- Last Updated: 02 December 2015 02 December 2015
The following is a summary of : "Gray Matter Volume Reduction in the Chronic Fatigue Syndrome," by de Lange F.P. et al., NeuroImage July 26 (3) (2005): 777-781.
The team conducted this important research at the Centre for Neuroimaging at Radboud University in Nijmegen in the Netherlands. They used "...an unbiased morphometric technique to test whether CFS patients display structural cerebral abnormalities (in the brain)."
Structural cerebral morphology (physical character) and volume were mapped in two separate groups of Chronic Fatigue Syndrome (CFS) patients (in total 28 patients) and healthy controls (also totaling 28 patients). This mapping was conducted using high-resolution structural magnetic resonance images "...using voxel-based morphometry (VBM). Additionally, we recorded physical activity levels to explore the relation between severity of CFS symptoms and cerebral anamolies." [Massachusetts CFIDS/ME & FM Association emphasis].
An important aspect of the research was the use "...of a fully automated, observer independent procedure [VBM, which]...provides an unbiased and validated...technique for measuring cerebral volume and tissue concentration..."
The team also used actigraphic assessment to measure the physical activity levels of patients as well as that of a portion of the healthy controls.
The study was restricted to women for several reasons—including the fact that more women than men suffer from CFS and also because of the differences in brain size and morphology between the sexes.
The first cohort consisted of 13 CFS patients (mean age: 28.9 years) and 15 healthy controls (mean age: 25.7 years). The two groups were matched for age, sex, and education. The second cohort consisted of "...15 older CFS patients (mean age 43.9 years)..." and an appropriately matched group of healthy controls. Two weeks prior to the scanning, 26 of the CFS patients and 14 of the healthy controls were evaluated for their physical activity level. This was done using a motion-sensing device that fits on the ankle. The device provides an activity score for each 5 min. of movement (multi-directional). This device was worn continuously day and night for at least the 14-day period.
Only patients meeting the 1994 CDC diagnostic criteria were included in the study—but, significantly, any patient exhibiting depression was excluded. (Note: while many patients with ME/CFS actually show secondary depression, the exclusion increased the likelihood that more patients who really do have ME/CFS were included in the study.)
Two other measures of the patient group were included: self-reported disease severity (measured by the Checklist of Individual Strength—a questionnaire that measures fatigue), and self-reported disease duration.
Images of the whole brain were analyzed "...for computational analysis of differences in global and local gray and/or white matter volume." Highly sophisticated techniques were used to provide valid comparisons by normalizing a variety of variables (including population-specific biases). Then, in a second stage, statistical methods were used to correct for non-uniformities in "...signal intensity and partitioned into gray and white matter, cerebrospinal fluid, and background."
In the statistical analysis, "Global differences in gray and white matter between groups were assessed..." taking into account age as a confounding covariant." Statistical methods were also used to assess, correct and correlate physical activity and gray matter volume, and regional differences (in the brain) in gray matter between groups taking into account age and other variables.
"Both cohorts of CFS patients showed significant reductions in gray matter volume...compared to healthy controls." Even when the two cohorts are put together the reduction of gray matter in patients remains "highly significant", amounting to a reduction of "approximately 8%".
The study, interestingly, did not find a difference in gray matter reduction by brain region— the reduction in gray matter was only significant globally. There were also no local foci of reduced gray matter.
"White matter volume was not significantly different between groups."
Correlation with physical activity
There was a positive correlation between daily physical activity and gray matter within the CFS patients. At the same time, there was no such correlation in the control group. The age variable was found not to affect the physical activity level in the CFS group. This means that the positive correlation between gray matter and physical activity in the CFS population is not countered by the age variable. "There were no significant correlations between gray matter and...illness duration or CFS severity...as measured by the Checklist of individual Stength."
"Our findings appear to provide a reliable somatic marker for CFS." The authors suggest the finding may corroborate the primary involvement of the central nervous system in ME/CFS. However, the authors acknowledge that the meaning of the findings may not be "straightforward". The correlation between reduced global gray matter and reduced physical activity in CFS cohorts might be causative—that is the reduced gray matter might be influencing the ability to conduct physical activity.
