Good morning and welcome, everyone, to the webinar Toxic Relationships When the Liver Meets Industrial Chemicals. I am Lily Dara, chair of the Hepatotoxicity SIG, and we welcome you on behalf of our special interest group. Today's webinar is about toxic chemicals. There's a gross lack of understanding and awareness in hepatology and the liver research community regarding the role of environmental hepatotoxicants in this activity. We aim to discuss the effect of volatile organic compounds, vinyl chloride, PFAS metals, persistent organic pollutants, and emerging toxicants such as microplastics and pit burn emissions on the liver and their relationship to fibrosis, cancer, liver injury, and mast cell. All involved in content development have reported their financial interests, and the ASLD has reviewed and resolved any relevant conflicts. In order to receive continuing education credits, we ask that you complete the evaluation, which will include some self-assessment questions, which will be emailed to you in addition with instructions on how to complete this evaluation. You will have access to the recording, and you'll be able to receive your certificate. The recording will not be required for about a week. After that week, it will become part of the required piece of the educational material. The ASLD will not be offering mock points or mock credits for this activity. Thank you for participating in today's webinar, and we hope that you will find this information extremely helpful. I will now hand it over to Dr. James Leyendyk, the Vice Chair of the Hepatotoxicity SIG from Michigan State University, who will introduce the speakers and moderators. Hi, everyone. I'm delighted to introduce our two speakers and also our moderator today. I'll begin with Dr. Andres Duarte, who's a clinical investigator and a professor of medicine and surgery at the Northwestern Feinberg School of Medicine. He directs liver transplantation and the living liver donor for the Comprehensive Transplant Center at Northwestern Medicine, NIH-funded investigator with research interests in physical fitness and exercise training in cirrhosis, healthcare information technology, and beyond, including non-invasive liver disease assessment, clinical outcomes of transplantation, what have you. He has done a residency in internal medicine, fellowship in gastroenterology, subspecialty fellowships in clinical hepatology and transplant hepatology, has a master's degree and a PhD, as you note, an ideal speaker for today. We also have Dr. Juliana Beyer, who's an assistant professor at the University of Pittsburgh School of Medicine in the Department of Medicine, has a secondary appointment there in the School of Public Health. Her research focuses on the interaction between environmental toxicants and metabolic liver diseases. Her R01-funded research program on vinyl chloride has contributed hugely to our understanding of how environmental chemicals can modify liver disease risk, particularly in the context of steatotic liver disease. Quite frankly, her expertise is nationally recognized following the East Palestine train derailment, forgive me, where she provided insights on vinyl chloride's health effects in numerous media appearances, and she remains engaged in a funded effort focused on that community. She has a strong publication record, received President's Choice Awards from AASLD, and I want to selfishly note that she is on the presidential chain of the Society of Toxicology's Mechanisms Specialty Section, so has cross-society service, as would be anticipated based on her research focus. And finally, as our additional panel discussion leader at the end, we have Dr. Matt Cave, who's a professor of medicine at the University of Louisville, triple-boarded physician-scientist in internal medicine, gastroenterology, and transplant hepatology. Dr. Cave has an R35 merit award specifically focused on environmental liver disease, is ranked among the top 2% most cited researchers in his field, and as you would anticipate, is involved in a whole bunch of direction of the liver research effort at the University of Louisville. His focus on liver disease, including toxic and associated steatohepatitis, his work with vinyl chloride at Louisville's Rubber Town Chemical Manufacturing Complex, is well-known to many of us, and now to you, and he has a whole bunch of research on other environmental chemical and exposures related to liver disease. So with that, I'm going to pass it off to Andres to get us kicked off. Thanks. Thank you, James, and thank you, Lily, for the invitation. Thank you to the ASLD, and thank you, Julia, also for thinking of me to present a couple of cases. So, you know, Julia and I, every time that I have a case where I think there is stash, I end up texting or calling Julia, and we frequently end up calling and texting Matt. And I think the reflection that I want to give with these two cases is what any daily practice in hepatology gets, and how can we move this field forward, and how can we make this more achievable and attainable for any practicing clinician just to be able to properly diagnose stash, and perhaps even move forward a policy where we can prevent stash in the future. So if you give me the next one, please. So two cases, they're going to be very brief. The first one is this cryptogenic steatotic liver disease, and addressing occupational exposures. Next. So this is a 61-year-old female, no medical history, pretty healthy, BMI is 27. At some point, she was a little bit, had more adiposity than that, but nothing terrible. She was never obese. Her liver disease was identified because she felt a pelvic mass in 2023, ended up having something that supposedly was diverticulitis, had a CT scan, and the CT scan showed the mass, and then, oh, wait a second, your liver looks erotic. This is around February of 2023. She had had previous liver function tests that were perfectly normal. She had a liver biopsy. The results are there. You can see that there is no doubt this is a steatohepatitis. There's 70% fatty filtration. She has an NAS of 5 out of 8, and she already has cirrhosis, and otherwise, all stains were negative. No alcohol exposure. Next. So, from this February, when this was found, incidentally, she eventually developed lower extremity edema, ascites, later on in 2024, it was already responsive. She had varices. Many LR3 lesions, ended up having a biopsy. That's why she ended up having the biopsy of the liver as well. She has not developed any hepatic encephalopathy, although she has some features that perhaps could be considered minimal hepatic encephalopathy. She's now listed for liver transplantation at our institution. As you can see on the labs, you know, except for a positive ANA and an ASMA, there is a typo there, an AMA, which, by the way, I took them as false positives because AST, ALT, and ACFOS are perfectly normal. Everything else is completely negative. She doesn't have dyslipidemia. She doesn't have any prediabetes that we need to be concerned. And so, when we start talking about, hey, what do you used to do for a living? She explains to me that in the past, she worked for 24 years at a facility where she actually was the one who produced the vacuum machines and the water heaters for