Continuum Audio August 2024 Autoimmune Neurology Issue With Dr. Eoin Flanagan
In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Eoin P. Flanagan, MBBCh, FAAN who served as the guest editor of the Continuum® August 2024 Autoimmune Neurology issue. They provide a preview of the issue, which publishes on August 1, 2024.
Dr. Jones is the editor-in-chief of Continuum: Lifelong Learning in Neurology® and is a professor of neurology at Mayo Clinic in Rochester, Minnesota.
Dr. Flanagan is a professor of neurology at Mayo Clinic in Rochester, Minnesota.
Additional Resources
Continuum website: ContinuumJournal.com
Subscribe to Continuum: shop.lww.com/Continuum
More about the American Academy of Neurology: aan.com
Social Media
Host: @LyellJ
Guest: @EoinFlanagan14
Transcript
Full episode transcript available here
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum, the premier topic-based neurology clinical review and CME journal from the American Academy of Neurology. Thank you for joining us on Continuum Audio, a companion podcast to the journal. Continuum Audio features conversations with the guest editors and authors of Continuum, who are the leading experts in their fields. Subscribers to the Continuum journal have access to exclusive audio content not featured on the podcast. If you're not already a subscriber, we encourage you to become one. For more information, please visit the link in the show notes.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today, I'm interviewing Dr Eoin Flanagan, who recently served as Continuum’s guest editor for our latest issue on autoimmune neurology. Dr Flanagan is a neurologist at Mayo Clinic in Rochester, Minnesota, where he's a professor of neurology. Eoin, why don't you introduce yourself to our listeners?
Dr Flanagan: Yeah, it's a great pleasure to be here today. I'm a neurologist. I'm originally from Ireland – I did my medical school training over there, and then came over to the Mayo Clinic to train in neurology and in neuroimmunology. And delighted to be able to edit this exciting issue of autoimmune neurology of Continuum. I think, um, it's a really fascinating area that's moving very quickly, and I'm hoping that we can educate listeners to be able to feel comfortable when they come to see these patients and to realize how much of a growing specialty it is and how we're getting treatments, and we can really help these patients.
Dr Jones: Yeah, it's a pretty exciting area. And, so, not only are you the Guest Editor for our latest issue of Continuum, this is the first-ever Continuum issue dedicated to autoimmune neurology, so I want to thank you for taking it on. This is something that our readers have been asking for for many years. I hope the topic wasn't too daunting.
Dr Flanagan: No, absolutely, it's a pleasure to be able to do it, and it's just great when you read all the articles to kind of feel where the field is going and how much of a benefit we can now make for our patients. So, that's been a real joy to do.
Dr Jones: Well, congratulations, and it's a magnificent issue. You have a lot to be proud of putting this group of authors together. So, for a few of our issues now, we've had the opportunity on the Continuum Audio podcast to interview the Guest Editor, which is really fun for me. I have to confess it's really a joy to talk to someone who is up to the minute not only in their narrow area of expertise at the article level, but, really, across the entire breadth of the subspecialty. And so, you've had an opportunity to delve into all relevant topics in autoimmune neurology. When you look at the issue as a whole, or the field as a whole, what do you think the biggest debate or controversy in the world of autoimmune neurology is right now?
Dr Flanagan: Yeah, I think there's some changes happening. You know, initially, people used to recognize a disease called Hashimoto’s encephalitis, where patients would have a presentation of encephalitis in the setting of thyroid antibodies. And what we're now realizing is that many of these patients actually have antibodies to neural-specific targets, because we know that the antibodies that target the thyroid don't really impact the brain. And what we're now realizing is that there's many antibodies out there that bind to different receptors in the brain (the NMDA receptor, for example, AMPA receptor), so we're really trying to refine the field towards these different antibody-associated disorders - and each different disorder may behave very differently. A patient with NMDA receptor encephalitis, for example, may be in the ICU, in hospital, may take them six, nine months to recover. On the other hand, a patient with LGI1-antibody encephalitis may get five days of steroids and be almost back to normal within a few weeks. So, it's a really broad spectrum. And, I think, what we’re now learning is that each antibody has a role in helping define the disease, guide your treatment, guide your search for cancer - but, also, they behave differently - so these neural-specific antibodies are really important, while the older antibodies (like the thyroid antibodies) may just be a bystander and something that's happening in the background in a patient who's more prone to autoimmune disease.
Dr Jones: Very helpful, and I think that resonates with our listeners who have taken care of patients with autoimmune neurologic disorders, and it really is, I think, a great prototype in our specialty, maybe (for lack of a better word) of how observations start at the bedside, and then discoveries are made at the bench, and those benefits are brought back to patients. You know, there's been a recognition of autoimmunity in neurology for a long time, right - responsiveness to immunosuppression, even before the biomarkers were discovered - tell us a little story about how that works for our listeners.
