Clinical Implications of HS and Hepatitis B/C

Jeffrey Cohen, MD, is a board-certified medical dermatologist at the Yale School of Medicine in New Haven, CT. His current research focuses on the epidemiology of skin conditions, relationships between skin disorders and other medical problems, and the way that dermatologic care is delivered. He authored more than 65 peer-reviewed articles on psoriasis and other topics in dermatology. Dr Cohen joined The Dermatologist for an interview on his recent study, “Hepatitis B and C Among Patients With Hidradenitis Suppurativa: A Population-based Study.”¹

Transcript:

Your study demonstrated an association between HS and both hepatitis B and hepatitis C. What is the significance of these findings?

These findings have a few different points of significance. The first thing that is important with all of these epidemiologic studies is that by realizing that these associations exist, we learn more about all of these disease states. We understand more about the pathophysiology and underlying immunopathology of HS and of hepatitis B and C.

In addition to that, we now have great treatments that we can use to cure hepatitis C (HCV) in many, many patients who have it. This is important, because it prevents some of the long term effects of HCV such as cirrhosis and also hepatocellular carcinoma.

Any risk factors that we can identify for HCV infection is very important, because it allows us to identify patients who have it more readily, which allows us to treat them and ultimately prevent some of those terrible things that can happen to people with long standing hepatitis C.

Finally, it's also important in terms of our treatment choice. People with hepatitis B (HBV) and hepatitis C have different considerations that come into play when you're going to choose a systemic treatment for an inflammatory skin condition, especially hidradenitis suppurativa.

A new and very important therapy that we're starting to use more and more for these patients are the biologics. Many of these medications require treatment for HBV or HCV before, and you certainly want to know if a patient has that.

Understanding that those with HS may be at somewhat higher risk of HBV or HCV reminds us that this is a really important thing to think about when we're considering treatment choice.

What are the important clinical implications and considerations dermatologists should take from your study?

There are a number of things that are relevant and important takeaways. The first one is a very practical takeaway, which is that understanding that people with HS may have an increased risk of HBV or HCV is important for us when we're looking at patients and trying to figure out how to treat their hidradenitis suppurativa.

Certain of the treatments that we use, many of them are somewhat immunosuppressive, certainly have issues with patients who have hepatitis B or C. We want to make sure that we know which patients have HBV or HCV.

I think this raises awareness of the importance of screening for that [HBV and HCV] in individuals with HS specifically if you're going to put them on a medication like a tumor necrosis factor alpha inhibitor like adalimumab, that would require attention to this before you commit to that therapy.

Additionally, since we can treat HCV more readily now, it's important to identify these patients to try to get them treated, not only to make it easier to treat their HS, but to prevent other long term outcomes such as cirrhosis or hepatocellular carcinoma.

This also helps us understand a little bit more about the pathophysiology of hidradenitis suppurativa. That's something that we are learning more and more about all the time in terms of what might be underlying this, what immunology is underlying this.

That's important for us, A, because we want to understand all skin diseases as well as we possibly can, but also, B, in terms of trying to come up with better treatment strategies, more effective treatment strategies, more durable treatment strategies, understanding the real core underlying pathophysiology can be the key to this.

Particularly in diseases like HS that can be relatively difficult to treat, even when people do have response to the current therapies, it's not always a complete response.

This disease, as is reflected in a large body of literature, has a really important impact not only on health outcomes, but also on quality of life, ability to function, ability to work. It's something that impacts our patients' lives in a very, very significant way.

When we looked at HBV, HCV, and HS and tried to think about why the relationship we saw existed, one thing that really popped out was interleukin 17. We know that interleukin 17 is an important interleukin in terms of skin immunology.

Many of the big advances in treating inflammatory skin disease, particularly in psoriasis, have been with the interleukin 17 inhibiting medications. Some of these are under study for hidradenitis suppurativa, and they may work quite well. We're still collecting data on this.

Understanding that interleukin 17 probably is at the core of HS is a really relevant finding. Trying to link that to HBV and HCV was very interesting, because it turns out that interleukin 17 is a profibrotic cytokine in the liver. It promotes liver fibrosis, which is the underlying process that occurs in liver cirrhosis, which we know occurs from hepatitis B and C.

Also, we know that people with interleukin 17 levels that were higher with HBV and HCV tended to have worse outcomes.

This opens the window of thinking about whether or not our study only sees the tip of the iceberg, because these things may be associated, but they may also be associated in terms of outcomes. It may be that people with both HS with HBV and HCV actually have worse hepatitis B and C outcomes than those who have HBV and HCV without HS.

That was well beyond the scope of our study. That's an interesting question that this opens up but would certainly be something that would warrant further study in the future.

These are some of the important take homes, both actionable items in terms of clinical care and things that would change our practice, but also things that may inspire more research and identifying more questions that we should answer going forward.

Anything else you’d like to share with your colleagues regarding HS and HCV/HBV?

I think that as more of these studies come out, and as we learn more and more about hidradenitis suppurativa, we're learning that while HS is, obviously, a primarily skin disease and is a disease that has its primary manifestations in the skin, that this is really a systemic inflammatory condition.

Just like we're learning with psoriasis, HS is associated with several very important comorbidities. In this study, we looked at hepatitis B and C. Other studies have looked at cardiac risk factors, metabolic risk factors. A lot of these conditions have very important implications for patients' overall health and overall health outcomes.

We need to think about this in terms of the way we view HS as a disease in understanding that it's really a systemic condition that has its primary manifestation in the skin.

If we can do that and think about that, not only as dermatologists but also in general as physicians, I think we'll have more success in managing these patients, not only with their skin disease, but also with other comorbidities that may arise more commonly in this group than in all comers.

I also think that this is really important for us, because it helps us understand that systemic treatment, which in the case of psoriasis has been shown to reduce certain of the outcomes that are associated with it, such as myocardial infarction.

Also thinking about this in terms of HS is something that's very important and understanding that when we treat people with HS with systemic agents, we may be doing more than just treating the skin in the most aggressive way, we may also be decreasing their inflammatory burden and preventing or decreasing the risk of some of these other outcomes that are associated with HS.

   
Reference
1. Cohen JM, Kridin KK, Perez-Chada LM, Merola JF, Cohen AD. Hepatitis B and C among patients with hidradenitis suppurativa: a population-based study. Int J Dermatol. Published online May 17, 2021;10.1111/ijd.15578. doi:10.1111/ijd.15578