Canadian Rheumatology Today

IL-17 Inhibition vs IL-23 Inhibition for Psoriatic Arthritis: An Ongoing Debate

Pankti Mehta, MD, Vinod Chandran, MD, MBBS, DM, PhD, FRCPC — Thu, 28 Aug 2025 00:00:00 +0000

The interleukin-17 (IL-17) and interleukin-23 (IL-23) pathways play a central role in the pathogenesis of psoriatic disease (PsD). This review outlines the immunobiology of these cytokine pathways and summarizes the current evidence on the efficacy and safety of IL-17 and IL-23 inhibitors across PsD domains, including peripheral arthritis, axial arthritis, enthesitis, dactylitis, psoriasis, and inflammatory bowel disease (IBD). IL-17 inhibitors, which target the effector cytokines IL-17A, IL-17F, or their receptors, have demonstrated robust efficacy in psoriasis, peripheral arthritis, and axial disease. IL-23 inhibitors act upstream by targeting the p19 subunit of IL-23 and show comparable efficacy in peripheral arthritis and psoriasis, though evidence for efficacy in axial disease remains limited. While IL-17 inhibitors carry a risk of IBD exacerbation, IL-23 inhibitors are considered therapeutic options for patients with coexisting IBD. In addition, radiographic progression appears better suppressed by IL-17 inhibitors, although emerging data suggest that IL-23 blockade may offer delayed benefits. Both IL-17 and IL-23 drug classes exhibit favourable safety profiles, with clinical trials suggesting slightly better tolerability for IL-23 inhibitors. Future directions include head-to-head comparisons, biomarker-guided treatment selection, and trials assessing long-term structural outcomes. Understanding the tissue- and cell-specific effects of inhibiting these cytokine pathways is key to optimizing therapy in PsD.

Can We Prevent Psoriatic Arthritis?

Alexandra Kobza, MD, FRCPC — Thu, 28 Aug 2025 00:00:00 +0000

Psoriatic arthritis (PsA) is a chronic, inflammatory musculoskeletal disease that often develops in individuals with psoriasis (PsO), typically following an average latency period of 7 years. Without treatment, PsA can lead to irreversible joint damage, functional impairment, and a range of comorbidities. Despite therapeutic advances, only a minority of patients achieve sustained remission, highlighting the need for new approaches, including disease prevention and early interception. This review explores the emerging concept of PsA prevention in individuals with psoriasis, by addressing modifiable risk factors—such as severe skin disease, nail involvement, and obesity—and predictors such as arthralgias and asymptomatic abnormalities on musculoskeletal ultrasound. Notably, PsO patients represent a unique preventive opportunity in rheumatology, as many treatments address both PsO and PsA, potentially minimizing additional therapeutic risks.

A recently proposed framework by the European Alliance of Associations for Rheumatology (EULAR) outlines three stages of progression from PsO to PsA, ranging from individuals ‘at higher risk’, to those with ‘subclinical PsA’, and finally to those with ‘clinical PsA’. Findings from observational studies suggest that treatment of modifiable risk factors may reduce PsA incidence, though prospective data remain limited. Subclinical inflammation detected on imaging and the presence of arthralgia may identify individuals at imminent risk who could benefit from escalation of therapy. Nonetheless, further refinement of this population is necessary to avoid overtreatment. Ongoing clinical trials are expected to help clarify whether early intervention can truly intercept PsA and alter its natural history. Ultimately, success in PsA prevention will require multidisciplinary collaboration, refinement of risk stratification, and thoughtful integration of these screening strategies into clinical practice.

Idiopathic Inflammatory Myopathy-Associated Cancer: A Review of Risk Factors and Screening Recommendations

Eugene Krustev, MD — Thu, 28 Aug 2025 00:00:00 +0000

Idiopathic inflammatory myopathies (IIMs) are a group of rare autoimmune diseases that are characterized by autoimmune myositis. However, systemic extramuscular manifestations are frequently observed. IIMs have been associated with cancer, and given the increased frequency of co-incident cancers in IIM, malignancy screening in newly diagnosed IIM patients is an important consideration. That being said, cancer risk varies across IIM subtypes, antibody specificities, and with clinicodemographic factors. As such, cancer screening should be tailored using a risk stratification approach. This review discusses the evidence regarding cancer risk in IIM, as well as recently-published guidelines for cancer screening in IIM.

What Can We Tell Our Patients About Rheumatoid Arthritis Risk?

Liam O’Neil, MD, MHSc, FRCPC, Hani El-Gabalawy, MD, FRCPC — Thu, 28 Aug 2025 00:00:00 +0000

You are seeing a 45-year-old female with a chief complaint of joint pain in the hands and feet. The symptoms have been apparent for 6 months. There was no preceding illness. She reports morning stiffness of the affected joints. The patient denies any joint swelling. Her medical history is notable for a strong family history of Rheumatoid Arthritis, and she currently smokes one pack of cigarettes daily. On physical examination, the joints appear normal, with full range of motion and no obvious tenderness to palpation. There is no evidence of synovitis or rashes. Laboratory investigations show elevated anti-citrullinated protein antibody level of 135, and her rheumatoid factor level is 45. C-reactive protein is within normal limits. Radiographs of the hands and feet are normal.

Questions:

1. What is her likelihood of developing rheumatoid arthritis within the next 3 years?

2. Are there any other tests you need to order?

3. Can rheumatoid arthritis be prevented in this individual? What advice can you provide her?