Evidence browser

E2 ModerateCohortPEM unclearObservational

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.

A multicenter blinded analysis indicates no association between chronic fatigue syndrome/myalgic encephalomyelitis and either xenotropic murine leukemia virus-related virus or polytropic murine leukemia virus.

Alter, Harvey J, Mikovits, Judy A, Switzer, William M et al.·mBio·2012

Earlier studies suggested that two viruses (XMRV and pMLV) might cause ME/CFS, but this finding was controversial. In this study, the same scientists who originally reported finding these viruses carefully re-examined blood samples from 147 ME/CFS patients and 146 healthy people without knowing which samples came from which group. They found no evidence that either virus was present in any of the samples, meaning the original finding could not be confirmed.

Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.

Jones, David E J, Hollingsworth, Kieren G, Jakovljevic, Djordje G et al.·European journal of clinical investigation·2012

This study looked at how muscles produce and use energy during exercise in ME/CFS patients compared to healthy people. Researchers found that ME/CFS patients' muscles became more acidic (like buildup of lactic acid) during exercise and took much longer to recover back to normal levels, even after repeated exercise sessions. This abnormal response to exercise may explain why some ME/CFS patients feel worse after exertion rather than better.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredObservational

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.

Predictors of Fatigue among Patients with Chronic Fatigue Syndrome.

Jason, Leonard A, Brown, Molly, Evans, Meredyth et al.·Journal Of Human Behavior In The Social Environment·2012

This study asked ME/CFS patients to keep detailed activity logs to understand what triggers their fatigue. Researchers looked at what patients were doing, what they had been doing 30 minutes earlier, and their fatigue levels to find patterns. The study suggests that tracking daily activities can help doctors and patients see which activities are most connected to fatigue flare-ups.

Immune SystemPost-Exertional Malaise

Association of active human herpesvirus-6, -7 and parvovirus b19 infection with clinical outcomes in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Chapenko, Svetlana, Krumina, Angelika, Logina, Inara et al.·Advances in virology·2012

This study tested 108 ME/CFS patients and 90 healthy people for three viruses: HHV-6, HHV-7, and parvovirus B19. The researchers found that about 65% of ME/CFS patients had active viral infections compared to only 13% of healthy people. Patients with active viral infections showed higher levels of inflammatory markers and experienced more severe symptoms, especially when infected with multiple viruses at once.

E2 ModerateCohortPEM not requiredObservational

Absence of evidence for bornavirus infection in schizophrenia, bipolar disorder and major depressive disorder.

Hornig, M, Briese, T, Licinio, J et al.·Molecular psychiatry·2012

Researchers tested whether a virus called Borna disease virus (BDV) might cause depression, bipolar disorder, or schizophrenia. They carefully compared blood samples from 198 patients with these conditions and 198 healthy people, looking for signs of the virus. They found no evidence that the virus was present in either group, suggesting BDV is not responsible for these psychiatric illnesses.

Comparison of chronic fatigue syndrome/myalgic encephalopathy with other disorders: an observational study.

Knudsen, Ak, Lervik, Lv, Harvey, Sb et al.·JRSM short reports·2012

Researchers looked at how many people were using online discussion forums for different health conditions in Norway in 2009. They found that ME/CFS forums were far more active than forums for other illnesses—with more users and more messages posted relative to how many people have the condition. This high activity might mean that people with ME/CFS are seeking answers and support online, especially since the condition is poorly understood and sometimes stigmatized.

Alternative diagnoses to chronic fatigue syndrome in referrals to a specialist service: service evaluation survey.

Devasahayam, Anoop, Lawn, Tara, Murphy, Maurice et al.·JRSM short reports·2012

This study looked at patients referred to a specialist ME/CFS clinic to see how often doctors correctly identified ME/CFS versus other conditions. Researchers found that about half of all referred patients actually had different medical or psychiatric conditions instead of ME/CFS—most commonly sleep disorders or depression. This shows that careful specialist assessment is important to make sure patients get the right diagnosis.

Diagnostics

Impaired blood pressure variability in chronic fatigue syndrome--a potential biomarker.

Frith, J, Zalewski, P, Klawe, J J et al.·QJM : monthly journal of the Association of Physicians·2012

ME/CFS is often associated with problems in the autonomic nervous system, which controls heart rate and blood pressure. This study measured how heart rate and blood pressure respond to position changes in 68 ME/CFS patients and 68 healthy controls. The researchers found that ME/CFS patients showed abnormal patterns in blood pressure variability that could potentially be used as a diagnostic test.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredObservational

No evidence of XMRV infection in immunocompromised patients and HIV-positive individuals from Germany.

