Chronic Fatigue Syndrome:
Posted 06-08-2005
It was 1984 when Dr. Carol Jessop, then an associate professor
in the department of internal medicine at UCSF, first saw the
patient she would never forget. A 40-year-old businesswoman who had
always been healthy and active came to the clinic with a bizarre story.
While driving on the freeway, this patient was suddenly hit by
such overwhelming nausea and fatigue she had to pull over. "It was
dramatic," remembers Jessop. "I'd never heard anything like this
before, that sudden. This woman absolutely felt drained and near
collapse."
The mystery quickly deepened. Jessop drew some endocrine labs,
checked the woman's cortisol level, looked at her CBC (complete
blood count), and "low and behold, everything comes back totally normal.
"And she's getting worse by the time I see her in follow-up. Now she's
aching all over, has some baseline headaches, she's not sleeping
well, and she just feels like she's caught in a flu."
Concerned, Jessop consulted with a colleague in infectious
disease at the university, and talked with another in endocrinology.
Within the month, a couple more patients had come in with similar
stories of overwhelming malaise and fatigue, muscle aches, confusion
and concentration problems.
"A lot of my colleagues said that these people must just be
depressed. Put them on tricyclic antidepressants," reports Jessop.
"I definitely felt that there was some criticism of my work and my
attempt to try and uncover what was going on."
But Jessop persisted. "I was clear in my head something was
happening, and I was willing to look in every direction." By 1986,
she was seeing more than 300 patients with the now-familiar
symptoms, and cluster outbreaks had been reported in cities and towns across the
country, including a well- publicized one at Lake Tahoe.
She consulted with UCSF virologist Jay Levy, who was then working to discover
the HIV virus. She and Levy wondered whether they were seeing a new
virus or something related to AIDS in a milder form. Somehow, they felt,
the immune system in these patients had been disrupted.
When we get sick with a flu, the fever, achiness and fatigue
are not caused by the virus itself but by the immune response, the
chemicals released to fight infection. Perhaps Jessop's patients had
an immune system stuck in the "on" position, creating persistent
flulike symptoms. But what virus was causing the disruption?
After investigating a number of potential culprits -- human herpesvirus 6
(HHV-6) and Epstein-Barr virus (EBV), among others -- Jessop and
Levy, like other investigators, came up empty.
In 1988,
the Centers for Disease Control and Prevention (CDC)
named the puzzling illness chronic fatigue syndrome (CFS), as if
this illness were about nothing more than being a little extra tired. The
moment the name was set in print, patients lambasted it for
trivializing a devastating illness and inviting psychiatric stigma. By
1991, Jessop was seeing 1,500 patients with CFS, marking the Bay
Area as one of the largest clusters of the nationwide epidemic.
Most of these patients had been ill for years -- some bed- or
housebound -- many were unable to work. Yet without a known
cause or laboratory evidence of abnormalities, the illness continued to be
subject to psychiatric explanations by physicians, disbelief by
family and friends of those who were ill and media ridicule as the "yuppie
flu."
It has been a long journey from those early days when only a
few renegade physicians like Jessop took this illness seriously.
After two decades of dogged advocacy work by patients and a handful of
concerned physicians and researchers, the facts about CFS are
coming to light. Today CFS -- also called chronic fatigue and immune
dysfunction syndrome (CFIDS) and myalgic encephalomyelitis
(ME) -- is known to be a "SERIOUS AND DISABLING ILLNESS"
affecting an estimated 800,000 adults in the United States, although it appears that only 10 to 17 percent of these cases have been diagnosed.
Studies by the CDC show that people with CFS can be as impaired
as someone with heart disease, cancer or multiple sclerosis and
that CFS costs the economy $9.1 billion a year in lost productivity.
Two to five times as many women as men have the illness, and contrary to
popular myth, minorities and people at lower socioeconomic levels
are at higher risk for CFS.
Jessop reflects on the change.
"I think today, physicians have studied fibromyalgia, have studied CFS, and many of them are more comfortable saying, 'OK, we don't know everything about it, but let's talk about what we can do.'"
While the cause is still unknown, the search for a single virus
no longer occupies most researchers. Most now suspect CFS has a
variety of triggers, alone or in some combination: one or more
pathogens, chemical and environmental exposures, stress or injury
and genetic predisposition. Whatever the initial provocation, the
autonomic, immune and neuroendocrine systems become
dysregulated, producing the constellation of symptoms:
Like Jessop, pediatrician David Bell saw a cluster of patients
with what looked like a severe viral illness in his clinic in
Lyndonville, N.Y., in 1985. He and his wife, Karen, an infectious
disease specialist, at first considered everything from typhus to
Rocky Mountain spotted fever to Q fever. They, too, suspected an
infectious origin, but couldn't find a specific bug.
