Evidence browser

E3 PreliminaryMechanismPEM unclearCross-Sectional

Membrane fusion and cell entry of XMRV are pH-independent and modulated by the envelope glycoprotein's cytoplasmic tail.

Côté, Marceline, Zheng, Yi-Min, Liu, Shan-Lu·PloS one·2012

This study examined how XMRV, a virus once suspected to be linked to ME/CFS, enters human cells. Researchers found that XMRV enters cells differently than many other viruses—it doesn't require acidic conditions inside the cell. They also discovered that a small tail-like structure on the virus's outer coating controls whether the virus can fuse with and infect cells.

No biological evidence of XMRV in blood or prostatic fluid from prostate cancer patients.

Mendoza, Ramon, Silverman, Robert H, Klein, Eric A et al.·PloS one·2012

Researchers tested blood and fluid samples from prostate cancer patients to see if they contained XMRV, a virus that was once thought to cause chronic fatigue syndrome. They found no evidence of the virus in any of the samples, including in nine patients who had previously tested positive for XMRV. This study supports the growing scientific consensus that XMRV does not actually infect humans.

E3 PreliminaryCohortPEM not required

Chronic fatigue syndrome after Giardia enteritis: clinical characteristics, disability and long-term sickness absence.

Naess, Halvor, Nyland, Morten, Hausken, Trygve et al.·BMC gastroenterology·2012

After a water contamination outbreak in Norway caused a bacterial infection (giardiasis), some patients developed long-lasting severe fatigue similar to ME/CFS. This study looked at 58 patients who met the official diagnostic criteria for CFS following this infection. Most patients reported their condition was getting worse over time, and all of them had to take extended time off work or school due to their fatigue and reduced ability to function.

Identification of XMRV infection-associated microRNAs in four cell types in culture.

Mohan, Ketha V K, Devadas, Krishnakumar, Sainath Rao, Shilpakala et al.·PloS one·2012

This study looked at how a virus called XMRV affects the behavior of microRNAs—tiny molecules that control how genes are expressed—in different types of human cells grown in the laboratory. Researchers infected four different cell types with XMRV and measured changes in microRNA patterns at different time points. They found that certain microRNAs changed in response to the virus infection.

E3 PreliminaryMechanismPEM unclear

In-depth investigation of archival and prospectively collected samples reveals no evidence for XMRV infection in prostate cancer.

Lee, Deanna, Das Gupta, Jaydip, Gaughan, Christina et al.·PloS one·2012

Scientists investigated whether a virus called XMRV could cause chronic fatigue syndrome or prostate cancer. Even though an earlier study claimed to find this virus in some patients, many follow-up studies couldn't confirm it. This research tested blood and tissue samples from 39 prostate cancer patients using multiple methods and found no sign of XMRV infection, suggesting the virus doesn't naturally infect humans—it likely came from contamination in laboratory experiments.

Inflammatory fatigue and sickness behaviour - lessons for the diagnosis and management of chronic fatigue syndrome.

Arnett, S V, Clark, I A·Journal of affective disorders·2012

This review examines how inflammation in the body can cause extreme tiredness and sickness-like symptoms similar to those seen in ME/CFS. The authors looked at how inflammatory chemicals in the brain trigger the body's sickness response—similar to how you feel when fighting an infection—and found that this same process may be happening in ME/CFS patients. They suggest that understanding this connection could help doctors diagnose and treat ME/CFS more effectively.

The in vivo infusion of hydrogen peroxide induces oxidative stress and differentially affects the activities of small intestinal carbohydrate digestive enzymes in the neonatal pig.

Lackeyram, D, Mine, Y, Widowski, T et al.·Journal of animal science·2012

Researchers gave young pigs either hydrogen peroxide (a substance that causes oxidative stress, similar to cellular damage) or saline over 10 days to study how oxidative stress might affect ME/CFS. Pigs given hydrogen peroxide showed reduced antioxidant levels, less physical activity, and decreased ability to digest certain carbohydrates in their intestines. This suggests that oxidative stress may interfere with how the gut breaks down food, which could contribute to fatigue and other ME/CFS symptoms.

Pain and SensitizationSleep

The role of antipsychotics in the management of fibromyalgia.

Calandre, Elena P, Rico-Villademoros, Fernando·CNS drugs·2012

This review examines whether antipsychotic medications—drugs typically used to treat psychiatric conditions—might also help people with fibromyalgia manage pain, sleep problems, fatigue, and mood disturbances. The authors found that some antipsychotics, particularly quetiapine, have shown promise in small studies and case reports, though most research is preliminary and more rigorous testing is needed.

E3 PreliminaryMechanismPEM unclearCase-Control

Lack of evidence for a role of xenotropic murine leukemia virus-related virus in the pathogenesis of prostate cancer and/or chronic fatigue syndrome.

Hong, Ping, Li, Jinming·Virus research·2012

A virus called XMRV was once thought to possibly cause ME/CFS and prostate cancer, but this review found no solid evidence supporting that connection. The authors looked at multiple studies and concluded that most positive findings were likely due to contamination in lab samples, not actual infection. This virus does not appear to play a role in causing ME/CFS.

Cytotoxic lymphocyte microRNAs as prospective biomarkers for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis.

