There’s now hope of a treatment for chronic fatigue syndrome Julien Magre/plainpicture

“I was completely revitalised,” says Karen. “Suddenly, I could be sociable again. I would go to work, go home, eat dinner and feel restless.”

Karen (not her real name) experienced this relief from chronic fatigue syndrome while taking a drug that is usually used to treat the blood cancer lymphoma and rheumatoid arthritis (see “Karen’s experience”, below).

She was one of 18 people with CFS who reported improvements after taking rituximab as part of a small trial in Bergen, Norway. The results could lead to new treatments for the condition, which can leave people exhausted and housebound.


Finding a cause for CFS has been difficult. Four years ago, claims that a mouse virus was to blame proved to be unfounded, and some have suggested the disease is psychosomatic.

The latest study implicates the immune system, at least in some cases. Rituximab wipes out most of the body’s B-cells, which are the white blood cells that make antibodies.

Øystein Fluge and Olav Mella of the Haukeland University Hospital in Bergen noticed its effect on CFS symptoms in 2004, when they used the drug to treat lymphoma in a person who happened to also have CFS.

Several months later, the person’s CFS symptoms had disappeared. A small, one-year trial in 2011 found that two-thirds of those who received rituximab experienced relief, compared with none of the control group.

The latest study, involving 29 people with CFS, shows that repeated rituximab infusions can keep symptoms at bay for years.

“Eleven of the 18 responders were still in remission three years after beginning the treatment, and some have now had no symptoms for five years,” says Fluge. “Suddenly, their limbs started to work again and their hands were no longer cold or sweaty.”

“I am very intrigued by the rituximab story,” says Nancy Klimas, an authority on CFS at Nova Southeastern University in Fort Lauderdale, Florida. “It’s particularly exciting when people seem to have experienced very long periods of remission, and even speak of recovery,” she says.

A crucial clue?

The researchers think the body’s own antibodies are to blame in at least a proportion of people with CFS. Relief started four to six months after the first dose of rituximab, approximately the time it would take for existing antibodies to be cleared from the body. Participants relapsed after about a year – roughly how long B-cells take to regrow and start making new antibodies.

“We think the pattern of responses and relapses involves some mechanism with these antibodies,” says Fluge.

An infection may trigger the body to produce antibodies that then turn against a person’s own tissues, he says. His team suspect that these antibodies may stop blood from circulating properly, preventing people from getting enough oxygen, explaining their extreme fatigue.

The researchers caution that their theory is just speculation for now, but they do have some very preliminary evidence. “We think the antibodies target the blood vessel system, because patients have very low anaerobic pressure, and produce waste lactate earlier, which stops muscles working,” says Mella.

If this theory turns out to be true, it would explain why people with CFS suffer muscle fatigue but show no signs of muscular abnormalities.

Clinicians who have focused on treating the disease psychiatrically have also welcomed the findings. “This uncontrolled treatment study of rituximab shows promising indications of effectiveness,” says Fred Friedberg of Stony Brook University in New York.

“There is now a strong case to be made for a larger trial,” says Simon Wessely of King’s College London, who has treated people using cognitive behavioural therapy. “The belief that [CFS] is all in the mind has been around since the beginning,” he says. “It’s tragic that it might take a study like this to take sufferers seriously.”

A 150-person study is now under way, and includes a control group. While the 2011 study included a placebo, the most recent trial did not, leaving it potentially vulnerable to the placebo effect.

But Karen, for one, is convinced that the benefits of rituximab were genuine. “They were absolutely 100-per-cent real,” she says. “There are some things you just can’t fake.”

Journal reference: PLoS One, DOI: 10.1371/journal.pone.0129898

Karen’s experience How were you before you tried rituximab? I was really bad. I was unable to work as a teacher, I couldn’t manage it any more. I just didn’t have any energy. I couldn’t focus, and it was painful in the joints and muscles. When I went to post a letter, it felt like I’d run a marathon. You were unknowingly in the placebo group for the earlier trial in 2011. What was that like? I waited, and was hoping, but nothing happened. Of course I was disappointed it didn’t show any effect. I thought okay, probably I got the placebo. I wanted to finish my university degree and have a social life and job, and I couldn’t. What was it like receiving the drug in this latest study? This time, I knew I was going to get the medicine. I was very excited, but also terrified – what if it didn’t work? There’s no other treatment so it was my only chance. I got an effect quite early on. I was suddenly getting bursts of energy for maybe a half-hour or so. Then gradually I felt better. Suddenly, it was okay to keep my body upright. I restarted my master’s degree and did it in half a year – I got an A. Then I started working full time. I was completely revitalised.