Research
Advances in Chronic Fatigue Syndrome: Impact on Treatment
Compiled
by R. Sanderson
Reviewed / edited by K. Casanova |
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Dr. Nancy Klimas
is Professor of Medicine at the University of Miami and the
Director of Research for the Clinical AIDS/HIV Research at
the Miami Veterans Affairs Medical Center. She has been a
leader in the field of CFIDS research, is a founding editor
of the Journal of Chronic Fatigue Syndrome and is
the current President of the International Association for
CFS. On Sunday, April 30, 2006, Dr. Klimas presented a lecture
titled, “Research Advances in Chronic Fatigue Syndrome:
Impact on Treatment,” at the Connecticut CFIDS &
FM Association’s Spring Conference.
As much as everyone
looks forward to hearing Dr. Klimas speak, the event is never
long enough. She always has a great deal of information to
share with her audience, and it can be very hard to keep up
with her. Therefore, please note that a lot of data was incorporated
directly from a copy of her Power Point presentation (which
includes complete information on the articles cited), along
with elaborations made by Dr. Klimas on specific topics. In
this way, we hope to provide you with as much information
as is possible on recent research advances. Since CFS was
the term used in the lecture, this name is used throughout
this summary.
Dr. Klimas began
her presentation with a brief review of issues that continue
to affect our patient population: including the clinical case
definition for CFS (Canadian Consensus Panel Clinical Case
Definition for CFS/ME vs. the CDC 1994 criteria); CFS epidemiology
and the higher percentage of undiagnosed CFS cases; and the
economic impact of CFS on productivity. She emphasized how
these issues, along with the trivializing name, have negatively
impacted treatment. Klimas acknowledged that many physician
attitudes show a negative bias towards CFS due to its name.
A survey of 811 GPs revealed that 44% did not feel confident
making the diagnosis [of CFS], and 41% did not feel confident
in treating it. Physicians had reported they would likely
have more confidence in the diagnosis if they had a friend
or family member with CFS. The doctors also reported that
education that emphasizes acceptance of CFS as a real entity
would improve their confidence in treatment. (Source: Bowen
J et al, Family Pract. 2005 April 1)
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She provided
an update regarding recent research advances and publications
(2003 through early 2006) using her well-known model as a
basis:
Model
for CFS Pathogenesis
Genetic Predisposition
Triggering event/ infection

Mediators (Immune, endocrine, neuroendocrine, psychosocial)

Health Outcome/ Persistence |
Genetic
Predisposition:
Dr. Klimas went
over some of HLA DR haplotypes identified in an earlier study
of CFS patients that revealed these patients were at a 4 to
6 fold increased relative risk for haplotypes DR4, DR3, and
DQ3 (Keller et al, 1992). Klimas explained that gene
array data can separate patients into subgroups by their patterns
of gene dysregulation in both immune and HPA gene clusters.
Technological progress has made it possible to analyze genes
to a greater depth than we are presently able to medically
understand what the data mean. Klimas further noted individuals
with CFS cannot be lumped together, as they are part of subgroups
and therefore should be treated differentially. |
Triggering
event/infection:
A brief review
was done of prior studies that demonstrated an association
between onset of CFS and an acute viral-like illness in 60-80%
of patients (Komaroff and Buchwald). Furthermore, a percentage
of patients remained sick after acute viral infections, such
as EBV, Q fever or Ross River Virus (according to Australian
and UK research). One of the newer theories of great interest
to Dr. Klimas is the possibility that only fragments of viruses
(like EBV) could “trash” [i.e., dysregulate] a
patient’s system.
Ronald Glaser et
al. have found evidence that regulatory peptides encoded by
EBV are expressed in CFS despite the absence of replicating
virus. These peptides are known to modulate immune function
by inducing pro-inflammatory and Type 2 cytokines.
A. Martin Lerner
and his group have found evidence of a two subgroups of CFS
patients with incomplete viral multiplication (CMV viral “fragments”
and EBV antigen.)
[The remainder
of this discussion of Lerner’s recent paper (see citation
below) departs from what Dr. Klimas presented in her lecture.
We reviewed Lerner’s paper and we present some of his
more interesting findings in the next three paragraphs. Then
we return to Dr. Klimas’s lecture.]
At the same time,
Lerner has found abnormal oscillating cardiac T-waves (by
24 Holter monitor) in a significant percentage of CFS patients
(as opposed to controls). A smaller percentage of patients
had Abnormal Cardiac Wall Motion.
Lerner suggests
that the findings of incomplete viral multiplication and cardiac
anomalies may be causally linked in subsets of CFS patients.
