Psoriatic Arthritis: A Physician’s Perspective

DAFNA GLADMAN, MD, is a rheumatologist at the Toronto Western Hospital and senior scientist at the Krembil Research Institute in Toronto, Ontario, Canada. For closeto 40 years, Dr. Gladman has built a career in rheumatology focused on finding answers about psoriatic arthritis. She was the recipient of the Verna Wright Prize for outstanding contribution to the field of psoriatic arthritis presented by theInternational Psoriatic Arthritis Group in Naples, Italy.

BSTQ: Tell us about your background and research in psoriatic arthritis (PsA).

Dr. Gladman: I have been working in the area of PsA since 1978, when I started the Psoriatic Arthritis Clinic at Women’s College Hospital. It became a program when other researchers joined me in the early 1980s. The PsA program moved with me, first to the Wellesley Hospital and then in 1995 to the Toronto Western Hospital. Our research has demonstrated that PsA is more severe and more common than previously recognized; we identified predictors for progression of clinical and radiological damage, as well as mortality. We have identified genetic factors for susceptibility and disease expression. We have also investigated patient reported outcomes and comorbidities in these patients.

BSTQ: What are the symptoms of PsA?

Dr. Gladman: PsA is an inflammatory form of arthritis. As such, patients present with pain and stiffness in the joints, which may be swollen and occasionally have a red discoloration. Patients may have swollen “sausage digits” called dactylitis, as well as inflammation at the insertion of tendons and ligaments into bone, called enthesitis. Enthesitis most often affects the insertion of ligaments and tendons into the ankle bone (Achilles and plantar fascia). About half the patients have arthritis in the back (spondylitis), which may or may not be symptomatic.

BSTQ: How is PsA typically diagnosed?

Dr. Gladman: PsA is diagnosed clinically based on the presence of psoriasis and/or nail changes and the symptoms provided by the patients coupled with a physical examination. Laboratory tests are often done to rule out other forms of arthritis. X-rays may be very helpful as they show specific changes that help confirm the diagnosis.

BSTQ: How does PsA differ from rheumatoid arthritis (RA)?

Dr. Gladman: Both PsA and RA are inflammatory forms of arthritis. While RA can occur together with psoriasis, nail lesions are more common in patients with PsA. PsA affects men and women equally, while RA affects women three times more often than men. RA affects the first row of knuckles, whereas PsA affects the end row in 53 percent of patients. Also, dactylitis and enthesitis are not features of RA, and patients with RA do not have spondylitis. On the other hand, patients with PsA do not have rheumatoid nodules or the other extra-articular features of RA.

BSTQ: Is PsA hereditary?

Dr. Gladman: Yes. Relatives of patients with PsA are 30 times more likely to have PsA than the general population. We (and others) have identified a number of genetic factors, and are now working on epigenetic factors.

BSTQ: You’ve been working to develop screening tools for earlier diagnosis. Tell us about that.

Dr. Gladman: We have developed a screening tool for PsA called the ToPAS (Toronto Psoriatic Arthritis Screen), and have modified it as ToPAS2. These instruments can identify PsA among patients with or without psoriasis and have worked very well in our center, as well as in Turkey. We are currently testing whether the ToPAS2 can screen for psoriasis in the general population.

BSTQ: Are there any promising treatments for PsA on the horizon?

Dr. Gladman: There are lots of new therapies for PsA. Since 2000, when the first anti-TNF agent etanercept became available, we now have four additional anti-TNF agents, including infliximab, adalimumab, golimumab and certolizumab. In addition, we have the antiIL12/23 agent ustekinumab, and more recently, anti-IL17 agents, including secukinumab and ixekizumab. We also have one oral agent, the PDE4 inhibitor apremilast, available for PsA. The JAK inhibitor tofacitinib, which is already approved for RA, has been proven effective for PsA and will likely be approved in the near future.