RVs. She was exposed to fumes. She was exposed to chemicals. She was a welder, so she will create these grids and drop them in these massive tanks. Not infrequently, her skin, her house will go completely into these chemicals, whatever they were. So, I had to do a lot of digging, a lot of Googling until I actually found something interesting, which is trichloroethane, which she was definitely exposed to. And she recognized that and actually was able to get that from some of the documents from her company. Next. So, regarding the math that she has, and I'm bringing this because desmodefibromatosis has not been associated to toxicants. However, leiomyosarcoma has. She does have this large mass with no other risk factors for its development, and actually that's what prompted everything to be diagnosed. Next. So, case number two is, is this only muscle? And here I'm trying to bring a little bit of consciousness, and you will hear more from Dr. Byer on this, that how do we address the alimentary exposures that our patients are getting as we are diagnosing a muscle. Next. So, also pretty brief, 36-year-old female. She's Hispanic. She is, she does have obesity. She's at her maximum weight right now. She was grade one. She had grade one obesity in the past. She has persistently elevated alkaline phosphatase within the range that I'm showing there. Very mild elevation of ALD and AST. She had a FibroScan, that's how she ended up with us. You can see the results there. She likely has some fibrosis, and definitely they have a stentosis based on the LSM and the cap. And then we do a liver biopsy where you can see that she has massive stentosis. She already has some fibrosis and an NAS of six out of eight with all other stains being negative. Next. She has not been able to lose weight. She has been trying throughout her life. She has otherwise all of the tests which are negative, including a PNPLA-3. She does have a little bit of this lipidemia, which will be the classical that we will see in somebody with metabolic syndrome. And her A1C, it's not even within what we will consider pre-diabetes, but she does have insulin resistance based on AHAMA. So she works on Amazon. She was a delivery, and she's not sedentary. She's actually very active, has kids, husband works as well. So she's really, really active, but no one cooks at home. So she eats whatever she can get on the road. She will go to a 7-Eleven and get whatever that goes in a single package, snack packs, fast food. She does not do soda because that's something that we were able to find or to eliminate during a previous visit to the clinic. Next. So here we go to a little bit of consciousness of where this is situated. If we go into the nomenclature that we're doing right now, we can see that toxic and associated hepatitis is just that little thing where it says miscellaneous after you rule out everything else. So it's not something that comes like to the front of our brain where we are addressing these patients with a statotic liver disease. And so we need to create awareness on how we, on this condition and how we approach it. Next. So more importantly, so do we have to start considering that some ALD also have a component on TASH, some muscle also have a component on TASH, just like we have the MET ALD. And I think this is something that we definitely have to start looking into and bring these just to our top differential diagnosis, especially in terms of the alimentary and environmental exposures so that we can better serve our patients. Next. And so when we think about how we practice from guidelines, you know, most basic clinicians will not have time to be as savvy as our panelists are here, and we will just go to guidelines. So when Julia and I started working together on some of my patients on this, and I have to read these guidelines, I have to say, this is from Isla, I have to say that I actually have more questions than answers. And even though they're very nicely written and they do bring the occupational exposure and they do bring some other hepatotoxins and things that you have to think about. For example, there is nothing on environmental exposure. There's nothing about food. There's nothing about ultra-processed food particularly. And so also, whenever I had some exposures, I end up having to just Google things because we don't have a source where we can actually identify a lot of these components, how people get exposed to this component, because the list that we have on the current guidelines is just so limited. So we will need to do a better job on that to serve our patients and our clinicians. And so here is the example of the patient that I found. So this patient was in trichloroethane, which by the way, it's basically a constant of trichloroethylene, which is in the guidelines. And as a matter of fact, the substance my patient was exposed to has been discontinued many years ago because of its known toxicity. So this clarification needs to be more attainable, accessible to us. We need to translate what occupations go with what chemicals and even organize better the data so we better can inform a policy, public policy. Next. And this goes especially on what we have to deal with ultra-processed food. And this is just a nice meta-analysis of 15 studies where you can see that the percentage of daily energy that is coming from ultra-processed food is over 50% in the USA and UK, the highest in the world. And just going down a figure that I put for you on the right, next, you can see that, for example, there will be endocrine disrupting chemicals that will be in many of these ultra-processed foods. You're going to hear about them from Dr. Byer in a minute. Next. And also advanced glycation end products that can also facilitate our patients getting diabetes, our patients getting lipotoxicity. So it wouldn't be surprising that somebody cannot lose weight when he's exposed to such a burden of ultra-processed food. Next. So to finalize, we need better guidelines that are more applicable. And we also need a better interface. Like for example, daily drug-induced liver injury, I think in the past it was so difficult to even deal with it. And now that we have a liver tox, it's just easy. So we need some way of creating an interface between the panelists and the experts that we have here and what the daily clinician is doing in the daily practice to better serve our patients and even create awareness and policy. Thank you. So we're now switching gears a little bit, and I am going to start with a personal story and then tell you a little bit about background and exposome, occupational hepatology, environmental hepatology mechanisms, examples of environmental hepatology research coming from my lab and others, and then intervention solutions and conclusions. So starting with my personal story, I am from Germany, and this came up recently in an interview I gave for NPR, where I was introduced as being from rural Germany, while I'm in fact from the outskirts of the biggest urban area in Germany, just right here, which is heavily So there's tons of cities, there's a lot of industry in that area, and a lot of coal mining. I'm from the city of Krefeld, which is, as I said, right on the outskirts of that, which technically doesn't belong