The link may be direct in terms of viral damage or mediated
by immune system activity. He stresses that further research
must be done in this area. He also notes that “one preliminary
trial of antiviral therapy (valacyclovir) in a cohort of CFS
patients with single virus Epstein-Barr Virus (EBV) persistent
infection is promising.” However, Lerner also notes
that the other subset of patients with CMV incomplete viral
multiplication did not respond to the antiviral. He says this
makes sense because the antiviral is known to have anti-EBV
effects, “but does not have significant anti-HCMV activity…”
Lerner, interestingly
for CFS patients, also discusses Gunther Stent’s theory
regarding: “Premature scientific discovery. Premature
scientific discoveries are met by the scientific community
with resistance and ridicule.” (Here Lerner is saying
that much of the pioneering CFS research remains in the “premature
scientific discovery” category.)]
Glaser R et
al, “Stress-associated Changes in the Steady-State Expression
of Latent Epstein–Barr virus: Implications for Chronic
Fatigue Syndrome and Cancer”. Brain, Behavior and Immunity
2005 19 (2): 91-103.
Lerner AM et
al, "Prevalence of Abnormal Cardiac Wall Motion in the
Cardiomyopathy Associated with Incomplete Multiplication of
Epstein-barr Virus and/or Cytomegalovirus in Patients with
Chronic Fatigue Syndrome". In Vivo 2004 Jul-Aug;18(4):417-24.
Dr. Klimas indicated
HHV6 is another prevalent virus in individuals with CFS. It
has been detected in 22%- 54% of patients in cross-sectional
studies (Ablashi, Krueger, and Knox) and in 79% of CFS patients
in longitudinal studies (HHV6 PCR assay, Knox). Dr. Klimas
emphasized that the only reliable lab for patient HHV-6 testing
is the Wisconsin Viral Research Group in Milwaukee, WI. This
is the laboratory in which Dr. Konstance Knox has done extensive
research on the virus. However, Klimas cautioned HHV-6 does
not respond to traditional antivirals, but requires aggressive
treatment with very potent agents administered through IVs.
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Mediators
(Immune, Endocrine, Neuroendocrine, Psychosocial):
An Immune Cascade
chart was used to illustrate how various immune response processes
are activated in response to an infection. Basically, the
helper T-cell function in individuals with CFS no longer remains
balanced; instead, it shifts to a Th2 pattern, which in turn,
triggers pro-inflammatory cytokines. (Please refer to our
featured article, “From Pathogenesis to Treatment”,
a summary of an earlier lecture given by Dr. Klimas published
in The UPDATE, Summer 2001 issue. This article provides an
in-depth explanation of how the immune system, endocrine abnormalities,
and autonomic dysfunction set in motion a cascade of problems
and dysregulation that drive the illness.)
More recent endocrinology
studies show evidence of reduced cortisol output (by the adrenals)
via several mechanisms, such as heightened negative feedback,
heightened receptor function and impaired ACTH and cortisol
responses to challenge. Research data also supports DHEA functional
abnormality, abnormal serotonin function, and IL-6 increase
associated with low cortisol. (The low cortisol is mediated
by a hypothalamic dysregulation of Cortisol Releasing Hormone.
See the chart on Endocrinology). In spite of these findings,
Dr. Klimas stated that cortisol treatment, especially long-term,
is not being recommended.
Cleare AJ,
“The Neuroendocrinology of Chronic Fatigue Syndrome”.
Endocrine Reviews 2003; 24 (2): 236-252.
Papanicolaou
DA et al (representing a large US panel), “Neuroendocrine
Aspects of Chronic Fatigue Syndrome”. Neuroimmunomodulation
2004; 11(2):65-74.
Some of the latest
research on Autonomic Nervous System abnormalities in CFS
(as shown on the chart for ANS) and other sources, are as
follows:
- Haemodynamic
Instability Score taken during tilt table testing predicts
CFS with 90% sensitivity.
- Heart rate variability
as a predictor of CFS.
- Gastric emptying
delayed in 23 out of 32 CFS subjects.
Naschitz J,
“The Head-up Tilt Test with Haemodynamic Instability
Score in Diagnosing Chronic Fatigue Syndrome.” QJM 2003
Feb;96(2):133-42.
Yamamoto et
al, “A Measure of Heart Rate Variability Is Sensitive
to Orthostatic Challenge in Women with Chronic Fatigue Syndrome”.
Experimental Biology and Medicine 2003, 228:167-174.
