Transcription:
Examining the Connection between COVID-19 and Pneumonia

Melanie Cole: Welcome. This is Better Edge, A Northwestern Medicine Podcast for physicians. Joining me today is Dr. Richard Wunderink. He's a Pulmonologist and a Professor of Medicine in the division of Pulmonary and Critical Care. And he's the Medical Director of Northwestern Memorial's Medical Intensive Care Unit. And he's also a leading expert in pneumonia. And today we're talking about the connection between pneumonia and the novel Coronavirus, COVID-19. Dr. Wunderink, thank you for joining us. Give us a brief history of Coronaviruses in general and how is COVID-19 different from the other versions of the virus we've seen before?

Dr. Wunderink: So the Coronaviruses have actually been around for a while. Probably did not recognize them until two things. One is the SARS epidemic, which was the first of the really dangerous kinds of infections with Coronaviruses. And then after that we found that there are other Coronaviruses that are circulating that actually cause adult respiratory diseases. And we actually Northwestern Memorial Hospital participated in a CDC study, looking at the epidemiology and, and causes of pneumonia. And we actually found Coronaviruses caused a fair number in adults. And these are circulating viruses. They tend to have a seasonal pattern. So, often in the winter I have recently been attending and seeing patients in the ICU. And in a week we had six different patients with Coronavirus, none of them COVID-19. So the big difference is with both SARS and COVID-19 they attach to cells in a different manner than the other Coronaviruses.

So all viruses kind of need something on the cell to attach to, to actually invade the cell, cause infection, take over the machinery of the cell to reproduce more viruses. And so the what the SARS viruses use is a so marker that is fairly specific for lower respiratory tract or at least a little bit more than some of the other attachment points for other viruses. And so that's why we're seeing more severe lower respiratory tract infections with the SARS viruses, then with the other Coronaviruses. And so the COVID-19 is similar to the SARS virus in fact that the technical name for the virus is actually SARS, Coronavirus type two, versus what we typically call the SARS virus, which is the number one. And there are different Coronavirus class and all of the others that routinely circulate.

Host: Well, thank you for that comprehensive answer. So tell us about your multi-omix study to understand the factors in the host that determine the susceptibility to pneumonia and how it relates to understanding who's going to develop pneumonia from viruses like COVID-19.

Dr. Wunderink: Yeah, so we have a study that is based on what we've seen more with bacterial pneumonia that there's this idea that if you have a bacterial pneumonia and you give antibiotics while you're cured. And we can take care of that. What we actually know from research is that many patients don't fully recover. They don't look, they look like they're persistently infected and don't return to what would be their normal state. And so we have this study called the script study studying successful clinical response in pneumonia treatment. In our idea there is looking at how the what, what factors predict that you don't have a good recovery from bacterial pneumonia. So we're trying to find out, is this that the actual bacteria persists? Do they develop resistance to our antibiotics? Do they have particular variance factors that make them harder to get rid of? Another possibility is that we now know that there's a normal bacterial flora in the lungs.

We used to think they were sterile, but now we know that they're not in. And so treating with our antibiotics may change that microbiome into something that fosters further infections or re infections, or just changes. In that normal flora that cause just persistent inflammation in patients looking like they're failing treatment. Or the bacterial pneumonia may initiate this response in the body and the host, that then gets perpetuated that you start this and this inflammation that's important to control the infection. But it becomes kind of a runaway train in nothing to put the brakes on, nothing to stop it. So that's the concept behind our study looking at bacterial pneumonia, especially serious bacterial pneumonia. And what we're seeing is that this kind of phenomenon is actually happening with viruses as well. We clearly see it with influenza virus. We think we'll probably see that with the COVID-19 virus, and is one of the theories for why patients don't do well with either of these serious viruses.

Host: Well then Dr. Wunderink, a really curious question is then why does a virus like COVID-19 cause mild symptoms in some and even life-threatening symptoms such as pneumonia in others? So are we relating your research back to COVID-19? Why does a virus like this cause a cold in some and kill others?

Dr. Wunderink: Yeah, so I think if we knew the answer to that, I'd probably be looking at a Nobel Prize. But this is actually something that we have seen and known for a long time. The same thing is true for influenza. We've, we have millions of cases of influenza every year, and yet it's actually this small minority that actually gets serious problems and an even smaller number that get to the ICU and get on breathing machines. And so I think it's the same with COVID-19. I think there's probably some genetic differences between people, in fact, that's probably the most likely explanation. We do know that, so the receptor that COVID-19 attaches to, there are differences, genetic differences in that receptor and in the whole pathway that is involved with that receptor and they have been associated with risk of ARDS.