to it, but it's right adjacent, and it's a major city of about 250,000 residents, and I grew up on the outskirts of it, in a neighborhood called Altgrundend. This is our neighborhood. It's a small neighborhood of about only 25 homes, including three farms, one, two, and three. And as you see, extensive farm country around. So we could see this red pin here is my childhood home. And as you can see from our yard, we could see all those fields. What always struck me that in this neighborhood, as I said, only about 25 homes, there were a lot of cancers related to the GI and kidney. So we had several pancreatic cancers, several stomach cancers, some liver cancers, and one or two kidney cancers. The yellow pins are homes with two cases. So this always struck me and it's always got me really interested in environmental chemicals. And so when this opportunity presented to me, you know, to pick up this project, I jumped on it just because of this, you know, personal story of mine. So now let me give you a little bit of background and talk a little bit about the exposome. So Andres did a really, really good job and thank you Andres for introducing all of this and also just alerting you all to the primary causes that we all so very well know. However, what my research and this talk focuses on a lot more after the introduction is about the risk modifiers. So the drivers of inter-individual risk, because as we know, not every patient or not, you know, everybody develops end-stage liver disease, even though they have primary causes and potential exposures. So one of the risk modifiers that we, that are really emerging these days is the exposome. And so for those of you that don't, aren't too familiar with the term exposome, that really means the entirety of exposures that an individual has. So this starts with the ecosystems. It also includes lifestyle, psychosocial factors. And then first and foremost in this talk, of course, the physical and chemical. So all these pollutants that we are exposed to. On the right hand side is a really nice scheme of the liver exposome in a recent review from Baruchi et al. So what are the sources of environmental pollutants? Of course, food production, food production, Andres already alluded to that. Then of course, probably the major one is industrial activity, personal and home care. So we are all exposed to anything like basically at all times. And then last but not least, medical care, including medical products, but also equipment. And on the right hand side, you see the chemicals. And it's important to note here that these are not just chemicals. These are just groups of chemicals. So each of those, and you see that they are repeating themselves between the sources. But some of these groups of chemicals include hundreds, if not even thousands of different chemicals. For example, PCBs, there's over 200 congeners. And then for PFAS, at this point, we have identified up to 12,000 of those. So we're looking at a huge, like a myriad of hepatotoxicants. And as I said, hepatotoxicants. So these are all damaging the liver. So a little bit of a history about pollution and liver complications. So I don't want to say it started with it, but one of the most prominent historic events is the turkey X disease in 1960, caused in turkeys by aflatoxin exposure and causing hepatic necrosis. And so at this point, I just want to point out really quickly, we are talking mainly about toxicants here. So toxins are natural products. Toxicants are manmade. But even if natural products do this, manmade toxicants, very similar, if not even more potent toxicity. So in 1974, a cluster of hepatic angiosarcoma diagnosis was found in workers in a rubber plant in Louisville, Kentucky. And really quickly, it became clear that this exposure or that these cases were due to high occupational exposure to vinyl chloride. Then already in 1991, people were talking about endocrine disrupting chemicals, which at the time, they were also including metabolism affecting chemicals. And we just moved away from that a little later. Then in 2005, even though that the exposome is really a recent emerging topic that we are focusing on, it was already described in 2005. And then in 2006, we were talking about obesogens. And a lot of you are probably familiar with just chemicals and drugs that are contributing to obesity. And in 2010, TASH came on the radar, and this was coined by Dr. Matt Cave, who is the moderator of this today. And I'm actually going to talk about that in a couple of slides. So I'm going to leave it here. And then in 2016, we were, or metabolism disrupting chemicals were named. And that's kind of taking the endocrine disrupting chemicals, which are really interfering with hormone action away from metabolism disrupting chemicals. And obesogens, that was named in 2006, is a subsection of metabolism disrupting chemicals, but not all metabolism disrupting chemicals are obesogens. And then in 2019, ESL came out with practice guidelines on occupational liver disease, which we probably can all agree needs to be further developed. So here are some key concepts in environmental hepatology. The liver clearly is the number one toxic target organ for toxic chemicals, clearly due to its role in xenobiotic metabolism. And on the right, you see ATSDR substance priority list of chemicals. And nine out of the top 10, there's currently 275, I believe, on there, on this list, nine out of the top 10 pollutants are associated with mazaldi. Then we have to talk about environmental justice. There is a lot of disparities and exposures. So age, race, and ethnicity, sex, and geography make a difference in this. And then there's also differentials in the response to exposure. Also race and ethnicity, sex, diet, windows of susceptibility, I'll talk about that in a minute. And then I'll talk about gene environmental interactions as well. And one of the major things that's like a red line throughout this talk is that environmental chemicals can be risk factors by themselves, but they can also be risk modifiers contributing to the development, severity, and complications of mazaldi. So let's talk about occupational hepatology first, and just one slide. So as I said, vinyl chloride was historically associated with hemangiosarcoma in a group of workers highly exposed to vinyl chloride. It has also been associated with HTC and fibrosis in the past. But then in 2010, Matt Cave got ahold of some of those biopsies from a repository that was formed in the 1970s and looked at 25 lean, non-drinking, highly exposed vinyl chloride workers and saw a significant incidence in steatosis, steatohepatitis, and fibrosis in these workers. Follow-up work showed that this was associated also with necrosis, antioxidant depletion, insulin resistant, and an increase in adipocytokines. And most importantly, the transaminases were normal, which is why this wasn't, even though pathologists in the 1970s have seen this, but it wasn't described as a disease until 2010. And keep in mind, this was, as I said, the 70s. We haven't, you know, mazaldi wasn't described, nafaldi at the time, until 1980. So this was occupational, but what about environmental exposures? And this is important to distinguish between occupational exposure, of course, describes