Burnet R, “Gastric
Emptying is Slow in Chronic Fatigue Syndrome” BMC Gastroenterology
2004, 4:32.
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Sleep
Physiology
H. Modolfsky’s
early studies have documented a variety of circadian sleep
disturbances in CFS patients, such as altered diurnal patterns
in cortisol, prolactin, and NK cell function, as well as alpha
wave intrusion on sleep EEG, and a reduced state of stage
III and IV sleep. A more recent study by Nathanial Watson
has shown a higher percentage of REM sleep in CFS twins (Twin
Study of 22 discordant twins). This finding suggests an element
of sleep-state dysregulation.
Dr. Klimas mentioned
there are several new Stage IV sleep inducer medications being
used. The strongest of these is Xyrem (a form of gamma hydroxybutyrate
(GHB)) -- a beneficial drug in treatment of narcolepsy; but
it is also known for its illegal use as a date-rape drug.
Currently, it is only available through enrollment in a special
program (not through retail pharmacies) and is so potent,
it must be taken when already in bed. Remeron is a medication
- actually, this is an antidepressant that promotes stage
III and IV sleep - that Klimas has prescribed, often in ¼
doses. She recommended that individuals with sleep problems
consult with sleep doctors and pointed out these physicians
are in two specialties: pulmonology and neurology. It is also
important to choose a doctor who will provide continuing care
after the initial evaluation.
Watson et al,
“Comparison of Subjective and Objective Measures of
Insomnia in Monozygotic Twins Discordant for Chronic Fatigue
Syndrome”. Sleep 2003 May 1;26(3):324-8.
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Muscle:
Though research
findings pertaining to muscle function/ disturbances, including
those of the heart, were not discussed in any great detail.
A summary of these findings is included for your information:
- An oxidative
stress study measuring protein carbonyls suggested higher
levels of protein oxidation in CFS subjects as opposed to
controls.
- Exercise testing
in 189 CFS subjects resulted in clinically significant subgroups
with 50% of subjects showing moderate to severe functional
impairment. An unexpected blunting of Heart Rate and Blood
Pressure responses was noted.
- Sarcoplasmic
reticulum defect: conduction and calcium transport abnormalities.
- Cardiac muscle
– cardiac output found related to illness severity
and the predicted exercise-induced relapse.
- Subset of CFS
patients with IgM EBV or CMV Antibody found to be at risk
for cardiac motility abnormalities and occasionally true
cardiomyopathy.
- Raises the issue
of incomplete viral replication activating immune responses
as suggested by Glaser et al.
[Again. for a moment
we depart from Klimas’ lecture. Our review of Glaser’s
paper sheds somewhat more light on Klimas’ note on his
research. Glaser’s team for a number of years has studied
the workings of EBV and its effects in a variety of illnesses.
In CFS, Glaser found strong indications that constituent components
or expressions of the latent virus may by themselves account
for immune dysregulation and symptoms in subgroups of CFS
patients. The same process may occur for other viruses, including
CMV and HHV 6.]
Sources:
Smirnova IV,
“Elevated Levels of Protein Carbonyls in Sera of Chronic
Fatigue Syndrome patients”, Mol Cell Biochem 2003 Jun;248(1-2):93-5.
Vanness JM
et al, "Subclassifying Chronic Fatigue Syndrome through
Exercise Testing." Med Sci Sports Exerc. 2003 Jun;35(6):908-913.
Fulle S et
al, “Modification of the Functional Capacity of Sarcoplasmic
Reticulum Membranes in Patients Ssuffering from Chronic Fatigue
Syndrome.” Neuromuscular Disorders 13 (2003) 479–484.
Peckerman A
et al, "Abnormal Impedance Cardiography Predicts Symptom
Severity in Chronic Fatigue Ssyndrome." Am J Med Sci.
2003 Aug;326(2):55-60.
Lerner AM et
al, "Prevalence of Abnormal Cardiac Wall motion in the
Cardiomyopathy Associated with Incomplete Multiplication of
Epstein-Barr Virus and/or Cytomegalovirus in Patients with
Chronic Fatigue Syndrome." In Vivo, 2004, 18, 4, 417-424.
Glaser R et
al, “Stress-associated Changes in the Steady-state Expression
of Latent Epstein–Barr virus: Implications for Chronic
Fatigue Syndrome and Cancer”. Brain, Behavior and Immunity
2005 19 (2): 91-103.
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New studies
on the brain – Important research findings published
over the last 12 months:
- After a fatigue-inducing
mental task, imaging studies showed decreased brain responsiveness
to auditory stimulation (study of 6 male CFS patients and
7 male healthy controls carried out by researchers in Japan).
