Expert committee redefines and renames ME/CFS

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Between 836,000 and 2.5m Americans suffer from myalgic encephalomyelitis/chronic fatigue syndrome – commonly referred to as ME/CFS. This disease is characterised by profound fatigue, cognitive dysfunction, sleep abnormalities, autonomic manifestations, pain, and other symptoms that are made worse by exertion of any sort. ME/CFS can severely impair patients’ ability to conduct their normal lives.

The US Department of Health and Human Services (HHS), the National Institutes of Health, the Agency for Healthcare Research and Quality, the Centres for Disease Control and Prevention, the Food and Drug Administration, and the Social Security Administration asked the Institute of Medicine (IOM) to convene an expert committee to examine the evidence base for ME/CFS. In Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness, the committee proposes new diagnostic criteria that will facilitate timely diagnosis and care and enhance understanding among health care providers and the public.

The committee said in the report that naming the condition SEID captures the fact that with this disease, exertion of any sort — physical, cognitive or emotional — can adversely affect patients in many organ systems and also in many aspects of their lives.

The group offered the following criteria for diagnosing SEID:

  • a substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social or personal activities that persists for more than six months and is accompanied by fatigue, which is often profound, of new or definite onset (not lifelong), not the result of ongoing excessive exertion and not substantially alleviated by rest;
  • post-exertion malaise; and
  • unrefreshing sleep.

At least one of two manifestations — cognitive impairment or orthostatic intolerance — also is required

Study co-author Dr Theodore Ganiats,of the department of family medicine and community health in the Miller School of Medicine at the University of Miami, roke down the key elements of the group’s research.

He told AAFP News that ME/CFS has been ignored or mismanaged by clinicians in the past because some doctors don’t consider it a real disease; other times, it’s simply misdiagnosed. Regarding the latter, Ganiats said that just as hypertension and diabetes may be missed during a clinical visit, ME/CFS can be misdiagnosed for a variety of reasons.

“Plus, there are many diagnostic strategies (for ME/CFS) out there, so it is confusing to doctors,” he said. “We hope that the IOM strategy, based in evidence and simpler, will facilitate the diagnostic process.”

Ganiats pointed to elements of the diagnostic criteria the IOM committee created that provide evidence that ME/CFS is a legitimate disease with a physiological basis.

“One of the three required elements is post-exertion malaise — there is objective evidence of that,” he said. “A person without the disease will perform about the same on exercise tests done on successive days. However, a person with this disease will perform much worse on the second day, even when putting out the same, maximal effort.”

He added that one of the two additional criteria is autonomic dysfunction — specifically, orthostatic intolerance, which can also be measured objectively.

Researchers also found pretty good evidence that many patients with ME/CFS have immune dysfunction.

“For example, natural killer cell count and cytokine production can be altered,” Ganiats said. “The reason this is important is twofold. First, it gives insight into a possible mechanism for the disease. Second, it provides the hope for a biomarker for the disease. However, at this time, none of the changes are sufficiently specific for it to be used as a biomarker. As such, research in this area continues.”

Ganiats said the IOM committee agreed collectively that the term “chronic fatigue syndrome” can result in stigmatization and trivialization and should no longer be used as the name of this illness.

“Patients don’t like the disease, and physicians now have the wrong idea about it,” he said. “By changing the name, we emphasize that the IOM has looked at the evidence and sees that the name is misleading.”

A patient of ME for 16 years questions, Julie Rehmeyer, an accomplished science and mathematics reporter, questions in The New York Times, whether the message from the Institute of Medicine (IOM) report will work. She says early indications are discouraging with many doctors dismissive of the IOM’s report. The 300-page report pointed out that chronic fatigue (the condition of being tired all the time) and chronic fatigue syndrome (an illness in which exhaustion is just one of many debilitating symptoms) are very different.

Rehmeyer notes that the hallmark symptom of chronic fatigue syndrome isn’t fatigue at all: It’s a dramatic worsening of symptoms after exertion (which for some patients can be as little as lifting a toothbrush). On top of that, patients have cognitive problems, sometimes so extreme they can’t talk or read; within half an hour of standing, their blood pressure drops or their heart rate soars; and sleep makes them feel no better. Most have additional symptoms, too, including pain and neurological and immune problems. But many doctors, it seems, aren’t persuaded by this scientific evidence.