a select group of individuals with high exposures. However, environmental exposures may be much less. And also important in the entire world, really, but especially in the US, obesity, diabetes, mazaldi, and mazaldi transplants are dramatically increasing. And one of the major questions now is, is the role of environmental metabolism and endocrine disrupting chemicals underestimated? How much are these, you know, partially these obesogens are actually contributing to that outside of the lack of exercise and overnutrition? And then also importantly, can lower exposures that are currently considered safe or just generally lower exposures influence and enhance underlying liver disease? So that brings us to environmental hepatology. And I have a few case or a few studies pointed out here. So these are environmental exposures causing direct liver damage. So it has been shown that PCBs, lead, mercury, and insecticides were associated with unexplained ALT increases in adult NHANES participants. A similar story happened with PFAS, also associated with higher risk of fatty liver disease. And then since, and more recent, exposome-wide association studies have been described, and these bring us forward a lot more with information because they consider multiple exposures as at once, because as you can imagine, nobody is exposed to just one or two chemicals at a, at a single time. So also these XWAS studies are minimized by us by utilizing existing data sets and validated questionnaires. And importantly, a recent study by Lisa Chatzi, she's in the audience and may actually potentially be able to answer some questions at the end of this, showed in children that prenatal PFAS exposures were associated with higher risk for liver injury in children. And a very interesting and scary thought. So I talked about this a couple of times already, risk modifiers in liver damage, and this is where my research mainly focuses. We are interested in what, you know, about risk modifiers at lower exposures, mainly considered safe exposures will do to preexisting liver disease and how they will enhance any given state, stage of liver disease. These exposures often happen in underserved areas. So areas of low income, lower socioeconomic status, and as we all are aware that these underserved areas also often have a higher incidence of obesity and underlying mass OD. Basically creating vicious cycles for these residents or workers. So here are some cases on liver disease severity and chemical exposures, talking about enhanced underlying liver damage. There was a study showing that an astonishingly high of 95.3% of NHANES participants with an enhanced, advanced liver fibrosis had PVC exposure in the highest quartile. This is the figure on the right. Similar studies showed that PFAS were associated with the severity of steatosis, steatohepatitis, and fibrosis in adults with mass OD. And then some metabolome wide association studies compared individuals with PFAS exposures showing changes or enrichment and metabolic pathways, specifically bile acids and lipids. So what about mass OD complications and pollution? For example, HCC, and I was talking about aflatoxin already earlier in the talk, aflatoxins have long been shown to be associated with HCC. However, many pollutants are actually associated with, well, many pollutants that are associated with mass OD are actually shown to be human carcinogens. And this includes all the chemicals that are already talked about, PFAS, PCBs, vinyl chloride, but also others. However, to this date, we have just a limited amount of information and data on pollutants, and this definitely needs to be researched more. Other mass OD complications are, for example, cardiovascular events. Dioxins have been associated with increased TMAO, which is a gut microbiota derived metabolite that has been linked to cardiovascular or coronary syndrome or cardiovascular disease risk. And then similarly, PFAS has been shown to be associated or have been shown to be associated with acute coronary syndrome and mass OD patients. So bring it back to occupational versus environmental. So as I said, occupational exposure is just a select group of patients with high exposures. However, environmental exposures and direct liver damage already includes more patients. But last but not least, environmental exposures and enhanced liver disease makes up for a much larger group because, as we know, the obesity rate in the country currently is at over 30%. So making potential of enhanced liver disease by environmental exposure is much more likely. So from here, let's move into mechanisms. This is out of a review that Matt and I just wrote. It was just accepted and is in press currently in a seminar on liver disease, talking about mechanisms and key concepts and how reverse translational approaches explained some of the things that we see in humans. And as you see, there is a myriad of mechanisms that are involved, and I will talk about a few of them in the next few slides. So for that, I'm going to give a few examples of environmental hepatology research from my lab and some others. One of the things that we wanted to do, this was early work. We are working on this since now almost 10 years, trying to show how vinyl chloride at concentrations that are currently considered safe by OSHA standards can enhance pre-existing liver disease. And for that, we exposed mice to vinyl chloride concentrations under the current OSHA limit, which is 1 ppm for eight hours of a workday. And we are doing 0.85 ppm for six hours for five days a week. And feed them Western-style diets, so high in fat and carbohydrates at the same time. What we did see is gross pathologic changes or we did not see any gross pathologic changes with vinyl chloride in the control diet. However, liver damage was enhanced with vinyl chloride in the Western diet. What we also see is an increase in fat and a decrease in glycogen stores suggesting metabolic dysregulation. That could potentially be due to dysregulation of the mitochondria. As you can see here, the mitochondria and the vinyl chloride group were swollen. This is independent of diet. As you can see in the graph, vinyl chloride even does this in the control group. This goes hand in hand with functional changes. This is oxygen consumption rate in mitochondria. This goes down with vinyl chloride independent of diet. We were also interested if these kinds of concentrations or exposures can cause tumor formation. We transiently gave vinyl chloride for 12 weeks as we did in the last slide, but then we let the mice sit and fed them a Western diet or control diet for another nine months and sacrifice a year later. This transient vinyl chloride exposure caused HCC in 80% of the cases. In 20% of the cases, we had some tumors that we believe are probably angiosarcoma, just similar to what we see in the patients from Robertown in Kentucky. We have another model which is a lot shorter. It's called an inside-out model where we use a sleeping beauty transposon and hydrodynamic tail vein injection to hepatocyte-specific overexpressed oncogenes. We were able to accelerate tumor formation dramatically with vinyl chloride, showing tumors all over the liver at seven weeks. Just to recap this a little bit, we did, of