- Decreased absolute
cortical blood flow in the brain (25 CFS patients, 7 controls).
When stratified for psychiatric disorders, CFS subjects
with psychiatric disorders had decreased blood flow in one
region only (left cerebral artery) in contrast to CFS subjects
without any psychiatric disorders who had reduced flow in
both the right and left middle cerebral arteries. Therefore,
those patients having CFS only (devoid of psychopathology)
had the largest reduction in flow.
- Using more brain
physiology to process tasks – A study using BOLD fMRI
done in NJ (see the brief summary below).
- Reduced grey
matter in the brain was linked to reduced activity (study
done in the Netherlands of 2 groups of 15 females each,
one group was younger than the other). [See synopsis of
this Study on our News Page.]
Briefly digressing
from Dr. Klimas’ lecture, information has been included
about the specific findings of the New Jersey study (the 3rd
one listed just above) by the researcher herself, Grudin Lange,
PhD at one of the afternoon workshops. Lange’s study
group, that also included Drs. DeLuca and Natelson (Univ.
of Medicine & Dentistry of NJ), looked at mental concentration
in CFS patients. Using a particular type of imaging technique
- Blood Oxygen Level Dependent (BOLD) functional MRI, they
measured differences in blood flow in the brains of CFS patients
compared to controls, especially when challenged with complex
auditory processing while doing a simple task. This study
shows that people with CFS have to exert more effort to process
the same data as healthy controls and provides “evidence
of increased neural resource allocation when processing more
complex auditory information.” This conclusion was taken
from the study, which can be retrieved in its entirety at:
http://www.cfids-cab.org/MESA/Lange.pdf.
Dr. Klimas remarked Japan has become very active in CFS research
and that more money is being spent on CFS research there than
in the US.
Tanaka M et
al, “Reduced Responsiveness is an Essential Feature
of Chronic Fatigue Ssyndrome: a fMRI Study.”
BMC Neurol. 2006 Feb 22;6:9.
Yoshiuchi K,
“Patients with Chronic Fatigue Syndrome have Reduced
Absolute Cortical Blood Flow.” Clin Physiol Funct Imaging.
2006 Mar;26(2):83-6.
Lange G et
al, "Objective Evidence of Cognitive Complaints in Chronic
Fatigue Syndrome: a BOLD fMRI Study of Verbal Working Memory."
Neuroimage. 2005 Jun;26(2):513-24.
De Lange FP
et al, "Gray Matter Volume Reduction in the Chronic Fatigue
Syndrome." Neuroimage. 2005 Jul 1;26(3):777-81.
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Microarray
Technology and Genes
In microarray testing,
samples are arranged in a grid-like order, within a defined
area, on glass microscope slides. This technology allows a
huge number of genes to be surveyed at one time. Samples appear
as series of spots (that represent genes) which undergo a
binding process and produce signals relating to the gene still
present from the samples. It is the intensity of these spots
(like an on/off type of mechanism) that provide the data –
so for example, the intensity of one spot (CFS) can be compared
to the intensity of the corresponding spot (control). Agents
are used to display the data in certain colors like red and
green to help facilitate analysis. In one sample chart, Dr.
Klimas pointed out how the red pattern was showing downregulated
mitochondrial function, while the green one was showing upregulated
cytokines. In that particular study, gene expression helped
to demonstrate a difference between sudden and gradual onset
of illness. The importance of this technology is that it will
help to identify specific gene markers associated with CFS
and ultimately lead to better treatments.
Gene research has
provided meaningful information about CFS (again, as taken
from Dr. Klimas’ presentation chart):
- CDC study of
20,000 genes studied the activity of 26 genes – activity
that could accurately predict which of 6 categories of chronic
fatigue a patient had on the basis of symptoms and other
clinical tests.
- Most of these
genes are involved in immune system regulation, the adrenal
gland, and the brain’s hypothalamus and pituitary
glands.
- Studies of hormones
and immune factors confirm these findings.
- Kerr’s
study revealed differential expression of 35 genes in 25
patients as compared with 25 controls. The differential
expression in patients suggested T cell activation and disturbances
of neuronal and mitochrondrial function.
- Other studies
have pinpointed 5 specific genes that correlate with an
apparent susceptibility to chronic fatigue - more specifically
with levels of serotonin and glutamate affected.