Brenu, Ekua W, Ashton, Kevin J, van Driel, Mieke et al.·Journal of affective disorders·2012

Researchers studied tiny molecules called microRNAs in immune cells from people with ME/CFS and healthy controls. They found that people with ME/CFS have lower levels of certain microRNAs in their immune cells, which may explain why their immune systems don't work as well. These microRNA changes could be useful biomarkers—like a fingerprint—to help diagnose or understand ME/CFS.

Loss of stress response as a consequence of viral infection: implications for disease and therapy.

Hooper, Philip L, Hightower, Lawrence E, Hooper, Paul L·Cell stress & chaperones·2012

This paper suggests that viral infections may damage the body's ability to handle stress at the cellular level, making tissues more vulnerable to injury. Rather than looking for one specific virus causing ME/CFS, the authors propose that ME/CFS might result from a general, nonspecific cellular damage response that occurs after many types of viral infections. Understanding this mechanism could open new treatment possibilities for conditions that have not responded well to existing therapies.

E3 PreliminaryCommentaryPEM not requiredEditorial

Recombinant origin, contamination, and de-discovery of XMRV.

Delviks-Frankenberry, Krista, Cingöz, Oya, Coffin, John M et al.·Current opinion in virology·2012

In the mid-2000s, scientists announced they found a virus called XMRV in people with ME/CFS, which raised hope for a breakthrough. However, after thorough testing by laboratories around the world, this discovery was proven wrong—the virus wasn't actually present in ME/CFS patients. The original findings were due to accidental contamination from mouse DNA and laboratory materials, and XMRV turned out to be a virus created accidentally in the lab decades earlier, not a natural infection in humans.

E3 PreliminaryMechanismPEM unclearMechanistic

Chronic fatigue syndrome or myalgic encephalomyelitis.

Burns, Dianne·Nursing standard (Royal College of Nursing (Great Britain) : 1987)·2012

ME/CFS is a serious illness that affects many body systems, especially the nervous and immune systems, and can impact anyone regardless of age, race, or background. This guideline article helps nurses and healthcare workers recognize and support ME/CFS patients by providing practical knowledge and management strategies. The recommendations can be used by healthcare professionals in different settings to better care for people living with this condition.

Diagnostics

Intrinsic DNA synthesis fidelity of xenotropic murine leukemia virus-related virus reverse transcriptase.

Barrioluengo, Verónica, Wang, Yi, Le Grice, Stuart F J et al.·The FEBS journal·2012

This study examined how accurately a virus called XMRV copies its genetic material when it infects human cells. Researchers compared XMRV's copying accuracy to two other viruses (HIV and another mouse virus) by measuring how often mistakes happen during the copying process. The study found that XMRV makes copies with reasonable accuracy, though with a different pattern of errors than HIV.

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Phylogenetic and biological analysis of a laboratory-generated gammaretrovirus xenotropic murine leukemia virus-related virus (XMRV).

Ma, Xiaochu, Zhou, Shiying, Wei, Meili et al.·Virus genes·2012

This study investigated whether XMRV, a virus previously thought to be associated with chronic fatigue syndrome, could actually infect human cells. Researchers found that XMRV is a laboratory-made virus created accidentally during experiments with mouse tissues, not a naturally occurring pathogen. Testing showed that XMRV cannot infect human immune cells, suggesting it is unlikely to cause disease in people.

Minimum data elements for research reports on CFS.

Jason, Leonard A, Unger, Elizabeth R, Dimitrakoff, Jordan D et al.·Brain, behavior, and immunity·2012

Researchers noticed that different ME/CFS studies were collecting and reporting information in very different ways, making it hard to compare results across laboratories. This paper outlines the essential information that all ME/CFS research studies should include—like how patients were selected, what their characteristics are, and how they were tested—so that future studies can be compared fairly and findings can be better understood.

Diagnostics

E3 PreliminaryCommentaryPEM unclearEditorial

Fatigue and disrupted sleep-wake patterns in patients with cancer: a shared mechanism.

Wu, Horng-Shiuann, Davis, Jean E, Natavio, Teofanes·Clinical journal of oncology nursing·2012

Cancer patients often experience severe tiredness and sleep problems at the same time, suggesting they may share a common cause. This paper proposes that stress hormones—particularly those controlled by a system called the HPA axis—may be disrupted in ways that trigger both fatigue and poor sleep. Because ME/CFS patients have similar symptoms and similar HPA axis problems, studying cancer-related fatigue might help us understand ME/CFS better.

Sleep

E3 PreliminaryMechanismPEM unclearCross-Sectional

Gene expression alterations at baseline and following moderate exercise in patients with Chronic Fatigue Syndrome and Fibromyalgia Syndrome.

Light, A R, Bateman, L, Jo, D et al.·Journal of internal medicine·2012

This study looked at how genes are turned on and off in people with ME/CFS before and after moderate exercise. Researchers found that about 71% of ME/CFS patients showed increased activity in genes related to nerve signaling and stress response after exercise, which correlated with their fatigue and pain levels. A smaller subgroup (29%) showed a different pattern, with decreased activity in one specific gene, and these patients were more likely to have orthostatic intolerance (dizziness when standing).

BiomarkersPost-Exertional Malaise

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Live sequence charts to model medical information.

Aslakson, Eric, Szekely, Smadar, Vernon, Suzanne D et al.·Theoretical biology & medical modelling·2012

Researchers developed a new way to organize and understand patient medical records by translating written descriptions of illness into visual diagrams. They tested this approach using an actual patient interview with someone who was later diagnosed with ME/CFS. This method could help doctors and researchers better track how diseases develop over time and identify important patterns in patient histories.