course, a lot more work on this. This is some of the things that we saw. In the Western diet and vinyl chloride interaction, we see a lot of injury and cell death and inflammation, autophagy, dysregulation. We see a lot of metabolic dyshomeostasis, including the metabolic dysregulation that I just talked about, but also ER stress, mitochondrial damage, so on and so forth. We see an increase in tumor regenesis. But what about other... My research mainly focuses on the Western diet interaction, so diet lifestyle choices, but what about other underlying diseases or factors? We recently published a review showing that there is lots of publications out there showing an interaction of environmental toxicants in several liver diseases, biliary atresia, PBC, PSC, not so much, but autoimmune hepatitis, and so on and so forth. Yes, there are studies out there, and they definitely deserve more attention. So do other environmental chemicals, of course. There's plenty of them. We talked about a few of them, and I will talk about a few more in the upcoming slides. But then, of course, we also can't forget about viral infections, pregnancy, childhood exposure. These are all understudied aspects of environmental hepatology. So here are some emerging and understudied exposures. Microplastics is a big thing that everybody's interested in, but also particulate matter and mixtures. As I was saying in one of the previous slides, none of us are exposed to one chemical at a time. So especially, and this becomes especially important for people that are like the military, military exposures, wildfires are dramatic in the US. WUIs, which is wildland urban interface fires. Think about the wildfires plus all the urban chemicals that are being burned. And then, of course, chemical incidents like what Jim was saying at the beginning, the train derailments, but also other disasters like oil spills, leaks, floods, and so on and so forth. So let's focus on the first two for now. Microplastics, the human hepatotoxicity data on microplastics is actually very limited. I really couldn't find much at all. There is plenty of preclinical studies out there showing that microplastics are associated with liver injury, inflammation, oxidative stress, and diabetes, but this has to be translated. Then particulate matter. There's plenty of studies out there on that, especially coming from China, which has a major issue on, a well-known issue on pollution, air pollution. So there are several studies and these three studies that I'm showing here are all only from 2025, showing that PM2 significantly associated with liver dysfunction, chronic liver disease, liver cancer, and colorectal cancer. And it has also additive and synergistic effects on the risks of cirrhosis, kidney disease, mass LD patients. And then one of the things that I found interesting, that becomes interesting in one of the next slides is that in developing countries, the risk level of mass LD due to PM2.5 is slightly higher than in developed countries, probably due to some dust. Mixers is what I'm going to talk about next, military exposures and some others, and then chemical incidences. So one of the projects that I'm involved in right now is the Rust Resilience Center. This is a Pittsburgh-based center at the University of Pittsburgh. We call it R2R, Rust Resilience. And this involves the most prominent toxicants in the Pittsburgh and Southwestern Pennsylvania area, including heavy metals, arsenic, cadmium, and lead. And then also PFAS are hugely prominent in the Pittsburgh area. On the left, you see a table that a member of our R2R center created. This is a mixing ratio that really reflects what we see here in Pittsburgh. And we have some funding from the university to establish this a little more. What we want to do is look at maternal exposure to metals and PFAS, plus and minus a Western diet, and then look at the mothers and the offspring down the road. This is a collaboration. We have some epidata, and we have some preclinical studies that we're doing. This is based on the MAMI database, which is the McGee-Obstetric, Maternal, and Infant Database and Biobank. So as I said, it's a Pittsburgh-specific biobank. And so we recently, we just finished this, started a pilot project on adults only, no offspring, looking at this mixing ratio of these chemicals in 1x, so this mixing ratio, and 100x in adult mice. This is what we saw. Body weights, of course, increased with Western diet, but there was no difference between the Western diet and exposures. And similarly, and interestingly, the transaminases even at the 100x dose. However, when we looked at the pathology, we saw there was clearly some inflammation, even with the 1x R to R mixing ratio chemicals, and especially at the 100x. And what you can also see is that the pattern of lipid accumulation changed with the 100x. So definitely linking us to, or, you know, pointing us into a future direction, looking at lipotoxicity potentially. The next thing I want to talk about is military burn pits. Since 9-11, over 5 million US service members have been deployed to Southwest Asia, and over 2 million have been deployed to Southwest Asia for over 30 days. The three main pollutant types that they are exposed to are geologic dust, burn pit smoke, and this is where the, what I was saying earlier in the particulate matter, where I was saying that it may be, that it's slightly higher in developing country, in developing countries. Burn pit smoke, of course, huge situation, and then heavy metal condensates. The symptoms from that, and so just to, for those of you that are not aware of burn pits, so in the camps, they have to get rid of their daily waste by burning it. This includes plastic, wood, medical supplies, and since all of this doesn't burn so well, they accelerate it with jet fuel. These people are exposed to heavy smoke in that area, and the symptoms of that are often referred to as chronic multi-symptom illness, CMI, which is inflammation, fatigue, pains, impaired cognition, GI disorders, respiratory problems, and skin rashes. There are some cohort studies coming out, but these are mainly focusing on respiratory and cardiovascular issues. Nothing really is known about the liver. However, we have a collaborator that is currently modeling this in rats. What they are doing is for two consecutive, so only two consecutive days of exposure for two hours on the first day, four hours on the second day, burning in these little ovens pellets of wood, rubber, and plastic, and also accelerated with jet fuel. I was able to harvest the livers from that. This is what they looked like. The liver to body weight ratios were normal, and transaminases were slightly elevated, but you can see that the livers had this pattern. I was immediately thinking, oh, cytochrome P450 activation. However, our pathologist actually said something different later, and I'll get to that in the next slide. Here you see the pathology. We do see inflammation, and we see some chicken wire fibrosis. Keep in mind, these are only a total of six hours exposed to these burn pit smokes. What our pathologist said is that it looks like ground glass hepatocytes to her. What she saw, we did some TEM, and you can see it here really well. These are two hepatocytes. This