Helpful Tips for Understanding Studies
Myalgic encephelomyelitis is the name given to a disease with outbreaks in the U.K. in the 1950s. Chronic fatigue syndrome is the name given to a disease with outbreaks in the US in the 1980s. While there is much controversy of the names or diagnostic criteria, most researchers consider the disease of these outbreaks to be the same illness. Research studies will often use these terms interchangeably or together.
Biological Abnormalities Found in ME/CFS Patients:
Immune System Abnormalities
- 2011 Haukeland University Hospital – B Cell depletion causes temporary remission in 67% of ME/CFS patients, leading to theory that ME/CFS is an autoimmune disease.
- 2011 Bond University – Immune abnormalities can be used as biomarkers and support the theory of chronic infection.
- 2010 University of Dundee - Children with ME/CFS show chronic inflammation, the body fighting an infection.
- 2010 University of Miami Study – ME/CFS patients can be diagnosed by testing for abnormally functioning Natural Killer Cells, a part of the immune system.
- 2009 University of Utah Study – Moderate exercise increases expression for sensory, adrenergic and immune genes in chronic fatigue syndrome patients, but not in normal subjects.
- 2009 University of Miami Study – ME/CFS patients show chronic inflammation, cytokine activity. This could be from an immune system abnormality or the body fighting chronic infections.
- 1992 National Institutes of Health – ME/CFS patients show chronic inflammation of the central nervous system. HHV-6 is also shown to be reactivated.
- 1991 University of Miami School of Medicine – Natural Killer (NK) cells, an important part of the immune system that kills tumors, is not functioning in ME/CFS patients. Cytokines and T cells, also part of immune system, are overactive, showing inflammation. Some of these findings are similar to what is seen in MS.
- 1987 Dana-Farber Cancer Institute - ME/CFS patients have lower number of some types of Natural Killer (NK) cells and NK cells do not function normally and therefore do not kill infections as well.
Cardiovascular System Abnormalities
Functional Impairment / Severity:
- 2011 London School of Hygiene & Tropical Medicine – “ME/CFS is disabling and has a greater impact on functional status and well being than other chronic diseases such as cancer.”
- 2010 EHC, Toronto - Functional impairment in chronic fatigue syndrome, fibromyalgia, and multiple chemical sensitivity.
- 2006 DePaul University – ME/CFS patients die on average 15-20 years earlier than the average, primarily from suicide, heart failure and cancer.
Xenotropic Murine Leukemia Virus-like Virus (XMRV) and Murine Leukemia Virus-like Viruses (MLV-like viruses) are a group of gamma retroviruses. A retrovirus has a distinctive way of replicating and becomes part of the person’s DNA. HIV is an example of a retrovirus. Most researchers believe that the previous positive findings of MLVs in ME/CFS patients are a result of contamination. However, in the U.S. two government-funded studies into murine leukemia viruses connection to ME/CFS are continuing and by most are considered to be comprehensive such as the results will be conclusive.
High Rate of Retrovirus in ME/CFS patients, also in general population:
These studies have been called into questions by many studies that either don’t find the retroviruses in the patients or find it is contamination.
Other Retrovirus Findings:
- 2011 Emory University – XMRV injection into animals causes high antibody response that diminishes rapidly, which may explain conflicting results in other studies.
- 2011 Emory University – Infection, viral dissemination and antibody responses of Rhesus macaques exposed to the human gammaretrovirus XMRV show virus disappears from the blood within a couple of weeks but remains in multiple organs.
- 2010 NIH – Retroviruses (XMRV and PMLV) that cause cancers and immunodefiency disease in other species have evolved and crossed from mice to humans, possibly directly. The resulting virus descendants are now genetically different from the original virus found in lab mice.
- 2010 German Study – XMRV in respiratory secretions, raising question of possible transmission through saliva, also found in 10% of immunosuppressed individuals.
- 2010 WPI Study – XMRV: Virological, immunological and clinical correlations in patients with chronic lymphocytic leukemia and mantle cell lymphoma