And so most likely this difference between some has to do with, with just your genetic makeup and how you respond to those kinds of viruses. We clearly know that you can alter that. So immunocompromised patients are more susceptible to these viruses, have less ability to respond and control them. And you know, I think that another big research project that our division is doing is trying to understand the whole process of aging. And so we see, in all kinds of pneumonia, but particularly in viral pneumonias like SARS, and influenza that the elderly are more likely to get severe disease, more likely to die. And there is some sense of waning of your ability to fight infections with time. So it's probably a combination of genetic susceptibility, underlying disease, and then aging that is having this kind of multifaceted role.

Host: Well then along those lines, Dr. Wunderink, There've been a number of deaths from the Coronavirus among Doctors who are young and as far as we know otherwise healthy is this reframing who we thought was at risk?

Dr. Wunderink: So I don't think it really does. I think we, we know that adults are susceptible. That the really interesting thing about COVID-19 is it doesn't appear to be such a severe disease in children. And you know, there's a lot of interest in why that is occurring. But ever since the beginning there've been deaths in younger people. I think a lot of this has to do with some of the underlying diseases issues with getting older and in your immune system getting older, make it a higher probability of dying and getting severe illness. But it has been occurring in younger people as well. So it really fits the epidemiology. Same thing with the original SARS virus. It clearly affected younger people. I think one of the things that you might be seeing is that, who's going to be first exposed? It's going to tend to be the healthcare workers. And this is one of the problems with the epidemic like this is that healthcare workers kind of get exposed before we know what's going on and may therefore not take protective actions may get a higher inoculum in a variety of things. So it does occur in younger people, it does occur in healthcare workers, and just in general healthcare workers are younger. So I think that that's just more of an epidemiologic issue then that younger people are more or less susceptible.

Host: So what is the recommended treatment plan for patients who develop pneumonia or severe respiratory illness from COVID-19. What are you seeing happening for these patients? And do you have any brief recommendations for healthcare settings? As far as protection for their healthcare workers?

Dr. Wunderink: Yeah, so the treatment of COVID-19 disease right now is purely supportive. There are a large number of clinical trials that have been done in China, and being done in the US and other places around the world. There's some reports that are, we're hearing that some of these studies are done and the reports may come out soon. But right now the main thing is supportive of trying to get them through the period of time, particularly their respiratory failure, to where their body can take care of the virus on its own. We do think that there are some things that we can do to avoid making it worse. So there's a tendency to give corticosteroids. Most of the information coming out is that that's probably not going to be a benefit, may actually harm. And predisposed to other infections. It's not clear that giving lots of antibiotics is going to be beneficial. And so one of the things we, that ties very much into our research project on multi-Omix of pneumonias to make an accurate diagnosis in pneumonia so that you use the antibiotics when you need it, but don't be using lots of antibiotics when it's not really needed. Our hope is that we can get some specific treatments and or vaccination to help with this. But right now it's, there's nothing specifically that we know that, that has benefit here.

Host: So as we wrap up, how do you envision your research translating into potential therapies for pneumonia and what else would you like other providers to know about your work or about treating patients with COVID-19, Dr. Wunderink?

Dr. Wunderink: So I think that what our research is hoping to do is to help us to understand what goes wrong when you do everything right. You know, when you've got the right antibiotics, when you feel like you've got an accurate diagnosis. And yet patients don't seem to get better. I think that once we get some antivirals. I mean we know that for influenza where we do have antivirals, there are still patients who despite the antivirals don't get completely better. And so we're trying to understand what that is. Is it the host, is it that the antibiotics are ineffective or is this something that we can intervene on? And that's where some of this multi Omix approach of looking at, you know, what genes are turned on or off in specific cell types where the microbiome and what antibiotics may disrupt the microbiome more will help us to understand this phenomenon better in the future.

Host: Well, thank you so much Dr. Wunderink, for coming on and sharing your expertise because this is something that other providers are really investigating now and everybody has questions. So thank you for coming on and telling us about your research. That wraps up this episode of Better Edge, A Northwestern Medicine Podcast for Physicians. To refer your patient or for more on the latest advances in medicine, please visit our website at nm.org to get connected with one of our providers. Please remember to subscribe, rate, and review this podcast and all the other Northwestern Medicine Podcasts. For more health tips and updates, please follow us on your social channels. I'm Melanie Cole.