Researchers, clinicians, and patients met this January in Seattle for three days of
presentations,
discussion, and networking at The American Association for Chronic Fatigue Syndrome’s (AACFS’s) fifth
International Research, Clinical, and Patient Conference.
The conference, held Jan. 27-29, 2001, showcased the latest findings in research and
treatment. This
year, several areas of emerging science were added to the conference program, including sessions on genetics
and the neurological aspects of chronic fatigue and immune dysfunction syndrome (CFIDS). A new international
session provided insight on theories being developed outside of the United States.
Following are highlights of some of the hundreds of scientific and clinical presentations
from the
conference.
Research/Clinical Presentations*
Genetics. This area of study
in CFIDS was
a major focus for the conference. Dr. Charles Shepherd, Director of the ME Association in Essex, England,
echoed the sentiments of many attendees when he pronounced the genetic research presented at the meeting
as "cutting-edge."
A registry of twins with CFIDS created by Dr. Dedra Buchwald’s research teams at the
University of
Washington and Harborview Medical Center in Seattle served as the impetus for several genetic studies
presented at the conference.
Dr. Niloo Afari studied the children of twin pairs where just one twin had CFIDS and
found that children
of ill twins had a higher risk of developing chronic fatigue or CFIDS. Dr. Leslie Aaron studied the prevalence
of coexisting conditions such as irritable bowel syndrome, headache, and fibromyalgia (FM) in twins where
one member of the pair had CFIDS and the other was healthy. She found coexisting illnesses were significantly
higher in the twins with CFIDS.
Dr. Jack Goldberg of the University of Illinois presented a study that used the twin
registry database
to assess the role of genetic and environmental factors in CFIDS. The study included 146 twin pairs that
were classified using three increasingly stringent definitions: chronic fatigue for six months; chronic
fatigue according to the 1994 international consensus criteria not explained by medical conditions; and
chronic fatigue not explained by the medical or psychiatric exclusionary criteria of the consensus criteria.
The researchers found that the concordance rate for each definition of fatigue is higher in identical
twins than in fraternal twins, suggesting that genes do play a role in the development of CFIDS.
Another twin study by Dr. Richard Herrell of the University of Illinois at Chicago examined
the relationship
between lifetime psychiatric symptoms and current psychiatric co-morbidity in twin pairs. Herrell found
that lifetime posttraumatic stress disorder, major depressive episode, and panic disorder were more common
in the twins with CFIDS than in the healthy twins.
Epidemiology. The U.S. Centers for
Disease Control and Prevention (CDC) presented a study that surveyed a fourth of
the Wichita, Kan. population to determine the prevalence of CFIDS. The study is
important because it identified patients who had never sought medical care for
their illness and then followed them and a group of controls for three years.
The CDC found that people who had not sought medical care for CFIDS appeared to
have a better prognosis than those who had been receiving medical care, although
it is possible that patients with more severe CFIDS seek medical care more
frequently.
Dr. Leonard Jason of DePaul University presented a study on illness severity. Researchers
examined
subgroups of people with CFIDS criteria identified in a community-based prevalence study and found that
women tend to have more severe symptoms than men; minorities tend to have more severe symptoms than whites;
and nonworking people tend to have more severe illness than working people.
Dr. Pascale De Becker, a Belgian researcher, found that people who met the 1988 CFS
definition were
more severely ill than those who meet only the 1994 (not the 1988) criteria. Consequently, research findings
may not be comparable between the two patient populations and most of the researchers agree that subtyping
patients may well lead to more appropriate treatment strategies.
Autonomic nervous system. Three
separate presentations at the conference by Drs. Patricia Soetekouw, University
Hospital, the Netherlands; Julian Stewart, New York Medical College; and Arnold
Peckerman, University of Medicine and Dentistry of New Jersey, showed that
although there is no single profile of autonomic nervous system dysfunction in
CFIDS, there is compelling evidence that patients’ sympathetic and
parasympathetic nervous systems are abnormal.
Dr. James Baraniuk of Georgetown University explained how blood pressure increases and
blood vessels
constrict when the sympathetic nervous system is activated. He used acoustic rhinometry to measure air
volume and blood vessel constriction in the nose to assess sympathetic activity in CFIDS patients. His
study also may help explain why people with CFIDS develop nasal irritation, watering, and blockage.
