Soumya Chakravarty, MD, PhD, FACP, FACR, strategic lead of the Rheumatology Therapeutic Area at Janssen, discussed the interlinked pathophysiology of psoriasis and psoriatic arthritis, and the involvement of inflammatory mediators for both conditions.
Psoriasis and psoriatic arthritis are 2 chronic immune-mediated inflammatory diseases that often precede one another in diagnosis, with both conditions having notable effects on physical and psychological functioning, said Soumya Chakravarty, MD, PhD, FACP, FACR, strategic lead of the Rheumatology Therapeutic Area at Janssen.
What are some key differences and similarities in the pathophysiology of psoriatic arthritis and psoriasis?
Both are disease states that are considered chronic immune-mediated inflammatory diseases. So, because of that chronic inflammation, it can actually lead to a lot of long-term sequela. So, inflammation, of course, can manifest itself as painful swelling in the joints, also wear on tendons and ligaments connected to the bone, what we call enthesitis. Then, of course, from a skin standpoint, you have plaque psoriasis that is a manifestation of that chronic inflammation.
Noting the use of the word chronic, I think that's a really important element here for both psoriasis and psoriatic arthritis that patients actually are having to live with these diseases for many, many years, and they can potentially worsen over time. During the course of these diseases, of course, there can be potential flares. So, patients can actually have periods of time where they are feeling better, but then also times where there are increases in their disease activity, what we call these flares.
In addition to the physical symptoms that can be potentially debilitating for these patients, there are other less visible consequences unfortunately, such as pain, fatigue, and these can have very significant impacts on quality of life. I think it's also interesting to note that there's a very intertwined link between psoriasis and psoriatic arthritis in the sense that, of those patients that have psoriasis, about 30% will go on to develop psoriatic arthritis. And so really, the vast majority of your patients with psoriatic arthritis have preceding psoriasis.
There are other risk factors that go into this. Having long-standing psoriasis, as well as nail psoriasis, dactylitis, having, obviously, family history, can also really unfortunately increase your risk for developing psoriatic arthritis.
I think the last point that I'll make is that from a pathophysiology standpoint, there's a lot of overlap in terms of the involvement of the interleukin (IL)-23 and T-helper (Th)-17 pathway. So, this is a very pro-inflammatory pathway that exists with IL-23 being that key upstream regulatory cytokine that really drives this whole downstream inflammatory process that can lead to the manifestations of both psoriasis and psoriatic arthritis. And I'm sure we'll be able to talk a little bit more about that in detail later.