Korn, K, Reil, H, Ensser, A et al.·Infection·2012

Researchers tested blood samples from 542 people in Germany—including those with weakened immune systems and people living with HIV—to see if they carried a virus called XMRV that had been suggested as a possible cause of ME/CFS. None of the 814 blood samples tested positive for XMRV, suggesting this virus is not present in these high-risk groups in Germany.

Prevalence, incidence, and classification of chronic fatigue syndrome in Olmsted County, Minnesota, as estimated using the Rochester Epidemiology Project.

Vincent, Ann, Brimmer, Dana J, Whipple, Mary O et al.·Mayo Clinic proceedings·2012

This study looked at how many people in one county had ME/CFS by reviewing medical records from 1998-2002. Researchers found that about 71 out of every 100,000 people had ME/CFS, and about 13 out of every 100,000 per year were newly diagnosed. Importantly, they discovered that 70% of people initially suspected of having ME/CFS actually had other medical conditions that explained their fatigue instead.

Diagnostics

Visible and near-infrared spectra collected from the thumbs of patients with chronic fatigue syndrome for diagnosis.

Sakudo, Akikazu, Kuratsune, Hirohiko, Kato, Yukiko Hakariya et al.·Clinica chimica acta; international journal of clinical chemistry·2012

Researchers used a special light-based scanner on patients' thumbs to see if they could tell the difference between people with ME/CFS and healthy people. The scanner detected subtle changes in how light passes through the skin in a specific wavelength range. When they analyzed the results using computer models, they were able to correctly identify about 70% of ME/CFS patients and 83% of healthy people, suggesting this method might someday help doctors diagnose ME/CFS more objectively.

Biomarkers

Evidence for inflammation and activation of cell-mediated immunity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): increased interleukin-1, tumor necrosis factor-α, PMN-elastase, lysozyme and neopterin.

Maes, Michael, Twisk, Frank N M, Kubera, Marta et al.·Journal of affective disorders·2012

This study examined whether people with ME/CFS have higher levels of inflammatory markers—substances in the blood that signal inflammation—compared to healthy people and those with regular fatigue. Researchers found that ME/CFS patients had significantly elevated levels of five different inflammatory markers, and these markers were linked to common ME/CFS symptoms like fatigue, brain fog, and flu-like feelings. The findings suggest that low-grade inflammation in the body may be contributing to ME/CFS symptoms.

E2 ModerateCohortPEM unclearLongitudinal

Longitudinal investigation of natural killer cells and cytokines in chronic fatigue syndrome/myalgic encephalomyelitis.

Brenu, Ekua W, van Driel, Mieke L, Staines, Donald R et al.·Journal of translational medicine·2012

This study tracked immune system changes in 65 people with ME/CFS over one year, comparing them to 21 healthy controls. Researchers found that people with ME/CFS had consistently lower natural killer (NK) cell activity—immune cells that help fight infections—throughout the year. They also found changes in inflammatory molecules called cytokines that fluctuated at different time points.

E2 ModerateCohortPEM not requiredLongitudinal

Understanding long-term outcomes of chronic fatigue syndrome.

Brown, Molly M, Bell, David S, Jason, Leonard A et al.·Journal of clinical psychology·2012

This study followed people who were diagnosed with ME/CFS 25 years earlier and compared them to healthy people. Most participants (20 out of 25) no longer had an ME/CFS diagnosis, but surprisingly, they still experienced significantly more health problems and limitations than healthy controls. This suggests that even when people stop meeting the criteria for ME/CFS, they may not fully recover to their previous level of health.

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.

Equity of access to specialist chronic fatigue syndrome (CFS/ME) services in England (2008-2010): a national survey and cross-sectional study.

Collin, Simon M, Sterne, Jonathan A C, Hollingworth, William et al.·BMJ open·2012

This study examined how fairly ME/CFS specialist services were distributed across England between 2008-2010. Researchers found that some areas had no specialist services at all, while others had very different numbers of patients being seen and diagnosed. In some regions, people living in poorer neighborhoods were less likely to access services than those in wealthier areas, even when services existed.

NMR metabolic profiling of serum identifies amino acid disturbances in chronic fatigue syndrome.

Armstrong, Christopher W, McGregor, Neil R, Sheedy, John R et al.·Clinica chimica acta; international journal of clinical chemistry·2012

Researchers used a specialized blood test called NMR to compare the levels of different chemicals in the blood of 11 people with ME/CFS and 10 healthy people. They found that people with ME/CFS had significantly lower levels of two amino acids (building blocks of protein): glutamine and ornithine. These findings suggest that people with ME/CFS may have problems with how their bodies process certain proteins and manage nitrogen, which are important for energy and cell function.

Biomarkers