Automatically transcribed and lightly edited
Michael Lyon: This is Heartbeat, conversations about medical science, research, and the discoveries that touch our lives in collaboration with the University of Nebraska Medical Center. I'm Michael Lyon, and my guest today is Jill Poole, MD, Chief, UNMC Division of Allergy and Immunology. Welcome.
Jill Poole: Thank you for having me.
Michael Lyon: You've spent much of your career studying how the environments where people live and work affect their lungs and immune systems. What first drew you to this field of research? I've been interested in this for over two decades now.
Jill Poole: Being an allergy immunologist, one of our big diseases is asthma. And so I've been interested of why people have asthma, why people don't have asthma, and then the allergy component to it. And what's been fascinating is that rural versus urban factors are a big deal about whether or not you develop disease and whether or not you develop allergy.
Michael Lyon: Probably most people listening right now hearing about allergy and immunology are going to think that we're going to talk about pollen or seasonal allergies, which is part of your work, I'm sure. But your work and your research look at something completely different. Tell us about the kinds of environmental exposures you're studying.
Jill Poole: So it's really these complex organic dusts. There's a lot of dust around Nebraska, Iowa, all of our region. But there's a lot of concentrated dust that is in the farming environments from the grain elevator, the swine confinement, the livestock, dairy, barns, poultry.Lots of dust, especially in the confinement facilities.
Michael Lyon: Things that you could describe then as agricultural dust.
Jill Poole: All these agricultural dusts.And they're really quite complicated. There's lots of bacteria components in it. There's particles in it.There's feed in it. There's minerals, metals in it. But really a lot of bacterial microbial components that are in this dust that humans also inhale.They work in it. They're around it. And they inhale it over long periods of time.And this results in a real significant lung disease for which we actually don't have as good of treatment as we do for maybe the classic pollen-induced allergens. Of course, there are allergens in agricultural dust as well. But it's really these other components, not the allergens, that are driving the disease.
Michael Lyon: I was wondering whether there were short-term effects from this dust. But of course, you've mentioned that this repeated exposure can become a serious health concern. What sort of form does that take?
Jill Poole: So with the repeated form, that can lead to asthma, it can lead to chronic bronchitis, which is more common, sometimes even COPD, emphysema.Or in the worst cases, lung fibrosis, an interstitial lung disease. So there is a continuum of it. And you're right, the acute exposures can be bad.In fact, one really bad exposure can cause significant long-term lung disease. But a lot of these repetitive low-dose exposure leads to these chronic lung disease where people, they cough a lot, they are short of breath, they have chest tightness, they don't feel as good. Your research has found also that this isn't just an issue for farmers.
Michael Lyon: So who else might encounter these types of airborne hazard in their work?
Jill Poole: There's a lot. Environmental exposures, occupation is probably the next one that comes to mind, from construction work to food processing to... Livestock workers, maybe. Livestock workers, yeah.Again, agriculture, the livestock workers. And then it even goes into military exposures and then high air pollution areas in some parts of our country. But all of those sorts of things that are exposed to this kind of organic dust.Yes. And each environment may be a little bit different, but these are complicated dusts that I generally refer to as organic dust. One of your studies explored a fascinating connection between agricultural dust exposure and rheumatoid arthritis.
Michael Lyon: Now, most of us, I'm sure, think of rheumatoid arthritis as a disease of the joints. How does the lung become part of that story?
Jill Poole: Oh, it's fascinating. And so for the last decade, I've been working with the rheumatologists and we've been really studying this lung-joint connection.But patients, unfortunately, with rheumatoid arthritis also have non-joint problems and lung disease is really quite prevalent. About 40% develop subclinical lung disease. 5 to 10% develop a real type of bad fibrosis of the lungs with rheumatoid arthritis.And what we feel, particularly in men versus women, is that these exposures to dust and organic dust and things in the environment, fumes and toxins, cause inflammation in the lung. And that's where the autoimmune disease is starting and then actually migrates to the joints. So they have both.But unfortunately, people with rheumatoid arthritis with the bad part lung disease have a higher rates of death.