Dr Flanagan: Yeah, so, I think one of the first steps is defining a clinical syndrome. So what you'll find is that some of these syndromes (for example, neuromyelitis optica spectrum disorder, where they have longitudinally extensive lesions within a spinal cord) provoked people to be interested that these looked different to MS, and then that went to the lab, and the aquaporin-4 antibodies were discovered - or, more recently, MOG antibodies were discovered. The aquaporin-4 antibody-associated neuromyelitis optica spectrum disorder is a good prototype, because that went to the laboratory. Initially, they saw complement deposition on the pathology of these patients, they saw antibody deposition - the antibody was then discovered to aquaporin-4. And then, many labs around the world went to their own labs and they tried to delve in to determine what the pathogenesis was, and they found that complement was important in cell killing, that interleukin-6 elevation was important, and that complement appeared to be important. So, then, what they did was they tried to find treatments that would target those pathways. So, and now, we have treatments that are successful for this disease that can target complement, target interleukin-6, and target B cells (be it CD19 or CD20). So, we now have many different treatments, and this disease used to be very severe (so, had a 33% mortality at five years), and now these patients can live a long life with these treatments. So, I think that gives you an example of how you can follow the immunology of the disease and use targeted treatments to help our patients, and I think we can use that as a good prototype for many of the other antibodies, because every year we discover two to three new antibodies, and each disease is a bit different in its mechanism. So, there are now clinical trials in NMDA receptor encephalitis starting up. There’s clinical trials in MOG antibody-associated disease. And I think we’re going to see that as we move forward, that these treatment trials will come and we’ll be able to help our patients better with proven treatments that we know work, rather than a history of we would just use five days of steroids and then we didn’t know exactly what to do in the long term - and we could manage some of the relapse as well, but we couldn’t really take care of the disease in the background - so, I think the NMO is a good model for moving forward, and the pharmaceutical companies are supporting moving forward with different trials for the disease.
Dr Jones: So, a key message there is understanding the biology so we can be a little more targeted and less indiscriminate in the immunomodulation we’re going to use. And we have parallels to that in the neuromuscular world, right, like using B-cell depletion for MuSK-associated neuromuscular junction disorders, as opposed to the trial-and-error approach, right? That's got to be a little more patient-centric and you get to a therapeutic response faster, right?
Dr Flanagan: I think so. Yeah, and I think, in the future, that might be something where, you know, a different patient, if they had elevated cytokines that pointed more to an IL-6 elevation, then maybe, in that patient, you would target IL-6, while the next patient with the same disease has more prominent complement activation, maybe you would target complement, or another patient has more prominent B-cell markers elevated, that you would target B cells. So, I think, we’re really moving towards a more individualized treatment in some of these disorders. So, it's a very exciting time, but we've only really made that breakthrough in one of the antibodies, and we have probably sixty, seventy antibody-mediated disorders now. So, it's going to get complicated, but it's also going to be, really, an exciting time for our patients, and I think an exciting time for neurology trainees and people who see patients in practice that we can now make diagnoses and guide their treatment that, previously, you know, these patients were told they might have presumed infectious encephalitis or we didn't know the exact cause.
Dr Jones: So targeted not only to the diagnosis, but to the individual.
Dr Flanagan: Yeah.
Dr Jones: So, that's a level of complexity that I think is going to blow a lot of our minds, right? And it's exciting, but I think it also is a little daunting, right?
Dr Flanagan: Absolutely. Yeah. Yeah, it's going to be complicated, and these are rare diseases, so they're difficult to do clinical trials in. But I think we can be guided, and our experience tells us that if you follow the mechanisms, that you can find targeted treatments. Now, you can also find targeted treatments in MS - you know, it took us a longer time to find successful high-efficacy treatments, but now we're doing much better with many high-efficacy treatments available. But, I think in these autoantibody-mediated diseases, really looking at the mechanisms and trying to figure out that and then targeting the treatment in that direction makes the most sense and is the most likely to be successful.
Dr Jones: So, one of the purposes of Continuum is to educate our readers and our listeners, and because neurology is so broad, because it is evolving so quickly, it's really hard to stay current. And so, again, that's part of the purpose of the journal. I think one of the challenging areas is autoimmune neurology, because it changes fast, and it's complicated, and the treatments are high stakes and complicated to administer - so, I think this is an important topic. I know from my own experience in clinical practice, one of the challenging scenarios is you see a patient who may have an autoimmune neurological disorder, you obtain some serum or CSF markers of neurologic autoimmunity, right? And of the ten antibodies you check, one of them comes back, and it's a low titer-positive antibody. I know that's something that you get a lot of questions about. How do you approach that?