is one, and here's the other. There are some inclusions, and we don't know. This has been shown for HBV, but this clearly isn't HBV, so we don't know yet what this means. Ground glass hepatocytes, we see an increase in collagen. This is collagen right here. We see lots of fragmented smooth endoplasmic reticulum, which is what you see here, and then a lot of dilated rough ER. This is the rough ER. Also here, you can see that it's dilated. Then we see a capillarized and dysfunctional sinusoidal endothelium. It lost the fenestrate, and it got a lot thinner. We see plenty of autophagosomes, but also lipid droplets and mitochondria contain this electron-dense material, which you see here. These are the lipid droplets. We believe these must be burn pit emission residues. You can see it right here. It's in the mitochondria, and it's just all over the place. It's really kind of scary what we see in these livers, so clearly there must be some sort of liver phenotype in burn pits or burn pit-exposed humans. Then last but not least, I want to talk a little bit about our East Palestine Environmental Exposure Health Data and Biospecimen Bank. This is a grant, R21, that we got from NIHS to follow the residents of East Palestine after the train derailment. What spilled there, for those of you that don't know, was vinyl chloride into the ground, and then they also tried to... This spilled from a couple of cars, and then they tried to control burn the other cars so it wouldn't explode. That set off a whole slew of other chemicals that were released into the area. East Palestine is about 50 miles northwest of Pittsburgh, so really kind of close to us. What we are looking into is monitoring homes, indoor air and water, looking for VOCs and PFAS. We are looking at soil and sediment all around the entire area, and then biospecimens and psychosocial data. We'll collect plasma, serum, genomic data, urine, and have psychosocial stress questionnaires. We don't have any data on that yet, but we are heavily collecting right now. And our endpoints are exposed residents with no pre-existing liver disease. Do they have increased markers? Will those with higher markers have higher levels of exposure? Then, in the exposed residents with a history of liver disease, is there a more rapid progression of CLD over time? Then, will those markers correlate with the development of a CLD outcome over time? Then, we are also looking, as I said, into psychosocial stress. Will that further negatively impact the health outcomes? Will this also result in an increased organismal inflammation and enhanced organ damage in these residents? Next and last couple of slides, intervention solutions and conclusions. What we need to look into is to reduce exposures. We can mitigate exposures during early windows of susceptibility, but also need to do it during the lifespan. Using an organic diet will decrease pesticide and oxidative stress biomarkers. Then, there are some studies showing that increased clearance, GI and renal, can get rid of these environmental chemicals faster out of the body. Then, we really need to understand the sources of the human exposure. We need to inform physicians, nurses, associates, and patients via websites, working groups, apps, and guidelines. Then, as Andres was stressing earlier, we really need to work on the clinical practice guidelines, or at least some guidance for physicians. Can those chemical exposures be folded into that? Importantly, since this is a DILI group, can we modify WCAM to include environmental chemicals? Last but not least, conclusions. Environmental chemicals are risk factors and risk modifiers, especially. There are some barriers of implementation in environmental health science and clinical hepatology practice, which need to be addressed. We need to incorporate the exposome and a future precision medicine approach in liver health. Of course, we talked about this several times. We need longitudinal data on all of these aspects that we talked about. And last but not least, increase awareness and guidance for anybody involved treating those patients. The picture on the right is a picture of Becky Wells at ASLD 2023, where she was pointing out some of our work, some of Dr. Cave's work, and some of my work at the liver meeting, which is hugely important to us because this increases awareness. At this point, I want to especially thank ASLD for giving us the platform to talk about it and really try to figure out these issues. Of course, thank my lab, thank my collaborators. Here's a picture of Matt, Andres, and I at DDW, I believe, in 2022. We've been talking about this already for a long time. And thank you. What a fantastic talk. Thank you so much. I think, Dr. Cave, I know we started late, so I think we can go over a little bit. Great, thank you. I'm having a little trouble getting my video turned back on, but regardless, we can start with some discussion. Andres, you gave a great lead-off and talked about some barriers to clinical implementation, which is what Juliana finished up with. I'd love to hear more from the panel about what these barriers are. The field has been driven, I think, largely by the mechanistic toxicologist and great environmental epidemiology. And now I'm really pleased to see so many hepatologists gaining increased interest in this, but what are the next steps? How do we move some of these concepts forward into clinical care of patients? Yeah, I, you know, I, the toxicant, the TASH, or Toxicant Associated Stereohepatitis, it, I actually want to say it was Julia who introduced me to that, to that term. And it was maybe no more than five, six years ago. So we really need, and this is why I also wanted to bring this, this picture of the nomenclature, we really have to increase awareness. And I think this is much more frequent that, than we think, either because of occupational, which we tend not to ask, you know, when, when we do our history of physical, we ask, what are you doing that? Oh, I don't work, retired. Okay. And, you know, many people don't even go, going to see what is it that these people did in the past, or they will look at that last job without really getting some more information. So I think that's something that is lost within our history and physical. So for the clinicians to suspect these cases, we have to bring the awareness, we have to bring TASH to, you know, the, the front end of the, of the nomenclature, not to the miscellaneous. So, so when we see a patient with stereohepatitis, we think about this. Really good point. You know, it's kind of reminds me of the days when it took people in our field, in the Dilley field, so long to get it across to the general hepatology community that you need to ask about herbal and dietary supplements, over-the-counter meds, when you're dealing with these abnormal liver enzymes. And now I feel like it's picked up a lot. I think 80, 90%, when, even when the residents and fellows present to me, they're asking about herbal and dietary supplements, right? So we kind of have to have a whole campaign raising awareness, and that would be the best step. Great. Jim, do you have any comments as a SOT president? You know, how can the toxicologists, how can we get them working with the epidemiologists and the