They, too, encountered disbelief from other specialists they consulted. Says
Bell, "The specialists wrote back and said that these kids are all
neurotic and they're just exaggerating the symptoms, which I knew
couldn't possibly be true. " After treating and studying CFS for 20
years, Bell has a clearer picture.
"I see this illness as a post-infectious dysautonomia
[autonomic nervous system dysfunction]. ... What that means is
that an infection initiates a process whereby the immune system starts
overreacting. And that process then causes reduction in cerebral
blood flow, abnormalities in the HPA axis [a key part of the endocrine
system] and a variety of other things."
Bell's description of a possible disease process in CFS reveals
the complexity of this illness: an immune system that is
overreacting, reduced blood flow to the brain, defects in the autonomic
system that controls heartbeat and blood pressure, abnormalities in the
endocrine system regulating production of hormones.
Multiple things are going wrong in the body of a person with
CFS, one affecting another in a cascade of interactions. Adding to
the complexity, the disease process may not be the same in all people
with CFS. Just as a painful, swollen joint can be caused by infection,
injury or arthritis, the symptoms of CFS may be the end result of
different processes. Researchers are recognizing the importance of
subtyping patients -- perhaps by similar symptoms or illness history,
or by the predominant organ systems involved -- to make both
treatment and research more effective.
One of the biggest obstacles to understanding CFS has been the
absence of a "big picture" view, and this absence is directly tied to
lack of federal research money. Until recently, most CFS studies
have been small, often funded by patient advocacy groups, and narrowly
focused. One study of 36 subjects might document difficulty with
multitasking; another study of 121 people with CFS shows they
have low levels of the hormone cortisol.
Like many, Bell is angered by the lack of federal investment in
research. "The amount of money being spent on research is trivial.
I mean, it's so small that it just doesn't count when you compare it to
other illnesses affecting huge numbers like this is." According to its
own documents, the National Institutes of Health (NIH) in 2003
spent $99 million on multiple sclerosis and $6 million on CFS, though
CFS affects twice as many people. Bell adds, "And a lot of that $6
million was spent on fatigue independent from chronic fatigue syndrome."
Adding insult to injury, documents released under a Freedom of
Information Act request made by CFS advocates revealed that
between 1995 and 1998, the CDC spent $12.9 million allocated for CFS on
other projects, and misrepresented its spending to Congress.
Under intense pressure from patient advocates, particularly the
CFIDS Association of America, the largest patient advocacy group,
the CDC restored the misallocated funds, mostly in fiscal years 2002
and 2003, and finally started a major research effort. Federal funding
for CFS research -- from both the NIH and the CDC -- was still only
$16 million in 2003, according to the CFIDS Association, and today is
on the decline. Nonetheless, the current federal undertaking is
significant.
The CDC's main goals are to understand whether CFS is
one disease or many, to define its natural history and clinical
presentation, to educate health care providers and to identify the
pathophysiology (disease process), causal agents and risk factors.
There's been quite a buzz about several studies under way.
Bell's voice rises with enthusiasm when he describes them. "One
was the Dubbo study by the CDC. Extraordinary study. Wonderful
science. What they're doing is, in the county of Dubbo, Australia, they're
prospectively looking at all cases of Epstein-Barr virus, Ross River
virus and Q fever, illnesses known to sometimes have a chronic
aftermath. And they are now seeing that 10 percent of these people
go on to develop chronic fatigue syndrome. ... This is implying that
those three infections cause CFS in otherwise healthy people.
That's very interesting.
"The other study ... that just knocked my socks off was hepatitis C.
This was a study done by a hepatitis specialist who was
treating hepatitis C with interferon," a protein that is part of the
body's antiviral response. ... "Seventy percent developed marked
fatigue, and 30 percent developed chronic fatigue syndrome. So it
was the interferon treatment that caused the CFS, not the actual virus
circulating in their system. ... The CFS is the immune response
from an infection." This finding is consistent with the idea that the
symptoms of CFS could be precipitated by an immune system in
overdrive.
A key component of the CDC research effort is the use of
microarray technology to analyze the genetic material of a person
with CFS. Researchers take a sample of blood or tissue; apply it to a
glass slide, called a "microarray," which contains more than 20,000 gene
identifiers; and are able to determine which genes in the sample
are being "expressed," that is, turned on or off, or turned up or down.
This gene expression profile provides a window into the disease
process.
Microbiologist Suzanne Vernon, team leader of the CDC's
molecular epidemiology program, explains: "We're using very
exploratory molecular technologies to try to understand what is
wrong in people with CFS. We've tried to focus on discovering biomarkers
that help us to further understand the pathophysiology of CFS and
also to perhaps identify diagnostic markers." Since 1988, CFS has been
diagnosed based on a patient's symptoms and by ruling out other
illnesses that can cause chronic fatigue. Finding a diagnostic
marker, a measurable biological abnormality that appears in all people with
CFS, would be an important step forward.