Immunology. Dr. Kevin Maher of the
University of Miami examined the role perforin, a protein found in the immune
system, plays in CFIDS, because animals genetically engineered to produce low
levels of perforin exhibit many of the same immune defects as CFIDS patients.
The study found that CFIDS patients had lower than normal concentrations of
perforin in their natural killer (NK) cells and cytotoxic T cells, which may
hinder those cells’ ability to protect the body against infection.
Dr. Eng Tan of the Scripps Research Institute presented a study that looked for the
presence of autoantibodies
to a cellular protein primarily found on neuronal cells (microtubule associated protein 2, or MAP 2).
Blood serum from CFIDS patients showed that antibodies to MAP2 are frequently present. Tan believes this
could possibly lead to a new marker for a subset of CFIDS patients, particularly those with neurocognitive
problems.
RNase L. The microbiology research
presented at the conference concentrated on possible cellular-level
abnormalities in CFIDS patients, particularly those involving RNase L, an enzyme
that helps the body fight viruses. Researchers hope that RNase L studies will
provide an objective biological marker that can be used as a definitive test for
the illness because the measurement of the enzyme is consistent with an
activated immune system in CFIDS.
Dr. Patrick Englebienne of RED Laboratories in Belgium presented his findings on how
RNase L may interact
with ATP binding cassette (ABC) transporters, resulting in the visual problems, cognitive difficulties,
pain, and other symptoms found in CFIDS patients. ABC transporters are one of the largest families of
proteins found in all cells and some may provide resistance to certain diseases.
The role of RNase L in exercise intolerance was explored by Dr. Christopher Snell of
the University
of the Pacific, whose research indicates elevated levels of RNase L in CFIDS patients are associated with
decreased oxygen consumption during exercise. His findings suggest that the RNase L immune system defect
in CFIDS may be connected to poor oxidative metabolism and, consequently, low energy levels.
HHV-6. Dr. Dharam Ablashi of
Advanced Biotechnologies in Columbia, Md. theorized that active human
herpesvirus 6 (HHV-6) may be invading CFIDS patients’ central nervous systems
and triggering neurocognitive problems.
Albashi found active HHV-6 infection in 14 of 24 CFIDS patients, then treated seven
of the 14 with
three antiviral drugs—foscarnet (Foscavir), ganciclovir (Cytovene), and valacyclovir (Valtrex). The results
were mixed; only some patients showed improvement. The patient treated with foscarnet clinically improved,
and no HHV-6 infection was detected afterward. Of the four patients treated with ganciclovir, one showed
slight clinical improvement, but HHV-6 infection could still be detected. One of the two patients treated
with valcyclovir improved clinically with no HHV-6 infection detected, while the other patient tested
HHV-6 negative without experiencing any clinical improvement.
Neurology. Dr. Dave Lewis of the
University of Washington presented a study of regional cerebral blood flow in
pairs of identical twins where just one twin has CFIDS. Lewis used single photon
emission computed tomography (SPECT) to construct images of the participants’
active brain regions. He found no evidence of a distinctive pattern of resting
cerebral blood flow abnormalities in the CFIDS twins compared to the healthy
twins.
Past studies have suggested that fibromyalgia (FM) patients abnormally process painful
sensations.
Dr. Richard Graceley of the National Institutes of Health showed in his study that the brains of FM patient
respond to stimuli more vigorously than healthy people. When FM patients were given the same painful stimulus
as the healthy controls, functional MRI scans showed more pain-evoked blood flow changes in their brains.
Dr. Roderick Mahurin from the University of Washington used SPECT scans to look at the
activity of
different parts of CFIDS patients’ brains during cognitive challenges. He found that when CFIDS patients
were given a complex cognitive task to complete, their brains used more neural resources to solve the
task than people without CFIDS. The study was not able to discern whether CFIDS patients were working
harder at cognitive tasks or if more parts of the brain were required to solve the task.
Dr. Daniel Clauw of the Georgetown University Chronic Pain and Fatigue Research Center
explored whether
Arnold-Chiari malformation and/or cervical spinal stenosis are more common in FM patients than in the
general population. Chiari malformation and cervical stenosis involve a narrowing of the opening of the
spinal cord. MRI studies showed no significant differences between the controls and the patients, but
neurological exams showed significant differences. A substantial number of FM patients manifested abnormalities
in sensory processing and reflexes during the neurological exam.
