Covid's metabolic signature
As we reported here on the Naked Scientists a couple of weeks ago, COVID-19 is a confusing illness - some doctors are dubbing it the weirdest disease they’ve ever treated. What makes it weird is the broad range of severity: some don’t even know they’ve been infected, while among others it can be lethal. Significant numbers of people are also reporting long term symptoms, including fatigue, sensations of pins and needles, and sometimes struggling to think clearly.So what’s causing this? Scientists think that the disease may be producing long term changes in a range of organs, possibly because of damage to those organs during the initial illness. Recently, researchers at Cambridge University sent samples from Covid-19 patients here to the Australian National Phenome Centre at Murdoch University in Perth. There, using very sensitive chemical techniques, they’ve been able to spot changes in a range of substances in the bloodstreams of these patients. These signature changes appear to be very specific for coronavirus infection, so they can be used as an accurate test for the disorder. They also provide insights into why people are developing some of the symptoms they are, and, in the future, may enable us to predict who is most at risk. Phil Sansom heard how from Jeremy Nicholson, who’s leading the study...
Jeremy - There is a very marked signature, in fact it's surprisingly strong. So what we see, is a pattern that's related to liver dysfunction, to diabetes, to potential cardiovascular damage and cardiac risk. The thing that makes it unique, is it has a multiple system failure signature, which means that it stands out like a sore thumb. We've never seen anything quite like it
Phil - Is this specifically for people who get really severe COVID?
Jeremy - It looks as though it's largely independent of the degree of respiratory symptoms, which is potentially quite surprising. But if you think about it, you know, there's been reports now of people having brain damage, strokes, heart failure, gut effects, kidney effects. And what we're seeing is the combination of pretty much everything that everybody's been talking about for the last couple of months.
Phil - How easy is that to detect for you?
Jeremy - We have various different types of advanced chemical equipment, and it's all based on spectroscopy, the study of the chemical signatures of molecules. Molecules can absorb energy, and radiate energy in lots of different ways. They can also have characteristic mass profiles, and it doesn't matter which one we use. There's always a signature for COVID-19.
Phil - In terms of this sort of being almost a test for who's been infected, how does it compare to the other tests in terms of how quick it is, how easy it is?
Jeremy - When we started the work back in February, I wasn't terribly interested in detection per se, because I made an assumption that the PCR methods for testing for the virus were extremely good. And it turns out there's a huge number of the tests that have very large numbers of false negatives, which of course is a bad thing for a test. And we're using NMR spectroscopy, we have a test that is 100% sensitive, that works in four minutes, costing about 15 pounds or something like that. And that is gender independent, age independent. It's also independent of severity.
Phil - You know, everyone talks about how strange this virus is, and how strange this disease is. And it's strange that the one constant, is how universally disruptive this is to people's bodies.
Jeremy - Yeah. There are probably a number of reasons for that. The most important one is this is a disease that attacks epithelial cells, cells that line or cover surfaces. So the lung has a double epithelium. It has the cells that face the air, and it also has the blood vessels, which are very, very close indeed. But the whole of the body is full of blood vessels. And there's lots of reports in the literature about blocking tiny blood vessels, and also major blood vessel blockages as well. And that means any organ in the body, technically can be affected by COVID.
Phil - Jeremy, when can we expect to be able to take your test?
Jeremy - Well, you can take the test in our laboratory tomorrow, but this is informally. The pathway to getting it to a test that could really work and be deployed at scale is not necessarily a long one. It might only be eight to 12 weeks in an ideal situation.
Phil - And I've been talking to lots of people who are still sick, after months and months and months. Does this discovery that you made give them any insight?
Jeremy - Well, that's an interesting question. So, at the moment we don't know enough about it. What we do know is in some people that we've looked at, we've looked at them several months after they've actually had an episode, and they're still mapping with the COVID positives who were in the hospital. When we monitor people, we'll be able to assess quantitatively, whether they are going back to normal. At the moment, we can't accelerate people going back to normal. But what we will be able to do, is to have a better way of assessing the health of people who've had COVID, in a long-term followup.