Speaking of the
recent CDC study, Dr. Klimas felt newspapers had misreported
the study findings and the role of stress. She stated there
is a “huge difference” between stress as implied
in these articles (assuming she meant how one might psychologically
cope under pressure) and one’s stress response. In the
latter, there are biological defense mechanisms called
into action, which involve everything from the autonomic nervous
system, the cardiovascular system, the neuroendocrine axis,
and the immune system. These systems react automatically to
stressors. Such stressors would include environmental triggers,
infections, or disruptions caused by illness. Klimas also
announced that on or around June 1st, the CDC is supposed
to release another press release. She is optimistic this may
have something to do with upcoming treatments.
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| Management
of CFS
Time had run out
by the time we got to this part of the presentation. Nearly
a dozen charts summarized a variety of interventions, which
were broken down into 4 major categories (pathogenisis directed):
immune modulatory approaches, HPA axis interventions, NMH
treatment, and sleep. Since many of these were not discussed
in detail, most have been left off because their use, benefit
or status is uncertain. (A number of therapies are in various
phases of study.)
Overall, Dr. Klimas
indicated that sleep should be one of the first problems to
be treated. Earlier, she talked about the Stage III and IV
sleep inducers. She also mentioned Doxepin as another helpful
medication for sleep. On her chart, it is noted that short
acting hypnotics should be avoided (as they can “trap”
a person in light alpha wave sleep).
Melatonin and Ritalin
were also noted as still being studied for effectiveness in
CFS, but the response/results to these appear to be rather
poor. (In one study of 60 CFS patients, placebo controlled,
using 10 mg. BID of Ritalin, only 17% of subjects reported
decreased fatigue with 22% showing improvement in concentration.)
The following information
on immune modulatory treatments comes not from her lecture,
but directly from Klimas’ power point notes. The text
of the notes is as follows: “Ampligen, a immune modulator
and antiviral (Phase 3 recently completed); Allergic immunotherapy
to down regulate allergic drive; Future immunomodulators (trials
underway): Isoprinosine, thalidomide, anti-TNFa monoclonal
Ab.”
Dr. Klimas’s
power point notes (not mentioned in lecture) also state, under
HPA axis interventions – “Growth hormone study
– phase 1 (Antwerp study).”
Dr. Klimas mentioned
a drug that is being used in Japan called Neurotropin is used
to treat reflex sympathetic dystrophy and other painful conditions.
Neurotropin is a “non-protein extract of cutaneous tissue
from rabbits inoculated with vaccinia virus” There is
some indication it may be helpful with CFS. However, the drug
has not undergone clinical therapeutic testing in the United
States.” (Source: Clinical Trials – NIH site).
A survey was been
done at the University of Iowa to determine things that patients
have tried and found to be helpful. (Bentler SE, J Clin
Psychiatry 2005 May;66(5):625-32). A few supplements:
coQ10, DHEA and ginseng were found to be helpful. [Ed. Note:
Treatment with DHEA can have very serious side effects and
must be managed and monitored by a competent physician. Also,
there is some literature that of 3 types of ginseng, only
one is helpful to CFS patients, while the other two types
may worsen symptoms.] Vitamins predicted improvement. Yoga
seemed to be the most helpful form of exercise and treatment.
However, the subjects in this study were described as having
“unexplained chronic fatigue of unknown etiology for
at least 6 months” – hence participants may or
may not have had CFS.
Another study at
the Univ. of Georgia (Black CD and McCully KK, Dynamic
Medicine 2005 Oct 28; 4:10) examined how people with
CFS were initially able to meet target goals in a prescribed
daily walking program (for 4 to 10 days), but then these individuals
developed exercise intolerance and worsening of symptoms.
Dr. Klimas feels exercise is beneficial, but it is usually
is best tolerated in short intervals (even 5 minutes at a
time) with many rest breaks in between.
Dr. Klimas’
power point presentation (not presented in lecture) also noted
certain dangers of nutritional interventions including: “Licorice
root - potassium deficiencies [that can affect the heart];
‘supplements’ that are actually hormones [including
DHEA]; ‘supplements’ that have iffy contents –
eg., St. John’s Wort, melatonin; Products that make
unsubstantiated claims; Under and overhydration.” [Ed.
note: either of these states can be very serious. Having enough
water is important, but drinking too much water can harm essential
physiological systems and processes.] Everyone should really
exercise caution about taking supplements without a full appreciation
of their side effects or interactions with current medications
So, what we can
take away from this latest presentation is that there have
been ongoing studies to help better understand CFIDS. The
breadth and depth of biologically-based CFIDS research is
expanding. There is some promise of more effective therapies
- targeted to specific physiological systems - becoming available.
Researchers conducting gene expression studies also hold out
hope that their research may yield effective therapies. |
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