Dr Flanagan: Yeah, I think, you know, we're all neurologists, and, you know, it's immediately back to the history, the examination, and the investigations, and what do they support - so, are you really dealing with an antibody-mediated disorder? And I think, from a neuroimmunology laboratory standpoint, we're always trying to get better tests, remove those less-specific tests (so, move away from the thyroid peroxidase antibodies) and really hone in on the exact targets and their mechanisms. So, I suppose, when you find a low-positive result, it's really important to go back to that clinical. And, I think, you know, that is job security for neurologists, right? Because you really have to interpret these in context. And, I think when you're seeing autoimmune cases, you need to have a good, broad understanding of differential diagnosis, because there are many different disorders that can present in a similar way, and you don't want to get distracted by that low-positive antibody and then put a patient on long-term immunosuppression that has many different risks. So, there is a potential for misdiagnosis, and I think that's an emerging area that we're recognizing that we always have to put the antibodies into clinical context. And, you know, there are more and more studies coming out that will help guide you, and I think the issue in Continuum will help guide you in terms of your understanding of, you know, what does a positive antibody mean? And it'll give a little bit on the methodology of how the antibodies are tested and how that can help you – or, sometimes, be it the titer may be very high that can help you. So, different aspects of the antibody test results can also help guide you in the likelihood of that being kind of a true positive versus a false positive. But I think always back to the history, exam, and the investigations, too.
Dr Jones: You're being very gracious there, and I'm glad you bring it up that it's really not just about the laboratory performance of the test, right? It's about the pretest probability of the clinical syndrome if it doesn't clinically resemble an autoimmune neurological disorder. So, I'm not going to pretend to be an expert in Bayesian statistics, but I think we should recognize that if we obtain any test when there's a low likelihood of the syndrome or the diagnosis being present, we're more likely to have false positives than in other scenarios or other settings. So, I think that is a charge to the clinician, where if we are obtaining these tests, we do really need to think about the likelihood of there being a clinical autoimmune neurology syndrome, right?
Dr Flanagan: That's exactly right. You know, one of the teachings that I sometimes give to the trainees is that, you know, if you have a ninety-year-old patient with mild cognitive impairment who comes into the emergency department with some worsened altered mental status, you know, you want to check for a urinary tract infection, you want to check a chest x-ray - you don't want to test neural antibodies upfront. So, you always have to consider the setting and avoid overtesting, because like any test, they’re not perfect, and you can run into trouble if you order it too frequently - so, that's another thing that we try to educate people. And then if you do order the test, we like to educate people on, you know, what the positive test results mean, and is there any potential for false positives like we talked about?
Dr Jones: And I think, keeping in mind - obviously, there are exceptions - but the subacute onset of multifocal neurological disorder is really suggestive of autoimmunity. It doesn't mean that it can't happen in other contexts. And it has been exciting not only on the diagnostic side, but on the therapeutic side. There are so many exciting new treatments. What do you think is on the horizon beyond what we've seen in the last few years with small- and large-molecule therapies for these disorders?
Dr Flanagan: Yeah, I think there's new things. You know, people are always looking at different approaches. So, for example, there's a lot of interest in tolerance, and is there a way you could tolerize yourself out of some of these autoimmune conditions? There's a lot of work on CAR-T treatments, looking particularly in the field of lupus and other systemic autoimmune diseases, and I suspect that they will also be applied to autoimmune neurologic conditions. And then the other thing to mention is that we're seeing the more frequent use of immune checkpoint inhibitors in patients with lots of different types of cancers, including neuroendocrine tumor. So I think, in the future, everybody's going to have to learn about autoimmune neurology, because we're going to be seeing these patients more often, because there's going to be more neurologic immune-related adverse effects related to those immune checkpoint inhibitor treatments – so, I think we're going to continue to see autoimmune neurologic disorders pop up. And, you know, the immune checkpoint inhibitors are almost real-world laboratory experiments, because you're ramping up the immune system, and you can trigger many different types of autoimmune conditions. We're actually learning a lot from these patients that can help us in the way we diagnose and the way we treat these patients in the future, but I will say that, sometimes, they can cause a challenge, because some of these patients have difficult-to-control cancer - you need to up their immune system, but then they get autoimmune complications. We try and dampen down the immune system, and then we need to kind of ramp it back up to treat the cancer. And we've had some challenges where managing such cases can be difficult with that balance of cancer-directed immunotherapy versus immune-related adverse events, and, sometimes, that can pose a challenge for autoimmune neurologists when we see these patients.
Dr Jones: So, those are challenges, and I imagine it's a challenging and often rewarding field. What is the most rewarding thing about caring for patients with autoimmune neurological disorders?
