An overactive immune system could trigger the debilitating condition chronic fatigue syndrome (CFS), a study has found.
CFS - also known as ME (myalgic encephalomyelitis) - is a long-term illness characterised by extreme tiredness, and affects approximately 250,000 people in the UK.
The underlying biology of the condition has remained a mystery, although many patients report their illness starting following an infection such as a viral illness.
Scientists at King’s College London have found that an immune system overreacting to an infection could help explain how the condition is contracted.
Lead researcher Dr Alice Russell said: “For the first time, we have shown that people who are prone to develop a CFS-like illness have an overactive immune system, both before and during a challenge to the immune system.
“Our findings suggest that people who have an exaggerated immune response to a trigger may be more at risk of developing CFS.”
Senior researcher Professor Carmine Pariante said the results were the “first step in identifying those at risk and catching the illness in its crucial early stages”.
Dr Neha Issar-Brown, of the Medical Research Council (MRC), said: “The MRC strongly encourages more research to better understand this condition.”