Other research. Dr. Renee Taylor
of DePaul University reported on a study that examined whether individuals with
CFIDS are more likely to have a history of childhood physical or sexual abuse.
Her data shows that CFIDS patients do not appear to report abuse at higher rates
than individuals with other fatiguing illnesses.
Dr. Lea Steele of the Kansas Commission on Veterans Affairs found a higher prevalence
of CFIDS among
Gulf War illness patients than in the community at large. Steele’s study also found that Gulf War veterans
who met CFIDS criteria had different symptoms than patients with CFIDS alone, more often experiencing
headache, diarrhea, and night sweats. Steele also found that the mean age of onset for CFIDS was a decade
earlier in Gulf War veterans than has been reported in civilian CFIDS patients.
Dr. Howard Urnovitz of the Chronic Illness Research Foundation presented a study on
circulating plasma
RNA conducted by Dr. Paul Cheney of the Cheney Clinic. The study examined the presence or absence of specific
RNA bands in individuals with CFIDS, individuals with Gulf War illness, and healthy controls. Cheney found
that 77% of CFIDS patients had a band sequence not found in any of the healthy controls. He theorized
that identifying disease-specific gene segments may one day be possible and that pharmaceutical therapy
to disrupt harmful gene transcription may be on the horizon.
Dr. Lana Tiersky of Fairleigh Dickinson University’s research found no correlation of
medically unexplained
symptoms and history of psychiatric illness in CFIDS patients. Her work refuted the commonly held perception
that patients who have more symptoms that are not part of the international consensus case definition
are more likely to have psychiatric illness or somatisation disorder. CFIDS patients studied showed no
higher rates of chronic pelvic pain, chronic fatigue, back pain, tinnitus, or psychopathology if they
had co-existing psychiatric illness.
Treatment Presentations**
Dr. Kottil Rammohan of Ohio State University presented
a study
on the use of Modafinil, a well-tolerated narcolepsy drug, to treat fatigue in multiple sclerosis (MS)
patients. The 72-patient study showed that modafinil (Provigil) significantly improved fatigue in MS and
the patients experienced no serious or adverse effects. Research on modafinil in CFIDS could result in
a useful treatment option.
Kristin Lambrecht, a physician assistant with the University of Minnesota, presented
a study of six
CFIDS patients using the drug etanercept (Enbrel), which blocks the action of tumor necrosis factor (TNF),
a harmful cytokine produced by the immune system. Patients receiving the drug reported reduced fatigue
and pain and improved exercise tolerance. Etanercept is used to treat rheumatoid arthritis, and investigations
of its use in CFIDS may be merited, although the drug is expensive ($18,000 to $20,000 a year).
A seven-year follow-up study of CFIDS patients taking gamma globulin presented by Dr.
Katherine Rowe
of the Royal Children’s Hospital in Australia showed patients experienced significant improvement. However,
this treatment for CFIDS is controversial because results of other studies have been mixed and gamma globulin
is costly and difficult to obtain.
Dr. Nancy Klimas of the University of Miami presented a immunotherapy that involved
surgically removing
the lymph nodes of 13 CFIDS patients, exposing the cells to a bath of chemicals designed to change the
physiology of the immune response, then infusing the cells back into the patients. Significant improvement
in the patients’ symptoms was reported following the therapy. Further research is needed to refine the
procedure and determine the long-term impact of treatment.
Several poster presentations reported symptomatic improvement using Ampligen, an experimental
drug
in clinical trials in the United States and Europe. Dr. Christopher Snell of the University of the Pacific
presented a study of two patients receiving Ampligen who reported improved cognitive function, vitality,
and decreased pain. Dr. David Strayer, of Hemispherx Biopharma, Inc., makers of Ampligen, reported that
patients receiving the drug reported considerable cognitive improvement. A study of 92 patients with severe
CFS treated with Ampligen by Alicia Shillington of EPI-Q in Oakbrook Terrace, Ill. found that the drug
significantly reduced the need for health resources, thereby reducing the cost of treatment. Double-blind
trials of the intravenous drug continue at numerous sites throughout the United States.
