London: What exactly causes Chronic Fatigue Syndrome (CFS) is still not known, but a new Norwegian study has found that a wayward immune system attacking the body could be the real culprit.
CFS, also known as ME, refers to severe and continued tiredness that is not relieved by rest and is not directly caused by other medical conditions. The illness has no known cure at present.
However, researchers at the Haukeland University Hospital in Bergen found that a cancer drug, which inhibited the immune system, relieved symptoms in some patients, the BBC reported.
For their study, the team selected 30 patients with CFS, half of whom were given two doses of Rituximab, a cancer drug which eliminates a type of white blood cell, while the other half were given a fake treatment.
In those receiving the drug, 67 per cent reported an improvement in a score of their fatigue levels. Just 13 per cent showed any improvement in the sham group, the researchers reported in PLoS One.
Study researcher Oystein Fluge, an oncologist at the hospital, said: "There was a varied response: none, moderate, dramatic relief of all symptoms.
"Two had no recurrence [of their symptoms], their life was turned completely around very dramatically."
Their theory is that a type of white blood cell, B lymphocytes, are producing an antibody which attacks the body.
The drug wipes out the lymphocytes which in some cases may "reset the immune system", but, in others the fatigue symptoms would return when more B lymphocytes were made.
"I think the fact that patients responded to treatment, improved cognitive function, fatigue and pain makes us believe we`re touching one of the central mechanisms," Fluge said.
"But we`re scratching at the surface, I would not characterise this as a major breakthrough."
The new study was based on the clues given by doctors in Norway in 2004. While treating a patient with both Hodgkin`s lymphoma -- a cancer of the white blood cells -- and CFS, they had found that her fatigue symptoms improved for five months while she received cancer treatment.
The researchers are now investigating the effect of giving more doses over a longer period of time.
If their hunch is right it will throw up more questions, such as what is the immune system actually attacking and whether or not an actual test for CFS/ME be developed.
Dr Charles Shepherd, the UK ME Association`s medical adviser, said: "The results of this clinical trial are very encouraging news for people with ME.
"First, they help to confirm that there is a significant abnormality in immune system function in this disease.
"Second, they indicate that altering the immune system response in ME could be an effective form of treatment for at least a subset of patients.
"We now need further clinical trials of such anti-cancer agents to see if other research groups can replicate these findings."