From The Times, 30 August 2016. Story by Tom Whipple, Science Editor. Online link to full story not available.
Chronic fatigue syndrome may be caused by the body mistakenly going into a semi-hibernation state, a study has suggested.
An estimated 250,000 people have CFS, also known as ME, in Britain. The mysterious disease, which is difficult to diagnose, causes people to suffer from persistent exhaustion and can strike with no obvious cause. Theories about the cause have ranged from a bacterial or viral infection to psychiatric issues, and there are few effective treatments.
A previous major study suggesting the best treatments involved cognitive behaviour therapy or exercise angered those suffering from ME, with many saying that it trivialised their disease and ignored possible biological causes.
Now US scientists have found a chemical signature of the disease in the blood of sufferers. They claim that it is similar to a state found in nematode worms called dauer. In this state, the metabolism adjusts to a difficult environment by slowing down — enabling existence, but not much more.
Writing in the journal Proceedings of the National Academy of Sciences, the researchers said that dauer “permits survival and persistence under conditions of environmental stress, but at the cost of severely curtailed function and quality of life”. For many ME sufferers that is an apt description of their condition.
All animals have ways of responding to changes in environmental conditions that threaten survival.
For their study, scientists screened the blood plasma of 85 people for metabolites. These are by-products of the chemical reactions in cells, including the breakdown of molecules to release energy. More than half of those screened had been told they had ME.
The aim of the study was to come up with a simple way to diagnose ME. At present, there is no blood test, so doctors have to judge if a patient’s lifestyle and behaviour fit the criteria.
However, as well as finding 20 markers that were indicative of the disease, Robert Naviaux, from the University of California, San Diego, found that these matched markers that would be expected in invertebrates in the dauer state.
This suggested that the condition could be a misfiring response to the environment, with the body mistakenly entering a state designed for survival in harsh conditions. Under this theory, just as allergies are overactive immune responses, ME could be an overactive response of the metabolic system.
“All animals have ways of responding to changes in environmental conditions that threaten survival,” Professor Naviaux said. “Historical changes in the seasonal availability of calories, microbial pathogens, water stress and other environmental stresses have ensured that we all have inherited hundreds to thousands of genes that our ancestors used to survive all of these conditions.”
Other scientists welcomed the research, but cautioned that it was too early to say what was going on. Andrew McIntosh, from the University of Edinburgh, said: “It is difficult to know whether the changes reported are a cause or an effect of CFS.”
DISEASE WORSENED BY STIGMA
A complex disease biologically, ME is equally fraught politically (Tom Whipple writes). For many sufferers this latest study is more than just an insight into a disease — it adds weight to their battle against another piece of research that was published in 2011.
The Pace trial, run by UK researchers, remains one of the most comprehensive investigations into treatment for ME. It concluded that cognitive behavioural therapy and exercise could treat it.
Some sufferers took this as implying that their condition was all in the mind. They questioned the methodology and amid bitter arguments have sought to gain access to the full data. Academics involved in the trial said they had received abuse just for doing their jobs.
Now, after a legal battle, Alem Matthees, who has ME, has succeeded in forcing Queen Mary, University of London to release data from the trial. He said: “There is a growing chorus of academics . . . speaking out about the methodological problems with the Pace trial, yet for many years patients were left to speak out alone.”
Those with ME often feel they are being judged, that people think they are lazy or “faking it”. In that context, yesterday’s study will be seen as a victory.
from ME Association