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between BHR, RNase L ratio
A CFS-related change in the body’s
antiviral pathway appears not to be responsible for the high percentage of CFS
patients with bronchial hyperresponsiveness (BHR), according to new research
The study focused on 137 CFS patients, seventy-three of whom
presented with BHR. This percentage is comparable to earlier research that found
60 percent of CFS patients showed signs of BHR.
All subjects were tested for the ratio between two different
forms of RNase L, a key protein in the antiviral pathway. Many people with CFS
have two forms, the normal 83 kilodalton (kDa) version and a lighter, 37 kDa
type that is formed by the cleaving of the 83 kDa protein.
The researchers report no differences in the 83 kDa/37 kDa
ratio between the BHR and non-BHR patients. There also were no differences in
total lung capacity or forced expiratory/forced vital capacity measures. These
results, the authors write, “refute any association” between the RNase L ratios
Study results did indicate that CFS patients with BHR showed
an overall higher immune system activation level than those without BHR.
Nijs J et al. “Associations Between Bronchial
Hyperresponsiveness and Immune Cell Parameters in Patients with Chronic Fatigue
Syndrome.” Chest. April 2003;123:998-1007.
Brain metabolism different in CFS
that patients with CFS may show different metabolism characteristics than
controls in the left basal ganglia region of the brain.
Eight patients with CFS and no psychiatric co-morbidity were
tested for metabolic activity using proton magnetic resonance spectroscopy (H
MRS), a relatively new tool for measuring brain function. Compared to controls,
the patient group showed elevated levels of choline-containing compounds in the
This could be an indication of higher cell membrane turnover
or changes in the signaling process between separate membranes, the authors say.
It is not understood why this may happen — although some researchers speculate
that exposure to infectious agents or neurotoxins may result in such increased
Chaudhuri A et al. “Proton magnetic resonance spectroscopy
of basal ganglia in chronic fatigue syndrome.” NeuroReport.
Tilt-test studies show mixed results
Researchers may be able to differentiate female CFS patients
from healthy controls using a measurement taken during the head-up tilt
The tilt test is commonly given to people with suspected
autonomic disorders; a large percentage of CFS patients have such conditions.
However, symptom presentation during the test has not proven effective in
separating CFS patients from controls.
But new research has found that measuring heart rate
variability (HRV), specifically a decrease in the aperiod fractal component of
HRV, can be used to differentiate the patient population. In this study of 24
female CFS patients and 22 controls, researchers reached sensitivity and
specificity measures of 90 percent and 72 percent, respectively.
Yamamoto Y et al. “A measure of heart rate variability is
sensitive to orthostatic challenge in women with chronic fatigue syndrome.”
Exp Biol Med. Feb. 2003;228(2):167-74.
In a separate study, researchers conclude that CFS patients do
not have a distinctive pattern of regional cerebral blood flow when placed under
This study, from
, looked at 26 patients
with CFS and 23 controls. Researchers measured blood flow volume in the middle
cerebral artery (MCA) at six points during tilt-table testing. The overall
results found no significant variation between the two test groups.
Some researchers have speculated that changes in regional
cerebral blood flow, as measured in the MCA, may be a hallmark of CFS.
In general, CFS patients do show higher rates of neurally
mediated hypotension and postural tachychardia syndrome than healthy controls on
Razumovsky AY et al. “Cerebral and systemic hemodynamics
changes during upright tilt in chronic fatigue syndrome.” J Neuroim. Jan.
NIH to Host CFS Research Workshop
“Neuro-Immune Mechanisms and CFS: Will understanding
central mechanisms enhance the search for the causes, consequences and treatment
The Office of Research on Women’s Health (ORWH) of the
National Institutes of Health (NIH) will host a scientific workshop designed to
enhance understanding of chronic fatigue syndrome by examining the interface
between the brain, immune system and symptoms of CFS and related disorders. The
workshop will be held June 12-13, 2003 at the Bethesda
Marriott Hotel. Dr. Leslie Crofford of the
Michigan and Dr. Dedra Buchwald of
the University of
Washington will chair.
Scientists from NIH and academic institutions, representing
diverse disciplines, will explore the mechanisms by which hormones, cytokines
and other mediators act as intermediaries between the brain and other body
systems. The potential application of new technologies in the study of these
mediators and their central and peripheral actions will also be discussed. NIH
intends for these deliberations to form the basis for future interdisciplinary
Presentations will be given on the HPA axis, autonomic nervous
system, neuroactive drugs, sleep, imaging studies (including PET and functional
MRI scans), genomics and more. Dr. Vivian Pinn, ORWH director, will deliver
opening remarks followed by introductory talks by Drs. Crofford and Buchwald.
The meeting has been organized by ORWH and the Trans-NIH
Working Group for Research on CFS. Continuing medical education units will be
available to medical professionals. For additional information, visit
Note to Readers
Beginning with this issue, The CFS Research Review will
be published on a twice-yearly schedule. The next issue will be mailed this
fall. The Review also has changed from a 12-page to a 16-page format, to
allow for more in-depth coverage of CFS issues. Thank you for your continued