Virus linked to ME

Two-thirds of patients with chronic fatigue syndrome carry a single virus in their blood cells, new research has found.

Chronic fatigue syndrome - also known as myalgic encephalitis or ME - affects about 250,000 people in the UK.

Symptoms usually include severe fatigue, tiredness, muscle pain and aching joints. A diagnosis of ME is usually made after all other possibilities have been excluded.

Although the cause of the condition is unknown, previous research has suggested that a viral infection may act as a trigger for the condition.

In the study, researchers at the Whittemore Peterson Institute, University of Nevada, examined blood samples taken from 101 patients diagnosed with chronic fatigue syndrome. Sixty-seven percent of the samples were found to contain genetic material from a type of retrovirus called murine leukaemia virus-related virus (XMRV), compared with only 3.7% of samples taken from healthy people.

The XMRV virus in the chronic fatigue patients was also shown to be infectious, as it could infect cell lines exposed to fluid taken from the blood cells of patients. No virus could be grown from the blood cells of healthy people.

However, scientists stressed that their results do not mean the XMRV virus is the cause of chronic fatigue syndrome. As people with chronic fatigue syndrome often have weakened immune systems, they may be more susceptible to this type of infection.

Also, past research has also shown that retroviruses like XMRV can activate a number of viruses which may be latent in the body such as the Epstein-Barr virus, also associated with ME.

However, Dr. Judy Mikovits, who led the study also commented: “Since the original Science paper was submitted, we have continued to refine our test for XMRV and have surprisingly found that 95% ME/CFS samples tested positive for XMRV antibodies in the plasma. This finding clearly points to the retrovirus as a significant contributing factor in this illness.”

This article was published on Mon 12 October 2009