Unfortunately, she says no one test can reliably distinguish patients who have chronic fatigue syndrome from those who don’t. The other thing that would change doctors’ attitudes is effective treatment, which is also what patients desperately need. But Rehmeyer points out, developing tests and treatments isn’t cheap. Every disease community argues that it needs more money, but the situation with CFS is extreme: The National Institutes of Health spends a mere $5m a year on CFS research, when an estimated 1m Americans are affected. By comparison, the NIH spends $3bn on HIV/Aids a year.

Rehmeyer says she hopes that the IOM report will help some patients get diagnoses more quickly and accurately. But, she says, to get anywhere close to the care that patients so desperately need, no report is enough. It will require objective tests and effective treatments and for that, she says, federal agencies will have to start making an investment in this disease that’s proportional to the devastation it causes.


Scientists have found distinct changes in the immune systems of patients with ME or chronic fatigue syndrome. Researchers at the Centre for Infection and Immunity at Columbia University’s Mailman School of Public Health identified distinct immune changes in patients diagnosed with chronic fatigue syndrome, known medically as myalgic encephalomyelitis (ME/CFS) or systemic exertion intolerance disease.

The findings could help improve diagnosis and identify treatment options for the disabling disorder, in which symptoms range from extreme fatigue and difficulty concentrating to headaches and muscle pain. These immune signatures represent the first robust physical evidence that ME/CFS is a biological illness as opposed to a psychological disorder, and the first evidence that the disease has distinct stages.

With funding to support studies of immune and infectious mechanisms of disease from the Chronic Fatigue Initiative of the Hutchins Family Foundation, the researchers used immunoassay testing methods to determine the levels of 51 immune biomarkers in blood plasma samples collected through two multi-centre studies that represented a total of 298 ME/CFS patients and 348 healthy controls. They found specific patterns in patients who had the disease three years or less that were not present in controls or in patients who had the disease for more than three years. Short duration patients had increased amounts of many different types of immune molecules called cytokines. The association was unusually strong with a cytokine called interferon gamma that has been linked to the fatigue that follows many viral infections, including Epstein-Barr virus (the cause of infectious mononucleosis). Cytokine levels were not explained by symptom severity.

“We now have evidence confirming what millions of people with this disease already know, that ME/CFS isn’t psychological,” states lead author Dr Mady Hornig, director of translational research at the Centre for Infection and Immunity and associate professor of epidemiology at Columbia’s Mailman School. “Our results should accelerate the process of establishing the diagnosis after individuals first fall ill as well as discovery of new treatment strategies focusing on these early blood markers.”

There are already human monoclonal antibodies on the market that can dampen levels of a cytokine called interleukin-17A that is among those the study shows were elevated in early-stage patients. Before any drugs can be tested in a clinical trial, Hornig and colleagues hope to replicate the current, cross-sectional results in a longitudinal study that follows patients for a year to see how cytokine levels, including interleukin-17A, differ within individual patients over time, depending on how long they have had the disease.

The study supports the idea that ME/CFS may reflect an infectious “hit-and-run” event. Patients often report getting sick, sometimes from something as common as infectious mononucleosis (Epstein-Barr virus), and never fully recover. The new research suggests that these infections throw a wrench in the immune system’s ability to quiet itself after the acute infection, to return to a homeostatic balance; the immune response becomes like a car stuck in high gear. “It appears that ME/CFS patients are flush with cytokines until around the three-year mark, at which point the immune system shows evidence of exhaustion and cytokine levels drop,” says Hornig. “Early diagnosis may provide unique opportunities for treatment that likely differ from those that would be appropriate in later phases of the illness.”

The investigators went to great lengths to carefully screen participants to make sure they had the disease. The researchers also recruited greater numbers of patients whose diagnosis was of relatively recent onset. Patients’ stress levels were standardised; before each blood draw, patients were asked to complete standardised paperwork, in part to engender fatigue. The scientists also controlled for factors known to affect the immune system, including the time of day, season and geographic location where the samples were taken, as well as age, sex and ethnicity/race.

Institute of Medicine material
Report brief
Clinicians guide
Full report in The New York Times
Columbia University material
Science Advances abstract
Full AAFP analysis
See also: Early menopause link with CFS

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