Outgoing AACFS President Dr. Sudhir Gupta summed up the feelings of many patients when
he said at the
conference, "I am concerned with the pace and quality of research in CFIDS and FM. We have many challenges
before us, including defining the pathogenesis of CFIDS, identifying a reliable and reproducible marker,
establishing credibility among our scientific community, and educating practicing clinicians."
Undoubtedly, research is progressing slowly on CFIDS and related illnesses, but the
AACFS conference
showed that there are many dedicated scientists and clinicians working to advance knowledge and improve
the lives of patients.
Lori Flaherty is Editor for The CFIDS Association of America.
* Editor’s Note: These short summaries can only scratch the surface of the complex
scientific issues
being discussed. If you would like more extensive information, see the box on page 5 for instructions
on how to obtain an abstract book from the conference.
** Editor’s Note: For more on treatment methods discussed at the
conference, see the "Clinicians
Share Experience, Insights" box in the Spring 2001 CFS Research Review.
|
FOR MORE INFORMATION The Fifth International AACFS Conference provided
a wealth of
information on CFIDS research. In addition to the platform talks described in this article, more than
150 researchers presented posters at the meeting. Posters are a way for scientists to showcase results
from smaller studies still underway. If you are interested in obtaining more details on the studies presented,
you can purchase a program book with abstracts from the AACFS. Program books are $20 for AACFS members
and $25 for nonmembers. Write to the AACFS, c/o Harborview Medical Center, 325 9th Ave., Box 359780, Seattle,
WA 98104. Make checks payable to the AACFS. |
CASE DEFINITION UPDATE The U.S. Centers for Disease
Control and
Prevention (CDC) reported on its efforts to clarify the CFS case
definition at a satellite meeting on Jan. 26 in Seattle. The CDC’s goal is
to create a definition based on scientific data to replace the 1994
definition based on researchers’ and clinicians’ opinions of the most
salient features of CFS
.
The CD is taking a hard look at the construct of fatigue in CFS, which is a feature
of most illnesses
and does not seem to differentiate CFS from other conditions. They are not certain whether "severe, debilitating"
fatigue can be quantified or considered the core feature of CFS when it is so common. This is a serious
impediment to formulating an empiric or "data-driven" definition.
Other issues the CDC is grappling with are: establishing instruments to quantify the
symptoms of CFS;
clarifying the ambiguous features of the current definition; and using statistical and medical models
to gather required scientific data.
Dr. Nancy Klimas, who is working with the CDC on the case definition, emphasized the
need to develop
a separate clinical definition that can be used by health care providers to diagnose CFS. The CDC is testing
a model called "severe chronic unwellness" defined by mood, cognition, sleep, inflammation, and infection
symptoms. In CDC’s study in Wichita, Kan., 83% of those who met the CFS case definition, 49% of those
who had some symptoms of CFS, but did not meet the full definition, and 0.5% of the non-fatigued population
met the "severe chronic unwellness" definition. The model may help CDC discriminate CFS from other illnesses
and result in a more reliable case definition.
The CDC is meeting an invitation-only scientific workshop this month. Kim Kenney, President
& CEO
of the CFIDS Association of America, will participate in this workshop, as she did in May 2000. |
|
BETTER PROGNOSIS FOR PEDIATRIC CFIDS? Some medical practitioners have voiced
concern about diagnosing CFIDS in children and adolescents, believing labeling young people with a chronic
illness may have negative long-term psychological effects. However, two studies on the prognosis of pediatric
CFIDS presented at the conference showed that the most improved patients were those who received early
diagnosis and treatment.
Dr. David Bell, a practicing physician in Lyndonville, N.Y., contacted patients whom he had seen 13
or more years earlier when they were adolescents or children and found that 80% had a "satisfactory" outcome,
although the majority still had mild or moderate symptoms. Only 20% reported still being ill.
Dr. Katherine Rowe, a practicing physician in Australia, also presented a follow-up study of 200 CFIDS
patients originally seen as adolescents. Rowe found that 30% felt they were well and 60% were able to
study or work full time.
Both studies show a more encouraging prognosis for children with CFIDS who are diagnosed and treated,
but the study conclusions could be misleading since it is not clear how improvement or recovery should
be defined. Some of the patients Bell and Rowe reported as "recovered," said they still had significant
symptoms. |