In preliminary work, Vernon's team has been able to use
microarray technology to distinguish between people with CFS and
healthy controls. More recently, they've been able to show
differences among people with CFS, confirming that CFS is a heterogeneous
illness.
Examining 3,800 genes in 23 women, they found that those with
sudden-onset illness (developing in one week) had a different gene
expression profile than those with gradual onset (developing over
several months). With further study, researchers hope to find a
common pattern or signature of gene expression that appears in all people
with CFS. They may find particular patterns that are specific to
subgroups as well. Eventually, the microarray could become a
routine diagnostic tool for CFS.
Even more ambitious is the team's effort to integrate this gene
expression data with epidemiologic (age, race, sex) and laboratory
(blood work, urinalysis) information. "We just recently finished all
of the gene expression profiling on a study that was conducted in
Wichita, Kan., a two-day clinical study of 250 subjects," Vernon
says. "We were able to profile 20,000 genes from 177 subjects, and we
are in the process of looking at those gene expression profiles."
These Wichita subjects, including people with CFS and healthy
people, also underwent a battery of neuroendocrine and immune
studies, sleep studies, and tests for cognitive function. "It's actually a very
rich and incredibly complex data set," Vernon says. "It's not just two
things that we're trying to put together, it's multiple things. For
instance your physical symptoms -- quantifying fatigue, levels of
cognitive impairment, sleep problems -- with other laboratory
measurements, in addition to gene expression measurements."
Vernon has assembled four teams of six investigators --from
disciplines including medicine, molecular biology, mathematics,
physics and computer science -- to tackle the Wichita clinical data
set to try to further the understanding of CFS pathophysiology. "Our
group is one of the few multidisciplinary groups there is that's
studying CFS. ... I think our group is realizing that it is going to
be the way to cure CFS. ... Because of the complexity of this
illness, you have to have many different perspectives."
How close are we to that diagnostic marker? Vernon pauses. "I
hope we're close, is what I would like to say." She laughs. "I don't
want to give a date because everybody in my lab will panic."
Finding effective treatment for CFS is another long-term goal. "Isn't that the
dream of any scientist?" Vernon says. With a better understanding
of the disease process, specific therapeutic interventions may one day
be possible. But for now, treatment for CFS is limited to managing
symptoms, such as pain or sleep problems. However, symptomatic
treatments don't address the underlying disease, which, Vernon
says, "could end up affecting people for the rest of their lives."
What happened to the woman Jessop first saw in her clinic in
1984? "I ran into her about a year ago," says Jessop, who is now an
administrator at several East Bay hospitals. "She never enjoyed the
life that she had before, but I think she was much better. Certainly
she was out of bed and doing things. " Like this woman, the
majority of people with CFS gradually improve, but only an estimated 10
percent enjoy full recovery. Many stay the same, and some worsen with
time.
Questions about who will recover and when remain unanswered.
How is CFS diagnosed?
Clinically evaluated, unexplained chronic fatigue can be
classified as chronic fatigue syndrome if the patient meets the
following criteria:
1. Clinically evaluated, unexplained persistent or relapsing
chronic fatigue that is of new or definite onset (i.e., not lifelong),
is not the result of ongoing exertion, is not substantially alleviated
by rest, and results in substantial reduction in previous levels of
occupational, educational, social or personal activities.
2. The concurrent occurrence of four or more of the following
symptoms: substantial impairment in short-term memory or
concentration; sore throat; tender lymph nodes; muscle pain;
multijoint pain without joint swelling or redness; headaches of a
new type, pattern or severity; unrefreshing sleep; and post-exertional
malaise lasting more than 24 hours. These symptoms must have
persisted or recurred during six or more consecutive months of illness and
must not have predated the fatigue.
Who gets CFS?
CFS strikes people of all ages and ethnic and socioeconomic
groups. Most cases in the United States are women between the
ages of 40 and 49, but CFS afflicts men, women and children of all ages. In
women, CFS is more common than multiple sclerosis, lupus, HIV
infection, lung cancer and many other well- known illnesses.
Do people with CFS get better?
Full recovery is estimated at 10 percent, with the greatest
chance of recovery appearing to be within the first five years of
illness. Some people cycle between periods of relatively good
health and illness, and some gradually worsen over time. Others neither
get worse nor better, while some improve gradually but never fully
recover.
Adapted from Introducing CFIDS, a pamphlet published by
the CFIDS Association of America.
For copies, call the Association's
resource line:
(704) 365-2343.
Dorothy Wall is author of
forthcoming from Southern Methodist University Press in
September.
Source: San Francisco Chronicle
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