Michael Lyon: Does this change in any way the way scientists think about autoimmune diseases? Could environmental exposures be playing a bigger role than we've appreciated before?
Jill Poole: That's what my group and myself and others definitely are studying and believe to be true that these environmental exposures, they trigger such an inflammatory reaction, in particular in the lung, that leads to the development of autoimmune disease.
Michael Lyon: Are there people that have a genetic predisposition?
Of course, yes.Definitely. It runs in families and we have identified specific genes.
Michael Lyon: So that repeated dust exposure then can trigger that inflammation, but I understand that it can also alter the proteins in the lung tissue.What sort of effect does that have? Why is that important?
Jill Poole: Well, that is by altering then the expression of the proteins that should not be expressed. Then that is kind of the key to autoimmunity is that the body should ignore it because it's a self-protein, but it's being displayed in probably a robust number and then the immune system starts reacting to itself. And autoimmunity is you have issues with your own proteins in your body that it reacts to and that causes inflammation.
Michael Lyon: Is it your hope that one day we might identify people who are at high risk before the disease actually develops?
Jill Poole: For sure. One of our big pushes is to try to find what we call biomarkers in the blood, it's easier to look at than in the lung, but there's also ways that we can identify the at-risk people so we could make interventions, whether it be therapeutic or get them out of the environments, and then we try to get so the environmental factors can be minimized. How complete is our understanding about how the immune system responds to these inhaled biohazards? We know a lot about what happens at high dose in the first 24 hours.What we know less about is what happens and how the body responds to it over time. And if it cleans it up or not cleans it up, what we're finding is these cells and proteins and mediators stick around for a lot longer than we'd like them to do and continually perpetuate the disease. And so trying to block them or get them removed has been a source of a lot of research.
Michael Lyon: Another major project, and I know your team is involved in looking at possible treatments for long-term damage and repair, but a major project is focused on finding ways to repair that lung damage that's caused by occupational exposures. Why has that been such a difficult problem to solve?
Jill Poole: It's been very difficult to solve because trying to understand the mechanisms of what's going on days, weeks after exposure is hard, and then reversing it. And the immune system is really kind of a delicate balance, and so trying to find the right strategies to intervene to prevent the progression of disease has been years in making, and making sure that it's safe and for how long we use this therapy and would that therapy itself have its own side effects, and so it's a balance.
Michael Lyon: You've mentioned biomarkers during our conversation, and I know also your team is searching for biomarkers that could identify the disease earlier. How could that make a difference for patients?
Jill Poole: Well, it'd be easy to give some blood and then have it processed and have a profile of your risk, and then based on which biomarkers are up, I mean we've had an explosion of medical therapies where we could target even those specific markers and decrease them or increase them if we needed to. Nebraska has very deep agricultural roots.
Michael Lyon: How important is it that research into this type of occupational health is happening right here at UNMC?
Jill Poole: Well, it's been a cornerstone of my career, so of course I think it's highly important to Nebraska and the United States. We have a lot of rural workers in the entire country, but particularly Nebraska, and at the University of Nebraska, we want to serve our state and help out the workers, and it's difficult with these farmers coming in and getting help. Sometimes they have to drive miles, and they're busy, and they're very productive, and they just want to be healthy and work hard.
Michael Lyon: And finally, what is the message you'd like listeners, especially those who work in agriculture or other high-exposure occupations, to take away from your research and this conversation?
Jill Poole: Well, I think they increasingly are. They need to be aware that they have risks in their environment and that simple things like putting on the N95 mask or the ventilation of the confinement facilities and putting on the mask and knowing when you're having the pesticides or the higher organic dust exposures, taking those precautions, and then it's really important to develop some baseline tests with your physician and not seeing your doctor. I mean, it's important to have these checkups and be tested.
I've been speaking today with Dr. Jill Poole, Chief, UNMC Division of Allergy and Immunology. This is Heartbeat. I'm Michael Lyon.