Dr Flanagan: I think it's a few things. You know, one is that it's a multidisciplinary area, so many of these patients will have different subspecialties of neurology involved. So, we'll get to work with our colleagues, and we may work with our oncology colleagues, we work with our ophthalmologist, and we work with our physical medicine and rehab team – so, it's a real team approach to help the patient. So, that's one aspect that's very enjoyable, because everybody needs to work together. And then, you know, these are treatable conditions. So we can have patients who are in the intensive care unit - you know, quadriplegic, in a coma - and then we treat them, we see them back, and they can be back close to normal. So, particularly, with some of these antibodies that target the cell-surface receptors (like NMDA receptor encephalitis, MOG antibodies), these patients can really go from being really, really sick in the ICU to coming back to normal – so, that's very satisfying, and much of that is related to the improvements we have in treatments, and then we can manage them in the long term with some of these newer treatments that are coming along for these diseases. So, I think it's a very exciting area and exciting time for our patients with these disorders, and we're getting more and more clinical trials, so we're hoping that we'll have more and more treatments available into the future.
Dr Jones: I think that has to be part of why the interest in autoimmune neurology has grown so much. I know as an educator - I hear this a lot from trainees - you know, the level of interest in MS and autoimmune neurology has really only grown over time. It must be because of better understanding of the pathobiology of disease, better treatment options, and something that our listeners may not know. Not only is Dr Flanagan an expert in autoimmune neurology - he’s very well trained, he did fellowship in MS and autoimmune neurology, and behavioral neurology, right?
Dr Flanagan: That's correct. Yeah. Yeah.
Dr Jones: And, you know, it's going to sound like I'm trying to flatter Eoin here, but I'm really not (this is going to lead to a question). Eoin is, you know, very well recognized for his work in autoimmune neurology and discovery in this area. Uh, he happens to be one of the best doctors I know. And Eoin, you've won the Teacher of the Year Award several times. So, for our listeners who are looking into their careers and trying to manage multiple areas of interest, how do you do it? You do so many different things so well.
Dr Flanagan: Well, you know, I'm lucky to have had the opportunity to work here at the Mayo Clinic and in the neuroimmunology lab. So, we have a lot of resources, and it's an exciting area, you know? We need to bring up the next generation of leaders, so we need to be enthusiastic about these conditions, and we really can do a lot for these patients. So I think when I cover on the hospital service - you work with the residents or work with the fellows and clinic - you know, these cases (when they come around) are really enjoyable to see you can get an answer, we can figure out what type of treatment to do, and we can really help these patients. So, I think that makes it a very exciting area and an easy area to teach residents and to convey some of the excitement that's happening in the field. So, it's just a great honor to be able to work with trainees to kind of let them know the field. And, you know, there's more and more fellowship opportunities in different centers in neuroimmunology, and I think more residents are becoming interested in the field of autoimmune neurology because of so much happening. But, in saying that, with these challenges, it's very hard to keep up with all these antibodies - I find it hard. There's 70 different antibodies - it's hard to know every single thing about every single one. So, we need to continue to educate, to try and simplify, to try and help our younger people be able to manage these patients, because no matter who it is in neurology, you're going to encounter these patients - if you cover the hospital, if you see regular patients in clinic, if you do consult service, you'll come across these patients - and we're going to see them more and more with immune checkpoint inhibitors and other treatments coming along. So, I think it's an exciting area, and it's an important area for everyone to be aware of. So, it's just a great pleasure to be able to be involved in the field and see such enthusiasm in junior people.
Dr Jones: So, in addition to doing all those things well, you're also very humble. So, that's a great answer, and I think it is important - even though these are collectively rare - the opportunity to treat these patients and have wonderful outcomes is great, and I think the ability to recognize and feel comfortable. And, hopefully, Continuum has a place in that. I think your issue, Dr Flanagan, is a stellar issue and, uh, will be a benchmark for a generation of neurologists and how to approach these disorders. So, I want to thank you for being our Guest Editor for that topic and joining us today for such a thorough and fascinating discussion on autoimmune neurology.
Dr Flanagan: Thanks so much. And thank you to the Continuum team for highlighting autoimmune neurology. It's an exciting field, and I think, really, there is a great group of authors that cover neuroimmunology comprehensively, and I think, hopefully, people will enjoy the edition.
Dr Jones: Again, we've been speaking with Dr Eoin Flanagan, Guest Editor for Continuum’s most recent issue on autoimmune neurology. Please check it out. And thank you to our listeners for joining today.
Dr Monteith: This is doctor Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use this link in the episode notes to learn more and subscribe. Thank you for listening to Continuum Audio.