Chester Oddis, MD: Myositis, Diagnosis and Management Challenges

September 16, 2020

An expert discusses the difficulties in diagnosing and managing myositis, as well as how the COVID-19 pandemic has affected clinical care.

Myositis encompasses a group of autoimmune diseases that has proven difficult to manage due its systemic nature. These conditions may involve muscles, skin, and even the lungs. Today, there still remain challenges in diagnosing and managing them.

Chester Oddis, MD, of the University of Pittsburgh Department of Medicine, is an expert in idiopathic inflammatory myopathies who presented at the Congress of Clinical Rheumatology East 2020 about clinical characteristics and treatment aspects of myositis. HCPLive® had the opportunity to speak with him about the current challenges in treating these types of conditions, promising new therapies for disease management, and how the COVID-19 pandemic has affected clinical practice in this area of rheumatology.

HCPLive: Can you give a brief overview of myositis?

Oddis: These are autoimmune diseases that not only affect muscle, but they are systemic in their nature. For example, it's very common to have muscle involvements and skin involvement in many patients — as well as lung involvement, which is what I talked about a lot extensively during my presentation.

So, these diseases can be challenging, because there is a lot of systemic manifestations. And it can actually be joint involvement and other problems, just like what occurs in the other systemic diseases in rheumatology, including lupus.

It's an autoimmune attack that causes a lot of different things, like muscle weakness, inflammation in the joints, and significant skin rash. Unfortunately, it is the lung disease that oftentimes is a factor that really can adversely affect these patients with morbidity and mortality.

HCPLive: What is the importance of accurately diagnosing and classifying these types of diseases?

Oddis: In terms of diagnosis, I think it's important to make sure you're dealing with a particular autoimmune disease because there are going to be some mimics. Now, it's easy, in a way, whenever there is a rash. That's because the rash indicates this is dermatomyositis, for example. But if a patient just has muscle weakness — they don't have a rash, they don't have lung involvement, they don't have joint involvement — then, you've got to make sure that you're dealing with an autoimmune disease as opposed to one of the mimics of myositis. They might be anything from muscular dystrophy, to a drug/medication reaction, to other things that can affect muscle. 

So, it's almost easier when they have a rash that's characteristic of dermatomyositis.

HCPLive: What are the challenges that come up in treating and managing myositis?

Oddis: Well, first you've got to diagnose it. And I think the challenge in diagnosing it is that you have to have the right collaborators. It's very easy, as I said, if they have a bad rash, and they're weak, and they have particular laboratory tests, such as autoantibody markers that are characteristic of the disease.

Now, the challenge in managing it is really significant, because a lot of these patients don't respond to conventional medications like steroids and methotrexate. Therefore, they require other disease modifying, or immunosuppressive, medications — especially when they get the involvement of lung, skin, joint, and muscle.

So, the challenge is to make the diagnosis in some instances, but also to get the right mix of treatment. These patients can have refractory muscle, skin, and other manifestations.

HCPLive: Are there any new, emerging therapies in this domain that are potentially promising?

Oddis: What we have now that we didn't have before is a multitude of potential biologic medications. We all know that the standard medication site, like steroids and methotrexate, work. But now we have had available many things, like rituximab, which depletes the B cells.

Also, there are a lot more trials that are available that are actually targeting specific cytokines in myositis. We're doing a trial, for example, looking at abatacept, which attacks the T cell in an effort to see if that improves the lung involvement and the muscle involvement in patients with myositis.

Another biologic therapy that is coming out is tofacitinib, or Xeljanz. It's an oral medication that is approved for rheumatoid arthritis. We've reported a small series of patients where the skin remarkably, and nicely, improved.

So, we're going to try anything that's going to work for other autoimmune diseases in this particular disease. You can go through the list of biologics. And it seems to me that the ones that help psoriasis skin rash might also help the rash of dermatomyositis.

HCPLive: To shift gears a bit, we've seen how the COVID-19 pandemic has largely affected certain practices in healthcare and within various specialties. What would you say is the biggest challenge that this pandemic posed for you — whether it's on the side on the healthcare provider or the patient?

Oddis: In rheumatology, I don't think it has been a dramatic effect. Everybody was thinking in the beginning, "Oh boy, these patients are all on immunosuppressive medication. We're going to have to stop them." But we didn't do that, and it was not the recommendation of the American College of Rheumatology to do that.

So, many of our patients remained on the medications that they were taking (biologics, steroids, methotrexate, etc.) even if they were significantly immunosuppressive. That wasn't an anticipated problem as one would expect.

What was a challenge for us with the pandemic is seeing the patient face-to-face. If you're treating a disease where the muscle strength is something you want to follow, then you can't check it. I can't check your muscle strength looking at you [through the computer]. I can try to do it and say, "Okay, are you weaker, are you stronger, what's the change since the last visit?" But the challenge has been the sensitivity of detecting change clinically.

But we can see rash. We can rely on the patient telling us if the rash is better. So, the challenge has been a bit more on management and on diagnosis if it's a new patient. We like to see them face-to-face.

So, I wouldn't say that treatment has been as much of a problem as the diagnosis and management part of it.

HCPLive: Do you have anything you want to add related to what we talked about or perhaps didn't discuss?

Oddis: What I would emphasize, which I did during my talk, is that many patients don't even have the muscle part of myositis. It's really the challenge of the things like I talked about earlier that really makes it difficult and interesting for us.

You've obviously heard of lupus, and the designation is systemic lupus. Well, all of our diseases are as equally systemic as lupus. And that's the challenge that I emphasized. Because I even presented cases during my lecture that really didn't have significant muscle problems.

So, it's the management of the many different manifestations. And it's also the appropriate diagnosis in terms of looking at autoantibodies that I emphasized. Those autoantibodies, those markers in the blood, are not only good for diagnosis, but they are also good for prognosis. By knowing what antibodies a patient has, you can also predict what types of problems they may get into later on. It always helps you to categorize and follow that patient.