomberg, Fredrik, Sjösten, Anna et al.·Clinical and vaccine immunology : CVI·2012

Researchers tested blood samples from ME/CFS patients and healthy blood donors to see if they had been infected with a mouse virus called XMRV, which had been proposed as a possible cause of ME/CFS. Using a sensitive new testing method that looked for multiple signs of XMRV infection, they found no difference in viral markers between the two groups, suggesting XMRV is not associated with ME/CFS.

E2 ModerateCohortPEM unclearCase-Control

Responses to exercise differ for chronic fatigue syndrome patients with fibromyalgia.

Cook, Dane B, Stegner, Aaron J, Nagelkirk, Paul R et al.·Medicine and science in sports and exercise·2012

This study compared how the bodies of ME/CFS patients respond to moderate exercise on a stationary bike. Researchers found that patients who have both ME/CFS and fibromyalgia (a condition causing widespread pain) showed different heart and breathing responses during exercise compared to healthy people, including higher perceived effort and different blood pressure patterns.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

No biological evidence of XMRV infection in cervical smears from HIV/ HPV positive and negative Kenyan women.

He, Xiaotong, Walker, Thomas D J, Maranga, Innocent O et al.·PloS one·2012

This study tested whether a virus called XMRV could be found in cervical samples from 224 Kenyan women, some with HIV and some without. Using sensitive lab techniques, the researchers found no trace of XMRV in any of the samples. This supports the idea that XMRV, once linked to ME/CFS, is likely a lab contamination rather than a real human infection.

[Epidemiology, diagnostics, and treatment of complications after neuroinfections: chronic fatigue syndrome].

Verner, O M, Murashko, N K·Likars'ka sprava·2012

This study looked at how often ME/CFS occurs in people who have had brain infections, finding that more than 20% of patients who recover from certain infections develop ME/CFS afterward. The condition was more common in people aged 40-59, and women were affected about 4 times more often than men. While the exact cause remains unknown, researchers think it may be related to genetics, immune system problems, or lingering effects from infections like Epstein-Barr virus.

Lyme disease in a British referral clinic.

Cottle, L E, Mekonnen, E, Beadsworth, M B J et al.·QJM : monthly journal of the Association of Physicians·2012

This UK study looked at 115 patients who were referred to a specialist clinic because doctors suspected they had Lyme disease. The researchers found that only 23% actually had Lyme disease, while about one-third had ME/CFS instead. Importantly, some ME/CFS patients had been incorrectly told they had Lyme disease by non-specialist doctors, leading them to take unnecessary antibiotics.

Antinuclear antibody detection by automated multiplex immunoassay in untreated patients at the time of diagnosis.

Op De Beéck, Katrijn, Vermeersch, Pieter, Verschueren, Patrick et al.·Autoimmunity reviews·2012

This study compared two different blood tests for detecting autoantibodies (proteins the immune system makes that attack the body's own cells) in patients with various autoimmune diseases and in people with ME/CFS. The researchers found that one newer automated test missed some antibodies that an older, more traditional test detected, and that having multiple antibodies together was much more common in autoimmune disease patients than in ME/CFS patients.