Alternatively, the reduction of physical activity caused by ME/CFS might be itself having the effect of reducing gray matter in the brain.
There is some research that lends credence to the effect of reduced physical activity on the amount of gray matter in the brain. However, interestingly, in this study illness duration was not found to affect the gray matter decrease in the CFS subjects. This would, obviously, suggest that the reduction of gray matter in the CFS subjects was not due to reduced physical activity.
The study found "...substantial and consistent reductions in gray matter volume...in CFS patients... This GM reduction was associated to the decline in physical activity in the CFS patients..."
- Last Updated: 02 December 2015 02 December 2015
For Immediate Release: April 20, 2006
Contact: CDC Media Relations
People who suffer from Chronic Fatigue Syndrome (CFS) have a genetic make up that affects the body's ability to adapt to change, according to a series of papers released today by the Centers for Disease Control & Prevention (CDC). These papers, which analyze the most detailed and comprehensive clinical study on CFS to date, are published in the April issue of Pharmacogenomics.
Over the past year, CDC scientists have worked with experts in medicine, molecular biology, epidemiology, genomics, mathematics, engineering, and physics to analyze and interpret information gathered from 227 CFS patients. The information was gathered during a study in which volunteers spent two days in a hospital research ward. During this time, they underwent detailed clinical evaluations, measurement of sleep physiology, cognitive function, autonomic nervous system function, and extensive blood evaluations, including an assessment of the activity of 20,000 genes, in an attempt to identify factors that potentially cause or are related to CFS.
"This study demonstrates that the physiology of people with CFS is not able to adapt to the many challenges and stresses encountered throughout life, such as infection, injury and other adverse events during life," said Dr. William C Reeves, who heads CDC's CFS public health research program. "These findings are important because they will help to focus our research efforts to identify diagnostic tools and more effective treatments which ultimately could alleviate a lot of pain and suffering."
The multidisciplinary approach to this study, which has been termed C3 or the CFS Computational Challenge, was developed by the CDC's Dr. Suzanne Vernon, Molecular Epidemiology Team Leader for the CFS Research Laboratory. It is an approach that could lead to advances with other diseases and disorders. "We put together four teams of different experts and challenged them to develop ways to integrate and analyze a wide range of medical data so as to identify those things that could improve the diagnosis, treatment, or understanding of CFS," Dr. Vernon said. "There is a clear biologic basis for CFS, and knowing the molecular damage involved will help us devise effective therapeutic intervention and control strategies."
It's estimated that over one million people in the United States alone are sick with CFS. The condition takes a tremendous personal and social toll—approximately $9 billion a year to the nation and $20,000 per family. It occurs most frequently in women ages 40-60 and can be as disabling as multiple sclerosis and chronic obstructive pulmonary disease.
The CDC is the principal agency in the United States for protecting the health and safety of all Americans. CDC is promoting CFS awareness through a national media and education campaign set to kick off later this spring.
The April issue of Pharmacogenomics, published by Future Medicine, includes 14 research papers, the culmination of C3. The journal Pharmacogenomics is dedicated to the rapid publication of original research on basic pharmacogenomics research and its clinical applications. Published eight times a year, the journal covers the effects of genetic variablity on drug toxicity and efficacy, the characterization of genetic mutations relevant to drug action, and the identification of novel genomic targets for drug development.
Kerr’s Team in London Finds Significant Differences in Gene Expression Between CFS Patients and Healthy Controls
- Last Updated: 02 December 2015 02 December 2015
Summary of journal article, Kaushik, N.; Kerr, J.R., et al.,“Gene Expression in peripheral blood mononuclear cells from patients with chronic fatigue syndrome,” Journal of Clinical Pathology Aug 58(8) (2005): 826-32.
The aim of the research was “to test the hypothesis that there are reproducible abnormalities of gene expression in patients with CFS compared to normal healthy persons.”
Gene expression in peripheral blood mononuclear cells was compared between a group of 25 CFS patients and a group of 25 healthy controls. The groups were matched for age, sex, and geographical location. Patients in the CFS group were selected according to the 1994 CDC diagnostic criteria. However, the reliability of the data was (in our view) enhanced by the fact that the most of the CFS subjects were severely ill and required bed rest for much of the day.