clinicians to advance this field forward? I, you know, this is all communication from my perspective, you know, getting everybody on the same page of this is a genuine problem because you have strong mechanistic toxicology, as you note, I mean, represented here on, on this talk and beyond, focused on this issue and then getting us in the room with hepatologists and, and quite frankly, just physician scientists in general, you know, in a, in a lot of cases, we'll have the toxicology community seeking out clinical expertise to inform on the, you know, the experimental setting that they're using. And, and I would love to see things go in the opposite direction. You know, we have so many challenging diseases to treat. And here we talk about one where I would love it. If hepatologists were getting on the phone, actively recruiting, you know, toxicologists to be a part of the team, you know, and, and yeah, as, as, as you know, definitely a plug, if we can get, you know, ASLD, SOT, other societies engaged in collective programming, just to build awareness, I think that would be great. So that's my two cents. And I would love to hear from our speakers today, their thoughts on that. I absolutely agree with that. I mean, it has been, and no criticism, this is just the way it has, it has been a struggle to get our research shown and, you know, gather interest from people at ASLD, because it's just not a subject that we talk about. And so, as Jim said, we really, really need to increase the communication on that. Well, the good news is your incoming SIG president is a toxicologist, because I'm stepping down this year, and I think Jim has plans for TLM 2026. And maybe this could be a great thing that we can discuss offline about focusing the seminar in 2026 on toxicology in, you know, toxicants and liver disease. Great. So please submit questions from the audience. If you have any, Jim's going to monitor for those coming in. So while Jim does that, let me ask just a few more questions. And Jim, please, when you get some questions coming in, please feel free to start with those for the sake of time. So Ileana, that was an excellent presentation, and I think you really did a good job of meeting all the three learning objectives that you were assigned. One thing that really struck me, and I guess Andres, you kind of started off with this, with food contaminants and diet. And of course, we heard some things about water and things along the way as well. It seems kind of intuitive that foods we eat and water we drink, you know, that'll go to the portal vein and the liver and cause problems. But then we also heard a lot about inhalational exposures, you know, starting really with your patient, Andres, that had the trichloroethane exposures, and then down to the vinyl chloride plants where they had inhalational exposures. But then finishing up with, I thought, what was really interesting and compelling were the animal models of the burn pit exposures. And so, you know, we have one panelist from Southern California and some other people, I think, joining us in the audience from Southern California and Western United States. But that immediately made me worry about wildfires. And so, are there any data, you know, so can we extend, you know, what we've learned from the plants to environmental health? By analogy, can we extend what we're learning from military and veterans health and burn pits into epidemiology of liver disease in civilian populations impacted by wildfires? So any comments about that? The expert is Juliana, but I'll tell you that we are all very worried about the foam, the firefighting foam that was used. And I think those contain PFAS, right, Juliana? I think, I don't know if- They do, they do. But I don't think, so yes, that's a huge problem, but just the wildfires, and as I said, the WUI, the wildland-urban interface is, I think, also a huge component of that. Yeah, the whole city was exposed to the smoke, not just, you know what I mean? It was for days, yeah. And how do we even conduct that type of research? You know, when the city is burning down and it's like everyone's in crisis mode, you know, how is it even possible to even think about research and to begin to conduct that during the middle of a disaster? Any thoughts? It's hard, and also we don't, the effect may not be immediate, right? So it may take years for this to show up. So it's very complicated. I think we need a collaboration between environmental toxicologists and epidemiologists and just build longitudinal cohorts to follow. Great. You know, we heard a lot about steatohepatitis and steatotic liver disease, some about various liver cancers, and relatively less about other liver conditions. Lily, I know you have expertise on autoimmune hepatitis and cholestatic liver disease, and I was wondering if you had any comments as the panel as well, you know, what at the current time appears to be the role, if any, of environmental exposures and autoimmune and cholestatic liver diseases? Yeah, it's very interesting because I think there's a really good amount of data in general with autoimmune diseases, such as lupus, rheumatoid arthritis, and environmental exposures, at least associations, right? Causality is hard to prove, but association has been shown. For example, the classic is that, you know, the UK studies with PPC occurring in areas where there was historically a lot of coal mining, and there's suggestion that increased cadmium levels may contribute to cholestatic liver disease. There's other data with obviously with autoimmune hepatitis, biotic exposure, and nobody really knows if there's like a direct causal relationship, but definitely for both autoimmune hepatitis and PPC, there has been well-described links, and you guys are more familiar with these, but cadmium is bad for you. Great. Likewise, Andres, are there any data that you're aware of in liver transplantation? So, do exposures impact acute cellular rejection, you know, recurrence of the underlying, you know, original liver disease indication for transplantation, primary non-function, anything of that nature? That is a great thought, and as a matter of fact, I do not. What I do believe where we need to focus some of our attention is on the recurrence of measles in patients or the novel measles in patients that have post-transplant, because it seems like in the literature, we have disregarded this, but the truth is that when you actually look, for example, the study in France that did the yearly biopsies for five years on these people, they actually found a recurrence of 70%. And so, definitely one in three patients will have measles after transplant. And since most of these patients are no longer working, and you could even assume that the exposome kind of has been rewinded because there is a new liver, I wonder how much of this is just our diet, and what do we need to do for ultra-processed diet to actually improve our patients' outcomes, including post-transplant, as you are asking me, Matt? Great. So, you know, there have been cases of, you know, transplanting livers with underlying genetic condition, hypercoagulable state, you know, into someone, and, you know, by analogy, PFAS accumulate in liver. So, some of the livers we put in people have higher PFAS