Robyn Williams: Here’s a puzzle, one that may now be solved. What is chronic fatigue syndrome, a malady affecting thousands and often unfairly misconstrued? Professor Warren Tate at the University of Otago in Dunedin has worked on it for years.

Warren Tate: The nomenclature is still being discussed and has been discussed for many years. In the United States it has been traditionally called chronic fatigue syndrome, but patients there are very upset with that name because everybody has fatigue that goes to see their GP, and it has led in a way to a quite serious illness not being taken as seriously as it should. In the United Kingdom it was known as myalgic encephalomyelitis. And in New Zealand we tend to use both names.

Robyn Williams: The big problem was that you felt normal but there was a non-specific syndrome. You described a whole number of things, feeling tired, feeling put off, no clear symptoms that you could necessarily investigate and confirm. Was that the problem way back?

Warren Tate: Well, it was really that there were many symptoms, and some, particularly for younger people like my daughter, they were incredibly severe, but when you did a blood test nothing really showed up on the blood screen. Things were a little bit out of kilter but nothing special. And so the medical profession really had no good feel for this illness. And so in my daughter's case for example, she was a 14-year-old girl, loved school, had a great network of friends before the illness came on. We were told, well, she just doesn't want to go to school. Well, as a parent you knew that just wasn't the explanation.

Robyn Williams: Very unfortunate when you are accused of bludging.

Warren Tate: Yes, and in fact that's a good phrase because in the United States that's exactly what many patients were accused of, not wanting to work and things like that. So in 2015 the Institute of Medicine of the Academy of Sciences in the United States actually had a big inquiry, and they came out and actually said this, that patients need to be taken seriously, the illness was quite serious.

And they suggested even another name, systemic exercise intolerance syndrome. But no one really likes that name, but it was to emphasise that there was a post exertional malaise. That is to say, when anyone does any activity, they basically often have to rest up for weeks at a time to recover. That's a serious symptom of the illness.

My daughter's case, as a 14-year-old, she could stagger to the shower about 20 metres, sit down, have a shower, get back to her bed, and she would have to take about three or four hours to recover from that activity.

Robyn Williams: How common is it in places like Australia and New Zealand?

Warren Tate: Well, it can be up to about 0.5% of the population. So in New Zealand, for example, it's estimated there are probably 20,000 to 25,000 people. But because the diagnosis is difficult to make, and we have one expert GP in New Zealand on the North Shore, Ros Vallings, who has been on the international body, and she understands the illness backwards and forwards. So she actually diagnoses many of the New Zealand patients. So we are, in a way, in quite a good place. But in many cases patients go to their doctors and they don't get a diagnosis.

Robyn Williams: Well, you've looked into it and tried to find out what the evidence is for its origins. What have you found?

Warren Tate: Well, when you look at the history there are outbreaks of people with an illness like that, for example, in Incline Springs in Nevada in 1984 there was…in this village there were two GPs and they started to see all of these patients that had come down with a severe fatigue illness, and they reported it to the CDC, but at the time it was just regarded as some sort of mass hysteria, so not taken seriously.

And in New Zealand we had Tapanui flu, which was a town in the South Island where a lot of the inhabitants also came down with a severe fatigue illness. And so we can see these kind of outbreaks that were suggested of an infectious disease. And certainly again if I can relate it back to my daughter, she had glandular fever a few months before and then her health went downhill into this chronic fatigue. So the general consensus is that actually a viral origin is likely, not necessarily one virus, although the Epstein-Barr virus is quite common, or it could be induced by a chemical toxin, because I've seen some people from rural areas in Hawke's Bay who have got the illness, and generally you would think they wouldn't be exposed to the same sort of viruses as people in a city. So agricultural chemicals. Or it may be a dramatic stress event in someone's life could actually switch them into this kind of illness.

Robyn Williams: And when you look at the genetics, what do you find?

Warren Tate: Well, there appears to be some genetic susceptibility in the sense that you can have multiple people infected with the illness in the same family, but of course that could still be an infectious disease cause. There are some suggestions of…when genome-wide screens have been done, of some suggestive genetic susceptibilities, but it's very crude at the moment.

Robyn Williams: So where are we now? What have you found as a result of this conference and your own work to be the clear indication? Obviously people have got a genuine illness.

Warren Tate: Yes. One of the things that might have been obvious at the beginning because of the fatigue, and as a biochemist I was interested and tried, when my daughter had the illness, to do a study on this, was to look at energy production because clearly they were really struggling in this area. But then international thought went away from an effect on our energy producing systems, the mitochondria, but more recently a Norwegian group actually of oncologists that originally stumbled upon when they were treating patients with myeloma that there was chronic fatigue patients who had actually got some remission of their illness when they were given a monoclonal antibody against a B-cell which was causing the myeloma. So that's what they were studying, but they got interested in the illness and they've set up a metabolic unit and have shown, which they reported on at the conference, that the last part of the energy production system seems to be defective. That is, it's what we call a tricarboxylic acid cycle or the TCA cycle, intermediates seemed to be lower and the enzyme which transitions the energy producing system into the final stage, pyruvate dehydrogenase complex, seems to be defective. So now there's excitement to actually look at patients, and there is new technology available, Seahorse technology, where you can look at live cells and mitochondrial function and determine what's called a bioenergetic index. So we are really excited about this and we're hoping to actually study New Zealand patients to see whether their bioenergetic index is low, which would be an indication that their mitochondria are in quite an unhealthy state.

Robyn Williams: So there is a test?

Warren Tate: This could be a test, absolutely. One of the other areas that have been stimulated, and we've done a preclinical study on this, is a result of the Institute of Medicine of the Academy of Science US review, was direct studies on the post-exertional malaise. And so we've collaborated with a cardio-physiologist on this who can do the exercise studies, and then we've looked at the blood of people before and after exercise and shown that whereas normal people when they exercise can re-exercise 24 hours later with no problem, and you can see normal molecular changes that are occurring. But in ME patients those don't occur. And of course 24 hours later all of their physiological measurements are much lower.

Robyn Williams: It must be such a relief to people suffering from something so debilitating, to know they are not being accused of being a malingerer any more.

Warren Tate: I think this is a tremendous relief to patients, and with the hope that now they will be treated like people with mainstream diseases like cancer or whatever, and with a hope that actually we might be able to find ways of alleviating the worst symptoms of the illness, maybe not actually eliminated totally. My daughter has had her illness for more than 25 years but she is certainly a lot more able to do constructive things in life as compared with during the acute phase. But managing the illness is an important thing. So if we develop good tools which help to manage the illness, then that will be a big benefit.

Robyn Williams: Warren Tate is professor of biochemistry at the University of Otago in New Zealand, on viruses and mitochondria.