Analysis of the cells for both groups was conducted using a single color microarray representing 9522 genes. Average difference values for each gene were compared between the two groups. For a gene to qualify as differentially expressed between the two groups, a standard of p value of 0.001 was used. (This means that a difference in expression according to chance would occur only once in a thousand times. So a high standard of reliability was used.) When a gene showed differential expression, a second test with greater specificity was used—the Taqman real-time polymerase chain reaction (PCR).
35 genes were differentiated between the groups by the microarray analysis.
The PCR further limited the differential to 16 genes—“15 of which were upregulated… and one of which was downregulated…”
“This profile suggests T-cell activation and perturbation of neuronal and mitochondrial function.”
“The expression of the 16 genes was significantly different…” between the patient and control groups. Most of the remaining portion of the article catalogs the potential effects of the upregulation and downregulation of the particular genes in the pathophysiology of ME/CFS, according to the following system and metabolic process dysfunctions:
T-cell activation hypothesized by the upregulation of one gene and the down regulation of a second.
Six genes may be implicated in neuronal and other disturbances in ME/CFS patients. One of these genes is involved in the mitochondrial process and “mutations have been shown to be associated with central nervous system hypomyelination [breakdown of nerve sheathing] and encephalopathy [brain pathology].”
The article speculates this could account for the findings of changes in the brain’s white matter in ME/CFS as well as the cognitive dysfunctions.
Other mitochondrial involvement may be caused by the upregulation of 3 other genes.
The cell cycle in ME/CFS patients may be disrupted by the upregulation of two genes, which assist in controlling cell division.
“The upregulation of [gene] EIF4G1 identified in our present study may represent a common host response to persistent infection with several viruses.”
Upregulation of two genes may be involved in transcriptional perturbation. Two other upregulated genes may be responsible for an increased defense to oxidative stress seen in CFS.
An important aspect of this article is the citing of similar research findings by gene, either for CFS or other illnesses of possible similar origins or pathophysiology. The recent gene expression research by the CDC (Whistler et al.) is cited: “…which is interesting in light of our finding of upregulation of EIF4G1 transcript 5…Whistler and his colleagues have also reported this finding in patients with CFS who have rapid onset ('triggered' by virus infection) as compared with insidious onset…Various viruses have developed strategies to divert EIF4G1 from utilization by the cellular machinery…The best characterized example is that of poliovirus…” as well as a number of other viruses.
Further Update as of Sept. 2005:
Attention US-based CFS patients
Dr. Derek Enlander, of NYC, is collaborating in the research led by Dr. Jonathan Kerr, St George's Hospital, London on an exciting RNA genetic study of CFS. Dr. Kerr's team believes that it has discovered biological markers for CFS. They have found differences in gene expression in white blood cells, which could explain how viruses trigger ME/CFS. There is a genetic abnormality in the protein production in the mitochondria.
So far the work has been carried out on 25 patients and 25 healthy controls, and the results will be published in the Journal of Clinical Pathology.
Now Dr. Kerr 's team is going to be testing 1000 patients. Not only do they hope to find this a diagnostic marker for ME/CFS but also they believe that this will lead to a treatment.
Dr. Enlander will be taking samples from ME/CFS patients who can get to NYC. The samples will then be sent to Dr. Kerr.
Funding for the research is by the British CFS Research Foundation and a small grant from the National CFIDS Foundation.
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Notice about names
The Massachusetts ME/CFS & FM Association would like to clarify the use of the various acronyms for Chronic Fatigue Syndrome (CFS), Chronic Fatigue & Immune Dysfunction Syndrome (CFIDS) and Myalgic Encephalomyelitis (ME) on this site. When we generate our own articles on the illness, we will refer to it as ME/CFS, the term now generally used in the United States. When we are reporting on someone else’s report, we will use the term they use. The National Institutes of Health (NIH) and other federal agencies, including the CDC, are currently using ME/CFS.
Massachusetts ME/CFS & FM Association changed its name in July, 2018, to reflect this consensus.