levels than others, and, you know, what kind of role that, if any, that has, I think, you know, remains to be seen. Jim, do we have any questions coming in? There are no questions coming in, but if we still have time, I would like to ask one of Dr. Byer real quick. And so, I guess it's the comment and question, and that is, you know, we talk about how complicated it is to get at the exposome, and you, you know, the graphics illustrated that, right, in people, but I guess, you know, there's comply, and I know you have collaborative studies, and you're doing this. How difficult is it to get the exposures to be realistic in the animal models, in particular, to, like, the complex mixtures and some of the exposures that have been brought up this far? I imagine there's engineering challenges for that, and how do you, how do you begin to get started on that one? Yes, it is, it is complicated. So, the best job we can do is go off what we see, actually, in humans, and go off of that. We, in the Rasta Resilience Center, we have some, and, I mean, we are a group of engineers and epis, epi people, and just a whole bunch of people working together, and they are the ones that took the MAMI database and, and based it also on NHANES, compared it to that, to create our R-to-R mixture, to make it specific for Pittsburgh. Of course, there's always those toxicologists that look at animal metabolism coming in and talk about how animal metabolism is different, but we have to start somewhere, right? And technically, mice have a faster metabolism, so using the concentrations that we use for humans, if it has an effect in mice, should have an effect in, but yeah, I'm not even going there, because it's gonna ask, and it's gonna bring up a whole bunch of other questions. So, yes, and then similar with the burn pin, we just went off, or they, this is Tim Nerkowitz at West Virginia University, they would just went off of what they see, you know, that is actually relevant to deploy Americans. No, I have to say the, the mouse models are just so clever, and so innovative, and so unique. It got me very excited when you were describing to me how you're doing this, and how you're modeling that, and this is, like you said, OSHA acceptable levels, right? And just kudos, it's just beautiful work. Thank you. Yeah, I'd like to add to that, that there are important species differences. So many of these environmental pollutants will directly or indirectly interact with hepatic nuclear receptors, and in many cases, there's a difference between mat and, or sorry, rat and mouse and human nuclear receptors, such as aryl hydrocarb, or related receptors like aryl hydrocarbon receptors, PPAR alpha, and related to that, and I was very impressed by Juliana's slide that showed all the different mechanisms. And so, if you think broadly of steatotic liver disease, you know, there's many different types of insults, whether it's metabolic syndrome, ALD, met ALD, that lead to the same pathologic phenotype, potentially even enhanced by the environmental exposures, but the mechanisms appear different in many cases. And some of these mechanisms involve signaling pathways that are involved in current muscle therapy, you know, so Juliana mentioned endocrine-disrupting chemicals, many disrupt thyroid signaling. Others, as she alluded to, will impact the microbiome and bile acids, you know, bringing into question varanusoid X receptor-targeted therapies, or PPARs, which are another target for steatotic liver disease. And so, one question I have for the panel is, do you think that, given that information, that it's possible that exposures can modify the response to therapy for current and future therapies for liver disease in general? Yeah, absolutely. I think that's a very astute observation, and I think your I think it's a lot more complicated, but it's true. I mean, we know that there's so many ways, not just by affecting the transcription factors or by, you know, by epigenetics, right? So, it's something that we are not studying enough, and I was, as you guys were talking about this, I was wondering if there should be a collaboration between you guys, Juliana, and specifically what you study, and the NASH CRN, right? They're biobanking all these people's CRM. Is there a way that we can actually, over time, look at their exposures and see who has been exposed to what? And then you have their geography, because there's multiple centers across the country, and I think you can get some very insightful data. Yeah, we're actually doing something similar on a very small scale right now. So, we just pulled southwestern Pennsylvania volatile organic compound data in the area, and we want to use UPMC data to get, you know, hot spots of liver disease. So, hopefully. The reason that I say NASH CRN is because these patients have been very well phenotyped. Everybody has biopsy, everybody has biological samples collected, and they've been longitudinally followed. So, you may be able to tease out a little bit more, because Matt also alluded to the fact that humans are different from mice, right? You may be able to tease out more if you can get that collaboration going. Yeah, that's actually really important, because of the nature of these studies, there are no, I mean, aside from occupational cohorts, we don't have any cohorts. And so, yes, absolutely important. And I'm actually, I'm going to echo that, because if, you know, as a clinician, we see how patients with presumable mast cell, right? They just do incredibly better once they change their diet, eliminating ultra-processed foods. So, if you, apart from this form of environmental, you start thinking into occupational toxicants. I mean, I think we need to better phenotype what is the type of substances that we identify, and the type of substances that we need to bring to policy regulation to just be eliminated from our food industry. So, we've recently measured the exposome in the CRN, and we're in the process of data analysis from the, we use samples from the Flint study, and the informatics is very, very challenging for this with, you know, approximately 100,000 data points per subject from exposures and metabolomics. Thank you for that, Matt. Is that like APLC? It's GC and LC-MS. Yeah, that would give you a lot of data. Are you ready to wrap up? We're probably getting short on time. I don't know if you'd like to give any closing remarks or Jim? Jim, go for it. Oh, no, I'm going to pass the ball to you for closing remarks. This was fun for me. That's all I would say. Learned a lot. Yeah, I learned a lot. I think this is going to be a very popular webinar. It is going to be on LiverLearn, and you will get an email with questions. Once you answer them, you'll get your certificate and your continuing education credits. We invite you to, into this field, we need more researchers and more people interested, and stay tuned. I think there's more coming from the Hepatotoxicity SIG on this very important issue. Thank you to the presenters and the panelists. Thank you all. Thank you. Thank you. Bye, everyone.

toxic relationships

liver health

environmental toxicants

hepatology

volatile organic compounds

vinyl chloride

PFAS metals

microplastics

liver disease

exposome

multidisciplinary approaches